Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Soil lacquer peel DIY: simply capturing beauty
    Stoof, C.R. ; Candel, J.H.J. ; Wal, Laszlo van der; Peek, G.J.W.C. - \ 2020
    Wageningen University & Research
    Visualization can greatly benefit understanding of concepts and processes, which in soil science and geology can be done using real life snapshots of soils and sediments in lacquer peels and glue peels. While it may seem complicated, anyone can make such a soil peel for use in classrooms, public places, homes and offices for teaching, outreach, decoration and awareness. Technological development has considerably simplified the making of soil peels, but this methodological innovation has not been described in the literature. Here, we report on a thoroughly tested and simple method for taking peels of sandy soils using readily available tools and materials. Our method follows the main previously published steps of preparing a soil face, impregnating the soil face with a fixation agent in the field, extracting the resulting peel and mounting it on a wooden panel. Yet instead of using lacquers and thinning agents, we use strong though flexible contact adhesive (glue), which has the major advantage that it no longer requires use and mixing of toxic chemicals in the field or reinforcement of the peel to prevent breaking. Moreover, the preservation potential is much higher than with the old method. This new twist to old methods makes creating of soil peels more safe, simple and successful, and a thereby true DIY (do it yourself) activity. The resulting increased accessibility of making soil and sediment peels can benefit research, teaching, and science communication and can thereby bring the value and beauty of the ground below our feet to students, schools, policy makers, and the general public.
    Quantifying the transmission of foot-and-mouth disease virus in cattle via a contaminated environment
    Colenutt, Claire ; Brown, Emma ; Nelson, Noel ; Paton, David J. ; Eblé, Phaedra ; Dekker, Aldo ; Gonzales, José L. ; Gubbins, Simon - \ 2020
    mBio 11 (2020)4. - ISSN 2161-2129
    Biosecurity - Environmental microbiology - Foot-and-mouth disease - Foot-and-mouth disease virus - Indirect transmission - Viral decay - Virus survival

    Indirect transmission via a contaminated environment can occur for a number of pathogens, even those typically thought of as being directly transmitted, such as influenza virus, norovirus, bovine tuberculosis, or foot-and-mouth disease virus (FMDV). Indirect transmission facilitates spread from multiple sources beyond the infectious host, complicating the epidemiology and control of these diseases. This study carried out a series of transmission experiments to determine the dose-response relationship between environmental contamination and transmission of FMDV in cattle from measurements of viral shedding and rates of environmental contamination and survival. Seven out of ten indirect exposures resulted in successful transmission. The basic reproduction number for environmental transmission of FMDV in this experimental setting was estimated at 1.65, indicating that environmental transmission alone could sustain an outbreak. Importantly, detection of virus in the environment prior to the appearance of clinical signs in infected cattle and successful transmission from these environments highlights there is a risk of environmental transmission even before foot-and-mouth disease (FMD) is clinically apparent in cattle. Estimated viral decay rates suggest that FMDV remained viable in this environment for up to 14 days, emphasizing the requirement for stringent biosecurity procedures fol-lowing outbreaks of FMD and the design of control measures that reflect the biology of a pathogen. IMPORTANCE Effective control of a disease relies on comprehensive understanding of how transmission occurs, in order to design and apply effective control measures. Foot-and-mouth disease virus (FMDV) is primarily spread by direct contact between infected and naive individuals, although the high levels of virus shed by infected animals mean that virus can also be spread through contact with contaminated environments. Using a series of transmission experiments, we demonstrate that environmental transmission alone would be sufficient to sustain an outbreak. Key observations include that a risk of transmission exists before clinical signs of foot-and-mouth disease (FMD) are apparent in cattle and that survival of virus in the environment extends the transmission risk period. This study highlights the role a contaminated environment can play in the transmission of FMDV and presents approaches that can also be applied to study the transmission of other pathogens that are able to survive in the environment.

    Cow and herd-level risk factors associated with mobility scores in pasture-based dairy cows
    O'Connor, A.H. ; Bokkers, E.A.M. ; Boer, I.J.M. de; Hogeveen, H. ; Sayers, R. ; Byrne, N. ; Ruelle, E. ; Engel, B. ; Shalloo, L. - \ 2020
    Preventive Veterinary Medicine 181 (2020). - ISSN 0167-5877
    Animal-health - Grass-based - Lameness - Locomotion - Risk-factors

    Lameness in dairy cows is an area of concern from an economic, environmental and animal welfare point of view. While the potential risk factors associated with suboptimal mobility in non-pasture-based systems are evident throughout the literature, the same information is less abundant for pasture-based systems specifically those coupled with seasonal calving, like those in Ireland. Therefore, the objective of this study was to determine the potential risk factors associated with specific mobility scores (0 = good, 1 = imperfect, 2 = impaired, and 3 = severely impaired mobility) for pasture-based dairy cows. Various cow and herd-level potential risk factors from Irish pasture-based systems were collected and analyzed for their association with suboptimal mobility, whereby a mobility score of 0 refers to cows with optimal mobility and a mobility score ≥ 1 refers to a cow with some form of suboptimal mobility. Combined cow and herd-level statistical models were used to determine the increased or decreased risk for mobility score 1, 2, and 3 (any form of suboptimal mobility) compared to the risk for mobility score 0 (optimal mobility), as the outcome variable and the various potential risk factors at both the cow and herd-level were included as predictor type variables. Cow-level variables included body condition score, milk yield, genetic predicted transmitting ability for ‘lameness’, somatic cell score, calving month and cow breed. Herd-level variables included various environmental and management practices on farm. These analyses have identified several cow-level potential risk factors (including low body condition score, high milk yield, elevated somatic cell count, stage of lactation, calving month, and certain breed types), as well as various herd-level potential risk factors (including the amount of time taken to complete the milking process, claw trimmer training, farm layout factors and foot bathing practices) which are associated with suboptimal mobility. The results of this study should be considered by farm advisors when advising and implementing a cow/herd health program for dairy cows in pasture-based systems.

    High levels of contact dermatitis and decreased mobility in broiler breeders, but neither have a relationship with floor eggs
    Oever, Anna C.M. van den; Bolhuis, Liesbeth ; Ven, Lotte J.F. van de; Kemp, Bas ; Rodenburg, Bas - \ 2020
    Poultry Science 99 (2020)7. - ISSN 0032-5791 - p. 3355 - 3362.
    broiler breeder - floor egg - foot pad dermatitis - genetic line - leg health

    Contact dermatitis, both on the foot pads and hocks, is a well-known health issue in broilers. Less is known about contact dermatitis in broiler breeders, however, although they have many risk factors for developing leg health problems in common with broilers. This study aimed to describe the prevalence and severity of contact dermatitis during the production cycle in 5 lines of broiler breeders, investigate possible causes of contact dermatitis, and study its relationship with gait, egg production, and floor egg percentage. Five commercially available genetic lines of broiler breeders were housed in 21 pens of 550 females and 50 males from 20 to 60 wk of age. Every 10 wk litter quality, leg health measurements (foot pad dermatitis, hock burn, and gait) and body weight were assessed of 50 random hens per pen. Total number of eggs, number of eggs laid outside the nest (floor eggs), and mortality were recorded daily per pen. Prevalence of foot pad dermatitis, hock burn, and gait problems increased with age. Litter quality started to decrease at 50 wk of age. Prevalence of foot pad dermatitis was affected by litter quality, whereas genetic line had little effect. One genetic line was more prone to developing hock burns, though generally the prevalence of hock burn (13%) was much lower than that of foot pad dermatitis (74%). The percentage of broiler breeders with gait problems increased up to 24% with age, but this was not related to the prevalence of contact dermatitis. The lines differed in body weight from 32 wk of age onwards, and a higher body weight was related to lower egg production and higher cumulative mortality. The percentage of floor eggs was not related to leg health parameters or genetic line. Broiler breeders thus have similar leg health problems as broilers, but these problems are not related to the percentage of floor eggs, suggesting that other factors are involved in the undesirable behavior of floor laying.

    Parallel genetic origin of foot feathering in birds
    Bortoluzzi, Chiara ; Megens, Hendrik-Jan ; Bosse, Mirte ; Derks, Martijn ; Dibbits, Bert ; Laport, Kimberley ; Weigend, Steffen ; Groenen, Martien ; Crooijmans, Richard - \ 2020
    Wageningen University
    PRJEB36674 - ERP119891 - chicken - parallel evolution - foot feathering - Gallus gallus
    Understanding the genetic basis of similar phenotypes shared between lineages is a long-lasting research interest. Even though animal evolution offers many examples of parallelism, for many phenotypes little is known about the underlying genes and mutations. We here use a combination of whole-genome sequencing, expression analyses, and comparative genomics to study the parallel genetic origin of ptilopody (Pti) in chicken. Ptilopody (or foot feathering) is a polygenic trait that can be observed in domesticated and wild avian species and is characterized by the partial or complete development of feathers on the ankle and feet. In domesticated birds, ptilopody is easily selected to fixation, though extensive variation in the type and level of feather development is often observed. By mean of a genome-wide association analysis, we identified two genomic regions associated with ptilopody. At one of the loci, we identified a 17 kb deletion affecting PITX1 expression, a gene known to encode a transcription regulator of hindlimb identity and development. Similarly to pigeon, at the second loci we observed ectopic expression of TBX5, a gene involved in forelimb identity and a key determinant of foot feather development. We also observed that the trait evolved only once as foot feathered birds share the same haplotype upstream TBX5. Our findings indicate that in chicken and pigeon ptilopody is determined by the same set of genes that affect similar molecular pathways. Our study confirms that ptilopody has evolved through parallel evolution in chicken and pigeon.
    Parallel Genetic Origin of Foot Feathering in Birds
    Bortoluzzi, Chiara ; Megens, Hendrik-Jan ; Bosse, Mirte ; Derks, Martijn F.L. ; Dibbits, Bert ; Laport, Kimberly ; Weigend, Steffen ; Groenen, Martien A.M. ; Crooijmans, Richard P.M.A. - \ 2020
    Molecular Biology and Evolution 37 (2020)9. - ISSN 0737-4038 - p. 2465 - 2476.
    Understanding the genetic basis of similar phenotypes shared between lineages is a long-lasting research interest. Even though animal evolution offers many examples of parallelism, for many phenotypes little is known about the underlying genes and mutations. We here use a combination of whole-genome sequencing, expression analyses, and comparative genomics to study the parallel genetic origin of ptilopody (Pti) in chicken. Ptilopody (or foot feathering) is a polygenic trait that can be observed in domesticated and wild avian species and is characterized by the partial or complete development of feathers on the ankle and feet. In domesticated birds, ptilopody is easily selected to fixation, though extensive variation in the type and level of feather development is often observed. By means of a genome-wide association analysis, we identified two genomic regions associated with ptilopody. At one of the loci, we identified a 17-kb deletion affecting PITX1 expression, a gene known to encode a transcription regulator of hindlimb identity and development. Similarly to pigeon, at the second loci, we observed ectopic expression of TBX5, a gene involved in forelimb identity and a key determinant of foot feather development. We also observed that the trait evolved only once as foot-feathered birds share the same haplotype upstream TBX5. Our findings indicate that in chicken and pigeon ptilopody is determined by the same set of genes that affect similar molecular pathways. Our study confirms that ptilopody has evolved through parallel evolution in chicken and pigeon.
    Green Challenges: plant en bodemweerbaarheidtegen ondergrondse ziekten
    Streminska, Marta ; Breeuwsma, Suzanne ; Huisman, Huei Ming ; Vos, Ric de; Eekelen, Henriette van; Stevens, Luc ; Salm, Caroline van der - \ 2020
    Bleiswijk : Stichting Wageningen Research, Wageningen Plant Research, Business unit Glastuinbouw (Rapport WPR 943) - 61
    Crops in soil-based and soilless greenhouse cultivation systems are susceptible to various soilborne diseases, such as foot and root rot and wilting, caused by pathogens as Fusarium and Pythium. The Grºeen Challenges project aims to reduce the use of chemical plant protection products and to develop new measures and strategies for disease and pest control through a system approach. This project investigated which measures can be taken to promote soil disease suppression and induced plant resistance against soilborne pathogens (Fusarium and Pythium) in different horticultural crops: vegetable crops (tomato and cucumber) and ornamental crop (lisianthus).
    The long road to lameness: considering walking distance as a challenge in pasture-based dairy production
    Crossley, R.E. ; Conneely, Muireann ; Browne, Natasha ; Sugrue, Katie ; Boer, I.J.M. de; Bokkers, Eddie - \ 2020
    In: WIAS Annual Conference 2020. - WIAS - p. 81 - 81.
    One challenge of pasture-based dairy production systems is that grazing cattle must walk greater distances from the paddock to the parlour to facilitate milking. In Ireland, cows spend an average of 241 days per year at grass, typically brought to the parlour for milking twice per day, resulting in a relatively large portion of their daily time budget spent walking.Longer walking distances, however, may be associated with increased lameness, thus impacting their welfare. To investigate the potential impact of walking distance on lameness and welfare, the first step is establishing a better picture of the typical distances covered by grazing dairy cattle in Ireland. During the grazing season (April-September 2019) 100 farms were visited throughout the primary dairy producing counties of Ireland. Farmers were surveyed regarding their grazing practices and their cows were mobility scored by trained observers using a 4-point scoring system (0 = good, 1 = imperfect, 2 = impaired, 3 = severely impaired mobility). Farms had a mean size of 45.2ha (range= 14-101ha), milking an average of 124 cows (range = 38-253) twice daily. According to farmers’ responses, the average walking distance between the parlour and the furthest grazing paddock had a mean of989m (range = 400-2000m). Cows could be travelling this path 4 times per day, thus cows walk on average up to 4.0km/d. On 51% of farms, cows were collected from paddocks on foot, while 31% of farmers used some type of motorised vehicle. Using vehicles to move cattle has been associated with increased hoof injuries as hurried animals have difficulty avoiding hazards on roadway surfaces, however, this was not reflected in the data from this survey. Mobility scoring indicated that the mean proportion of cows across farms with score 0 was 36% (range = 9-76%), score 1 was 54% (range = 22-76%), score 2 was 9% (range= 1-27%), and score 3 was 1% (range = 0-5%). A relatively low level of cows scored 2/3,however, a high proportion of cows scored 1 which may reflect other underlying issues,such as roadway conditions, another key factor associated with lameness. While this survey illustrates the potential stress imposed on grazing dairy cattle through long walking distances,further study is required to investigate possible associations with lameness and welfare.
    The Impacts of Suboptimal Mobility in Pasture-based Dairy Systems
    O'Connor, A. ; Bokkers, Eddie ; Boer, I.J.M. de; Hogeveen, H. ; Sayers, R. ; Byrne, N. ; Ruelle, E. ; Shalloo, L. - \ 2020
    In: WIAS Annual Conference 2020. - WIAS - p. 30 - 30.
    Suboptimal mobility refers to any abnormality to a cow’s gait which causes a deviation from the optimal walking pattern of a cow. Suboptimal mobility is an area of concern from an economic, environmental and animal welfare point of view. While the potentialrisk factors and impacts of suboptimal mobility in non-pasture-based systems are reported on throughout the literature, the same information is lacking for seasonal calving, pasture-based systems. The overall aim of this project was to determine the impacts of suboptimal mobility in a pasture-based dairy system. To achieve this we determined 1) the association between claw disorders and suboptimal mobility; 2) the cow and herd-level risk factors associated with suboptimal mobility; 3) the production and reproductive impacts associated with suboptimal mobility; 4) the economic and environmental consequences of suboptimal mobility. Data from 11,116 cows from 68 Irish pasture-based dairy herds were collected. Cows were mobility scored and body condition scored (BCS). Production data(milk, fat, and protein yields, and somatic cell count), reproductive data (calving dates,calving interval, and culling), and other cow-level data (breed type, and genetic transmitting abilities for health and production traits) were available for each cow. Herd-level data including cow path quality and maintenance practices, distances cows walk to and from pasture each day, and foot bathing regimes on farm were collected for each herd via an online survey completed by the herd owners. Our study showed that all severities of claw disorders (ranging from mild to severe), are associated with specific mobility scores. Furthermore,cows with higher yields, elevated SCC, less body condition, and cows with a genetic predisposition for lameness are all potential risk factors for suboptimal mobility. We also found that certain cow breeds such as Jersey type cows are associated with a reduced risk for having suboptimal mobility. At the herd-level, both the quality of cow paths and the distance cows must walk each day are associated with an increased proportion of suboptimal mobility. Finally, herds with higher proportions of suboptimal mobility have lower economic returns and higher total costs. These herds are also associated with increased greenhouse gas emissions per kg of fat and protein corrected milk yield.
    The Impacts of Suboptimal Mobility in Pasture-based Dairy Systems
    O'Connor, Aisling ; Bokkers, E.A.M. ; Boer, Imke de; Hogeveen, Henk ; Sayers, R. ; Byrne, N. ; Ruelle, E. ; Shalloo, L. - \ 2020
    Suboptimal mobility refers to any abnormality to a cow’s gait which causes a deviation
    from the optimal walking pattern of a cow. Suboptimal mobility is an area of concern
    from an economic, environmental and animal welfare point of view. While the potential
    risk factors and impacts of suboptimal mobility in non-pasture-based systems are reported
    on throughout the literature, the same information is lacking for seasonal calving, pasture-
    based systems. The overall aim of this project was to determine the impacts of suboptimal
    mobility in a pasture-based dairy system. To achieve this we determined 1) the
    association between claw disorders and suboptimal mobility; 2) the cow and herd-level risk
    factors associated with suboptimal mobility; 3) the production and reproductive impacts
    associated with suboptimal mobility; 4) the economic and environmental consequences
    of suboptimal mobility. Data from 11,116 cows from 68 Irish pasture-based dairy herds were
    collected. Cows were mobility scored and body condition scored (BCS). Production data
    (milk, fat, and protein yields, and somatic cell count), reproductive data (calving dates,
    calving interval, and culling), and other cow-level data (breed type, and genetic transmitting
    abilities for health and production traits) were available for each cow. Herd-level data
    including cow path quality and maintenance practices, distances cows walk to and from
    pasture each day, and foot bathing regimes on farm were collected for each herd via an
    online survey completed by the herd owners. Our study showed that all severities of claw
    disorders (ranging from mild to severe), are associated with specific mobility scores. Furthermore,
    cows with higher yields, elevated SCC, less body condition, and cows with a genetic
    predisposition for lameness are all potential risk factors for suboptimal mobility. We also
    found that certain cow breeds such as Jersey type cows are associated with a reduced
    risk for having suboptimal mobility. At the herd-level, both the quality of cow paths and the
    distance cows must walk each day are associated with an increased proportion of suboptimal
    mobility. Finally, herds with higher proportions of suboptimal mobility have lower economic
    returns and higher total costs. These herds are also associated with increased green house
    gas emissions per kg of fat and protein corrected milk yield.
    Emergency foot-and-mouth disease vaccines a Malaysia 97 and A22 Iraq 64 offer good protection against heterologous challenge with a variant serotype a ASIA/G-IX/SEA-97 lineage virus
    Nagendrakumar, B. ; Dekker, Aldo ; Eblé, Phaedra L. ; Hemert-Kluitenberg, Froukje van; Weerdmeester, Klaas ; Horsington, Jacquelyn ; Wilna, Vosloo W. - \ 2020
    Vaccines 8 (2020)1. - ISSN 2076-393X
    Cross-protection - FMD - Foot-and-mouth disease virus - Heterologous protection - Vaccine - Vaccine efficacy

    The continuous emergence of foot-and-mouth disease virus (FMDV) serotype A variants in South East Asia is of concern for international FMDV antigen banks, especially when in vitro tests predict a low antigenic match. A vaccination-challenge study was performed by using two emergency FMDV vaccines with A22 Iraq 64 (A22 IRQ) and A Malaysia 97 (A MAY 97) strains, against challenge with a variant strain of FMDV A/Asia/G-IX/SEA-97 lineage at 7- and 21-day post-vaccination (dpv). At 7 dpv, three of five female calves vaccinated with A MAY 97 and four of five vaccinated with A22 IRQ did not show lesions on the feet and were considered protected, while at 21 dpv all five calves were protected with each vaccine, indicating equal efficacy of both vaccine strains. Calves were protected despite relatively low heterologous neutralizing antibody titers to the challenge virus at the time of challenge. All the calves developed antibodies to the non-structural proteins, most likely due to the direct intradermolingual (IDL) inoculation. Only one calf from the A MAY 97-7 group had infectious virus in the serum 1–3-day post-challenge (dpc), while no virus could be isolated from the serum of cattle challenged on 21 dpv. The virus could be isolated from the oral swabs of all calves, 1–7 dpc with viral RNA detected 1–10 dpc. Nasal swabs were positive for virus 1–6 dpc in a small number of calves. The time between vaccination and infection did not have an impact on the number of animals with persistent infection, with almost all the animals showing viral RNA in their oro-pharyngeal fluid (probang) samples up to 35 dpc. Despite the poor in vitro matching data and field reports of vaccine failures, this study suggests that these vaccine strains should be effective against this new A/Asia/G/SEA-97 variant, provided they are formulated with a high antigen dose.

