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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Effect of nutritional interventions with quercetin, oat hulls, β-glucans, lysozyme and fish oil on performance and health status related parameters of broilers chickens
Torki, M. ; Schokker, D. ; Duijster-Lensing, M. ; Krimpen, M.M. van - \ 2018
British Poultry Science (2018). - ISSN 0007-1668
Broiler - gene expression - gut microbiota - nutritional interventions - performance - rapeseed meal

1. An experiment was conducted to evaluate the effects of technical feed ingredients between 14 and 28 d of age on performance and health status of broilers (d 14–35) fed diets with a high inclusion rate of rapeseed meal as a nutritional challenge. It was hypothesized that the feed ingredients would improve health status related parameters. 2. A total of 1008 one-day-old male Ross 308 chicks were distributed over 36 floor pens and allocated to one of six iso-caloric (AMEN 13 MJ/kg) growing diets (d 15–28): a control and five test diets supplemented with quercetin (400 mg/kg), oat hulls (50 g/kg), β-glucan (100 mg/kg), lysozyme (40 mg/kg) or fish oil ω-3 fatty acids (40 g/kg), with six replicate pens per treatment. 3. Dietary inclusion of oat hulls and lysozyme resulted in a reduction in broiler performance during the first week after providing the experimental diets. 4. No effect of interventions on the microbiota diversity in the jejunum and ileum was observed. Ileal microbiota composition of birds fed oat hulls differed from the other groups, as shown by a higher abundance of the genus Enterococcus, mainly at the expense of the genus Lactobacillus. 5. In the jejunum, villus height and crypt depth of lysozyme-fed birds at d 28 were decreased compared to the control group. Higher total surface area of villi occupied by goblet cells and total villi surface area in jejunum (d 21 and 28) were observed in chickens fed oat hulls compared to other groups. 6. Genes related to the growth-factor-activity pathway were more highly expressed in birds fed β-glucan compared to the control group, while the genes related to anion-transmembrane-transporter-activity pathway in the quercetin- and oat hull-fed birds were less expressed. The genes differently expressed between dietary interventions did not seem to be directly involved in immune related processes. 7. It was concluded that the tested nutritional interventions in the current experiment only marginally effected health status related parameters.

The importance of surface reflectance anisotropy for cloud and NO2 retrievals from GOME-2 and OMI
Lorente, Alba ; Boersma, K.F. ; Stammes, Piet ; Tilstra, L.G. ; Richter, Andreas ; Yu, Huan ; Kharbouche, Said ; Muller, Jan Peter - \ 2018
Atmospheric Measurement Techniques 11 (2018)7. - ISSN 1867-1381 - p. 4509 - 4529.

The angular distribution of the light reflected by the Earth's surface influences top-of-atmosphere (TOA) reflectance values. This surface reflectance anisotropy has implications for UV/Vis satellite retrievals of albedo, clouds, and trace gases such as nitrogen dioxide (NO2). These retrievals routinely assume the surface to reflect light isotropically. Here we show that cloud fractions retrieved from GOME-2A and OMI with the FRESCO and OMCLDO2 algorithms have an east-west bias of 10% to 50 %, which are highest over vegetation and forested areas, and that this bias originates from the assumption of isotropic surface reflection. To interpret the across-track bias with the DAK radiative transfer model, we implement the bidirectional reflectance distribution function (BRDF) from the Ross-Li semi-empirical model. Testing our implementation against state-of-the-art RTMs LIDORT and SCIATRAN, we find that simulated TOA reflectance generally agrees to within 1 %. We replace the assumption of isotropic surface reflection in the equations used to retrieve cloud fractions over forested scenes with scattering kernels and corresponding BRDF parameters from a daily high-resolution database derived from 16 years' worth of MODIS measurements. By doing this, the east-west bias in the simulated cloud fractions largely vanishes. We conclude that across-track biases in cloud fractions can be explained by cloud algorithms that do not adequately account for the effects of surface reflectance anisotropy. The implications for NO2 air mass factor (AMF) calculations are substantial. Under moderately polluted NO2 and backwardscattering conditions, clear-sky AMFs are up to 20% higher and cloud radiance fractions up to 40% lower if surface anisotropic reflection is accounted for. The combined effect of these changes is that NO2 total AMFs increase by up to 30% for backward-scattering geometries (and decrease by up to 35% for forward-scattering geometries), which is stronger than the effect of either contribution alone. In an unpolluted troposphere, surface BRDF effects on cloud fraction counteract (and largely cancel) the effect on the clearsky AMF. Our results emphasise that surface reflectance anisotropy needs to be taken into account in a coherent manner for more realistic and accurate retrievals of clouds and NO2 from UV/Vis satellite sensors. These improvements will be beneficial for current sensors, in particular for the recently launched TROPOMI instrument with a high spatial resolution.

