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.
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