    Cross-protection induced by a A/MAY/97 emergency vaccine against intra-serotype heterologous challenge with a foot-and-mouth disease virus from the A/ASIA/G-VII lineage
    Dekker, Aldo ; Sanz-Bernardo, Beatriz ; Singanallur, Nagendrakumar Balasubramanian ; Ludi, Anna B. ; Horsington, Jacquelyn ; Eblé, Phaedra L. ; King, Donald P. ; Vosloo, Wilna - \ 2020
    Vaccines 8 (2020)1. - ISSN 2076-393X
    Cross-protection - FMD - Foot-and-mouth disease - Heterologous protection - Potency test - Vaccine

    Since 2015, outbreaks of foot-and-mouth disease (FMD) in the Middle East have been caused by a new emerging viral lineage, A/ASIA/G-VII. Invitro vaccine matching data indicated that this virus poorly matched (low r1-value) with vaccines that were being used in the region as well as most other commercially available vaccines. The aim of this study was to assess the performance of two candidate vaccines against challenge with a representative field virus from the A/ASIA/G-VII lineage. The results from an initial full dose protection study provided encouraging data for the A/MAY/97 vaccine, while the A22 /IRQ/64 vaccine only protected 2/7 vaccinated animals. In view of these promising results, this vaccine was tested in a potency test (PD50) experiment in which 5 cattle were vaccinated with a full dose, 5 cattle with a 1/3 dose and 5 cattle with a 1/9 dose of vaccine. At 21 days post vaccination these vaccinated cattle and 3 control cattle were challenged intradermolingually with a field isolate from the A/ASIA/G-VII lineage. The intra-serotype heterologous potency test resulted in an intra-serotype heterologous potency of 6.5 PD50 /dose. These data support previous studies showing that a high potency emergency vaccine can protect against clinical disease when challenged with a heterologous strain of the same serotype, indicating that not only the r1-value of the vaccine, but also the homologous potency of a vaccine should be taken into account when advising vaccines to control an outbreak.

    How the neurotoxin β-N-Methylamino-L-Alanine accumulates in bivalves: distribution of the different accumulation fractions among organs
    Lepoutre, Alexandra ; Faassen, E.J. ; Zweers, A.J. ; Lurling, M.F.L.L.W. ; Geffard, Alain ; Lance, E. - \ 2020
    Toxins 12 (2020)2. - ISSN 2072-6651
    The environmental neurotoxin β-methylamino-l-alanine (BMAA) may represent a risk for human health. BMAA accumulates in freshwater and marine organisms consumed by humans. However, few data are available about the kinetics of BMAA accumulation and detoxification in exposed organisms, as well as the organ distribution and the fractions in which BMAA is present in tissues (free, soluble bound or precipitated bound cellular fractions). Here, we exposed the bivalve mussel Dreissena polymorpha to 7.5 µg of dissolved BMAA/mussel/3 days for 21 days, followed by 21 days of depuration in clear water. At 1, 3, 8, 14 and 21 days of exposure and depuration, the hemolymph and organs (digestive gland, the gills, the mantle, the gonad and muscles/foot) were sampled. Total BMAA as well as free BMAA, soluble bound and precipitated bound BMAA were quantified by tandem mass spectrometry. Free and soluble bound BMAA spread throughout all tissues from the first day of exposure to the last day of depuration, without a specific target organ. However, precipitated bound BMAA was detected only in muscles and foot from the last day of exposure to day 8 of depuration, at a lower concentration compared to free and soluble bound BMAA. In soft tissues (digestive gland, gonad, gills, mantle and muscles/foot), BMAA mostly accumulated as a free molecule and in the soluble bound fraction, with variations occurring between the two fractions among tissues and over time. The results suggest that the assessment of bivalve contamination by BMAA may require the quantification of total BMAA in whole individuals when possible.
    Invited review: Compost-bedded pack barns for dairy cows
    Leso, L. ; Barbari, M. ; Lopes, M.A. ; Damasceno, F.A. ; Galama, P. ; Taraba, J.L. ; Kuipers, A. - \ 2020
    Journal of Dairy Science 103 (2020)2. - ISSN 0022-0302 - p. 1072 - 1099.
    animal welfare - compost-bedded pack barn - dairy cow - housing system

    Compost-bedded pack barns (CBP) are receiving increasing attention as a housing system for dairy cows that has potential to improve animal welfare. This article reviews current scientific knowledge about CBP with the aim of providing a comprehensive tool for producers and researchers using this housing system. In CBP, cows are provided with an open bedded pack area rather than the individual stalls and concrete alleys found in freestall systems. The bedded pack, a mixture of organic bedding and cattle excreta, is cultivated frequently (1–3 times per day) to incorporate fresh manure and air into the pack, thus promoting an aerobic composting process. To function well, CBP generally require a large area per cow. Optimal animal densities over the bedded area range from 7.4 to more than 15 m2/cow depending on several factors, including climate, bedding, pack management, and cow characteristics. Studies have indicated that CBP, compared with conventional systems such as freestall barns, have the potential to improve the welfare of dairy cows. In particular, the main reported benefits include improved comfort during resting, better foot and leg health, and more natural animal behavior. Research has also indicated that adequate udder health can be achieved in CBP. However, because the bedded pack has been shown to contain high bacterial concentrations, proper management is essential to maintain adequate cow cleanliness and reduce the risk of mastitis. Controlling pack moisture is consistently indicated as the most important issue with CBP. Especially under cold and humid weather conditions, large amounts of bedding may be necessary to keep the pack adequately dry and comfortable for the cows. Nevertheless, the improvements in cow health may offset the higher costs of bedding.

    Predicting survival in dairy cattle by combining genomic breeding values and phenotypic information
    Heide, E.M.M. van der; Veerkamp, R.F. ; Pelt, M.L. van; Kamphuis, C. ; Ducro, B.J. - \ 2020
    Journal of Dairy Science 103 (2020)1. - ISSN 0022-0302 - p. 556 - 571.
    dairy cow - individual prediction - longevity - survival

    Advances in technology and improved data collection have increased the availability of genomic estimated breeding values (gEBV) and phenotypic information on dairy farms. This information could be used for the prediction of complex traits such as survival, which can in turn be used in replacement heifer management. In this study, we investigated which gEBV and phenotypic variables are of use in the prediction of survival. Survival was defined as survival to second lactation, plus 2 wk, a binary trait. A data set was obtained of 6,847 heifers that were all genotyped at birth. Each heifer had 50 gEBV and up to 62 phenotypic variables that became gradually available over time. Stepwise variable selection on 70% of the data was used to create multiple regression models to predict survival with data available at 5 decision moments: distinct points in the life of a heifer at which new phenotypic information becomes available. The remaining 30% of the data were kept apart to investigate predictive performance of the models on independent data. A combination of gEBV and phenotypic variables always resulted in the model with the highest Akaike information criterion value. The gEBV selected were longevity, feet and leg score, exterior score, udder score, and udder health score. Phenotypic variables on fertility, age at first calving, and milk quantity were important once available. It was impossible to predict individual survival accurately, but the mean predicted probability of survival of the surviving heifers was always higher than the mean predicted probability of the nonsurviving group (difference ranged from 0.014 to 0.028). The model obtained 2.0 to 3.0% more surviving heifers when the highest scoring 50% of heifers were selected compared with randomly selected heifers. Combining phenotypic information and gEBV always resulted in the highest scoring models for the prediction of survival, and especially improved early predictive performance. By selecting the heifers with the highest predicted probability of survival, increased survival could be realized at the population level in practice.

    Quantifying soil carbon stocks and humification through spectroscopic methods: A scoping assessment in EMBU-Kenya
    Claessens, L.F.G. ; Segnini, A. ; Posadas, A. - \ 2019
    Journal of Environmental Management 234 (2019). - ISSN 0301-4797 - p. 476 - 483.
    A soil carbon assessment was performed comparing agricultural cropping systems with natural vegetation along a sampling transect spanning different agro-ecologies on the eastern foot slopes of Mount Kenya in Embu county, 125 km from Nairobi, Kenya. The aim was to determine differences in soil carbon stocks and carbon recalcitrance and relate these to soil textural class, altitude, climatic parameters and land use. Soils from main agricultural systems as tea, coffee and maize-based intercropping, as well as from natural vegetation cover were sampled in triplicates, in five layers from 0 to 30 cm in depth and processed for total carbon analysis. The whole soil samples were also analysed using Laser-Induced Fluorescence Spectroscopy (LIFS) to assess carbon humification. Prototype portable equipment intended for future in situ analysis was used in the lab to ascertain the structure of the most recalcitrant and stable carbon present in different agro-ecosystems. In addition, Near Infrared Spectroscopy (NIRS) was tested for the quantitative analysis of soil carbon, showing that it is a reproducible and low-cost method that provided satisfactory results under the processing conditions of the samples. Results showed wide variation in the level and quality of carbon stored in the soils, depending on soil texture, land use, elevation, climate, agricultural practices and land use history. Considering the heterogeneous nature of sampled soils and the performance of NIRS and LIFS, these results can be used as a basis for the development of fully portable systems able to provide rapid, clean and potentially cost-effective relevant information for soil management.
    Soft dendritic microparticles with unusual adhesion and structuring properties
    Roh, Sangchul ; Williams, Austin H. ; Bang, Rachel S. ; Stoyanov, Simeon D. ; Velev, Orlin D. - \ 2019
    Nature Materials 18 (2019). - ISSN 1476-1122 - p. 1315 - 1320.

    The interplay between morphology, excluded volume and adhesivity of particles critically determines the physical properties of numerous soft materials and coatings1–6. Branched particles2 or nanofibres3, nanofibrillated cellulose4 or fumed silica5 can enhance the structure-building abilities of colloids, whose adhesion may also be increased by capillarity or binding agents6. Nonetheless, alternative mechanisms of strong adhesion found in nature involve fibrillar mats with numerous subcontacts (contact splitting)7–11 as seen in the feet of gecko lizards and spider webs12–17. Here, we describe the fabrication of hierarchically structured polymeric microparticles having branched nanofibre coronas with a dendritic morphology. Polymer precipitation in highly turbulent flow results in microparticles with fractal branching and nanofibrillar contact splitting that exhibit gelation at very low volume fractions, strong interparticle adhesion and binding into coatings and non-woven sheets. These soft dendritic particles also have potential advantages for food, personal care or pharmaceutical product formulations.

    Stripping chronopotentiometry at scanned deposition potential (SSCP) : An effective methodology for dynamic speciation analysis of nanoparticulate metal complexes
    Town, Raewyn M. ; Leeuwen, Herman P. van - \ 2019
    Journal of Electroanalytical Chemistry 853 (2019). - ISSN 1572-6657
    Chemical heterogeneity - Dynamic metal speciation - Humic substances - Lability - Nanoparticulate complexants

    The features of stripping chronopotentiometry at scanned deposition potential (SSCP) are reviewed and placed in context with voltammetric and other dynamic speciation techniques. The advantages of SSCP for speciation analysis of nanoparticulate metal complexes are highlighted. Analogous to other electrochemical techniques, the SSCP wave is rich in information: the measurements from the foot to the plateau of the wave access the relevant parts of the stability distribution and the rate constant distributions. The complete depletion regime of SSCP offers particular advantages due to its ability to unambiguously distinguish between various factors that can confound interpretation of data from other electroanalytical methods, including electrochemical irreversibility, kinetically controlled currents, reduced diffusion coefficient of the metal complex species as compared to the free metal ion, and chemical heterogeneity in the intrinsic binding affinity.

    Healing gardens as therapeutic landscapes
    Veen, E.J. ; Doughty, Karolina - \ 2019
    Although survival rates for cancer are improving, survivors suffer an increased risk of chronic illnesses such as cardiovascular disease and depression. In order to prevent patients from developing these diseases, lifestyle guidelines have been developed. Adherence to these guidelines, however, is low and short-lived. Many patients lack the aspiration, capacity or energy to make lifestyle changes. In this paper we explore a communal ‘healing garden’ as a potential alternative to these lifestyle guidelines, exploring whether it may function as a ‘therapeutic landscape’ for cancer survivors, particularly in stimulating physical activity and healthy eating, but also in facilitating social peer support. Our paper discusses a pilot project in the Netherlands, in which five participants gardened together one-and-a-half hours a week, under supervision, in ten square foot gardening containers. Using a series of physical tests and semi-structured interviews with participants (before, during and after the project), we show that physically the gardening experience did not meet expectations. Nevertheless, the gardening activity was highly satisfying for participants, for a variety of reasons (the activity as such, the harvest, the pleasure of manual labour, and mental rest). Participants reported that the gardening group formed a supportive environment. However, they did not agree on whether that is sufficient to consider the gardening activity a form of social peer support. We conclude that even though the project did not have measurable physical results, it can be regarded a therapeutic landscape for its social benefits.
    Risk assessment of exotic disease incursion and spread
    Cabral, M. ; Taylor, R. ; Vos, C.J. de - \ 2019
    EFSA Journal 17 (2019)S2. - ISSN 1831-4732
    generic model - Import risk assessment - introduction risk - livestock disease - validation

    This Technical Report describes the activities developed in the scope of the EU-FORA Fellowship, within the work programme of risk assessment (RA) of exotic disease incursion and spread, developed at Wageningen Bioveterinary Research (WBVR). The programme focused on the work carried out in the Generic risk assessment for introduction of animal diseases (G-RAID) project, which brings together a number of different generic RA tools from multiple European partners. The aim of the fellowship was to gain understanding of veterinary import risk assessment by using different RA tools and to learn how different algorithms can be used to calculate disease incursion risks. G-RAID's tools cover a wide range of RA methodologies; from purely qualitative, to semi-quantitative and fully stochastic quantitative methods, which allowed the fellow to understand a variety of algorithms used to produce the final risk estimate. The fellowship programme provided the fellow with the chance to learn in detail about how generic RAs are performed across Europe, understanding how to deal with the uncertainty and variability involved in RAs and the potential problems of data availability and reliability. The fellow made an inventory of publicly available databases on disease occurrence and international trade that could be used for import RA and assessed their quality and usefulness for the different generic RA tools. The programme also provided the fellow the opportunity to perform several import risk assessments using the RA tools of G-RAID. She completed a RA on African swine fever using the MINTRISK model developed by WBVR. Furthermore, she assessed the risk of foot and mouth disease introduction using the Rapid Risk Assessment Tool (RRAT) model developed by WBVR and the COMPARE model developed by the Animal and Plant Health Agency (APHA). To this end, the fellow completed a short-term visit to APHA, enabling her to have additional training in quantitative RA and to expand her professional network in this area.

    Finding out why frogs' feet stick
    Langowski, J.K.A. - \ 2019
    Soil lacquer peel do-it-yourself: Simply capturing beauty
    Stoof, Cathelijne R. ; Candel, Jasper H.J. ; Wal, Laszlo A.G.M. Van Der; Peek, Gert - \ 2019
    SOIL 5 (2019)2. - ISSN 2199-3971 - p. 159 - 175.

    Visualization can greatly benefit understanding of concepts and processes, which in soil science and geology can be done using real-life snapshots of soils and sediments in lacquer peels and glue peels. While it may seem complicated, anyone can make such a soil peel for use in classrooms, public places, homes, and offices for teaching, outreach, decoration, and awareness. Technological development has considerably simplified the making of soil peels, but this methodological innovation has not been described in the literature. Here, we report on a thoroughly tested and simple method for taking peels of sandy soils using readily available tools and materials. Our method follows the main previously published steps of preparing a soil face, impregnating the soil face with a fixation agent in the field, extracting the resulting peel, and mounting it on a wooden panel. Yet instead of using lacquers and thinning agents, we use strong though flexible contact adhesive (glue), which has the major advantage that it no longer requires use and mixing of toxic chemicals in the field or reinforcement of the peel to prevent breaking. Moreover, the preservation potential is much higher than with the old method. This new twist to old methods makes creation of soil peels safer, simpler, and more successful, and thereby a true DIY (do-it-yourself) activity. The resulting increased accessibility of making soil and sediment peels can benefit research, teaching, and science communication and can thereby bring the value and beauty of the ground below our feet to students, schools, policy makers, and the general public.

    Short communication: The effects of regrouping in relation to fresh feed delivery in lactating Holstein cows
    Smid, Anne Marieke C. ; Weary, Daniel M. ; Bokkers, Eddie A.M. ; Keyserlingk, Marina A.G. von - \ 2019
    Journal of Dairy Science 102 (2019)7. - ISSN 0022-0302 - p. 6545 - 6550.
    management - mixing - social stress - welfare

    This study tested whether separating regrouping from the time of fresh feed delivery mitigated the effects of regrouping on cow behavior and milk production. Cows (n = 26) were individually introduced into a stable group of 11 animals/pen fed twice daily. Animals were randomly assigned to early regrouping (at 0300 h, approximately 10.5 h after fresh feed delivery and 3.5 h before the next fresh feed delivery) and late regrouping (between 0630 and 0730 h, coinciding with access to fresh feed). For 3 d, starting immediately after regrouping, video recordings continuously monitored feeding and perching (i.e., standing with the 2 front feet in the lying stall) behavior and displacements at the feed bunk. Data loggers were used to quantify lying time and the number of standing bouts; milk production was automatically recorded at each milking. Daily feeding and lying times and the number of standing bouts per day did not differ between treatments or experimental days. Daily perching time and the number of displacements at the feed bunk did not differ between treatments but decreased with experimental day. Average milk production on d 2 and 3 after regrouping (30.6 ± 1.5 kg/d) was lower than during the 3 d before regrouping (32.3 ± 1.5 kg/d), but we observed no effect of treatment on this decline. We conclude that regrouping at a time not associated with fresh feed delivery does not mitigate the negative effects of regrouping.

    Residual dune ridges: sedimentary architecture and potential as climate archive (southern North Sea)
    Reimann, T. ; Lindhorst, Sebastian - \ 2019
    - p. 21 - 21.
    Sedimentary architecture and genesis of residual dune ridges are presented and it is shown that these ridges bear a so far unread archive of changes in precipitation rate and wind-field configuration on to decadal time scales.
    Residual dunes are common features of wet aeolian siliciclastic systems. They form sets of shallow ridges in upwind-direction of active dunes, oriented perpendicular to the prevailing wind direction. Residual dune ridges
    are vegetated and typically elevate 1 to 3 m above the local deflation surface, which is controlled by the long-term mean position of the ground-water table. Ground-penetrating radar data show that they are composed of windward
    as well leeward dipping sedimentary beds, with the dipping of the latter being comparable to the foreset angles of active dunes. Dating based on optically stimulated luminescence (OSL), however, indicate a complete reworking
    of sediments during construction of the ridge and, as a consequence, ridges do not contain preserved bottom sets of their parent dunes.
    Residual dune ridges develop on the stoss side of active dunes during periods of elevated ground-water table and hence colonization of the foot of the active dune by rapid growing pioneer vegetation. These plants trap sand blown off the parent dune and stabilize the ridge when it detaches from the parent dune in the course of theirfurther downwind migration. Multi-annual to multi-decadal variability in precipitation leads to the development of sequences composed of tens of ridges, spanning a time period of several centuries, as indicated by OSL ages. Comparison with meteorological data, however, shows that the spacing of individual ridges in these sequences is controlled not by variable precipitation alone, but also reflects changes in the rate of migration of the parental dune due to long-term changes in wind intensity.
    Dynamical indicators of resilience in postural balance time series are related to successful aging in high-functioning older adults
    Gijzel, Sanne ; Leemput, I.A. van de; Scheffer, M. ; Bon, Geert van; Weerdesteyn, V. ; Eijsvogels, T.M.H. ; Hopman, Maria T.E. ; Olde Rikkert, M.G.M. ; Melis, René J.F. - \ 2019
    Journals of Gerontology. Series A: Biological Sciences & Medical Sciences 74 (2019)7. - ISSN 1079-5006 - p. 1119 - 1126.
    Background: Finding ways to quantify resilience as a predictor of a person’s resistance to health challenges is important to improve healthy aging. This study investigated a unique sample of high-functioning older persons in whom traditional markers of frailty and functional decline are largely absent. Translating complex dynamical systems theory to humans, dynamical indicators of resilience in postural balance time series may sensitively discriminate levels of resilience. Methods: This study investigated 240 high-functioning older adults (mean age 83.9 ± 2.9 years, 59% male), of whom 94 hikers of the Nijmegen Four Days Marches. Participants stood upright on a force plate with eyes open and feet at shoulder width for 30 seconds. Center of pressure data were analyzed for dynamical indicators of resilience (variance and temporal autocorrelation). After 1 year, participants were compared on a modified Successful Aging Index. Results: Mediolateral center of pressure displacement of hikers exhibited significantly lower variance (2.2 vs 2.8 mm, p < .001) and temporal autocorrelation (0.59 vs 0.65, p = .006), compared with nonhikers. Multivariably adjusted, mediolateral variance was significantly associated with successful aging at baseline (b = −1.43, p = .003) and 1-year follow-up (b = −1.94, p < .001), while mediolateral temporal autocorrelation was not. Conclusions: Two dynamical indicators of resilience (variance and temporal autocorrelation) calculated on time series of mediolateral center of pressure displacement differed between hikers and nonhikers within a group of high-functioning older adults. In the whole group, variance was independently associated with successful aging at baseline and after 1 year. Our results support the hypothesis that resilience of older persons may be estimated from time series of natural fluctuations of bodily functions.
    A Delta plan with a resilience assessment please!
    Dewulf, Art - \ 2018

    A delta plan can help keep feet dry but it can also have other, sometimes unintended, effects. Public Administration expert Art Dewulf is coordinating a study of the effects of delta interventions in Vietnam and Bangladesh. Who decides policy, who benefits from it, and who gets the short straw? Key issues for the resilience of a delta region.