Intergovernmental relations for public health adaptation to climate change in the federalist states of Canada and Germany
Austin, Stephanie E. ; Ford, James D. ; Berrang-Ford, Lea ; Biesbroek, Robbert ; Tosun, Jale ; Ross, Nancy A. - \ 2018
Global environmental change : human and policy dimensions 52 (2018). - ISSN 0959-3780 - p. 226 - 237.
Canada - Climate change adaptation - Federalism - Germany - Intergovernmental relations - Public health

Climate change is a significant threat to public health, and governments at all scales will need to adapt to protect the health of their populations. The impacts of climate change are highly localized and thus federal systems theoretically have the inherent advantage of allowing for regional diversity and policy experimentation in adaptation. However, there are also higher levels of conflict and stalemates in federal systems than in unitary systems, complicating intergovernmental relations and coordination necessary for public health adaptation. We examine how intergovernmental dynamics are patterned across national, regional and local levels of government for public health adaptation to climate change, drawing upon semi-structured interviews (n = 28) in comparative embedded case studies of Canada and Germany. We find that coordination between levels of government specifically for climate change and health is rare, but climate change issues are occasionally discussed through working groups or through existing methods of public health coordination. These findings have implications for national and regional governments in federal systems seeking to enable sub-national public health adaptation to climate change and create synergies between levels of government.

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.
Genetic covariance components within and among linear type traits differ among contrasting beef cattle breeds
Doyle, Jennifer L. ; Berry, Donagh P. ; Walsh, Siobhan W. ; Veerkamp, Roel F. ; Evans, Ross D. ; Carthy, Tara R. - \ 2018
Journal of Animal Science 96 (2018)5. - ISSN 0021-8812 - p. 1628 - 1639.
Beef - Breeds - Cattle - Type traits

Linear type traits describing the skeletal, muscular, and functional characteristics of an animal are routinely scored on live animals in both the dairy and beef cattle industries. Previous studies have demonstrated that genetic parameters for certain performance traits may differ between breeds; no study, however, has attempted to determine if differences exist in genetic parameters of linear type traits among breeds or sexes. Therefore, the objective of the present study was to determine if genetic covariance components for linear type traits differed among five contrasting cattle breeds, and to also investigate if these components differed by sex. A total of 18 linear type traits scored on 3,356 Angus (AA), 31,049 Charolais (CH), 3,004 Hereford (HE), 35,159 Limousin (LM), and 8,632 Simmental (SI) were used in the analysis. Data were analyzed using animal linear mixed models which included the fixed effects of sex of the animal (except in the investigation into the presence of sexual dimorphism), age at scoring, parity of the dam, and contemporary group of herd-date of scoring. Differences (P < 0.05) in heritability estimates, between at least two breeds, existed for 13 out of 18 linear type traits. Differences (P < 0.05) also existed between the pairwise within-breed genetic correlations among the linear type traits. Overall, the linear type traits in the continental breeds (i.e., CH, LM, SI) tended to have similar heritability estimates to each other as well as similar genetic correlations among the same pairwise traits, as did the traits in the British breeds (i.e., AA, HE). The correlation between a linear function of breeding values computed conditional on covariance parameters estimated from the CH breed with a linear function of breeding values computed conditional on covariance parameters estimated from the other breeds was estimated. Replacing the genetic covariance components estimated in the CH breed with those of the LM had least effect but the impact was considerable when the genetic covariance components of the AA were used. Genetic correlations between the same linear type traits in the two sexes were all close to unity (≥0.90) suggesting little advantage in considering these as separate traits for males and females. Results for the present study indicate the potential increase in accuracy of estimated breeding value prediction from considering, at least, the British breed traits separate to continental breed traits.

Effects of dietary protein level and age at photo stimulation on reproduction traits of broiler breeders and progeny performance
Emous, R.A. van; Cruz, C.E. de la; Naranjo, V.D. - \ 2018
Poultry Science 97 (2018)6. - ISSN 0032-5791 - p. 1968 - 1979.