    Harare : Informality and urban citizenship - housing struggles in Harare, Zimbabwe
    Muchadenyika, Davison ; Chakamba, Molin K. ; Mguni, Patience - \ 2018
    In: The Routledge Handbook on Informal Urbanization / Rocco, Roberto, van Ballegooijen, Jan, New York : Taylor and Francis - ISBN 9781138183889 - p. 124 - 134.
    This chapter explores the interface between informality and national politics in Harare, the capital city of Zimbabwe. We argue that urban land is used by opposing political parties as a currency with which to buy political loyalty from citizens and this spurs informality in the city, in a context of democratic deficit. The government of Zimbabwe has used its power to regularize informal settlements accommodating predominantly supporters of the ruling party, the Zimbabwe African National Union Patriotic Front (Zanu-PF), thus bypassing the opposition-led council of the City of Harare. Regularization is a strategy to reward those active in politics and also loyal to the ruling party. Simultaneously, this process plays a vital role in allowing citizens to occupy land and set foot in the city. Whilst the use (and abuse) of space in Harare is political and largely determined by the interests of the ruling party, social movements and housing cooperatives also play into these dynamics, carving out socio-political spaces for the urban poor to navigate the hitherto rigidly controlled housing development arena. As a result, there are signs of changing attitudes towards slum upgrading and legalization in Harare.
    Mapping soil texture with a gamma-ray spectrometer : comparison between UAV and proximal measurements and traditional sampling : validation study
    Egmond, F.M. van; Veeke, S. van der; Knotters, M. ; Koomans, R.I. ; Walvoort, D.J.J. ; Limburg, J. - \ 2018
    Wageningen : Statutory Research Tasks Unit for Nature & the Environment (WOt-technical report 137) - 56
    The need for up-to-date soil information for e.g. spatial planning, infrastructure, agriculture and nature conservation has resulted in the Dutch Key Registration of the Subsurface (BRO), which also contains the 1: 50,000 soil map of the Netherlands. Classifying properties for this map are a.o. related to soil texture. Therefore, methods are needed that efficiently and effectively measure these at the right scale level and with the required accuracy. This report describes a validation study into the possibility, accuracy and costs of mapping clay and loam content of the tillage layer (0 - 30 cm) by augering, by measuring gamma radiation from a UAV (unmanned aerial vehicle or drone) or on foot. The research was carried out in an agricultural area of 40 ha in the Flevoland polder, the Netherlands. The results show that the accuracy and precision of the UAV and soil-bound measurements is largely comparable. A higher point density and smaller spatial support of the ground-bound sensor have a positive effect on capturing spatial patterns, accuracy and precision. After correction for the difference in point density, results are comparable. The difference in deployment costs is limited. The effect of the use of a national reference calibration set on costs and accuracy is a lot bigger and lowers both. However, when using national calibration scale accuracy could be increased with the inclusion of more soil geographic situations. We advise assessing similar questions by first assessing the required accuracy, measurement depth and resolution, then select possible platforms and choose calibration scale within budget limits. Gamma radiation measurements for mapping soil texture is potentially a scalable and cost-efficient technique for supporting actualisation of the Soil Map of the Netherlands and for applications with higher resolution such as precision agriculture and local spatial planning.---De behoefte aan actuele bodeminformatie voor bijv. ruimtelijke ordening, infrastructuur, landbouw en natuurbehoud heeft geresulteerd in de Basisregistratie Ondergrond (BRO) van Nederland die onder andere de 1: 50.000 Bodemkaart van Nederland bevat. Classificerende eigenschappen hiervoor zijn onder meer gerelateerd aan de bodemtextuur. Daarom zijn methoden nodig die deze op het juiste schaalniveau en met de vereiste nauwkeurigheid efficiënt en effectief inmeten. Dit rapport beschrijft een validatiestudie naar de mogelijkheid, nauwkeurigheid en kosten voor het karteren van klei en leemgehalte van de bouwvoor (0 - 30 cm) door boringen, door metingen van gammastraling vanaf een UAV (unmanned aerial vehicle of drone) of lopend. Het onderzoek is uitgevoerd op een landbouwareaal van 40 ha in de polder van Flevoland. De resultaten laten zien dat de nauwkeurigheid en precisie van de UAV-metingen grotendeels vergelijkbaar zijn met de grondgebonden metingen. Een hogere puntdichtheid en kleinere ruimtelijke ondersteuning van de lopende meting heeft een positief effect op het verklaren van de ruimtelijke patronen, nauwkeurigheid en precisie. Wanneer voor puntdichtheid wordt gecorrigeerd, zijn de resultaten vergelijkbaar. Het verschil in kosten van de inzet van de verschillende platforms is beperkt. Het effect van het gebruik van een nationale referentie kalibratieset op de kosten en nauwkeurigheid is een stuk groter, beide worden dan lager. De nauwkeurigheid met nationale kalibratieschaal kan worden verhoogd wanneer meer bodemtypen en grondsoorten zouden zijn opgenomen. We adviseren om bij een vergelijkbare vraag eerst de vereiste nauwkeurigheid, meetdiepte en resolutie te beoordelen, vervolgens mogelijke platforms te selecteren en de kalibratieschaal te kiezen binnen budgetgrenzen. Gamma-stralingsmetingen voor het karteren van bodemtextuur vormt in potentie een schaalbare en kostenefficiënte techniek om het actualiseren van de Bodemkaart van Nederland te ondersteunen en voor toepassingen met hogere resolutie zoals precisielandbouw en lokale ruimtelijke planning.
    The impact of diseases in dairy cows on greenhouse gas emissions of milk production
    Mostert, P.F. ; Middelaar, C.E. van; Bokkers, Eddie ; Boer, I.J.M. de - \ 2018
    In: 11th International Conference on Life Cycle Assessment of Food 2018 (LCA Food) in conjunction with 6th LCA AgriFood Asia and 7th International Conference on Green and Sustainable Innovation (ICGSI). - Kasetsart University - p. 169 - 169.
    Combining life cycle assessment with a dynamic stochastic simulation model allows to simulate the dynamics and consequences of diseases in livestock, and to reduce the environmental impact of our food production systems. This study aims to estimate the impact of diseases in dairy cows on greenhouse gas (GHG) emissions of milk production, using the Dutch situation as a case study, and contributes to reaching the sustainability development goals by providing information about climate change mitigation. Three diseases with a high incidence in intensive milk production systems were included: foot lesions, clinical mastitis, and subclinical ketosis. First, a dynamic stochastic Monte Carlo simulation model was used to simulate the impact of diseases on dairy cow productivity. Cows received a parity (1-5+), a potential milk production, and a risk of a disease. Based on type of disease, cows had a reduced daily milk yield, discarded milk if treated with antibiotics, a prolonged calving interval, and an increased risk of removal. Second, an LCA was performed to quantify the impact of diseases on GHG emissions from cradle-to-farm gate. Emissions of carbon dioxide, methane and nitrous oxide were estimated for processes along the dairy production chain that were affected by the consequences of diseases, including feed production, manure management and enteric fermentation. System expansion was applied to account for the production of meat from culled animals. Emissions of GHGs were estimated for a cow and herd with and without one of the diseases and were expressed as the sum of kg CO2 equivalents (100 years’ time horizon) per ton of fat-and-protein-corrected milk (kg CO2e/t FPCM). On average, GHG emissions increased by 1.5% per case of foot lesions, 6.2% per case of clinical mastitis, and 2.3% per case of subclinical ketosis. The increase in GHG emissions showed a high variation between parity and type of disease. Removal of cows was an important contributor for all diseases, and can increase GHG emissions by >50%. At the national level, the increase in GHG emissions resulting from these three diseases was estimated to be 0.4 Mton CO2e per year in total, which equals 15% of the total emission reduction target for the agricultural sector that is set by the Dutch government. In conclusion, reducing diseases in dairy cows is an effective strategy to mitigate GHG emissions of milk production and can contribute to sustainable development of the dairy sector.
    World's largest vertical farm to feed Middle East's high-fliers
    Marcelis, L.F.M. - \ 2018

    The 130,000-square foot, $40 million facility will begin construction in November, and is a joint venture between agri-tech firm Crop One Holdings and Emirates Flight Catering, suppliers of approximately 225,000 meals every day from its base at Dubai International Airport.

    Effect of constant or weekly varied eggshell temperature during incubation on broiler performance up until slaughter age
    Wijnen, H.J. ; Roovert-Reijrink, Inge Van; Priester, Marieke ; Pol, C.W. van der; Molenaar, R. ; Brand, H. van den - \ 2018
    broiler - eggshell temperature - incubation - performance - compensatory growth - delayed nutrition - early nutrition
    During incubation, embryo development is particularly influenced by temperature. Thevast majority of commercial hatcheries aim at a constant eggshell temperature (EST) of37.8°C throughout incubation. However, it has been shown recently that lowering EST(36.7°C) in the last week of incubation might improve embryo development, as higher(yolk-free) body mass and relative organ weights at hatch were found. In addition,raising EST slightly in phases during which oxygen is not limited yet (before the lastweek of incubation), might improve embryo development as well. It is hypothesizedthat a lower EST (36.7°) in the last week of incubation and a higher EST (38.9°C) in thesecond week of incubation improve embryo development and perinatal chick qualitycompared to a constant intermediate EST (37.6°) throughout incubation. Moreover,EST during incubation might have long term effects on broiler performance as theincubation period covers a substantial part of their whole lifespan and as it is knownfor many animal species that perinatal experiences have an impact in later life. Totest this hypothesis, Ross 308 eggs from a prime parent flock were incubated in a 2x2experimental design. All eggs were incubated at a normal (37.8°C) EST until embryonicday (E) 7. Thereafter, eggs were either incubated at a normal (37.8°C) or high (38.9°C)EST during the second week (E7 – E14) of incubation and a normal (37.8°C) or low(36.7°C) EST during the last week (E14 – E21) of incubation. Within 6 hours afterhatch, chick development was evaluated by chick weight, length, navelscore, and organweights. Posthatch, 5 males and 5 females were housed in a 2 m2 pen with 8 replicatesper treatment (n=320) and reared until slaughter age (D42). Growth and feed intakewere monitored weekly. At D28, D35, and D39 gait was scored from all animals. Atslaughter, foot-pad dermatitis, hock burns, and carcass characteristics were determined.Preliminary results indicate that a low EST from E15 onwards results in slower growthand on average 103 g. lower body weight at slaughter. Other parameters were notsignificantly different or not analysed yet (e.g. carcass characteristics) at the moment ofabstract submission.
    Risk of between-herd transmission of foot-and-mouth disease virus by milk collection. Interventions in wild and domestic animals: synergy or antagonism
    Vos-de Jong, C.J. de; Dekker, A. - \ 2018
    Risk of between-herd transmission of foot-and-mouth disease virus by milk collection
    Vos-de Jong, C.J. de; Dekker, A. - \ 2018
    Living Soil: basis for our life
    Faber, J.H. ; Bloem, J. ; Goede, R.G.M. de - \ 2018
    Wageningen : Wageningen University & Research, Nature & Biodiversity blog
    ”The soil is the poor man’s tropical rain forest.” These words by the Scottish biologist M.B. Usher are spot on: one does not have to travel far to discover a wide diversity of life forms on a small area. Instead, a look under one’s feet may surpass the stoutest expectations, as soils are teeming with life. Apart from the occasional earthworm or woodlouse, one normally will see little of all that: many soil animals are just a few millimetres in size, the majority is even much smaller. To observe micro-organisms, one needs a microscope. A handful of fertile soil however contains thousands of species, billions of bacteria and meters of fungal hyphae. Nowadays, the above quote is even more relevant than when it was written around 1980, since soils have been deteriorating rapidly worldwide. This threatens the quality of our lives and livelihood by posing global challenges to food safety, climate change and adaptability, water quality and soil biodiversity.
    The potential of unmanned aerial systems for sea turtle research and conservation : A review and future directions
    Rees, Alan F. ; Avens, Larisa ; Ballorain, Katia ; Bevan, Elizabeth ; Broderick, Annette C. ; Carthy, Raymond R. ; Christianen, Marjolijn J.A. ; Duclos, Gwénaël ; Heithaus, Michael R. ; Johnston, David W. ; Mangel, Jeffrey C. ; Paladino, Frank ; Pendoley, Kellie ; Reina, Richard D. ; Robinson, Nathan J. ; Ryan, Robert ; Sykora-Bodie, Seth T. ; Tilley, Dominic ; Varela, Miguel R. ; Whitman, Elizabeth R. ; Whittock, Paul A. ; Wibbels, Thane ; Godley, Brendan J. - \ 2018
    Endangered Species Research 35 (2018). - ISSN 1863-5407 - p. 81 - 100.
    Aerial survey - Behaviour - Conservation - Drone - Ecology - Population biology - Sea turtle - UAV

    The use of satellite systems and manned aircraft surveys for remote data collection has been shown to be transformative for sea turtle conservation and research by enabling the collection of data on turtles and their habitats over larger areas than can be achieved by surveys on foot or by boat. Unmanned aerial vehicles (UAVs) or drones are increasingly being adopted to gather data, at previously unprecedented spatial and temporal resolutions in diverse geographic locations. This easily accessible, low-cost tool is improving existing research methods and enabling novel approaches in marine turtle ecology and conservation. Here we review the diverse ways in which incorporating inexpensive UAVs may reduce costs and field time while improving safety and data quality and quantity over existing methods for studies on turtle nesting, at-sea distribution and behaviour surveys, as well as expanding into new avenues such as surveillance against illegal take. Furthermore, we highlight the impact that high-quality aerial imagery captured by UAVs can have for public outreach and engagement. This technology does not come without challenges. We discuss the potential constraints of these systems within the ethical and legal frameworks which researchers must operate and the difficulties that can result with regard to storage and analysis of large amounts of imagery. We then suggest areas where technological development could further expand the utility of UAVs as data-gathering tools; for example, functioning as downloading nodes for data collected by sensors placed on turtles. Development of methods for the use of UAVs in sea turtle research will serve as case studies for use with other marine and terrestrial taxa.

    Consequences of seasonal migration : How goose relocation strategies influence infection prevalence and pathogen dispersal
    Yin, Shenglai - \ 2018
    Wageningen University. Promotor(en): W.F. de Boer; H.H.T. Prins. - Wageningen : Wageningen University - ISBN 9789463435048 - 152

    Millions of birds undertake seasonal migration between breeding and wintering sites. Bird migration causes various ecological effects such as affecting local predator-prey relationships and transporting pathogens, seeds and energy. Among these effects, pathogen dispersal has caused a large debate, including how migratory birds disperse pathogens, and how migratory birds interact with pathogens during their migration. A better understanding of pathogen dispersal is urgently needed because it is relevant to both wildlife and human health. Therefore, empirical studies such as spatial-temporal correlations between infection outbreaks and migration trajectories, genetic studies between outbreaks and infection dynamics in migratory populations, and theoretical modelling have been carried out.

    Although previous studies suggested that bird migration can disperse pathogens along migration route of birds, however, bird migration may also reduce infection prevalence and limit pathogen dispersal by so-called ‘migratory escape’ and ‘migratory culling’. Therefore, migration can affect pathogen dispersal and infection prevalence in a population, but its effects may vary among host-pathogen systems.

    Most migratory bird species use stopover sites where they refuel and rest during their migration. The movement of birds connects these stopover sites, together with their breeding and wintering sites, in a migration network. Some stopover sites are selected over others, and this selection varies between species, and over time and space within a certain species, so configurations of migration network change, and can be characterised by ‘serial stopover sites’ (when the birds are migrating over a narrow front) or ‘parallel stopover sites’ (when migration occurs over a broad front). These patterns have been clearly observed by previous studies through satellite telemetry tracking.

    Apart from various spatial configurations, migratory birds vary their timing of departure as well, and this synchrony in departure can vary from weeks to months. The combinations of the various patterns in network configuration and departure synchrony influence aggregation size, resting duration at stopover sites, and contact probabilities among individuals. However, the effects of network configuration and migration synchrony on pathogen dispersal and infection dynamic has not been fully examined yet.

    Furthermore, although stopover sites are crucial for migratory birds to complete their migration, the availability of suitable stopover sites in the East Asian-Australasian Flyway decreased, especially in China, where 30% of natural wetlands were lost over the last two decades. In reaction to this wetland loss, the migration network becomes restricted to fewer remaining sites, and bird abundance on the remaining sites correspondingly increases. This intensive use of remaining sites may increase the probability of site infection and infection prevalence in the population. However, the impact of wetland loss on infection dynamics has not been investigated before.

    Network analysis is a promising tool to analyse pathogen dispersal by migratory birds. For example, it was used to study the dispersal of severe acute respiratory syndrome, and foot and mouth disease. Real world networks such as trade networks and transport networks, are often recognized as scale-free networks. Such networks are very efficient in dispersing pathogens over the network. When extensive habitat loss occurs, however, the scale-free topology could disappear, which can make pathogen dispersal among sites less effective. Alternatively, the infection prevalence in migratory birds might be increased due to larger aggregations at remaining sites. However, the topologies of bird migration networks have rarely been examined in empirical studies or in theoretical work, although it could provide a better understanding of the variables that influence pathogen dispersal.

    In this study, I focused on avian influenza viruses (AIVs), an influenza virus that is adapted to infect birds, especially waterfowl, such as many duck, goose and swan species. It infects mainly birds, but in some cases, it can also infect mammals such as swine, horses, whales, bats and humans. Avian influenza viruses can be classified into two groups: low pathogenic avian influenza viruses (LPAIVs) and highly pathogenic avian influenza viruses (HPAIVs), based on the severity of the illness that they cause in chickens. Infection of LPAIVs in wild birds only causes mild symptoms, however, subtypes H5 and H7 can mutate to HPAIV when multiple low pathogenic avian influenza subtypes co-infect one host, especially in poultry farms with low bio-security and large numbers of domestic birds.

    HPAIV attracted a lot of attention due to their rapid dispersal and large impacts. For example, the highly pathogenic avian influenza H5N1 was for the first time detected in a domestic goose in 1996 in Guangdong, China, and then detected in wild birds in 2002 in Hong Kong, China. It suggested that migratory wild birds were infected with avian influenza virus from domestic birds. Furthermore, a H5N1 outbreak was detected in wild birds in 2005 at Qinghai Lake, China, killing more than 6000 birds. Within a few months, the H5N1 was detected in Europe, Middle East and Africa. Although intensive studies have focused on dispersal of avian influenza virus, most of these were carried out in duck species such as mallard. Few studies have examined the role of other migratory waterfowl, such as goose species. Since HPAIV can spill-over to humans and could cause high mortality rates, it is urgent to understand the mechanism of avian influenza virus dispersal.

    Overall, the aim of this study is to obtain a better understanding of the impact of migration on dispersing avian influenza virus by combining modelling and spatial-temporal statistical approaches.

    In chapter 2, I examined the infection dynamic of LPAIV in migratory goose species. I analysed throat and cloaca samples that were collected from three species from their breeding sites, stopover sites and wintering sites. I examined the infection prevalence on these sites, and analysed the temporal patterns in infection prevalence. My results showed that migratory geese were probably not infected with LPAIVs before arrival on their wintering sites, as they had a relatively low infection prevalence just after the arrival, but the prevalence increased over the winter period. My results suggest that migratory geese were exposed to the LPAIV shortly after their arrival, indicating that they might not disperse the virus during autumn migration, but more likely disperse it during spring migration.

    In chapter 3, I examined the effects of spatial and temporal migration patterns on the dynamics of low pathogenic avian influenza infection prevalence. I applied a discrete-time SIR (Susceptible-Infected-Recovered) model, with environmental transmission and migration, to various migration strategies, including networks with serial, and/or parallel stopover sites, and with various levels of migration synchrony. My results showed that both an increase in the number of serial stopover sites and an increase in the synchrony of departure timing reduces the infection prevalence due to ‘migratory escape’. Whereas increasing the number of parallel stopover sites increases the infection prevalence, because the migratory population is exposed to a larger total amount of virus in the environment, speeding-up the accumulation of infections. Furthermore, my simulations suggest that if migratory species adopt a migration pattern with multiple serial stopover sites and with high migration synchrony, the AIV transmission becomes less efficient in the population, and thereby lead to a low infection prevalence.

    In chapter 4, I tested whether habitat loss facilitates pathogen dispersal and infection prevalence in a migratory population. I identified all potential stopover sites of greater white-fronted geese in the East Asian-Australasian Flyway, and constructed migration networks with various habitat loss scenarios. I used Agent-based models to simulate bird migration over various migration networks, and integrated these with SIR-type infection dynamics to simulate epidemiological processes. I studied the dynamic of infection prevalence in migratory populations and the infection probability at stopover sites under various habitat loss scenarios. Consistent with my previous findings, I found that migration can reduce infection prevalence in a population due to migratory escape. However, the population cannot lose infection completely due to a relay effect that resting birds can be infected with avian influenza viruses that were shed by previous resting birds. Moreover, under severe levels of habitat loss, i.e., removing all sites with area decrease, geese start aggregating earlier in the fewer remaining sites, and thereby facilitate infection. In addition, habitat loss increases the infection probability for the remaining sites due to a larger amount of visiting birds, which potentially carry the virus. These results thus suggest that habitat loss facilitates outbreak of avian influenza virus infection in a migratory population and increases the probability for pathogen dispersal.

    In chapter 5, I summarized the historical HPAIV outbreaks in swan goose and bar-headed goose and compared their contact opportunities with avian influenza outbreaks areas and with the distribution areas of domestic birds in their migration corridors. Their migration corridors were estimated from GPS tracking data, using a dynamic Brownian Bridge Movement Models (dBBMMs). I found that swan geese were more likely to come into contact with outbreak areas, but fewer outbreaks occurred in their population. In contrast to swan geese, bar-headed geese were less likely to come into contact with outbreak areas, but more outbreaks occurred in their population. Moreover, I found that the densities of domestic ducks in the migratory corridor of swan geese were higher compared with those of bar-headed geese. On the basis of these findings, I proposed two possible explanations for these contrast infection patterns. First, frequent contact and a long contact history with domestic ducks may have caused higher levels of innate immunity in swan goose. Second, the migration strategy of bar-headed goose may compromise immunity, so that bar-headed geese are more vulnerable to HPAIV.