age at photo stimulation - broiler breeder - dietary crude protein - progeny - reproduction

A study with a 2 × 2 factorial arrangement was conducted to determine the effects of 2 dietary crude protein levels, high (CPh) or low (CPl), supplemented with free amino acids (AA), and 2 ages at photo stimulation (PS) - early (21 wk; PSe) or late (23 wk; PSl) - on reproduction traits of broiler breeders and progeny performance. Diets were isocaloric, and calculated CP content of the CPl diets was 15 g/kg lower than the CPh diets during all phases. A total of 480 female and 64 male Ross 308 breeders of 20 wk of age were used. Total egg production was similar between CPl and CPh birds during phase 1 and 2 but was reduced by 2.8 eggs for CPl birds during phase 3. For the overall laying period, CPl birds tended (P = 0.075) to produce 4.7 fewer total eggs. Hatchability of set eggs was similar between CPl and CPh birds during phases 1 and 2 but tended (P = 0.064) to be lower for CPl birds in phase 3. PSe birds showed an advanced age at sexual maturity and age at peak production of 4.6 and 5.3 d, respectively, resulting in 2.5 more total eggs during phase 1. During phase 1, PSe birds showed an almost 5% increased fertility. Chick production in phase 1 was higher for PSe birds resulting in a tendency (P = 0.071) to higher overall chick production of almost 8 chicks. Progeny from early PS breeders showed an overall significant lower feed conversion ratio (FCR). It was concluded that egg and chick production during phases 1 and 2 were not affected by dietary CP level, but egg and chick production was reduced for CPl birds during phase 3. On the other hand, PSe birds showed an increased number of chicks. It is possible to decrease CP level of breeder diets with comparable reproduction from 22 to 46 wk; however, this is questionable for phase 3. For maximal chick production, early PS is recommended.

Consumer-friendly food allergen detection : moving towards smartphone-based immunoassays
Ross, Georgina M.S. ; Bremer, Monique G.E.G. ; Nielen, Michel W.F. - \ 2018
Analytical and Bioanalytical Chemistry 410 (2018)22. - ISSN 1618-2642 - p. 5353 - 5371.
Citizen science - Consumer - Food allergen - Immunoassay - Multiplex - Smartphone
In this critical review, we provide a comprehensive overview of immunochemical food allergen assays and detectors in the context of their user-friendliness, through their connection to smartphones. Smartphone-based analysis is centered around citizen science, putting analysis into the hands of the consumer. Food allergies represent a significant worldwide health concern and consumers should be able to analyze their foods, whenever and wherever they are, for allergen presence. Owing to the need for a scientific background, traditional laboratory-based detection methods are generally unsuitable for the consumer. Therefore, it is important to develop simple, safe, and rapid assays that can be linked with smartphones as detectors to improve user accessibility. Smartphones make excellent detection systems because of their cameras, embedded flash functions, portability, connectivity, and affordability. Therefore, this review has summarized traditional laboratory-based methods for food allergen detection such as enzyme-linked-immunosorbent assay, flow cytometry, and surface plasmon resonance, and the potential to modernize these methods by interfacing them with a smartphone readout system, based on the aforementioned smartphone characteristics. This is the first review focusing on smartphone-based food-allergen detection methods designed with the intention of being consumer-friendly. [Figure not available: see fulltext.]
High spatial variation in population size and symbiotic performance of Rhizobium leguminosarum bv. trifolii with white clover in New Zealand pasture soils
Wakelin, Steven ; Tillard, Guyléne ; Ham, Robert van; Ballard, Ross ; Farquharson, Elizabeth ; Gerard, Emily ; Geurts, Rene ; Brown, Matthew ; Ridgway, Hayley ; O’Callaghan, Maureen - \ 2018
PLoS One 13 (2018)2. - ISSN 1932-6203
Biological nitrogen fixation through the legume-rhizobia symbiosis is important for sustainable pastoral production. In New Zealand, the most widespread and valuable symbiosis occurs between white clover (Trifolium repens L.) and Rhizobium leguminosarum bv. trifolii (Rlt). As variation in the population size (determined by most probable number assays; MPN) and effectiveness of N-fixation (symbiotic potential; SP) of Rlt in soils may affect white clover performance, the extent in variation in these properties was examined at three different spatial scales: (1) From 26 sites across New Zealand, (2) at farm-wide scale, and (3) within single fields. Overall, Rlt populations ranged from 95 to >1 x 108 per g soil, with variation similar at the three spatial scales assessed. For almost all samples, there was no relationship between rhizobia population size and ability of the population to fix N during legume symbiosis (SP). When compared with the commercial inoculant strain, the SP of soils ranged between 14 to 143% efficacy. The N-fixing ability of rhizobia populations varied more between samples collected from within a single hill country field (0.8 ha) than between 26 samples collected from diverse locations across New Zealand. Correlations between SP and calcium and aluminium content were found in all sites, except within a dairy farm field. Given the general lack of association between SP and MPN, and high spatial variability of SP at single field scale, provision of advice for treating legume seed with rhizobia based on field-average MPN counts needs to be carefully considered.
Butyrate presence in distinct gastrointestinal tract segments modifies differentially digestive processes and amino acid bioavailability in young broiler chickens
Moquet, P.C.A. ; Salami, S.A. ; Onrust, L. ; Hendriks, W.H. ; Kwakkel, R.P. - \ 2018
Poultry Science 97 (2018)1. - ISSN 0032-5791 - p. 167 - 176.
Butyrate - broiler - digestibility - digesta retention time - location effect
The hypothesis was tested that butyrate presence in the digesta of distinct gastrointestinal tract (GIT) segments of broilers leads to differential effects on digesta retention time, gut morphology, and proteolytic enzymatic activities, ultimately resulting in differences in protein digestibility. A total of 320 male day-old Ross 308 broilers were randomly assigned to 5 dietary treatments: 1) control (no butyrate), 2) unprotected butyrate (main activity in the crop and gastric regions), 3) tributyrin (main activity in the small intestine), 4) fat-coated butyrate (activity in the whole GIT) and 5) unprotected butyrate combined with tributyrin, each replicated 8 times. Rapeseed meal was used in combination with a fine dietary particle size in order to challenge the digestive capacity of young broilers. Birds were dissected at 22, 23, and 24 d of age and samples of digesta at various GIT locations as well as tissues were collected. Butyrate concentration varied significantly across GIT segments depending on treatment, indicating that the dietary contrasts were successful. The apparent ileal digestibility of methionine tended to increase when butyrate and/or propionate was present in colonic and cecal contents, possibly due to modifications of GIT development and digesta transit time. Butyrate presence in the digesta of the crop, proventriculus and gizzard, on the contrary, decreased the apparent ileal digestibility of several amino acids (AA). In addition, butyrate presence beyond the gizzard elicited anorexic effect that might be attributable to changes in intestinal enteroendocrine L-cells secretory activities. The present study demonstrates that, in broilers, effects of butyrate on digestive processes are conditioned by the GIT segment wherein the molecule is present and indicates its influence on digestive function and bioavailability of AA.
Effect of whole wheat inclusion and pellet diameter on pellet quality and performance in broilers
Raaijmakers, M.M.P. ; Loon, Jorik van; Elling-Staats, M.L. ; Poel, A.F.B. van der; Kwakkel, R.P. - \ 2017
- 4 p.
Whole wheat (WW) is mainly fed to broilers along with a pelleted feed, which allows birds to select particles leading to inconsistent results. WW inclusion in a pellet may require larger pellets to maintain coarse structure and pellet quality. The effect of WW vs ground wheat (GW) inclusion and pellet diameter (4 vs 6 mm) on pellet quality and performance was investigated, using a 2x2 factorial design with 6 replicates per treatment (9 Ross 308 males per pen). An additional group was fed a reference diet (RD) containing GW in a 3 mm pellet diameter. From day 0-7, all birds received a crumble starter diet (250 g/kg GW). From day 8-14, one group received the RD and the other 4 groups a 4 mm pelleted diet, which included either GW or WW. From day 15-34, half of these 4 groups received the 6 mm pelleted diets (GW or WW). Formulations of all diets from day 8-34 were similar (350 g/kg wheat). Pellet durability, tested using a Ligno tester, was the highest in the RD (75.5%), tested with sieve size 2.1 mm. When tested with sieve size 3.6 mm, GW 6 mm had the highest durability (59.7%) and the lowest durabilities were found using both sieves in WW 6 mm diets (60.8% and 36.6% for 2.1 and 3.6 mm, respectively). Feed intake (FI) and feed conversion ratio (FCR) was higher for GW vs WW diets from day 8-14 (53.6 vs 51.1 g/d, P=0.032 and 1.314 vs 1.269, P=0.038, respectively). For RD the lowest FCR (1.240, P=0.031) and highest bodyweight gain (BWG) (44.0g, P=0.010) was found. From day 15-34, FI and BWG was also higher for GW vs WW diets (154.9 vs 148.6 g, P<0.001 and 107.8 vs 103.9 g, P<0.001, respectively). Furthermore, FCR was better for the 4 mm pellet compared to the 6 mm pellet (1.408 vs 1.425, P=0.014); RD showed the lowest FI (145.5 g/d, P<0.001) and BWG (102.7 g, P=0.011), FCR remained unaffected. Overall, these results showed that 4 and 6 mm pellets vs 3 mm improve FI and BWG and that WW in pellets (vs GW) reduces FI and BWG, but improves FCR.
Natural variation in Arabidopsis thaliana reveals shoot ionome, biomass, and gene expression changes as biomarkers for zinc deficiency tolerance
Campos, A.C.A.L. ; Kruijer, W.T. ; Alexander, Ross ; Akkers, R.C. ; Danku, J. ; Salt, D.E. ; Aarts, M.G.M. - \ 2017
Journal of Experimental Botany 68 (2017)13. - ISSN 0022-0957 - p. 3643 - 3656.