    These studies broaden the knowledge of bird species’ roles in affecting avian influenza virus infection dynamic and the virus dispersing during seasonal migration. The environmental transmission plays an important role in keeping the virus circulating in a migratory population, and I therefore recommend increasing the efforts for monitoring virus concentrations in water bodies used during migration. Moreover, since swan goose may have higher levels of innate immunity and be more resistant to infection by HPAIVs, I also recommend increasing active surveillance that covers not only the well-known affected goose species such as bar-headed goose, but also goose species which are less often found dead due to infection with HPAIVs.

    Although this study focused on the interactions between host migration and infectious pathogens in the goose-AIVs system, the findings can be generalized to other migratory host-pathogen systems such as butterflies-parasite systems, if the pathogen can persist in the environment.

    Identification of risk factors and prevalence of injuries at different stages of the broiler slaughter process
    Jong, I.C. de; Gerritzen, Marien ; Reimert, H.G.M. ; Lohman, T. - \ 2018
    In: The XVth European Poultry Conference: Conference Information and Proceedings / Prukner-Radovčić, Estella, Medić, Helga, Zagreb : - ISBN 9789082915709 - p. 240 - 240.
    Broiler, Handling, Injuries, Slaughter, Welfare
    Transport and handling of broilers during the (pre)slaughter process are risk factors for welfare. The impact of preslaughter treatments on injuries and thus the effect on welfare is poorly known. Moreover, it is unclear which proportion of carcass damage can be attributed to the conscious phase, and affects welfare, and which proportion of carcass damage can be attributed to handling after stunning and killing of birds and is related to product quality. We first analysed routinely collected data of a Dutch slaughter plant to identify risk factors for carcass damage. It was included whether or not prevalence of carcass damage was related to flock welfare status. Data collected in 2014-2016 from five farms with low foot pad dermatitis (FPD) score (<40 points) and five farms with high FPD score (>80 points) were analysed (N=771 flocks), assuming that FPD score was indicative of flock welfare status. A regression model was applied. The model showed positive associations between live body weight (P=0.000; B=0.001), number of dead-on-arrival (P=0.001; B=0.004), and wing damage. A negative association was found between wing damage and number of broilers per tray (P=0.037; B=-0.015). No relation between FPD score and carcass damage was found. Second, prevalence of injuries or damage during the slaughter process was determined in 20 flocks. Wing, leg and breast bruises, wing dislocations, and wing and leg fractures were scored between lairage and post-plucking. An increase in wing fractures from lairage (0,99%), post-shackling (1.67%), post-stunning (2.73%) and post-plucking (5.02%) was found (P=0.000 between all stages). Medium and large breast bruises increased between lairage and post-plucking (P=0.000). Small wing bruises decreased between lairage and post-plucking (P=0.047). This study showed that flock welfare status was not related to injuries, and that weight and crate density could be identified as risk factors for wing damage. Injuries and damage do mainly occur during the slaughter process. However, it was difficult to determine whether or not carcass damage originated from handling live animals, and thus is an animal welfare problem, or after stunning and therefore is a product quality issue. It is advised to develop an accuratebruise and damage scoring system that can be used to determine whether or not carcassdamage was caused in live animals.
    Replacement of foot-and-mouth disease virus cattle tongue titration by in vitro titration
    Dekker, Aldo ; Hemert-Kluitenberg, Froukje van; Oosterbaan, Anna H. ; Moonen, Kimberly ; Mouton, Laure - \ 2018
    Altex 35 (2018)4. - ISSN 1868-596X - p. 489 - 494.

    Titration of foot-and-mouth disease cattle challenge virus in cattle tongue has been the standard for many years in many countries, although titration in animals has been replaced by in vitro methods for all other applications. The objective of the analysis was the replacement of in vivo titration of cattle challenge virus by in vitro titration. Using data from 32 in vivo titration experiments together with the in vitro titration results of the same samples obtained by plaque count on primary lamb or pig kidney cells, as well as data from the virus isolation control chart used in the laboratory, we show that the reproducibility of the in vitro titration is much higher than that of the in vivo titration. The titer on primary kidney cells was on average 1.4 log10 higher than the titer determined by titration in cattle tongue (PFU/ml compared to bovine ID50/ml), but the difference varied among different strains. The study also shows that the probability of infection in cattle tongue is high even when a lower challenge dose is used, which makes the variability between strains less important. Based on these results, we propose to change the standard dose for cattle challenge from 104 bovine ID50 to 105.4 PFU, and to replace the in vivo cattle tongue titration method with the in vitro titration method.

    Using 'omic approaches to compare temporal bacterial colonization of lolium perenne, lotus corniculatus, and trifolium pratensein the Rumen
    Elliott, Christopher L. ; Edwards, Joan E. ; Wilkinson, Toby J. ; Allison, Gordon G. ; McCaffrey, Kayleigh ; Scott, Mark B. ; Rees-Stevens, Pauline ; Kingston-Smith, Alison H. ; Huws, Sharon A. - \ 2018
    Frontiers in Microbiology 9 (2018)SEP. - ISSN 1664-302X - 16 p.
    16S rRNA gene - Birds foot trefoil - CowPI - FTIR - Microbiome - Perennial ryegrass - Red clover - Rumen

    Understanding rumen plant-microbe interactions is central for development of novel methodologies allowing improvements in ruminant nutrient use efficiency. This study investigated rumen bacterial colonization of fresh plant material and changes in plant chemistry over a period of 24 h period using three different fresh forages: Lolium perenne (perennial ryegrass; PRG), Lotus corniculatus (bird's foot trefoil; BFT) and Trifolium pratense (red clover; RC). We show using 16S rRNA gene ion torrent sequencing that plant epiphytic populations present pre-incubation (0 h) were substantially different to those attached post incubations in the presence of rumen fluid on all forages. Thereafter primary and secondary colonization events were evident as defined by changes in relative abundances of attached bacteria and changes in plant chemistry, as assessed using Fourier transform infrared (FTIR) spectroscopy. For PRG colonization, primary colonization occurred for up to 4 h and secondary colonization from 4 h onward. The changes from primary to secondary colonization occurred significantly later with BFT and RC, with primary colonization being up to 6 h and secondary colonization post 6 h of incubation. Across all 3 forages the main colonizing bacteria present at all time points post-incubation were Prevotella, Pseudobutyrivibrio, Ruminococcus, Olsenella, Butyrivibrio, and Anaeroplasma (14.2, 5.4, 1.9, 2.7, 1.8, and 2.0% on average respectively), with Pseudobutyrivibrio and Anaeroplasma having a higher relative abundance during secondary colonization. Using CowPI, we predict differences between bacterial metabolic function during primary and secondary colonization. Specifically, our results infer an increase in carbohydrate metabolism in the bacteria attached during secondary colonization, irrespective of forage type. The CowPI data coupled with the FTIR plant chemistry data suggest that attached bacterial function is similar irrespective of forage type, with the main changes occurring between primary and secondary colonization. These data suggest that the sward composition of pasture may have major implications for the temporal availability of nutrients for animal.

    The impact of foot lesions in dairy cows on greenhouse gas emissions of milk production
    Mostert, P.F. ; Middelaar, C.E. van; Boer, I.J.M. de; Bokkers, E.A.M. - \ 2018
    Agricultural Systems 167 (2018). - ISSN 0308-521X - p. 206 - 212.
    Cow health - Disease - Global warming - Lameness

    The dairy sector is an important contributor to greenhouse gas (GHG) emissions. Foot lesions in dairy cows result in production losses and, therefore, might increase GHG emissions per kg milk. The objective of this study was to estimate the impact of foot lesions in dairy cows on GHG emissions. A dynamic stochastic simulation model was developed to estimate dynamics of digital dermatitis (DD), white line disease (WLD), and sole ulcer (SU), and associated production losses within one lactation. Production losses included were reduced milk production, prolonged calving interval (CI), and culling. Subsequently, a life cycle assessment was performed to estimate the impact of foot lesions on GHG emissions per ton of fat-and-protein-corrected milk (kg CO2e/t FPCM). GHG emissions increased on average by 14 (1.5%) kg CO2e/t FPCM per case of foot lesions (i.e. DD, WLD, and SU combined), ranging from 17 kg CO2e/t FPCM in parity 1, to 7 kg CO2e/t FPCM in parity 5. Emissions of GHGs increased on average by 4 (0.4%) kg CO2e/t FPCM per case of DD, by 39 (4.3%) kg CO2e/t FPCM per case of WLD, and by 33 (3.6%) kg CO2e/t FPCM per case of SU. A prolonged CI explained the majority of the increase in GHG emissions for cows with DD, whereas culling was most important for cows with WLD or SU. DD had the lowest impact on GHG emissions, but the highest prevalence, and, therefore, contributed most to the average impact of foot lesions. This study showed that preventing different types of foot lesions can reduce GHG emissions from the dairy sector. The increasing attention for global warming and possible policies to reduce GHG emissions from agriculture might give dairy farmers another incentive to prevent foot lesions. The impact of foot lesions on GHG emissions, however, can vary among dairy farms, because of differences in prevalence of foot lesions and associated production losses, and in farm management.

    Protection in sheep against heterologous challenge with serotype Asia-1 foot-and-mouth disease virus using high potency vaccine
    Horsington, Jacquelyn ; Nfon, Charles ; Gonzales, Jose L. ; Singanallur, Nagendrakumar ; Bittner, Hilary ; Vosloo, Wilna - \ 2018
    Vaccine 36 (2018)41. - ISSN 0264-410X - p. 6095 - 6102.
    Foot-and-mouth disease virus - Heterologous challenge - Sheep - Vaccine efficacy

    Foot-and-mouth disease virus (FMDV) serotype Asia-1 is prevalent in countries considered high risk for incursion into Australia, and has recently been responsible for a number of outbreaks in India, Bangladesh, Pakistan and Turkey. In vitro vaccine matching has shown a number of contemporary FMDV Asia-1 strains vary antigenically to the Asia-1 Shamir vaccine strain, which could result in poor protection with use of this vaccine. Therefore it was important to test the ability of the Asia-1 Shamir vaccine to protect sheep from challenge with a recent, heterologous strain at different days post-vaccination (dpv), including in an emergency vaccination scenario (challenge 4 or 7 dpv). Sheep (5 per group) were challenged with the Asia-1/PAK/19/2014 isolate by intra-nasopharyngeal instillation 21 (V21), 7 (V7) or 4 (V4) dpv with high-potency (>6 PD50) Asia-1 Shamir vaccine. An additional five sheep were mock-vaccinated with adjuvant only (antigen-free preparation) 4 days prior to challenge (A4), and five unvaccinated (UV) control sheep were also challenged. All V21, V7 and V4 sheep were protected from clinical FMD. Eighty percent of V21 sheep and 40% of V7 sheep had sterile immunity, however all V4 sheep became systemically infected. Vaccination reduced excretion of virus in nasal and oral secretions but had no effect on the development of persistent infection. All A4 sheep and UV control sheep developed clinical FMD. The high-potency Asia-1 Shamir vaccine will protect against disease should an outbreak of contemporary Asia-1 viruses occur. Intranasopharyngeal instillation is an effective challenge method for use in vaccine efficacy studies in sheep.

    Chimeric O1K foot-and-mouth disease virus with SAT2 outer capsid as an FMD vaccine candidate
    Kotecha, Abhay ; Perez-Martin, Eva ; Harvey, Yongjie ; Zhang, Fuquan ; Ilca, Serban L. ; Fry, Elizabeth E. ; Jackson, Ben ; Maree, Francois ; Scott, Katherine ; Hecksel, Corey W. ; Harmsen, Michiel M. ; Mioulet, Valérie ; Wood, Britta ; Juleff, Nick ; Stuart, David I. ; Charleston, Bryan ; Seago, Julian - \ 2018
    Scientific Reports 8 (2018)1. - ISSN 2045-2322

    Foot-and-mouth disease virus (FMDV) is highly contagious and infects cloven-hoofed domestic livestock leading to foot-and-mouth disease (FMD). FMD outbreaks have severe economic impact due to production losses and associated control measures. FMDV is found as seven distinct serotypes, but there are numerous subtypes within each serotype, and effective vaccines must match the subtypes circulating in the field. In addition, the O and Southern African Territories (SAT) serotypes, are relatively more thermolabile and their viral capsids readily dissociate into non-immunogenic pentameric subunits, which can compromise the effectiveness of FMD vaccines. Here we report the construction of a chimeric clone between the SAT2 and O serotypes, designed to have SAT2 antigenicity. Characterisation of the chimeric virus showed growth kinetics equal to that of the wild type SAT2 virus with better thermostability, attributable to changes in the VP4 structural protein. Sequence and structural analyses confirmed that no changes from SAT2 were present elsewhere in the capsid as a consequence of the VP4 changes. Following exposure to an elevated temperature the thermostable SAT2-O1K chimera induced higher neutralizing-antibody titres in comparison to wild type SAT2 virus.

    Changes in iron metabolism during prolonged repeated walking exercise in middle-aged men and women
    Terink, Rieneke ; Haaf, D. ten; Bongers, C.W.G. ; Balvers, M.G.J. ; Witkamp, R.F. ; Mensink, M. ; Eijsvogels, T.M.H. ; Klein Gunnewiek, J.M.T. ; Hopman, M.T.E. - \ 2018
    European Journal of Applied Physiology 118 (2018)11. - ISSN 1439-6319 - p. 2349 - 2357.
    Fe - Hb - Hp - Repetitive exercise

    Purpose: The aim of the present study was to assess the effect of prolonged and repeated exercise on iron metabolism in middle-aged adults and to compare differences between sexes. Methods: 50 male (58.9 ± 9.9 year) and 48 female (50.9 ± 11.2 year) individuals were monitored on 4 consecutive days at which they walked on average 8 h and 44 min per day at a self-determined pace. Blood samples were collected 1 or 2 days prior to the start of the exercise (baseline) and every day immediately post-exercise. Samples were analysed for iron, ferritin, haemoglobin, and haptoglobin concentrations. Results: Plasma iron decreased across days, while ferritin increased across days (both p < 0.001). Haptoglobin showed a decrease (p < 0.001) after the first day and increased over subsequent days (p < 0.001). Haemoglobin did not change after the first day, but increased during subsequent days (p < 0.05). At baseline, 8% of the participants had iron concentrations below minimum reference value (10 µmol/L), this increased to 43% at day 4. There was an interaction between sex and exercise days on iron (p = 0.028), ferritin (p < 0.001) and haemoglobin levels (p = 0.004), but not on haptoglobin levels. Conclusion: This study showed decreases in iron, increases in ferritin, a decrease followed by increases in haptoglobin and no change followed by increases in haemoglobin. This is most likely explained by (foot strike) haemolysis, inflammation, and sweat and urine losses. These processes resulted in iron levels below minimum reference value in a large number of our participants.

    Glycine plus serine requirement of broilers fed low-protein diets : a dose response study
    Harn, J. van; Dijkslag, M.A. ; Krimpen, M.M. van - \ 2018
    Wageningen : Wageningen Livestock Research (Wageningen Livestock Research report 1116) - 36
    In a study with 910 Ross 308 male broilers, housed in 70 floor pens bedded with wood shavings, the effect of digestible glycine+serine content (5 levels ranging from 12.4 to 15.7 g/kg and 11.4 to 14.9 g/kg in grower and finisher diets, respectively) in low-protein diets was studied from 10 – 35 days of age. In this study, also the glycine-sparing effect of threonine was studied. In total seven different treatments were studied: a control treatment (a normal/high protein diet), five low-protein dietary treatments with increasing levels of digestible glycine+serine and a low-protein dietary treatment in which extra threonine was supplemented to the diet with the lowest glycine+serine level. Growth performance results, slaughter yields, litter quality, litter composition and footpad score were measured. This study showed that the glycine+serine level in low-protein feed did not have a noticeable effect on the production results, slaughter yields, litter quality and foot pad lesion. Based on this study it was concluded that a digestible glycine+serine dose in low-protein diets of 12.4 g/kg and 11.4 g/kg in grower and finisher phase, respectively, is sufficient.
    The impact of diseases in dairy cows on greenhouse gas emissions and economic performance
    Mostert, Pim - \ 2018
    Wageningen University. Promotor(en): I.J.M. Boer, co-promotor(en): E.A.M. Bokkers; C.E. van Middelaar. - Wageningen : Wageningen University - ISBN 9789463432740 - 150

    The world population is expected to grow to about 10 billion in 2050. To supply the future human population with food while sustaining a liveable planet, food should be produced sustainably. One of the most urgent environmental issues is climate change, induced by greenhouse gas (GHG) emissions. The dairy sector is a large contributor to GHG emissions. Important GHGs related to milk production are carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), mainly emitted during feed production, enteric fermentation, and manure management. Diseases in dairy cows can reduce milk production, reproduction performance and longevity, and increase the amount of discarded milk. The objectives of this thesis were to estimate the impact of diseases (subclinical ketosis, clinical mastitis, and foot lesions) on GHG emissions, and to understand the relation between impact of diseases on GHG emissions and economic performance. First, a dynamic stochastic simulation model was developed to simulate the dynamics of the diseases and the associated production losses (reduced milk production, discarded milk, a prolonged calving interval, and removal (culling or dying on the farm)) per cow during one lactation. This model was combined with a life cycle assessment to quantify the impact of diseases on GHG emissions per ton fat-and-protein-corrected milk (kg CO2equivalents/t FPCM) from cradle to farm gate. Processes included were feed production, enteric fermentation, and manure management. The emissions of GHGs of cows with a disease increased on average by 21 (2.3%) kg CO2e/t FPCM per case of subclinical ketosis, by 58 (6.2%) kg CO2e/t FPCM per case of clinical mastitis, by 4 (0.4%) kg CO2e/ t FPCM per case of digital dermatitis, by 39 (4.3%) kg CO2e/ t FPCM per case of white line disease, and by 33 (3.6%) kg CO2e/ t FPCM per case of sole ulcer. An economic analyses was performed to estimate the costs of subclinical ketosis and related diseases. The total costs of subclinical ketosis were €130 per case per year. Comparing the impact of production contributors from a GHG emissions and economic perspective showed that a reduction in milk production had the highest impact on the economic performance, whereas removal and discarded milk had the highest impact on increase in GHG emissions. Prevalence, pathogen type, farm management (e.g. culling, feed, and manure), and prices (e.g. milk and feed) will affect the impact of production contributors on GHG emissions and economic performance. Therefore, specific farm analyses are needed to estimate the impact of diseases for a specific dairy farm. Diseases in dairy cows increase GHG emissions by approximately 0.4 Mton per year, which equals 15% of the Dutch governmental goal of GHG emission reductions in agriculture in 2030. Reducing diseases can decrease GHG emissions, can increase the income of the farmer, and can improve animal welfare. Therefore, reducing diseases can contribute to sustainable development of the dairy sector.