Zinc (Zn) is an essential nutrient for plants, with a crucial role as a cofactor for many enzymes. Approximately one-third of the global arable land area is Zn deficient, leading to reduced crop yield and quality. To improve crop tolerance to Zn deficiency, it is important to understand the mechanisms plants have adopted to tolerate suboptimal Zn supply. In this study, physiological and molecular aspects of traits related to Zn deficiency tolerance were examined in a panel of 19 Arabidopsis thaliana accessions. Accessions showed a larger variation for shoot biomass than for Zn concentration, indicating that they have different requirements for their minimal Zn concentration required for growth. Accessions with a higher tolerance to Zn deficiency showed an increased expression of the Zn deficiency-responsive genes ZIP4 and IRT3 in comparison with Zn deficiency-sensitive accessions. Changes in the shoot ionome, as a result of the Zn treatment of the plants, were used to build a multinomial logistic regression model able to distinguish plants regarding their Zn nutritional status. This set of biomarkers, reflecting the A. thaliana response to Zn deficiency and Zn deficiency tolerance, can be useful for future studies aiming to improve the performance and Zn status of crop plants grown under suboptimal Zn concentrations.
Effect of iso-energetic exchange of dietary fat and starch on growth performance and body composition of broilers : Experiment 2
Veldkamp, T. ; Dekker, R. ; Smit-Heinsbroek, A. ; Lee, A. van der; Jansman, A.J.M. - \ 2017
Wageningen : Wageningen UR Livestock Research (Livestock Research rapport 1062) - 33
Dietary factors such as the concentrations of protein/amino acids, fat, and starch + sugar and their ratio, may affect the post-absorptive metabolism of energy and protein and energy deposition in the body. In a 2x3 factorial block design, the effects of two dietary crude protein (high protein (HP) vs. low protein (LP) concentrations; 200/190 vs. 170/160 g/kg) in grower and finisher phase and three dietary fat/starch concentrations (high fat (HF); fat and starch 120 and 350 g/kg, respectively, medium fat (MF); fat and starch 80 and 425 g/kg and low fat (LF); fat and starch 40 and 500 g/kg, respectively) on growth performance and body composition of Ross 308 broilers were studied (8 to 38 d). From this experiment it can be concluded that dietary energy source and protein level in isoenergetic diets, balanced for first limiting essential amino acids, influence growth performance and body composition of broilers.
Effect of iso-energetic exchange of dietary fat and starch on growth performance and body composition of broilers : Experiment 1
Veldkamp, T. ; Schamp, T. ; Harn, J. van; Dekker, R. ; Sosef, M. ; Jansman, A.J.M. - \ 2017
Wageningen : Wageningen UR Livestock Research (Livestock Research rapport 1061) - 34
Dietary factors such as the concentrations of protein/amino acids, fat, and starch + sugar and their ratio, may affect the post-absorptive metabolism of energy and protein and energy deposition in the body. In a 2x2 factorial design, the effects of two dietary crude protein (high protein (HP) vs. low protein (LP) concentrations; 200/190 vs. 170/160 g/kg in grower and finisher phase) and two dietary fat/starch concentrations; (high fat (HF); fat and starch 105 and 340 g/kg, respectively) and (low fat (LF); fat and starch 65 and 420 g/kg, respectively) on growth performance and body composition of Ross 308 broilers were studied (9 to 35 d). From this experiment it can be concluded that dietary energy source and protein level in iso-energetic diets, balanced for first limiting essential amino acids, influence growth performance and body composition of broilers.
Contribution of Dairy to Nutrient Intake in the Western Diet
Hettinga, Kasper ; Valenberg, Hein van - \ 2017
In: Nutrients in Dairy and Their Implications for Health and Disease / Watson, Ronald Ross, Collier, Robert J., Preedy, Victor R., Academic Press - ISBN 9780128097625 - p. 251 - 258.
Dairy - Dietary patterns - Minerals - Nutrient density - Omega-3 fatty acids - Protein quality - Vitamins

Milk and dairy products play an important role in providing nutrients in both Western and developing countries. Most research in this area focuses on the intake of individual nutrients from food products, like dairy products. However, nutrients are not consumed, and do not function, in isolation. Looking at nutrient intake from the perspective of whole food products, or even whole dietary patterns, may be a more suitable way to quantify the contribution of dairy to the intake of nutrients. A mathematical approach, the nutrient-rich food score, is explained and discussed in this chapter. Such models could in the future even be extended beyond nutrition (e.g., including sustainability or cost parameters) to even better guide healthy eating habits for consumers.

Comparison of Eimeria Infection Dynamics between Broiler Flocks with a Conventional or On-farm Hatching System.
Velkers, Francisca ; Jong, I.C. de; Ven, Lotte van de; Reep, L. Van de; Stegeman, A. - \ 2017
In: Proceedings of the XXthe Veterinary Poultry Congress, Edinburg. - - p. 197 - 197.
Broiler Chickens, Coddidiosis, Eimeria, Enteric Disease, On-farm hatching
An increasing trend in Europe is placing 18 days incubated eggs on trays in broiler houses for on-farm hatching. Chicks are not transported and have immediate access to food and water, which promotes early intestinal tract and immune system development. It was hypothesized that these physiological effects may affect the response to intestinal infections. Moreover, on-farm hatched chicks may be exposed to environmental Eimeria oocysts earlier than hatchery chicks. Therefore we compared Eimeria infection dynamics for in hatchery (R) and on-farm hatched (F) Ross 308 broilers in two field studies on commercial broiler farms and in one study in an experimental facility.
In field study 1, a poultry house was divided in a part with F and R hatching for two rounds. Ten flocks on four farms were included in field study 2 with on each farm F flocks and R flocks originating from the same parent flock. In study 3, four groups of F and R broilers were placed in experimental pens, each with 1150 birds from the same parent flock. From the second week of life onwards, oocyst excretion in faeces (OPG = oocysts per g), collected in weekly (study 2) or biweekly (studies 1 and 3) intervals, was determined with the McMaster counting technique. In both field studies an Eimeria-species specific OPG was determined with qPCR (GD Deventer, the Netherlands) on weekly pools of colonic and caecal faeces collected three times per week. Lesion scores for E. acervulina, E. maxima and E. tenella were determined during post-mortem examinations of five to six randomly selected birds on one to three occasions per production round from the third week of life onwards. Use of coccidiostats, antibiotics and production performance was recorded.
Results of qPCR showed that E. acervulina, E. tenella (studies 1 and 2) and E. maxima (study 2) were detected, without differences in species distribution between F and R flocks. In study 3, where qPCR results were not available, lesion scores indicated presence of E. acervulina and E. maxima, but not E. tenella in both F and R flocks. In all studies lesion scores were generally mild and not significantly different between F and R flocks. Oocyst excretion patterns throughout the production period were similar for F and R flocks in study 1, but in study 2 F flocks on average showed a later excretion peak (R peaked between day 22-28 and F between days 22-28 or 28-34). In study 3 oocyst output dynamics were comparable in F and R pens. In this study oocyst excretion did not reach a clear peak by the end of the round at day 40, due to a late (day 33) start of excretion. OPG determined by qPCR and the McMaster technique in studies 1 and 2 gave similar results. Production performance could not be compared between F and R flocks in the field studies, due to differences in disease occurrence and antibiotic treatments.
Only small differences in the course of Eimeria infections were detected, but the number of flocks was too small to draw accurate conclusions about effects of hatching system on coccidiosis and how this affects production performance. Small differences in infection dynamics, e.g. time of peak excretion, may affect body weight at slaughter or influence opportunities for secondary infections. Therefore, if more commercial on-farm hatching and comparable reference flocks become available, further research is warranted.
Nitrogen performance indicators for dairy production systems
Klein, Cecile A.M. De; Monaghan, Ross M. ; Alfaro, Marta A. ; Gourley, Cameron J.P. ; Oenema, Oene ; Mark Powell, J. - \ 2017
Soil Research 55 (2017)5-6. - ISSN 1838-675X - p. 479 - 488.
animal NUE - crop NUE - dairy systems - nitrogen use efficiency (NUE) - whole-farm NUE
Nitrogen (N) is invaluable for maintaining agricultural production, but its use, and particularly inefficient use, can lead to environmental losses. This paper reviews N use efficiency (NUE) and N surplus indicators for dairy production systems to assess their utility for optimising N use outcomes and minimising environmental N losses. Using case-study examples, we also assess realistic goals for these indicators and discuss key issues associated with their use. Published whole-farm NUE and whole-farm N surplus values ranged within 10-65% and 40-700kg N ha-1 year-1 respectively. In a study of five catchments across New Zealand, whole-farm NUE was more strongly affected by catchment differences in soil and climatic conditions than by differences in management. In contrast, whole-farm N surplus differed both between-and within-catchments and was a good indicator of N losses to water. Realistic goals for both NUE and N surplus thus depend on the agro-climatic context of the dairy system and on its economic and environmental goals. Crop and animal NUE values can be valuable indicators for optimising fertiliser and feed use and minimising N losses. However, global or national whole-farm NUE values appear of limited value if the ultimate goal for setting targets is to reduce the environmental impact of N use; whole-farm level targets based on N surplus would be a more useful indicator for this purpose. Our review also reinforces the importance of standardising the variables that should be used to estimate NUE and N surplus values, to ensure equitable comparisons between different systems. Finally, NUE and N surplus targets should also be set in the context of other agro-environmental considerations.
Effects of rye inclusion in grower diets on immune competence-related parameters and performance in broilers
Krimpen, M.M. van; Torki, M. ; Schokker, D. - \ 2017
Poultry Science 96 (2017)9. - ISSN 0032-5791 - p. 3324 - 3337.