    Agroecological integration of shade- and drought-tolerant food/feed crops for year-round productivity in banana-based systems under rain-fed conditions in Central Africa
    Blomme, G. ; Ocimati, W. ; Groot, J.C.J. ; Ntamwira, J. ; Bahati, L. ; Kantungeko, D. ; Remans, R. ; Tittonell, P. - \ 2018
    In: 10th International Symposium on Banana. - International Society for Horticultural Science (Acta Horticulturae ) - ISBN 9789462611924 - p. 41 - 54.
    Intensification - Resilience - Small-scale farming - Year-round productivity - Yield gaps
    Yield gaps in banana-based production systems have increased in the past two decades due to declining soil fertility, drought and biotic stresses. Sustainable, environmentally sound and economically viable strategies for intensification in these systems are urgently needed. Agroecological practices, such as the integration of shade- and drought-tolerant crops, nitrogen-fixing and cover crops could potentially improve soil fertility and moisture retention, reduce the weed burden, narrow yield gaps and increase overall plot/farm productivity in these systems. In Malaysia, leguminous crops like Pueraria phaseoloides, Calopogonium caeruleum and Centrosema pubescens are often cultivated as cover crops (to suppress weeds, and reduce moisture loss and soil erosion) in young rubber and oil palm plantations with low shade levels. Even in mature oil palm plantations with less than 30% light intensity, various shade-tolerant crops are grown, e.g., elephant foot yam, turmeric and arrow root. In humid tropical Africa, Colocasia (taro) and Xanthosoma (cocoyam) are reported to tolerate shade conditions and hence often planted under perennial banana/plantain plantations. Drought tolerance is a less common feature of most annual crops grown in the humid tropics. A few root and tuber crops (e.g., cassava, taro, yam and sweetpotato) remain in the field during the dry season in Central Africa and are then harvested according to household needs. This paper also reports on crops (Mucuna, lablab and chickpea) with potential for integration into banana-based systems during the dry season, if planted during the last month of the rainy season. These crops are reported to use the residual soil moisture content for continued growth during the dry season months. The paper concludes with detailed descriptions (from a literature review) on drought- and shade-tolerance characteristics of various crops which have long been integrated in Central African banana-based cropping systems, crops with a more recent cultivation history and crops with potential for system integration.
    Fusarium riograndense sp. nov., a new species in the Fusarium solani species complex causing fungal rhinosinusitis
    Dallé Rosa, P. ; Ramirez-Castrillon, M. ; Valente, P. ; Meneghello Fuentefria, A. ; Diepeningen, A.D. Van; Goldani, L.Z. - \ 2018
    Journal de Mycologie Medicale 28 (2018)1. - ISSN 1156-5233 - p. 29 - 35.
    Antifungal susceptibility - Fusarium - MLST - Molecular phylogeny - Morphology
    Invasive fusariosis has a high mortality and is predominantly observed in patients with leukemia. We report the first case of a novel species of Fusarium, Fusarium riograndense sp. nov, isolated from a lesion in the nasal cavity lesion of a patient with acute lymphoblastic leukemia. The etiological agent was identified by Multilocus Sequencing Typing (MLST), including RPB2, TEF-1α, and ITS-LSU sequences, the gold standard technique to identify new species of Fusarium. MLST and phenotypic data strongly supported its inclusion in the F. solani species complex (FSSC). The new species produced a red pigment in the Sabouraud Dextrose Agar similar to other members of the complex. The macroconiodia developed from phialides on multibranched conidiophores which merge to form effuse sporodochia with a basal foot-cell instead of papilla in basal cell shape. The microconidia were ellipsoidal, 0-1-septated, produced from long monophialides. Chlamydospores were produced singly or in pairs. Amphotericin B (MIC 1. μg/mL) was the most active drug, followed by voriconazole (MIC 8. μg/mL). The patient was successfully treated with voriconazole. Our findings indicate another lineage within FSSC capable causing of invasive human infection.
    Abrupt Climate Change in an Oscillating World
    Bathiany, S. ; Scheffer, M. ; Nes, E.H. Van; Williamson, M.S. ; Lenton, T.M. - \ 2018
    Scientific Reports 8 (2018)1. - ISSN 2045-2322
    The notion that small changes can have large consequences in the climate or ecosystems has become popular as the concept of tipping points. Typically, tipping points are thought to arise from a loss of stability of an equilibrium when external conditions are slowly varied. However, this appealingly simple view puts us on the wrong foot for understanding a range of abrupt transitions in the climate or ecosystems because complex environmental systems are never in equilibrium. In particular, they are forced by diurnal variations, the seasons, Milankovitch cycles and internal climate oscillations. Here we show how abrupt and sometimes even irreversible change may be evoked by even small shifts in the amplitude or time scale of such environmental oscillations. By using model simulations and reconciling evidence from previous studies we illustrate how these phenomena can be relevant for ecosystems and elements of the climate system including terrestrial ecosystems, Arctic sea ice and monsoons. Although the systems we address are very different and span a broad range of time scales, the phenomena can be understood in a common framework that can help clarify and unify the interpretation of abrupt shifts in the Earth system.
    A foot-and-mouth disease SAT2 vaccine protects swine against experimental challenge with a homologous virus strain, irrespective of mild pathogenicity in this species
    Mouton, Laure ; Dekker, Aldo ; Bleijenberg, Meindert ; Blanchet, Michel ; Coco-Martin, Jose ; Hudelet, Pascal ; Goutebroze, Sylvain - \ 2018
    Vaccine 36 (2018)15. - ISSN 0264-410X - p. 2020 - 2024.
    Challenge - Foot-and-mouth disease - Pigs - Serotype SAT - Vaccine efficacy
    FMDV serotype SAT2 is most frequently associated with outbreaks in ruminants. However, the risk of it spreading from cattle to pigs cannot be excluded. To assess the efficacy of an SAT2-type FMD inactivated vaccine against homologous challenge in pigs, a suitable challenge strain adapted to pigs was produced. After two passages in two pigs each, a FMDV stock of SAT2 challenge strain was produced. This material was used to infect two groups of five pigs. The first group being vaccinated 28 days before challenge and the other one left as an unvaccinated control. Clinical signs were recorded, virus shedding was assessed on mouth swabs, and neutralising antibody titres were determined. At least 80% of the vaccinated pigs were protected against clinical disease. Furthermore, no virus shedding was observed in any of the vaccinated pigs. This study shows that experimentally inoculated pigs can become infected with a SAT2 serotype. Furthermore, vaccination offers protection against generalisation and viral excretion, confirming the potential of vaccination as an important tool in the control of FMD in pigs.
    Soya bean meal increases litter moisture and foot pad dermatitis in maize and wheat based diets for turkeys but maize and non-soya diets lower body weight
    Hocking, P.M. ; Vinco, L.J. ; Veldkamp, T. - \ 2018
    British Poultry Science 59 (2018)2. - ISSN 0007-1668 - p. 227 - 231.
    Cereal - dermatitis - diet - electrolyte balance - feed - feed intake - litter moisture - protein
    1. A 2 × 2 factorial experiment was conducted to compare the effects of wheat or maize based diets differing in dietary electrolyte balance (DEB) on litter moisture and foot pad dermatitis (FPD) at 4, 8 and 12 weeks of age in heavy-medium turkeys. A second objective was to investigate the effects on foot pad dermatitis of the interaction between dietary composition and artificially increasing litter moisture by adding water to the litter. 2. High DEB diets contained soya as the main protein source whereas low DEB diets did not contain soya bean meal. Diets were formulated to be iso-caloric and iso-nitrogenous in each of 3 successive 4-week phases following recommended dietary compositions. DEB concentrations were 330, 290 and 250 mEq/kg in high DEB diets and 230, 200 and 180 mEq/kg in low DEB diets. 3. Litter moisture and mean FPD score were higher in turkeys fed on high DEB diets compared with low DEB diets whereas there was no difference between maize and wheat. 4. Food intake was similar and body weight was lower after litter moisture was artificially raised in the wet compared with the dry litter treatment and there was no interaction with dietary composition. 5. Mean body weight and feed intake were higher in turkeys fed on wheat compared with maize and in high DEB compared with low DEB diets at 12 weeks of age. 6. Lowering dietary DEB for turkeys may improve litter moisture and lower the prevalence of FPD in commercial turkey flocks.
    The impact of diseases in dairy cows on greenhouse gas emissions of milk production
    Mostert, Pim - \ 2018
    Diseases in dairy cows result in inefficient production because of a decrease in milk production and fertility, and an increased risk of culling. Therefore, diseases also will have an impact on greenhouse gas (GHG) emissions per kg milk. The objective of this study was to estimate the impact of diseases in dairy cows on GHG emissions. Three diseases with a high incidence were included: foot disorders, clinical mastitis, and subclinical ketosis.
    Digital Dermatitis in dairy cattle : The contribution of different disease classes to transmission
    Biemans, Floor ; Bijma, Piter ; Boots, Natasja M. ; Jong, Mart C.M. de - \ 2018
    Epidemics 23 (2018). - ISSN 1755-4365 - p. 76 - 84.
    Basic reproduction ratio - Cow - Hairy heel wrat - Infection - Infectivity - Mortellaro
    Digital Dermatitis (DD) is a claw disease mainly affecting the hind feet of dairy cattle. Digital Dermatitis is an infectious disease, transmitted via the environment, where the infectious "agent" is a combination of bacteria. The standardized classification for DD lesions developed by Döpfer et al. (1997) and extended by Berry et al. (2012) has six distinct classes: healthy (M0), an active granulomatous area of 0-2 cm (M1), an ulcerative lesion of >2 cm (M2), an ulcerative lesion covered by a scab (M3), alteration of the skin (M4), and a combination of M4 and M1 (M4.1).We hypothesize that classes M1, M2, M3, M4, and M4.1 are the potentially infectious classes that can contribute to the basic reproduction ratio (R0), the average number of new infections caused by a typical infected individual. Here, we determine differences in infectivity between the classes, the sojourn time in each of the classes, and the contribution of each class to R0. The analysis is based on data from twelve farms in the Netherlands that were visited every two weeks, eleven times.We found that 93.89% of the transitions from M0 was observed as a transition to class M4, and feet with another class-at-infection rapidly transitioned to class M4. As a consequence, about 70% of the infectious time was spent in class M4. Transmission rate parameters of class-at-infection M1, M2, M3, and M4 were not significantly different from each other, but differed from class-at-infection M4.1. However, due to the relative large amount of time spend in class M4, regardless of the class-at-infection, R0 was almost completely determined by this class. The R0 was 2.36, to which class-at-infection M4 alone contributed 88.5%.Thus, M4 lesions should be prevented to lower R0 to a value below one, while painful M2 lesions should be prevented for animal welfare reasons.
    Identification of a practical and reliable method for the evaluation of litter moisture in turkey production
    Vinco, L.J. ; Giacomelli, S. ; Campana, L. ; Chiari, M. ; Vitale, N. ; Lombardi, G. ; Veldkamp, T. ; Hocking, P.M. - \ 2018
    British Poultry Science 59 (2018)1. - ISSN 0007-1668 - p. 7 - 12.
    Bedding quality - environment - foot pad dermatitis - litter moisture - poultry - welfare
    1. An experiment was conducted to compare 5 different methods for the evaluation of litter moisture. 2. For litter collection and assessment, 55 farms were selected, one shed from each farm was inspected and 9 points were identified within each shed. 3. For each device, used for the evaluation of litter moisture, mean and standard deviation of wetness measures per collection point were assessed. 4. The reliability and overall consistency between the 5 instruments used to measure wetness were high (α = 0.72). 5. Measurement of three out of the 9 collection points were sufficient to provide a reliable assessment of litter moisture throughout the shed. 6. Based on the direct correlation between litter moisture and footpad lesions, litter moisture measurement can be used as a resource based on-farm animal welfare indicator. 7. Among the 5 methods analysed, visual scoring is the most simple and practical, and therefore the best candidate to be used on-farm for animal welfare assessment.
    An automated positioning system for monitoring chickens' location: Effects of wearing a backpack on behaviour, leg health and production
    Stadig, Lisanne M. ; Rodenburg, T.B. ; Ampe, Bart ; Reubens, Bert ; Tuyttens, Frank A.M. - \ 2018
    Applied Animal Behaviour Science 198 (2018). - ISSN 0168-1591 - p. 83 - 88.
    Body weight - Broiler chicken - Habituation - Position monitoring - Ultra-Wideband - Welfare

    Automated tracking of the location of individual chickens is becoming more common in behavioural research. This technology has several advantages including gathering large amounts of data and monitoring of individual animals as opposed to flocks. To ensure the quality of the research the transmitters or tags attached to the bird as part of the automated positioning system should not have any effect on bird behaviour, welfare and production. Tag-related effects may lead to unreliable results which cannot be extrapolated to untagged birds. Therefore, we tested the effects of wearing a backpack containing a tag as part of an ultra-wideband system for automated position monitoring. The chickens' behaviour, leg health, cleanliness and body weight gain were studied. Sixty slow-growing broiler chickens (Sasso XL451) were housed in groups of 10 birds. Per pen, five birds were fitted with a 36-g tag (TAG) in a backpack from day 35-70 and the other five were identified using colour markings (CON). Behavioural observations from video recordings of TAG and CON chickens were performed twice daily (15-min periods) every other day. Birds were weighed on day 35 and 70, and on day 70 foot pad and hock dermatitis, gait, and cleanliness were scored. TAG birds walked less than CON birds in week 6, but this difference was absent from week 7 onwards. CON birds pecked more at TAG birds than other TAG birds did in week 6, probably due to the novelty of the tags, whereas the TAG birds could investigate their own tag instead of pecking at other birds' tags. No significant differences were observed for scores for foot pad and hock dermatitis, gait and cleanliness scores or weight gain between TAG and CON birds. These results indicate that the backpacks with tags had only minor, non-persistent effects on slow-growing broiler chickens' behaviour. The effects of colour-marking on behaviours observed in this study are likely to be small. The results indicate that the tags can be used for further studies in which these behaviours, welfare measures and production parameters play an important role.

    First report of Podosphaera xanthii causing powdery mildew on Ageratum conyzoides in China
    Mukhtar, I. ; Peer, A.F. van - \ 2017
    Plant Disease 101 (2017)8. - ISSN 0191-2917 - 1 p.

    Ageratum conyzoides L. is a member of the Asteraceae and a competitive weed for crops in the subtropics and tropics. In September 2016, we observed that a plant community of A. conyzoides was 85% infected with powdery mildew in a forest park at Fujian Agriculture and Forestry University (FAFU), Fuzhou, China. Initially, circular to irregular white powdery colonies or thinly effuse white mycelial patches formed on both sides of the leaves and on the stems. In later stages, entire leaves were covered with white mycelium, followed by leaf yellowing and senescence. Fungal hyphae were septate, branched, flexuous to straight, and 5 to 7 μm wide. Appressoria were indistinct to slightly nipple-shaped and solitary. Conidiophores (80 to 215 × 10 to 12 μm) were erect and unbranched, slightly constricted at the basal septa, with cylindrical foot-cells (35 to 70 × 10 to 12 µm) and 1 to 3 cells shorter than the foot-cell. Conidia (25 to 40 × 14 to 23 μm) were hyaline, catenescent, ellipsoid-ovoid to barrel-shaped, with a length/width ratio of 1.3 to 2.0, and containing distinct fibrosin bodies. Simple to forked germ tubes were observed on subterminal or lateral position of germinating conidia. No chasmothecia were observed in the collected infected samples. Based on the morphology of the imperfect state, the isolate was identified as Podosphaera xanthii (Castagne) U. Braun & N. Shishkoff (Braun and Cook 2012). A 565-bp amplicon (KY274485) of the internal transcribed spacer (ITS) region generated with primers ITS1/ITS4 (White et al. 1990) was 100% identical with other P. xanthii sequences (AB040351, AB462804) and showed phylogenetic grouping with P. xanthii isolates from Asteraceae and Verbenaceae. Pathogenicity tests were completed by dusting conidia from an infected leaf onto young leaves of three asymptomatic, potted plants and covered with plastic bags. Noninoculated plants were used as controls. Inoculated leaves showed powdery mildew symptoms after 6 days at 20°C and 80% relative humidity in green house. Control plants exhibited no disease symptoms. The fungal morphology on inoculated leaves was identical to that observed on initially diseased leaves. A voucher specimen (HMAS 247182) was deposited in Institute of Microbiology Chinese Academy of Sciences (CAS) Herbarium Mycologium (HMAS), Beijing, China. Previously, Euoidium agerati has been mentioned as powdery mildew pathogen on A. conyzoides in Taiwan (Braun and Cook 2012). However, this pathogen is quite different from the present collection by not having fibrosin bodies in conidia. Powdery mildew of A. conyzoides caused by P. xanthii has been recorded in Pakistan and India (Gautam 2015; Mukhtar et al. 2013). In China, A. conyzoides is used as medicinal plant to treat a variety of conditions and diseases. Incidence of P. xanthii on this plant will add information on pathogen’s range and will be helpful for future investigation. To our knowledge, this is the first report of P. xanthii on A. conyzoides in China.

    First report of powdery mildew caused by Podosphaera xanthii on Euphorbia hirta in China
    Mukhtar, I. ; Peer, A.F. Van - \ 2017
    Plant Disease 101 (2017)7. - ISSN 0191-2917 - 1 p.

    Euphorbia hirta is an important medicinal herb that can be found on grassland, roadsides, and field pathways in tropical regions of world. In late October and early November 2016, powdery mildew was observed on E. hirta growing along roadsides in Fujian Agriculture and Forestry University (26°5’16”N, 119°14’6”E), Fuzhou, China. Disease incidence approached 100%, with fungal colonies present on stems and both sides of the leaves. At the initial stages of infection, colonies were circular to irregular and later covered the entire leaf surface. Hyphae were septated, branched, flexuous to straight, up to 8 μm wide with indistinct to slightly nipple-shaped appressoria. Conidiophores were unbranched, straight, 90 to 260 × 10 to 13 μm in size. Foot-cells of the conidiophores were cylindrical, 40 to 80 μm long, with slight constriction at basal septa, and followed by 1 to 3 short cells. Conidia were hyaline, formed in chains of 2 to 6 cells with distinct fibrosin bodies visible in their cytoplasm, ellipsoid-ovoid to barrel-shaped, about 30 to 45 × 14 to 20 μm in size, with a length to width ratio of mostly 1.5 to 2.0. Chasmothecia were absent. The rDNA internal transcribed spacer (ITS) region was amplified from pools of conidia on infected leaves by using primers ITS1/ITS4 () and directly sequenced. BLASTn analysis of the 569 bp (KY388504) amplicon revealed 100% sequence identity with respective rDNA sequences of Podosphaera xanthii isolates from Asteraceae (Bidens pilosa [KM260740], Youngia denticulata [AB040351]), Euphorbiaceae (Euphorbia thymifolia [KM260731]), Solanaceae (Physalis angulata [KM260744]), and Verbenaceae (Verbena brasiliensis [KJ472787]). Phylogenetic analysis also indicated clustering of E. hirta fungal isolate with P. xanthii strains. Based on the morphological characteristics and ITS sequences, the fungal species was identified as P. xanthii (Castagne) U. Braun & Shiskoff (). Pathogenicity of the fungal isolate was confirmed by gently pressing diseased leaves onto the leaves of three healthy E. hirta plants, resulting in the formation of white powdery mildew colonies after 7 days at 20°C and 80% relative humidity in a greenhouse. Fungal colonies on the inoculated plants were morphologically identical to the collected fungal specimen, whereas control plants of E. hirta developed no symptoms of powdery mildew. Until now, P. euphorbiae-hirtae was documented on E. hirta, E. tithymaloides, and A. australis (;). However, recently Golovinomyces orontii has also been reported on E. hirta in India (). E. hirta is an important medicinal plant in China and present information will be helpful in understanding the range of pathogen that can infect this plant. To our knowledge, this is the first report of P. xanthii on E. hirta.

    Bayesian inference of epidemiological parameters from transmission experiments
    Hu, Ben ; Gonzales, Jose L. ; Gubbins, Simon - \ 2017
    Scientific Reports 7 (2017)1. - ISSN 2045-2322
    Epidemiological parameters for livestock diseases are often inferred from transmission experiments. However, there are several limitations inherent to the design of such experiments that limits the precision of parameter estimates. In particular, infection times and latent periods cannot be directly observed and infectious periods may also be censored. We present a Bayesian framework accounting for these features directly and employ Markov chain Monte Carlo techniques to provide robust inferences and quantify the uncertainty in our estimates. We describe the transmission dynamics using a susceptible-exposed-infectious-removed compartmental model, with gamma-distributed transition times. We then fit the model to published data from transmission experiments for foot-and-mouth disease virus (FMDV) and African swine fever virus (ASFV). Where the previous analyses of these data made various assumptions on the unobserved processes in order to draw inferences, our Bayesian approach includes the unobserved infection times and latent periods and quantifies them along with all other model parameters. Drawing inferences about infection times helps identify who infected whom and can also provide insights into transmission mechanisms. Furthermore, we are able to use our models to measure the difference between the latent periods of inoculated and contact-challenged animals and to quantify the effect vaccination has on transmission.
    Open soil science: technology is helping us discover the mysteries under our feet
    Hobley, E.U. ; Schultze, D.G. ; Robinson, D.A. ; Jahanshiri, E. ; Aitkenhead, M. ; Batjes, N.H. ; Hengl, T. - \ 2017
    The Conversation
    Isolation of single-domain antibody fragments that preferentially detect intact (146s) particles of foot-and-mouth disease virus for use in vaccine quality control
    Harmsen, Michael ; Seago, Julian ; Perez, Eva ; Charleston, Bryan ; Eblé, Phaedra L. ; Dekker, Aldo - \ 2017
    Frontiers in Immunology 8 (2017). - ISSN 1664-3224 - 12 p.
    Enzyme-linked immunosorbent assay - Foot-and-mouth disease - Foot-and-mouth disease virion - Single-domain antibody - Vaccine quality control - Virion stability

    Intact (146S) foot-and-mouth disease virus (FMDVs) can dissociate into specific (12S) viral capsid degradation products. FMD vaccines normally consist of inactivated virions. Vaccine quality is dependent on 146S virus particles rather than 12S particles. We earlier isolated two llama single-domain antibody fragments (VHHs) that specifically recognize 146S particles of FMDV strain O1 Manisa and shown their potential use in quality control of FMD vaccines during manufacturing. These 146S-specific VHHs were specific for particular O serotype strains and did not bind strains from other FMDV serotypes. Here, we describe the isolation of 146S-specific VHHs against FMDV SAT2 and Asia 1 strains by phage display selection from llama immune libraries. VHHs that bind both 12S and 146S particles were readily isolated but VHHs that bind specifically to 146S particles could only be isolated by phage display selection using prior depletion for 12S particles. We obtained one 146S-specific VHH—M332F—that binds to strain Asia 1 Shamir and several VHHs that preferentially bind 146S particles of SAT2 strain SAU/2/00, from which we selected VHH M379F for further characterization. Both M332F and M379F did not bind FMDV strains from other serotypes. In a sandwich enzyme-linked immunosorbent assay (ELISA) employing unlabeled and biotinylated versions of the same VHH M332F showed high specificity for 146S particles but M379F showed lower 146S-specificity with some cross-reaction with 12S particles. These ELISAs could detect 146S particle concentrations as low as 2.3–4.6 µg/l. They can be used for FMD vaccine quality control and research and development, for example, to identify virion stabilizing excipients.

    Effect of crude protein concentration and dietary electrolyte balance on litter quality, foot pad dermatitis, growth performance and processing yields in two medium heavy turkey hybrids
    Veldkamp, T. ; Hocking, P.M. ; Vinco, L.J. - \ 2017
    British Poultry Science 58 (2017)5. - ISSN 0007-1668 - p. 557 - 568.
    1. An experiment was conducted to investigate the effect of crude protein (CP) concentration and dietary electrolyte balance (DEB) on growth performance, processing yields, litter quality and foot pad dermatitis (FPD) in male turkeys from two commercial hybrids. Soya bean meal was replaced by vegetable protein sources selected for lower K concentrations to lower DEB in order to improve litter quality and subsequent quality of foot pads.

    2. Effects of CP on litter friability and wetness were not consistent during the production period. FPD in turkeys fed on diets with low CP was significantly lower than FPD in turkeys fed on diets with high CP until 84 d. Growth performance was adversely affected at low CP. Processing yields were not affected by CP.

    3. Litter was significantly dryer in pens of turkeys fed on diets with low DEB than in pens of turkeys fed on diets with high DEB. FPD in turkeys fed on diets with low DEB was significantly lower than in turkeys fed on diets with high DEB. Growth performance and processing yields were adversely affected at low DEB.