An experiment was conducted to investigate the effects of dietary inclusion of rye, a model ingredient to increase gut viscosity, between 14 and 28 d of age on immune competence-related parameters and performance of broilers. A total of 960 day-old male Ross 308 chicks were weighed and randomly allocated to 24 pens (40 birds per pen), and the birds in every 8 replicate pens were assigned to 1 of 3 experimental diets including graded levels, 0%, 5%, and 10% of rye. Tested immune competence-related parameters were composition of the intestinal microbiota, genes expression in gut tissue, and gut morphology. The inclusion of 5% or 10% rye in the diet (d 14 to 28) resulted in decreased performance and litter quality, but in increased villus height and crypt depth in the small intestine (jejunum) of the broilers. Relative bursa and spleen weights were not affected by dietary inclusion of rye. In the jejunum, no effects on number and size of goblet cells, and only trends on microbiota composition in the digesta were observed. Dietary inclusion of rye affected expression of genes involved in cell cycle processes of the jejunal enterocyte cells, thereby influencing cell growth, cell differentiation and cell survival, which in turn were consistent with the observed differences in the morphology of the gut wall. In addition, providing rye-rich diets to broilers affected the complement and coagulation pathways, which among others are parts of the innate immune system. These pathways are involved in eradicating invasive pathogens. Overall, it can be concluded that inclusion of 5% or 10% rye to the grower diet of broilers had limited effects on performance. Ileal gut morphology, microbiota composition of jejunal digesta, and gene expression profiles of jejunal tissue, however, were affected by dietary rye inclusion level, indicating that rye supplementation to broiler diets might affect immune competence of the birds.
Large-scale GWAS identifies multiple loci for hand grip strength providing biological insights into muscular fitness
Willems, Sara M. ; Wright, D.J. ; Day, Felix R. ; Trajanoska, Katerina ; Joshi, P.K. ; Morris, John A. ; Matteini, Amy M. ; Garton, Fleur C. ; Grarup, Niels ; Oskolkov, Nikolay ; Thalamuthu, Anbupalam ; Mangino, Massimo ; Liu, Jun ; Demirkan, Ayse ; Lek, Monkol ; Xu, Liwen ; Wang, Guan ; Oldmeadow, Christopher ; Gaulton, Kyle J. ; Lotta, Luca A. ; Miyamoto-Mikami, Eri ; Rivas, Manuel A. ; White, Tom ; Loh, Po Ru ; Aadahl, Mette ; Amin, Najaf ; Attia, John R. ; Austin, Krista ; Benyamin, Beben ; Brage, Søren ; Cheng, Yu Ching ; Ciȩszczyk, Paweł ; Derave, Wim ; Eriksson, Karl Fredrik ; Eynon, Nir ; Linneberg, Allan ; Lucia, Alejandro ; Massidda, Myosotis ; Mitchell, Braxton D. ; Miyachi, Motohiko ; Murakami, Haruka ; Padmanabhan, Sandosh ; Pandey, Ashutosh ; Papadimitriou, Ioannis ; Rajpal, Deepak K. ; Sale, Craig ; Schnurr, Theresia M. ; Sessa, Francesco ; Shrine, Nick ; Tobin, Martin D. ; Varley, Ian ; Wain, Louise V. ; Wray, Naomi R. ; Lindgren, Cecilia M. ; MacArthur, Daniel G. ; Waterworth, Dawn M. ; McCarthy, Mark I. ; Pedersen, Oluf ; Khaw, Kay Tee ; Kiel, Douglas P. ; Pitsiladis, Yannis ; Fuku, Noriyuki ; Franks, Paul W. ; North, Kathryn N. ; Duijn, C.M. Van; Mather, Karen A. ; Hansen, Torben ; Hansson, Ola ; Spector, Tim D. ; Murabito, Joanne M. ; Richards, J.B. ; Rivadeneira, Fernando ; Langenberg, Claudia ; Perry, John R.B. ; Wareham, Nick J. ; Scott, Robert A. ; Oei, Ling ; Zheng, Hou Feng ; Forgetta, Vincenzo ; Leong, Aaron ; Ahmad, Omar S. ; Laurin, Charles ; Mokry, Lauren E. ; Ross, Stephanie ; Elks, Cathy E. ; Bowden, Jack ; Warrington, Nicole M. ; Murray, Anna ; Ruth, Katherine S. ; Tsilidis, Konstantinos K. ; Medina-Gómez, Carolina ; Estrada, Karol ; Bis, Joshua C. ; Chasman, Daniel I. ; Demissie, Serkalem ; Enneman, Anke W. ; Hsu, Yi Hsiang ; Ingvarsson, Thorvaldur ; Kähönen, Mika ; Kammerer, Candace ; Lacroix, Andrea Z. ; Li, Guo ; Liu, Ching Ti ; Liu, Yongmei ; Lorentzon, Mattias ; Mägi, Reedik ; Mihailov, Evelin ; Milani, Lili ; Moayyeri, Alireza ; Nielson, Carrie M. ; Sham, Pack Chung ; Siggeirsdotir, Kristin ; Sigurdsson, Gunnar ; Stefansson, Kari ; Trompet, Stella ; Thorleifsson, Gudmar ; Vandenput, Liesbeth ; Velde, Nathalie Van Der; Viikari, Jorma ; Xiao, Su Mei ; Zhao, Jing Hua ; Evans, Daniel S. ; Cummings, Steven R. ; Cauley, Jane ; Duncan, Emma L. ; Groot, Lisette C.P.G.M. De; Esko, Tonu ; Gudnason, Vilmundar ; Harris, Tamara B. ; Jackson, Rebecca D. ; Jukema, J.W. ; Ikram, Arfan M.A. ; Karasik, David ; Kaptoge, Stephen ; Kung, Annie Wai Chee ; Lehtimäki, Terho ; Lyytikäinen, Leo Pekka ; Lips, Paul ; Luben, Robert ; Metspalu, Andres ; Meurs, Joyce B. van; Minster, Ryan L. ; Orwoll, Erick ; Oei, Edwin ; Psaty, Bruce M. ; Raitakari, Olli T. ; Ralston, Stuart W. ; Ridker, Paul M. ; Robbins, John A. ; Smith, Albert V. ; Styrkarsdottir, Unnur ; Tranah, Gregory J. ; Thorstensdottir, Unnur ; Uitterlinden, Andre G. ; Zmuda, Joseph ; Zillikens, M.C. ; Ntzani, Evangelia E. ; Evangelou, Evangelos ; Ioannidis, John P.A. ; Evans, David M. ; Ohlsson, Claes - \ 2017