    4. FPD in turkey hybrid A was higher than in turkey hybrid B at 28 d of age. Thereafter, no differences in FPD between turkey hybrids were observed. Growth performance and processing yields were not affected by turkey hybrid.

    5. Overall, a significant interaction effect of CP × DEB was observed for FCR: in turkeys fed on the high DEB treatment, FCR of turkeys fed on the high CP diets was lower than FCR of turkeys fed on the low CP (LCP) diets whereas on the low DEB treatment, FCR was not affected by CP treatment.

    6. It was concluded that litter quality can be improved and FPD may be decreased in turkeys fed on diets containing lower CP and DEB levels.
    Litter moisture assessment and foot pad dermatitis scoring as animal welfare indicators in commercial turkey production
    Vinco, L.J. ; Giacomelli, S. ; Campana, L. ; Lombardi, G. ; Hocking, P.M. ; Veldkamp, T. - \ 2017
    In: Proceedings of the 9th Hafez International Symposium on Turkey Production. -
    Protective effects of high-potency FMDV O1 Manisa monovalent vaccine in cattle challenged with FMDV O/SKR/2010 at 7 or 4 days post vaccination
    Horsington, Jacquelyn ; Perez, Claudia Beascoechea ; Maradei, Eduardo ; Novo, Sabrina Galdo ; Gonzales, Jose L. ; Singanallur, Nagendrakumar B. ; Bonastre, Paula ; Vosloo, Wilna - \ 2017
    Vaccine 35 (2017)38. - ISSN 0264-410X - p. 5179 - 5185.
    Cattle - Foot-and-mouth disease virus - Heterologous challenge - Vaccine efficacy
    Serotype O foot-and-mouth disease (FMD) virus belonging to the SEA topotype continues to be a significant problem in the Eastern Asia region, with outbreaks in Japan and South Korea resulting in the culling of over 3.5 million cattle and pigs in recent years. High-potency O1 Manisa vaccine was previously shown to provide protection in cattle 21. days post vaccination (dpv) following challenge with a representative virus, O/SKR/2010. This study tested the ability of the O1 Manisa vaccine to protect cattle from infection and disease with the O/SKR/2010 virus within just 4 or 7. days post vaccination. The vaccine protected 50% of cattle from clinical disease when administered 7. days prior to challenge, but was not protective with just 4. days between vaccination and challenge. Viraemia was significantly reduced in animals challenged 7 dpv but not 4 dpv, compared to unvaccinated controls, however, there were no effects on the level of virus detected in nasal and oral secretions regardless of vaccination time. The level of neutralising antibodies detected in cattle challenged 7 dpv correlated with protection from clinical disease. All animals seroconverted to FMDV non-structural proteins, suggesting no sterile protection. An equal number of animals became persistently infected in both vaccine groups. The results indicated that high-potency O1 Manisa vaccine administered just 7. days prior to challenge should provide partial protection of cattle if an outbreak of O/SKR/2010, or related viruses, occurs, and would be useful to limit spread of FMDV when used in conjunction with other control measures.
    Predicting the ability of preclinical diagnosis to improve control of farm-to-farm foot-and-mouth disease transmission in cattle
    Nelson, Noel ; Paton, David J. ; Gubbins, Simon ; Colenutt, Claire ; Brown, Emma ; Hodgson, Sophia ; Gonzales Rojas, Jose - \ 2017
    Journal of Clinical Microbiology 55 (2017)6. - ISSN 0095-1137 - p. 1671 - 1681.
    Diagnostics - Early detection - FMD - Foot-and-mouth disease virus - PCR - Sensitivity - Surveillance - Transmission

    Foot-and-mouth disease (FMD) can cause large disruptive epidemics in livestock. Current eradication measures rely on the rapid clinical detection and removal of infected herds. Here, we evaluated the potential for preclinical diagnosis during reactive surveillance to reduce the risk of between-farm transmission. We used data from transmission experiments in cattle where both samples from individual animals, such as blood, probang samples, and saliva and nasal swabs, and herd-level samples, such as air samples, were taken daily during the course of infection. The sensitivity of each of these sample types for the detection of infected cattle during different phases of the early infection period was quantified. The results were incorporated into a mathematical model for FMD, in a cattle herd, to evaluate the impact of the early detection and culling of an infected herd on the infectious output. The latter was expressed as the between-herd reproduction ratio, Rh, where an effective surveillance approach would lead to a reduction in the Rh value to <1. Applying weekly surveillance, clinical inspection alone was found to be ineffective at blocking transmission. This was in contrast to the impact of weekly random sampling (i.e., using saliva swabs) of at least 10 animals per farm or daily air sampling (housed cattle), both of which were shown to reduce the Rh to <1. In conclusion, preclinical detection during outbreaks has the potential to allow earlier culling of infected herds and thereby reduce transmission and aid the control of epidemics.

    Identifying on-farm factors affecting foot pad lesions.
    Vinco, L.J. ; Giacomelli, S. ; Campana, L. ; Lombardi, G. ; Hocking, P.M. ; Veldkamp, Teun - \ 2017
    In: Proceedings of the 11th Turkey Science and Production Conference. - Chester : - p. 28 - 33.
    Efficacy of a high potency O1 Manisa foot-and-mouth disease vaccine in cattle against heterologous challenge with a field virus from the O/ME-SA/Ind-2001 lineage collected in North Africa
    Fishbourne, Emma ; Ludi, Anna B. ; Wilsden, Ginette ; Hamblin, Pip ; Statham, Bob ; Bin-Tarif, Abdelghani ; Brocchi, Emiliana ; Grazioli, Santina ; Dekker, Aldo ; Eblé, Phaedra ; King, Donald P. - \ 2017
    Vaccine 35 (2017)20. - ISSN 0264-410X - p. 2761 - 2765.
    Challenge - Foot-and-mouth disease virus - In vivo potency - Vaccine

    Outbreaks of foot-and-mouth disease (FMD) in North Africa (2013) and the Gulf States (2013) of the Middle East have been caused by a FMD viral lineage (O/ME-SA/Ind-2001) that was before 2013 restricted to the Indian Sub-continent. This study was undertaken to assess the in vivo efficacy of a FMD virus emergency vaccine type O1 Manisa against heterologous challenge with a representative field virus (O/ALG/3/2014) from this emerging lineage. This widely available vaccine was selected since in vitro vaccine-matching results gave inconclusive results as to whether or not it would be protective. Three groups of five cattle were vaccinated with O1 Manisa (homologous potency ≥6PD50/dose) using study guidelines outlined in the European Pharmacopeia, and challenged at 21 days post-vaccination by tongue inoculation. All animals that were vaccinated with the lowest dose (1/16) of vaccine developed generalised FMD, defined as vesicular lesions at the feet. One animal vaccinated with a 1/4 dose of the vaccine also developed generalised disease, as did two animals vaccinated with the full dose of vaccine. These results indicate that the heterologous potency of this high potency O1 Manisa vaccine was approximately 3.5 PD50/dose. These data support the use of the O1 Manisa vaccine for FMD control in areas where FMDV is endemic e.g. North Africa, and motivate further studies to evaluate other vaccine candidates (or multivalent combinations) that might be potentially used for emergency purposes in FMD-free settings.

    Less foot pad lesions by nutritional adjustments
    Veldkamp, T. ; Hocking, P.M. ; Vinco, L.J. - \ 2017
    In: Proceedings of the 11th Turkey Science and Production Conference. - - p. 24 - 25.
    Do foot pad scores measure Turkey welfare
    Hocking, P.M. ; Harkness, A. ; Veldkamp, Teun ; Vinco, L.J. - \ 2017
    In: Proceedings of the 11th Turkey Science and Production Conference. - - p. 20 - 23.
    The main aim of the project was to assess the painfulness of different levels of foot pad dermatitis (FPD) in turkeys. Three different analgesics (butorphanol, carprofen and meloxicam) were used to assess their effect on behaviour. Video recordings were taken when the birds were treated with either saline or one of the analgesics in a crossover experiment, with the aim of investigating whether or not FPD is a painful condition. The results did not show significant pain in affected turkeys. Carprofen may have an effect on behavior, whereas butorphanol and meloxicam did not.
    Ensemble modelling and structured decision-making to support Emergency Disease Management
    Webb, Colleen T. ; Ferrari, Matthew ; Lindström, Tom ; Carpenter, Tim ; Dürr, Salome ; Garner, Graeme ; Jewell, Chris ; Stevenson, Mark ; Ward, Michael P. ; Werkman, Marleen ; Backer, Jantien ; Tildesley, Michael - \ 2017
    Preventive Veterinary Medicine 138 (2017). - ISSN 0167-5877 - p. 124 - 133.
    Disease management - Ensemble modelling - Foot and mouth disease - Policy - Structured decision-making
    Epidemiological models in animal health are commonly used as decision-support tools to understand the impact of various control actions on infection spread in susceptible populations. Different models contain different assumptions and parameterizations, and policy decisions might be improved by considering outputs from multiple models. However, a transparent decision-support framework to integrate outputs from multiple models is nascent in epidemiology. Ensemble modelling and structured decision-making integrate the outputs of multiple models, compare policy actions and support policy decision-making. We briefly review the epidemiological application of ensemble modelling and structured decision-making and illustrate the potential of these methods using foot and mouth disease (FMD) models. In case study one, we apply structured decision-making to compare five possible control actions across three FMD models and show which control actions and outbreak costs are robustly supported and which are impacted by model uncertainty. In case study two, we develop a methodology for weighting the outputs of different models and show how different weighting schemes may impact the choice of control action. Using these case studies, we broadly illustrate the potential of ensemble modelling and structured decision-making in epidemiology to provide better information for decision-making and outline necessary development of these methods for their further application.
    Foot-and-Mouth Disease Seroprevalence in Cattle in Eritrea
    Tekleghiorghis, T. ; Weerdmeester, K. ; Hemert-Kluitenberg, Froukje van; Moormann, R.J.M. ; Dekker, Aldo - \ 2017
    Transboundary and Emerging Diseases 64 (2017)3. - ISSN 1865-1674 - p. 754 - 763.
    Administrative regions - Eritrea - Foot-and-mouth disease virus - Seroprevalence - Serotypes - Vaccination
    Information about seroprevalence of foot-and-mouth disease (FMD) and virus serotypes in Eritrea is unavailable, but is very important as it may guide the choice of intervention measures including vaccination to be implemented. We carried out a cross-sectional study from February to June 2011 in Eritrea with a two-stage cluster design, sampling cattle in 155 villages with the objective of determining the seroprevalence of FMD in four administrative regions of the country. We analysed cattle sera (n = 2429) for FMD virus antibodies using the non-structural ELISA (NS ELISA) and virus neutralization test (VNT). The overall seroprevalence was 26% and 30% for the NS ELISA and VNT, respectively. FMD virus serotypes O (14%) and A (11%) were the most prevalent. Gash Barka showed the highest (39%) seroprevalence both in NS ELISA and VNT compared to the other three administrative regions. Strategic FMD virus vaccination with type O and A (matching circulating strains) in combination of zoo-sanitary measures would be the best control option for Eritrea which could be started in areas where the disease is less endemic.
    The welfare consequences of different foot pad scores in male turkey poults
    Hocking, P.M. ; Harkness, A. ; Veldkamp, T. ; Vinco, L.J. - \ 2016
    British Poultry Abstracts 12 (2016)1. - ISSN 1746-6202 - p. 21 - 22.
    Removal of soya bean meal from wheat- and maize-based diets decreased litter moisture and foot pad dermatitis in turkeys
    Hocking, P.M. ; Veldkamp, T. ; Vinco, L.J. ; Woodward, P. ; Harkness, A. - \ 2016
    British Poultry Abstracts 12 (2016)1. - ISSN 1746-6202 - p. 15 - 16.
    Effect of dietary electrolyte balance and crude protein content on foot pad dermatitis in commercial turkeys
    Veldkamp, Teun ; Hocking, Paul ; Vinco, Leonardo James - \ 2016
    - p. 617 - 617.
    Factors such as dietary electrolyte balance (EB) and crude protein (CP) content, age, and strain may affect the prevalence of foot pad dermatitis (FPD). The objective of the study was to evaluate the effect of decreasing EB (high EB (HEB) vs. low EB (LEB)) and CP (high CP (HP) vs. low CP (LP)) in two turkey strains on growth performance, litter quality and FPD in a 2x2x2 factorial block design. A total of 1920 male poults were housed in 64 pens (3 m wide x 4 m deep) littered with wood shavings at a stocking rate of 30 poults/pen. Diets were formulated isocaloric for 5 phases (0- 28, 2S8- 56, 56-84, 84-112 and 112-134 days of age) and containing per phase 290 vs. 260, 270 vs. 240, 230 vs. 200, 200 vs. 170, 170 vs. 140 g CP/kg, respectively; and EB (240 vs. 130 mEq/kg) in all phases. Free amino acids were supplemented to the diets according to breeder recommendations. LEB diets were formulated by exchange of soya bean meal by maize gluten meal, peas, potato protein, rapeseed meal and sunflower seed meal. Water and feed were provided ad libitum. Body weight, feed intake, litter moisture and FPD scores were recorded at 28, 56, 84, 112 and 134 days of age. Body weight gain was not affected by CP and FCR was significantly higher on LP than on HP diets (2.56 vs. 2.50; P=0.002). FPD score of turkeys fed on LP was lower than on HP until 84 days (P<0.001). LEB resulted in a significantly lower feed intake (420 vs. 435 g/d) and body weight gain (166 vs. 172 g/d) over the period 28 to 124 days and lower body weight (18588 vs. 19405 g) at 134 days of age compared with HEB whereas FCR was not affected. Litter was significantly dryer on LEB than HEB diets (P<0.001). FPD score on LEB was significantly lower than on HEB diets (P< 0.001). FPD was not affected by turkey strain. It is concluded that litter quality can be improved and FPD can be decreased in turkeys fed on diets containing lower CP and EB levels. Keywords: foot pad dermatitis, growth performance, litter quality, protein, turkeys
    Abatement of particulate matter emission from experimental aviary housings for laying hens by spraying rapeseed oil
    Winkel, A. ; Riel, J.W. van; Emous, R.A. van; Aarnink, A.J.A. ; Groot Koerkamp, P.W.G. ; Ogink, N.W.M. - \ 2016
    Poultry Science 95 (2016)12. - ISSN 0032-5791 - p. 2836 - 2848.
    In alternative systems for laying hens, concentrations and emission rates of particulate matter (PM) give reason for concern with regard to working conditions, bird health and productivity, and health of residents living near farms. Previously, we found that spraying a film of rapeseed oil onto the litter of broilers could substantially reduce PM concentrations and emissions. The objective of this study was to establish dose-response effects of oil spraying in aviaries on concentrations and emission rates of PM with aerodynamic diameters less than 10 μm (PM10) and 2.5 μm (PM2.5), on stockmen's exposure to PM10, on egg production, exterior quality and behavior of the hens, and on the litter. An experiment was carried out with 4 treatments: 0 (control), 15, 30, and 45 mL/m2 per d (oil treatments). Each treatment was applied in 2 rooms with different aviary systems (8 rooms in total). The experiment was repeated during a second period, both lasting 35 days. From d 11 to d 35, oil was applied daily using a spraying gun. Applying 15, 30, or 45 mL/m2 per d significantly reduced emission rates of PM10 by 27, 62, and 82%, and emission rates of PM2.5 by 71, 83, and 94%, respectively. No significant effects of oil spraying were found on mortality, egg production, dust bathing behavior, scratching behavior, plumage soiling, DM content of the litter, or friability of the litter. A significant worsening of the plumage condition was found only for the body spot back/wings/tail (not for: throat/neck, chest/breast, or legs) in the 45 mL/m2 per d treatment. Egg quality shifted significantly towards more second-class eggs in the oil treatments (1.9% versus 1.4%; P = 0.004). Remarkably, foot soiling decreased with increasing oil application. In conclusion, PM concentrations and emission rates in aviaries can be effectively reduced by spraying 15 to 30 mL/m2 per d with minor side effects within a 25 d application period.
    Water Footprint’s feet of clay? Peruvian smallholder irrigation realities in times of global water accountability
    Verzijl, Andres - \ 2016
    Anyone for duckweed soup? Researchers probe whether green canal sludge could be new superfood
    Meer, Ingrid van der - \ 2016
    duckweed - Hivos project
    Proper Timing of Foot-and-Mouth Disease Vaccination of Piglets with Maternally Derived Antibodies Will Maximize Expected Protection Levels
    Dekker, A. ; Chénard, G. ; Stockhofe, N. ; Eble, P.L. - \ 2016
    Frontiers in Veterinary Science 3 (2016). - ISSN 2297-1769
    We investigated to what extent maternally derived antibodies interfere with foot-and-mouth disease (FMD) vaccination in order to determine the factors that influence the correct vaccination for piglets. Groups of piglets with maternally derived antibodies were vaccinated at different time points following birth, and the antibody titers to FMD virus (FMDV) were measured using virus neutralization tests (VNT). We used 50 piglets from 5 sows that had been vaccinated 3 times intramuscularly in the neck during pregnancy with FMD vaccine containing strains of FMDV serotypes O, A, and Asia-1. Four groups of 10 piglets were vaccinated intramuscularly in the neck at 3, 5, 7, or 9 weeks of age using a monovalent Cedivac-FMD vaccine (serotype A TUR/14/98). One group of 10 piglets with maternally derived antibodies was not vaccinated, and another group of 10 piglets without maternally derived antibodies was vaccinated at 3 weeks of age and served as a control group. Sera samples were collected, and antibody titers were determined using VNT. In our study, the antibody responses of piglets with maternally derived antibodies vaccinated at 7 or 9 weeks of age were similar to the responses of piglets without maternally derived antibodies vaccinated at 3 weeks of age. The maternally derived antibody levels in piglets depended very strongly on the antibody titer in the sow, so the optimal time for vaccination of piglets will depend on the vaccination scheme and quality of vaccine used in the sows and should, therefore, be monitored and reviewed on regular basis in countries that use FMD prophylactic vaccination.
    Welfare assessment of broiler chicken flocks from different hatching systems
    Jong, I.C. de; Gunnink, H. ; Gouw, P. de; Leijten, F. ; Raaijmakers, Mariël ; Zoet, Lisa ; Ven, L.J.F. van de; Brand, H. van den - \ 2016
    In: Welfare quality network seminar. - Finland : University of Helsinki - 1 p.
    On-farm hatching of broiler chickens is increasingly applied in The Netherlands. Eggs are transported to the farm at E18 and chicks are provided with feed and water immediately after hatching, in contrast to chickens hatched at the hatchery. The aim of the study was to assess the welfare of broilers hatched on-farm as compared to hatchery hatched broilers. Sixteen broiler flocks hatched on-farm in the X-treck system (X) were paired to 16 control flocks (C) from the same parent stock, reared in identical houses on the same farm and subjected to similar management. Welfare indicators, based on the Welfare Quality broiler assessment protocol, were measured at d21 and slaughter age. In addition, behavioural observations were carried out and technical performance was registered. Analysis of variance was used to test effects of treatment and age; data were transformed if necessary. X broilers had a lower incidence of foot pad dermatitis at d21 and at slaughter (p<0.05) and had numerically better hock burn scores at slaughter age than C broilers (P=0.56). X broilers were more dirty at d21 and at slaughter age than C broilers (p=0.08). Litter quality was better in Xhouses than in C houses at d21 (P=0.07), which seems to be in contradiction to bird cleanliness but in agreement with foot and hock scores. An age x treatment interaction was found for gait score, with X broilers having worse scores at d21 but having better scores at slaughter age than C broilers. Significant differences in behaviour were found at d21 and slaughter age, indicating that X broilers were less active than C broilers. Although technical performance of X broilers was better during the first weeks as compared to C broilers, no significant differences were found at slaughter age. This study indicates that on-farm hatching may positively affect broiler welfare.
    Ramps and hybrid effects on keel bone and foot pad disorders in modified aviaries for laying hens
    Heerkens, J.L.T. ; Delezie, E. ; Ampe, B. ; Rodenburg, T.B. ; Tuyttens, F.A.M. - \ 2016
    Poultry Science 95 (2016)11. - ISSN 0032-5791 - p. 2479 - 2488.
    aviary - foot health - keel bone - laying hens

    Non-cage systems provide laying hens with considerable space allowance, perches and access to litter, thereby offering opportunities for natural species-specific behaviors. Conversely, these typical characteristics of non-cage systems also increase the risk of keel bone and foot pad disorders. The aim of this study was twofold: 1) to investigate if providing ramps between perches (housing factor) reduces keel bone and foot pad disorders and 2) to test for genetic predisposition by comparing 2 different layer hybrids. In a 2 × 2 design, 16 pens were equipped either with or without ramps between perches and nest boxes (8 pens/treatment), and housed with either 25 ISA Brown or Dekalb White birds per pen (in total 200 birds/hybrid). Keel bone injuries and foot health were repeatedly measured via palpation and visual assessment between 17 and 52 wk of age and daily egg production was recorded. The relationships between the dependent response variables (keel bone and footpad disorders, egg production) and independent factors (age, ramps, hybrid) were analyzed using generalized linear mixed models and corrected for repeated measures. Ramps reduced keel bone fractures (F1,950 = 45.80, P <0.001), foot pad hyperkeratosis (F1,889 = 10.40, P = 0.001), foot pad dermatitis (F1,792 = 20.48, P <0.001) and bumble foot (F1,395 = 8.52, P <0.001) compared to pens without ramps. ISA Brown birds sustained more keel bone fractures (F1,950 = 33.26, P <0.001), had more foot pad hyperkeratosis (F1,889 = 44.69, P <0.001) and laid more floor eggs (F1,1883 = 438.80, P <0.001), but had fewer keel bone deviations (F1,1473 = 6.73, P <0.001), fewer cases of foot pad dermatitis (F1,792 = 19.84, P <0.001) and no bumble foot as compared to Dekalb White birds. Age, housing and hybrid showed several interaction effects. Providing ramps proved to be very effective in both reducing keel bone and foot pad problems in non-cage systems. Keel bone and foot pad disorders are related to genetic predisposition. These results indicate that adaptation of the housing systems and hybrid selection may be effective measures in improving laying hen welfare.

    Are dairy farmers willing to invest in technology to detect lameness?
    Olde, E.M. de; Jensen, E.M. ; Oudshoorn, F.W. ; Sorensen, C.A.G. - \ 2016
    Lameness in dairy cows is a symptom caused by a variety of foot and leg disorders. It is a severe problem in livestock farming, not only from the perspective of animal welfare, but also economically, since it reduces milk yield and gives expenses for the necessary treatments. A range of systems using smart sensor technology has been developed in order to detect lameness as early, accurate and safely as possible, for example Gaitwise and Stepmetrix. However, currently no system exists on the market that is in widespread practical use. The aim of this study was to analyse the lameness challenges in Danish dairy farming and the willingness of dairy farmers to invest in technologies to detect lameness. A questionnaire targeting relevant stakeholders in Danish dairy farming was carried out. Two types of questionnaires were developed; one for farmers and one for companies (i.e. advisors, veterinarians). Invitations for both questionnaires were spread through dairy farming websites. The questionnaire was developed to allow for three different ways of answering, through SMS, email or through a website. The results demonstrate different perceptions between farmers and companies regarding the estimated lameness incidence of Danish farms. The majority of farmers estimated the lameness incidence on their farm as below 10%, whereas the majority of companies estimated the lameness incidence of the farms they visit above 10%. One of the reasons for this divergence could be the differences in the observation and understanding of lameness. The willingness to invest in lameness detection technology varies considerably amongst farmers. Moreover, an observed skepticism by some farmers could be a result of the current economic recession in Danish dairy farming.
    The serological response against foot and mouth disease virus elicited by repeated vaccination of dairy cattle
    Elnekave, Ehud ; Dekker, Aldo ; Eble, Phaedra ; Kluitenberg-van Hemert, Froukje ; Gelman, Boris ; Storm, Nick ; Klement, Eyal - \ 2016
    Vaccine 34 (2016)41. - ISSN 0264-410X - p. 4920 - 4926.
    Cattle - Dairy - FMD - Neutralizing antibody titers (NAT) - Repeated vaccinations - Serology

    In Israel, cattle are annually vaccinated against foot and mouth disease (FMD). If infections with FMD virus occur in dairy farms it mainly involves heifers and calves, while older dairy cows seldom become infected. We hypothesized that this difference in susceptibility between adult cows and the young heifers and calves is due to stronger and more stable immune response elicited by multiple vaccinations. In order to test this hypothesis, 99 dairy cattle, divided into six groups according to number of prior vaccinations, were annually vaccinated with a trivalent vaccine (A, O and Asia-1) and followed during two consecutive years. In total 988 sera were sampled at 11 time points. Virus neutralization tests (VNT) were performed in order to determine the neutralizing antibody titers (NAT) against the vaccine homologous serotypes: O-4625, O-Manisa, Asia-1-Shamir and the heterologous serotype A-Turkey-20/2006. A similar NAT pattern was observed to all serotypes and therefore statistical analysis was restricted to O-4625 serotype. In the ‘high vaccination’ groups (cows that were vaccinated at least four times before the study), high NAT were found on the beginning of the trial and no or only a mild increase of NAT was observed following further vaccinations. Additionally, in the ‘high vaccination’ groups, the percentage of cows that had a NAT higher than 2.0 (log10) by the end of the 1st year was significantly higher than in the ‘low vaccination’ groups (cows vaccinated only three times or less before the study). We conclude that starting from the 5th vaccination, the NAT increase following vaccination is mild and NAT are persistent, suggesting reduction of the frequency of routine vaccination after multiple vaccinations is possible.

    The long term effect of age and maternally derived antibodies against foot and mouth disease on the serological response following vaccination in young dairy calves
    Elnekave, Ehud ; Dekker, Aldo ; Eble, Phaedra ; Kluitenberg-van Hemert, Froukje ; Gelman, Boris ; Storm, Nick ; Klement, Eyal - \ 2016
    Vaccine 34 (2016)41. - ISSN 0264-410X - p. 4927 - 4934.
    Calves - Dairy - FMD - Maternally derived antibodies (MDA) - Neutralization antibody titers (NAT) - Serology

    In Israel, occurrence of foot and mouth disease (FMD) in dairy farms is rare. However, when FMD outbreaks occur, dairy calves are the most affected, despite routine vaccination. Contradictory findings exist regarding the effect of age and maternally derived antibodies (MDA) on the serological response following vaccinations against FMD in dairy calves. Furthermore, the long term effect of FMD vaccination regimen during early life was rarely assessed. This study was conducted in order to assess both the short and long term effects. In total 44 non-vaccinated calves were divided into four groups of different age. Calves were vaccinated up to four times and 484 serum samples were collected on 11 time points in a period of 70 weeks. Virus neutralizing tests were performed in order to determine the neutralizing antibody titers (NAT) against the vaccine strains (homologous serotypes): O-4625, O-Manisa, ASIA-1-Shamir and the heterologous serotype A-Turkey-20/2006. A similar NAT pattern was observed to all serotypes and therefore statistical analysis was restricted to O-4625 serotype. The MDA titer was negatively associated with the age of the calves and the MDA half-life was 22 days. We demonstrated that early vaccination of calves (younger than three months) resulted in low NAT, even after four repeated vaccinations, compared with vaccination of calves older than three months. The percentage of time in which these calves had a NAT above 2.0 (log10) between the age of six months and 1.5 years was significantly lower compared to older calves (older than three months). Additionally, we found that by increasing the frequency of vaccination in calves older than three months, it is possible to reach high NAT by the age of one year. Adoption of such a vaccination regimen in Israel as well as other FMD endemic countries may allow better protection against FMD in dairy calves and reduction in FMD incidence.

    Cost-benefit analysis of foot and mouth disease control in Ethiopia
    Jemberu, W.T. ; Mourits, M.C.M. ; Rushton, J. ; Hogeveen, H. - \ 2016
    Preventive Veterinary Medicine 132 (2016). - ISSN 0167-5877 - p. 67 - 82.
    Foot and mouth disease (FMD) occurs endemically in Ethiopia. Quantitative insights on its national economic impact and on the costs and benefits of control options are, however, lacking to support decision making in its control. The objectives of this study were, therefore, to estimate the annual costs of FMD in cattle production systems of Ethiopia, and to conduct an ex ante cost-benefit analysis of potential control alternatives.

    The annual costs of FMD were assessed based on production losses, export losses and control costs. The total annual costs of FMD under the current status quo of no official control program were estimated at 1354 (90% CR: 864–2042) million birr. The major cost (94%) was due to production losses. The costs and benefits of three potential control strategies: 1) ring vaccination (reactive vaccination around outbreak area supported by animal movement restrictions, 2) targeted vaccination (annual preventive vaccination in high risk areas plus ring vaccination in the rest of the country), and 3) preventive mass vaccination (annual preventive vaccination of the whole national cattle population) were compared with the baseline scenario of no official control program. Experts were elicited to estimate the influence of each of the control strategies on outbreak incidence and number of cases per outbreak. Based on these estimates, the incidence of the disease was simulated stochastically for 10 years. Preventive mass vaccination was epidemiologically the most efficient control strategy by reducing the national outbreak incidence below 5% with a median time interval of 3 years, followed by targeted vaccination strategy with a corresponding median time interval of 5 years. On average, all evaluated control strategies resulted in positive net present values. The ranges in the net present values were, however, very wide, including negative values. The targeted vaccination strategy was the most economic strategy with a median benefit cost ratio of 4.29 (90%CR: 0.29–9.63). It was also the least risky strategy with 11% chance of a benefit cost ratio of less than one.

    The study indicates that FMD has a high economic impact in Ethiopia. Its control is predicted to be economically profitable even without a full consideration of gains from export. The targeted vaccination strategy is shown to provide the largest economic return with a relatively low risk of loss. More studies to generate data, especially on production impact of the disease and effectiveness of control measures are needed to improve the rigor of future analysis.
    New approaches in housing and management to improve foot pad health in fattening poultry
    Jong, I.C. de; Harn, J. van - \ 2016
    - p. 47 - 47.
    Footpad dermatitis, a condition of inflammation and necrotic lesions of the plantar surface of the foot, is a common problem in broiler and turkey production, despite the fact that monitoring footpad health has become part of broiler welfare legislation in some European countries.
    Severe footpad lesions are painful and not only have a negative effect on broiler welfare in itself, but are also related to impaired product quality, impaired technical performance and other welfare problems such as impaired locomotion and increased incidence of hock burns.
    In Denmark and Sweden, where footpad dermatitis has been monitored already for years, the prevalence in broiler flocks is generally low. However, in other countries there can be a large variation in the prevalence of footpad dermatitis between individual broiler and turkey flocks.
    Wet and/or sticky litter is generally considered to be the most important causal factor of footpad dermatitis, but there are many housing and management aspects that affect litter quality. In this presentation we will provide an overview of recent studies on management and housing factors influencing litter quality and thus the prevalence of footpad dermatitis in broilers and turkeys,
    such as feed composition and feed form, bedding type and depth, temperature and relative humidity, drinking water management, light intensity and light programmes. Apart from these factors, (infectious) diseases causing diarrhoea affect the litter quality, and genetic background of the birds also plays a role in the risk to develop footpad dermatitis. More recent studies showed that not only housing or management, but also broiler breeder feeding programmes
    and incubation conditions may play a role in the risk to develop footpad dermatitis in broiler chickens by affecting the development of the skin of the feet. This area needs further study, because if these relationships indeed exist a production chain approach will help to reduce the incidence of footpad dermatitis in fattening poultry.
    Effect of hatching conditions on indicators of welfare and health in broiler chickens
    Jong, I.C. de; Gunnink, H. ; Gouw, P. de; Leijten, F. ; Raaijmakers, Mariël ; Zoet, Lisa ; Wolfs, E. ; Ven, L.F.J. van de; Brand, H. van den - \ 2016
    - p. 182 - 182.
    On-farm hatching of broiler chickens is increasingly applied, because farmers report improved performance compared to broilers hatched at the hatchery. However, there is little scientific evidence for these effects. Aim of the study was to find evidence for long-lasting effects of hatching conditions on performance and welfare of broiler chickens. Broilers hatched at the hatchery (n=16 control flocks) or on-farm (X-treck system, n=16 flocks). Each X-treck flock was paired to a control flock from similar parent stock, reared in identical houses and subjected to similar management. In the X-treck, eggs are transferred to the stable at d18 of incubation and hatch in the stable. Chicks have immediate access to feed and water. Chicks from the hatchery received their first feed and water when they arrived at the farm. Indicators of welfare were measured at d0 (arrival of hatchery chicks), d21 and just before slaughter. Analysis of variance was used to test effects of treatment and age; data were transformed if necessary. X-treck broilers were heavier at d0 compared to control broilers (P<0.01) due to immediate access to feed and water after hatching. Quality of X-treck chicks was impaired compared to control chicks, as indicated by on average a worse navel and leg quality (P=0.01), which might be due to selection of chicks at the hatchery, which did not happen in the X-treck system. Control chicks showed a more stressful response (more vocalisations) in a novel environment test at d0 compared to X-treck chicks (P<0.01), but there were no treatment differences at d21. No treatment differences in gait score at d21 and at slaughter age were found, indicating that hatching conditions did not affect lameness. X-treck broilers had less foot pad dermatitis at d21 and slaughter age (P<0.05) and had numerically better hock burn scores at slaughter age than control broilers (P=0.56). X-treck broilers were more dirty at d21 and at slaughter age than control broilers (P=0.08). Litter quality was better in X-treck houses than in control houses, which seems to be in contradiction to bird cleanliness but in agreement with foot and hock scores. Farm records of the majority of flocks indicated a lower rejection rate at slaughter and a lower mortality for X-treck flocks compared to control flocks, although these figures need to be confirmed in the final analysis. Thus, first results of this study indicate that effects of hatching conditions on welfare of broiler chickens may indeed be long-lasting.
    Companion Animals as a Source of Viruses for Human Beings and Food Production Animals
    Reperant, L.A. ; Brown, I.H. ; Haenen, O.L.M. ; Jong, M.D. de; Osterhaus, Albert D.M.E. ; Papa, A. ; Rimstad, E. ; Valarcher, J.F. ; Kuiken, T. - \ 2016
    Journal of Comparative Pathology 155 (2016)1. - ISSN 0021-9975 - p. S41 - S53.
    Companion animals comprise a wide variety of species, including dogs, cats, horses, ferrets, guinea pigs, reptiles, birds and ornamental fish, as well as food production animal species, such as domestic pigs, kept as companion animals. Despite their prominent place in human society, little is known about the role of companion animals as sources of viruses for people and food production animals. Therefore, we reviewed the literature for accounts of infections of companion animals by zoonotic viruses and viruses of food production animals, and prioritized these viruses in terms of human health and economic importance. In total, 138 virus species reportedly capable of infecting companion animals were of concern for human and food production animal health: 59 of these viruses were infectious for human beings, 135 were infectious for food production mammals and birds, and 22 were infectious for food production fishes. Viruses of highest concern for human health included hantaviruses, Tahyna virus, rabies virus, West Nile virus, tick-borne encephalitis virus, Crimean–Congo haemorrhagic fever virus, Aichi virus, European bat lyssavirus, hepatitis E virus, cowpox virus, G5 rotavirus, influenza A virus and lymphocytic choriomeningitis virus. Viruses of highest concern for food production mammals and birds included bluetongue virus, African swine fever virus, foot-and-mouth disease virus, lumpy skin disease virus, Rift Valley fever virus, porcine circovirus, classical swine fever virus, equine herpesvirus 9, peste des petits ruminants virus and equine infectious anaemia virus. Viruses of highest concern for food production fishes included cyprinid herpesvirus 3 (koi herpesvirus), viral haemorrhagic septicaemia virus and infectious pancreatic necrosis virus. Of particular concern as sources of zoonotic or food production animal viruses were domestic carnivores, rodents and food production animals kept as companion animals. The current list of viruses provides an objective basis for more in-depth analysis of the risk of companion animals as sources of viruses for human and food production animal health
    Effect of dietary protein source and crude protein content on growth performance, litter quality and foot pad dermatitis in two commercial turkey strains
    Veldkamp, T. ; Hocking, P.M. ; Vinco, L.J. - \ 2016
    - p. 54 - 58.
    Genome-wide association study for behavior, type traits, and muscular development in Charolais beef cattle
    Vallée, A. ; Daures, J. ; Arendonk, J.A.M. van; Bovenhuis, H. - \ 2016
    Journal of Animal Science 94 (2016)6. - ISSN 0021-8812 - p. 2307 - 2316.
    Association study - Beef cattle - Behavior traits - Charolais - Muscular development - Type traits

    Behavior, type traits, and muscular development are of interest for beef cattle breeding. Genome-wide association studies (GWAS) enable the identification of candidate genes, which enables genebased selection and provides insight in the genetic architecture of these traits. The objective of the current study was to perform a GWAS for 3 behavior traits, 12 type traits, and muscular development in Charolais cattle. Behavior traits, including aggressiveness at parturition, aggressiveness during gestation period, and maternal care, were scored by farmers. Type traits, including udder conformation, teat, feet and legs, and locomotion, were scored by trained classifiers. Data used in the GWAS consisted of 3,274 cows with phenotypic records and genotyping information for 44,930 SNP. When SNP had a false discovery rate (FDR) smaller than 0.05, they were referred to as significant. When SNP had a FDR between 0.05 and 0.20, they were referred to as suggestive. Four significant and 12 suggestive regions were detected for aggressiveness during gestation, maternal care, udder balance, teat thinness, teat length, foot angle, foot depth, and locomotion. These 4 significant and 12 suggestive regions were not supported by other significant SNP in close proximity. No SNP with major effects were detected for behavior and type traits, and SNP associations for these traits were spread across the genome, suggesting that behavior and type traits were influenced by many genes, each explaining a small part of genetic variance. The GWAS identified 1 region on chromosome 2 significantly associated with muscular development, which included the myostatin gene (GDF8), which is known to affect muscularity. No other regions associated with muscular development were found. Results showed that the myostatin region associated with muscular development had pleiotropic effects on udder volume, teat thinness, rear leg, and leg angle.

    Full protection of swine against foot-and-mouth disease by a bivalent B-cell epitope dendrimer peptide
    Blanco, Esther ; Guerra, Beatriz ; Torre, Beatriz de la; Defaus, Sira ; Dekker, A. ; Andreu, D. ; Sobrino, Francisco - \ 2016
    Antiviral Research 129 (2016). - ISSN 0166-3542 - p. 74 - 80.
    Foot-and-mouth disease virus (FMDV) causes a highly contagious disease of cloven-hoofed animals. We have reported (Cubillos et al., 2008) that a synthetic dendrimeric peptide consisting of four copies of a B-cell epitope [VP1(136–154)] linked through thioether bonds to a T-cell epitope [3A(21–35)] of FMDV [B4T(thi)] elicits potent B- and T-cell specific responses and confers solid protection in pigs to type C FMDV challenge. Herein we show that downsized versions of this peptide bearing two copies of a B-cell epitope from a type O isolate and using thioether [B2T(thi)] or maleimide [B2T(mal)] conjugation chemistries for their synthesis elicited in swine similar or higher B and T-cell specific responses than tetravalent B4T(thi). Moreover, while partial protection was observed in animals immunized with B4T(thi) (60%) and B2T(thi) (80%), B2T(mal) conferred full (100%) protection against FMDV challenge, associated to high levels of circulating IgG2 and mucosal IgGA, and entirely prevented virus shedding. Interestingly, B2T(mal) is also the most advantageous option in terms of synthetic practicality. Taken together, the results reported here point out to B2T(mal) as a highly valuable, cost-effective FMDV candidate vaccine.
    Aerosol transmission of foot-and-mouth disease virus Asia-1 under experimental conditions
    Colenutt, C. ; Gonzales, J.L. ; Paton, D.J. ; Gloster, J. ; Nelson, N. ; Sanders, C. - \ 2016
    Veterinary Microbiology 189 (2016). - ISSN 0378-1135 - p. 39 - 45.
    Aerosol - Exposure dose - Foot-and-mouth disease virus - Transmission
    Foot-and-mouth disease virus (FMDV) control measures rely on understanding of virus transmission mechanisms. Direct contact between naïve and infected animals or spread by contaminated fomites is prevented by quarantines and rigorous decontamination procedures during outbreaks. Transmission of FMDV by aerosol may not be prevented by these control measures and this route of transmission may allow infection of animals at distance from the infection source. Understanding the potential for aerosol spread of specific FMDV strains is important for informing control strategies in an outbreak. Here, the potential for transmission of an FMDV Asia 1 strain between pigs and cattle by indirect aerosol exposure was evaluated in an experimental setting. Four naïve calves were exposed to aerosols emitted from three infected pigs in an adjacent room for a 10 h period. Direct contact between pigs and cattle and fomite transfer between rooms was prevented. Viral titres in aerosols emitted by the infected pigs were measured to estimate the dose that calves were exposed to. One of the calves developed clinical signs of FMD, whilst there was serological evidence for spread to cattle by aerosol transmission in the remaining three calves. This highlights the possibility that this FMDV Asia 1 strain could be spread by aerosol transmission given appropriate environmental conditions should an outbreak occur in pigs. Our estimates suggest the exposure dose required for aerosol transmission was higher than has been previously quantified for other serotypes, implying that aerosols are less likely to play a significant role in transmission and spread of this FMDV strain
    Risk factors associated with keel bone and foot pad disorders in laying hens housed in aviary systems
    Heerkens, J.L.T. ; Delezie, E. ; Rodenburg, T.B. ; Kempen, I. ; Zoons, J. ; Ampe, B. ; Tuyttens, F.A.M. - \ 2016
    Poultry Science 95 (2016)3. - ISSN 0032-5791 - p. 482 - 488.
    aviary - foot health - housing system - keel bone

    Aviary systems for laying hens offer space and opportunities to perform natural behaviors. However, hen welfare can be impaired due to increased risk for keel bone and foot pad disorders in those systems. This cross-sectional study (N = 47 flocks) aimed to assess prevalences of keel bone and foot pad disorders in laying hens housed in aviaries in Belgium to identify risk factors for these disorders and their relation to egg production. Information on housing characteristics and egg production were obtained through questionnaire-based interviews, farm records, and measurements in the henhouse. Keel bone (wounds, hematomas, fractures, deviations) and foot pad disorders (dermatitis, hyperkeratosis) were assessed in 50 randomly selected 60-week-old laying hens per flock. A linear model with stepwise selection procedure was used to investigate associations between risk factors, production parameters, and the keel bone and foot pad disorders. The flock mean prevalences were: hematomas 41.2%, wounds 17.6%, fractures 82.5%, deviations 58.9%, hyperkeratosis 42.0%, dermatitis 27.6%, and bumble foot 1.2%. Identified risk factors for keel bone disorders were aviary type (row vs. portal), tier flooring material (wire mesh vs. plastic slats), corridor width, nest box perch, and hybrid. Identified risk factors for foot pad disorders were aviary type (row vs. portal), free-range, and hybrid. Percentage of second-quality eggs was negatively associated with keel bone deviations (P = 0.029) at the flock level. Keel bone and foot pad disorders were alarmingly high in aviary housing. The identification of various risk factors suggests improvements to aviary systems may lead to better welfare of laying hens.