Nature Communications 8 (2017). - ISSN 2041-1723
Hand grip strength is a widely used proxy of muscular fitness, a marker of frailty, and predictor of a range of morbidities and all-cause mortality. To investigate the genetic determinants of variation in grip strength, we perform a large-scale genetic discovery analysis in a combined sample of 195,180 individuals and identify 16 loci associated with grip strength (P<5 × 10-8) in combined analyses. A number of these loci contain genes implicated in structure and function of skeletal muscle fibres (ACTG1), neuronal maintenance and signal transduction (PEX14, TGFA, SYT1), or monogenic syndromes with involvement of psychomotor impairment (PEX14, LRPPRC and KANSL1). Mendelian randomization analyses are consistent with a causal effect of higher genetically predicted grip strength on lower fracture risk. In conclusion, our findings provide new biological insight into the mechanistic underpinnings of grip strength and the causal role of muscular strength in age-related morbidities and mortality.
Scaling, similarity, and the fourth paradigm for hydrology
Peters-Lidard, Christa D. ; Clark, Martyn ; Samaniego, Luis ; Verhoest, Niko E.C. ; Emmerik, Tim Van; Uijlenhoet, Remko ; Achieng, Kevin ; Franz, Trenton E. ; Woods, Ross A. - \ 2017
Hydrology and Earth System Sciences 21 (2017)7. - ISSN 1027-5606 - p. 3701 - 3713.
In this synthesis paper addressing hydrologic scaling and similarity, we posit that roadblocks in the search for universal laws of hydrology are hindered by our focus on computational simulation (the third paradigm) and assert that it is time for hydrology to embrace a fourth paradigm of data-intensive science. Advances in information-based hydrologic science, coupled with an explosion of hydrologic data and advances in parameter estimation and modeling, have laid the foundation for a data-driven framework for scrutinizing hydrological scaling and similarity hypotheses. We summarize important scaling and similarity concepts (hypotheses) that require testing; describe a mutual information framework for testing these hypotheses; describe boundary condition, state, flux, and parameter data requirements across scales to support testing these hypotheses; and discuss some challenges to overcome while pursuing the fourth hydrological paradigm. We call upon the hydrologic sciences community to develop a focused effort towards adopting the fourth paradigm and apply this to outstanding challenges in scaling and similarity.
The evolution of process-based hydrologic models : Historical challenges and the collective quest for physical realism
Clark, Martyn P. ; Bierkens, Marc F.P. ; Samaniego, Luis ; Woods, Ross A. ; Uijlenhoet, Remko ; Bennett, Katrina E. ; Pauwels, Valentijn R.N. ; Cai, Xitian ; Wood, Andrew W. ; Peters-Lidard, Christa D. - \ 2017
Hydrology and Earth System Sciences 21 (2017)7. - ISSN 1027-5606 - p. 3427 - 3440.
The diversity in hydrologic models has historically led to great controversy on the "correct" approach to process-based hydrologic modeling, with debates centered on the adequacy of process parameterizations, data limitations and uncertainty, and computational constraints on model analysis. In this paper, we revisit key modeling challenges on requirements to (1) define suitable model equations, (2) define adequate model parameters, and (3) cope with limitations in computing power. We outline the historical modeling challenges, provide examples of modeling advances that address these challenges, and define outstanding research needs. We illustrate how modeling advances have been made by groups using models of different type and complexity, and we argue for the need to more effectively use our diversity of modeling approaches in order to advance our collective quest for physically realistic hydrologic models.
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