    Foot-and-mouth Disease Transmission in Africa : Implications for Control, a Review
    Tekleghiorghis, T. ; Moormann, R.J.M. ; Weerdmeester, K. ; Dekker, A. - \ 2016
    Transboundary and Emerging Diseases 63 (2016)2. - ISSN 1865-1674 - p. 136 - 151.
    Africa - Animal husbandry - Foot-and-mouth disease - Serotype - Topotype - Transmission - Wildlife

    In Africa, for the control of foot-and-mouth disease (FMD), more information is needed on the spread of the disease at local, regional and inter-regional level. The aim of this review is to identify the role that animal husbandry, trade and wildlife have on the transmission of FMD and to provide a scientific basis for different FMD control measures in Africa. Review of literature, published reports and databases shows that there is more long distance spread of FMD virus serotypes within North, West, Central and East Africa than in southern Africa. In North, West, Central and East Africa migratory animal husbandry systems often related with search for grazing and water as well as trade are practiced to a greater extent than in southern Africa. In southern Africa, the role of African buffalo (Syncerus caffer) is more extensively studied than in the other parts of Africa, but based on the densities of African buffalo in Central and East Africa, one would assume that buffalo should also play a role in the epidemiology of FMD in this part of Africa. More sampling of buffalo is necessary in West, Central and East Africa. The genetic analysis of virus strains has proven to be valuable to increase our understanding in the spread of FMD in Africa. This review shows that there is a difference in FMD occurrence between southern Africa and the rest of the continent; this distinction is most likely based on differences in animal husbandry and trade systems. Insufficient data on FMD in wildlife outside southern Africa is limiting our understanding on the role wildlife plays in the transmission of FMD in the other buffalo inhabited areas of Africa.

    Decision-making for foot-and-mouth disease control : Objectives matter
    Probert, William J.M. ; Shea, Katriona ; Fonnesbeck, Christopher J. ; Runge, Michael C. ; Carpenter, Tim E. ; Dürr, Salome ; Garner, M.G. ; Harvey, Neil ; Stevenson, Mark A. ; Webb, Colleen T. ; Werkman, Marleen ; Tildesley, Michael J. ; Ferrari, Matthew J. - \ 2016
    Epidemics 15 (2016). - ISSN 1755-4365 - p. 10 - 19.
    Decision making - Epidemiology - Foot-and-mouth disease - Management - Objectives - Optimisation

    Formal decision-analytic methods can be used to frame disease control problems, the first step of which is to define a clear and specific objective. We demonstrate the imperative of framing clearly-defined management objectives in finding optimal control actions for control of disease outbreaks. We illustrate an analysis that can be applied rapidly at the start of an outbreak when there are multiple stakeholders involved with potentially multiple objectives, and when there are also multiple disease models upon which to compare control actions. The output of our analysis frames subsequent discourse between policy-makers, modellers and other stakeholders, by highlighting areas of discord among different management objectives and also among different models used in the analysis. We illustrate this approach in the context of a hypothetical foot-and-mouth disease (FMD) outbreak in Cumbria, UK using outputs from five rigorously-studied simulation models of FMD spread. We present both relative rankings and relative performance of controls within each model and across a range of objectives. Results illustrate how control actions change across both the base metric used to measure management success and across the statistic used to rank control actions according to said metric. This work represents a first step towards reconciling the extensive modelling work on disease control problems with frameworks for structured decision making.

    Mussel-inspired chemistry and its application
    Yang, J. - \ 2016
    Wageningen University. Promotor(en): Martien Cohen Stuart; Marleen Kamperman. - Wageningen : Wageningen University - ISBN 9789462576254 - 213
    polymer chemistry - bonding - pyrocatechol - synthesis - coatings - binders - biomimicry - polymerization - polymeerchemie - binding (scheikundig) - pyrocatechol - synthese - afdeklagen - zelfbinders - biomimicry - polymerisatie

    Mussels can affix themselves to a variety of wet surfaces under harsh marine conditions by secreting liquid mussel foot proteins (mfps) as superglues. Inside the mussel, the superglues are fluid-like and are kept at low pH, i.e. pH 3. Upon secretion into seawater at pH 8, the superglues are cured efficiently through crosslinking of the catecholic amino acid 3, 4-dihydroxyphenylalanine (DOPA). Currently, a lot of efforts have been devoted to developing functional materials using biomimetic polymers, although the crosslinking chemistry of the catechols in DOPA is still under debate. The goal of this thesis is twofold : 1) better understanding of crosslinking chemistry of catechols; 2) the design and synthesis of catechol-containing functional materials.

    To gain better understanding of the crosslinking mechanism, we summarized the possible crosslinking mechanisms of catechols that have been proposed in the last few decades. We rationalize the parameters that may affect the crosslinking pathways and kinetics such as pH, temperature, types of oxidant and so on. Motivated by the open questions as discussed in the literatures, we investigate the crosslinking mechanism of catechols with amines using model compounds 4-methyl catechol (4MC) and propylamine (PA) in aqueous media. From the spectroscopic and chromatographic studies, we find that the reaction between 4MC and PA is very fast and complicated. In the first five minutes, more than 60 products have already been formed. These products are mainly formed via three pathways, i.e., Michael-type addition, Schiff-base reaction, and phenol-phenol coupling. Among these products, the majority are amine-catechol adducts formed by Michael-type addition.

    In addition, we also designed catechol-containing functional copolymers. We designed a copolymer containing both functionalities-amines and catechols: poly(dopamine acrylamide-co-2-aminoethyl methacrylamide hydrochloride). We synthesized the copolymer in aqueous medium using free radical polymerization. The polymer is pH-responsive and meets two important requirements for a binder that can be used in water-borne coatings: (1) it is water-soluble at acidic pH during storage; (2) during drying and curing at basic pH, it becomes water-insoluble. The aqueous solubility switch is ascribed to the crosslinking reactions between catechols and amines at basic pH. Besides fulfilling the requirement of solubility switch, the coatings should also have proper adhesion properties. Therefore, we synthesize five copolymers with different amount of catechols from free radical polymerization of N-(3,4-dihydroxyphenethyl)methacrylamide (DMA) and 2-methoxyethyl methacrylate (MEA) with different compositions. We find that, under dry and wet conditions, an optimal composition for the best adhesion is achieved at 5 mol% of DMA. Polymers with a higher concentration of DMA show little adhesion, which is attributed to the high stiffness of the material, resulting in poor contact with the probe.

    Where have all the commons gone?
    Narain, Vishal ; Vij, Sumit - \ 2016
    Geoforum 68 (2016). - ISSN 0016-7185 - p. 21 - 24.
    (Peri) urban - Common property resources - Depleting factors - India

    Common property resources (CPRs) have provided a basis for sustenance to countless households, especially those that lack access to private assets. Several factors have eroded the access of CPR dependent communities, such as, conscious policy decisions of the state, elite domination, the process of land consolidation and commercialization. In the period of neo-liberal reforms in India, after 1991, the nature of threats to the commons has changed. Emerging factors such as urbanization, land acquisition and real estate development have played a more significant role in depleting the CPRs. The commons have increasingly come to bear the ecological foot-print of urbanization as they got acquired or encroached upon for urban expansion and required infrastructure. This compromises the livelihood security of those who depend on them for sustenance. There is a need for debate on alternative and more sustainable models of urbanization.

    Bioeconomic modelling of foot and mouth disease and its control in Ethiopia
    Jemberu, W.T. - \ 2016
    Wageningen University. Promotor(en): Henk Hogeveen, co-promotor(en): Monique Mourits. - Wageningen : Wageningen University - ISBN 9789462576872 - 175
    foot-and-mouth disease virus - economic models - mathematical models - epidemiology - animal diseases - cattle - cattle diseases - ethiopia - mond- en klauwzeervirus - economische modellen - wiskundige modellen - epidemiologie - dierziekten - rundvee - rundveeziekten - ethiopië

    Keywords: Control, cost-benefit, economic impact, epidemiology, Ethiopia, Foot and mouth disease, intention, modelling, production system.

    Bioeconomic Modelling of Foot and Mouth Disease and Its control in Ethiopia

    Foot and mouth disease (FMD) is a highly contagious viral disease which affects cloven hoofed animals. FMD is endemic in Ethiopia with potential impact both on national and household economies because of its effect on production and trade. The general objective of this PhD research was to provide insight into the epidemiology and economics of FMD and its control in Ethiopia to support decision making in the control of the disease.

    A study of the national incidence of FMD outbreak revealed that the disease is endemic in all regional states affecting more than a quarter of the country every year, with the highest frequency of outbreaks occurring in the central, southern and southeastern parts of the country. The type of production system, presence of a major livestock market and/or route, and adjacency to a national parks or wildlife sanctuary were associated with the risk of outbreaks in the districts.

    Field outbreak study indicated that FMD morbidity rates of 85% and 95 % at herd level; and 74% and 61% at animal level in the affected herds in the crop–livestock mixed system (CLM) and pastoral system, respectively. The herd level economic loss estimates were on average USD 76 per affected herd in CLM and USD 174 per affected herd in the pastoral production system.

    Study of motivation of farmers to implement FMD control, through the Health Belief Model (HBM) framework, revealed that almost all farmers had high intention to implement FMD vaccination free of charge, which decreases, especially in CLM system, if the vaccine is charged. Farmers in the pastoral and crop-livestock mixed production systems had low intention to implement herd isolation and animal movement restriction control measure. Among the HBM perception constructs perceived barrier was found to be the most important predictor of the intention to implement FMD control measures.

    A modelling study on the national economic impact and cost-benefit analysis FMD control strategies showed that the annual cost of the disease is about 1,354 million birr. A stochastic cost-benefit analysis of three potential FMD control strategies indicated that all the strategies on average have a positive economic return but with variable degree of uncertainty including possibility of loss. Targeted vaccination strategy gives relatively the best economic return with relatively less risk of loss.

    What is being measured, and by whom? Facilitation of communication on technical measures amongst competent authorities in the implementation of the European Union Broiler Directive (2007/43/EC)
    Butterworth, A. ; Jong, I.C. de; Keppler, C. ; Knierim, U. ; Stadig, L. ; Lambton, S. - \ 2016
    Animal 10 (2016)2. - ISSN 1751-7311 - p. 302 - 308.
    The European Union (EU) Broiler Directive (2007/43/EC) is unique amongst current EU Directives, which address animal welfare, in that it uses outcome data collected at abattoirs and on farm to monitor on-farm broiler welfare and vary the maximum permitted stocking density on farm. In this study, we describe how, by bringing together personnel from the competent authorities in 22 member states (MSs) who have responsibility for implementing the Directive, and engaging in exchange of information and technical methods regarding the Broiler Directive, it has been possible to identify differences in approach with regard to ‘what data is being collected, and by whom’ across EU MSs. Online questionnaires and workshop exercises enabled us to identify priority areas for knowledge transfer and training. For example, foot pad dermatitis, hock burn, dead on arrival and total rejections (birds rejected as unfit for human consumption by the meat inspection staff at slaughter) were identified by the MSs as measures of medium-to-low priority in terms of knowledge transfer because there are assessment methods for these conditions that are already well accepted by competent authorities. On the other hand, breast lesions, cellulitis, emaciation, joint lesions, respiratory problems, scratches, wing fractures and a number of environmental measures were identified as having high priority in terms of knowledge transfer. The study identified that there is significant variability in the stage of implementation between MSs, and responses from the participating MSs indicated that sharing of guidance and technical information between MSs may be of value in the future set-up process for those MSs engaged in implementation of the Directive.
    Epidemiology of Foot and Mouth Disease in Ethiopia: a Retrospective Analysis of District Level Outbreaks, 2007–2012
    Jemberu, W.T. ; Mourits, M.C.M. ; Sahle, M. ; Siraw, B. ; Vernooij, J.C.M. ; Hogeveen, H. - \ 2016
    Transboundary and Emerging Diseases 63 (2016)6. - ISSN 1865-1674 - p. e246 - e259.
    This study aimed at determining the incidence, distribution, risk factors, and causal serotypes of foot and mouth disease (FMD) outbreaks in Ethiopia based on 5 years of retrospective outbreak data (September 2007 until August 2012). District level outbreak data were collected from 115 randomly selected districts using a questionnaire administered to district animal health officers. The national incidence of FMD outbreaks during the study period was 1.45 outbreaks per five district years. Outbreaks were geographically widespread affecting all major regional states in the country and were more frequent in the central, southern, and southeastern parts of the country. Neither long-term nor seasonal trends were observed in the incidence of outbreaks. A mixed effects logistic regression analysis revealed that the type of production system (market oriented system versus subsistence systems), presence of a major livestock market and/or route, and adjacency to a national parks or wildlife sanctuary were found to be associated with increased risk of outbreaks in the districts. FMD virus serotypes O, A, SAT 2, and SAT 1 were identified as the causal serotypes of the outbreaks during the study period. Whereas O was the dominant serotype, SAT 2 was the serotype that showed increase in relative frequency of occurrence. The estimated incidence of outbreaks is useful in assessing the economic impacts of the disease, and the identified risk factors provide important knowledge to target a progressive FMD control policy for Ethiopia.
    Risicoanalyse dierenwelzijn eierketen : Deskstudie en expert opinie
    Visser, Kathalijne ; Ouweltjes, Wijbrand ; Jong, Ingrid de; Gerritzen, Marien ; Niekerk, Thea van - \ 2015
    Wageningen : Wageningen UR Livestock Research (Livestock Research rapport 888) - 60
    Eén van de taken van de Nederlandse Voedsel- en Warenautoriteit (NVWA) is het controleren ofregelgeving op het gebied van onder andere het welzijn van landbouwhuisdieren, diergezondheid envoedselveiligheid wordt nageleefd. Hiervoor voert de NVWA een risicoanalyse en risicoprofilering uitover al haar domeinen waarbij integraal plant- en diergezondheid, dierenwelzijn, voedsel- enproductveiligheid worden meegenomen. Doel van NVWA is het formuleren van maatregelen tervermindering van de risico’s inclusief het risk-based herijken van het toezicht. De NVWA voert dezerisicoanalyses uit vanuit een ketenbenadering (van primair bedrijf tot en met het slachthuis). Daarbijworden in ieder geval de volgende ketens onderscheiden: roodvleesketen, zuivelketen, witvleesketen,wildketen en eierketen.NVWA/ BuRO heeft Wageningen UR Livestock Research gevraagd om aan de hand van een deskstudieen expert opinie een risicoanalyse dierenwelzijn voor de eierketen uit te voeren waarbij de impact vanhet welzijnsprobleem op het dier in beeld wordt gebracht (op een schaal van 1-7) en de prevalentievan het welzijnsprobleem wordt geschat. Daarnaast is Wageningen UR Livestock Research gevraagdom ook aan te geven welke risicofactoren (‘hazards’) een bijdrage kunnen leveren aan het ontstaanvan het welzijnsprobleem.Als eerste stap in deze studie zijn de mogelijke dierenwelzijnsproblemen geïdentificeerd en zo concreetmogelijk omschreven. Het inventariseren is uitgevoerd door dierenwelzijnsonderzoekers vanWageningen UR Livestock Research. Zij hebben hun input in het project gebaseerd op opgebouwdekennis en expertise op hun specifieke vakgebied (diersoort en/of fase in het leven van de betreffendediersoort). Daarnaast hebben zij gebruik gemaakt van beschikbare (inter-)nationale rapporten enwetenschappelijke literatuur. De daaruit ontstane lijst met mogelijke welzijnsproblemen is hetresultaat van een inventarisatie van alléén de experts van de Wageningen UR Livestock Research.De lijst met geïdentificeerde welzijnsproblemen is ingedeeld aan de hand van de vier principes vanWelfare Quality® te weten: goede voeding, goede huisvesting, goede gezondheid en normaal gedrag.Daarna is in stap twee de impact van het welzijnsprobleem voor het dier uitgedrukt in een cijfertussen de 1 en 7. Het bepalen van de impact bestaat uit het inschatten van de ‘ernst’ van hetwelzijnsprobleem (=hoeveel last heeft het dier van het welzijnsprobleem) en het inschatten van de‘duur’ van het welzijnsprobleem. Voor het inschatten van de ‘duur’ is uitgegaan van de ‘duur’ van hetongerief per fase. Daarvoor zijn, voor de leghen de volgende fasen onderscheiden: broederij,opfokperiode, legperiode, transport en slachterij. Daarnaast is in de opfokperiode onderscheidgemaakt tussen de volgende huisvestingssystemen: biologisch, uitloop/scharrel, kooihuisvesting. Voorde legperiode is onderscheid gemaakt tussen: biologisch/uitloop, scharrel, kooihuisvesting.De volgende matrix, zoals deze is opgesteld in het rapport risicoanalyse dierenwelzijn zuivelketen, isook gebruikt om de impact op basis van ‘ernst’ en ‘duur’ voor de eierketen in te schatten: Het vóórkomen van welzijnsproblemen (prevalentie) en de impact van een welzijnsprobleem op hetdier (het lijden) zijn in deze deskstudie afzonderlijk van elkaar beschouwd. Voor wat betreft de impactop het dier is uit de expert opinie naar voren gekomen dat welzijnsproblemen met een sterke negatieve impact zich vooral voordoen bij gezondheid. Een deel van deze gezondheidsproblemen komtechter zeer weinig voor. Van de gezondheidsproblemen met een hoge negatieve impact op welzijnhebben de borstbeenbreuken en de parasitaire aandoeningen ook nog een hoge prevalentie. Dit zijnde belangrijkste knelpunten voor de eierketen. Daarnaast worden afwijkingen van het normalegedragspatroon door de experts ook beschouwd als welzijnsproblemen met een hoge negatieve impactop het dierenwelzijn. De belangrijkste achterliggende oorzaak voor veel van deze problemen is terugte vinden in de manier van huisvesting en management van de hennen. Huisvestingssystemen kunnenverschillen in mogelijkheden om bepaalde management maatregelen toe te passen. De impact van dewelzijnsproblemen wordt voor de verschillende huisvestingssystemen niet/nauwelijks verschillendingeschat. Wel is ingeschat dat bepaalde welzijnsproblemen veel meer voorkomen (hogere prevalentiehebben) bij het ene ten opzichte van het andere houderij systeem (zoals beperkt gedragsrepertoire enectoparasitaire aandoeningen), problemen die specifiek zijn voor een bepaalde fase (zoals na-effectenvan snavelbehandeling, borstbeenbreuken, bumble foot, opbranden en uitzichtloos lijden van hennen).Rondom transport en op de slachterij worden vleugelbreuken en –dislocaties gezien als ernstigongerief voor de dieren.Voor de belangrijkste welzijnsproblemen in de eierketen konden prevalenties worden bepaald.Problemen waarvoor nog nader onderzoek gedaan zou moeten worden om prevalenties te bepalen zijnverminderde voedingstoestand in de broederij (in feite spelen hier de omstandigheden tijdens hetbroedproces een belangrijke rol en is dit niet zozeer een probleem van de eierketen, maar meer in zijnalgemeenheid een aandachtspunt voor alle broederijen), het doden van dieren op het primaire bedrijf,ongerief als gevolg van beperkt gedragsrepertoire, problemen met de thermoregulatie tijdenstransport, vleugelbreuken en dislocaties op transport en in de slachterij en ongerief als gevolg vanhandelingen op de slachterij (zoals aanhaken en bij bewustzijn aansnijden).
    High water intake is associated with soya compared with non-soya protein sources and may be associated with foot pad dermatitis in growing turkeys
    Hocking, P.M. ; Veldkamp, T. ; Vinco, L.J. ; Woodward, P. - \ 2015
    British Poultry Abstracts 11 (2015)1. - ISSN 1746-6202 - p. 33 - 34.
    Replacing soya bean meal with alternative protein sources will reduce water consumption and may lead to dryer litter and decrease the incidence of foot pad dermatitis in growing turkeys
    Genetic parameters for large-scale behavior traits and type traits in Charolais beef cows
    Vallée, A. ; Breider, I. ; Arendonk, J.A.M. van; Bovenhuis, H. - \ 2015
    Journal of Animal Science 93 (2015)9. - ISSN 0021-8812 - p. 4277 - 4284.
    Beef cattle - Behavior traits - Charolais - Heritability - Type traits

    In the last decades, beef cattle breeding mainly focused on improving production and reproduction traits. Nowadays, there is a growing interest to include behavior and type traits in the breeding goal. There is an interest in behavior as it is associated with human safety and workability and in type traits as they might be associated with longevity of cows. The objective of the current study was to estimate the heritability for behavior and type traits in Charolais and to estimate the genetic correlations among these traits. Behavior traits, including aggressiveness at parturition, aggressiveness during gestation period, and maternal care, were scored by farmers using an on-farm recording system to enable large-scale collection of phenotypes. Type traits, including udder traits (n = 3), teat traits (3), feet and leg traits (5), and locomotion (1), were scored by 10 trained classifiers. Data was available on 6,649 cows in parity 1 to 12 and located in 380 herds. Results showed that differences between herds explained up to 23% of the total phenotypic variance in behavior traits. This might be due to differences in management or to consistent differences in scoring between farmers. Aggressiveness at parturition had higher heritability (0.19) and higher genetic coefficient of variation (CVa = 11%) than aggressiveness during gestation (h2 = 0.06 and CVa = 4%) and maternal care (h2 = 0.02 and CVa = 2%). Heritabilities for udder traits (0.14 to 0.20) and teat traits (0.17 to 0.35) were higher than for feet and leg traits (0.02 to 0.19). Genetic coefficients of variation for udder and teat traits were also higher (up to 21%) than for feet and leg traits (up to 11%). Strong genetic correlations were found between behavior traits (with absolute values from 0.71 to 0.98). The genetic correlations indicate that it is difficulty to simultaneously improve maternal care and reduce aggressiveness. We concluded that there are good opportunities to implement selection for improved udder and teat traits and against aggressiveness at parturition using a simple on-farm recording system of behavior.

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