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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    Bepaling samenstelling van vaste mest met NIRS
    Rietra, R.P.J.J. ; Oenema, O. - \ 2017
    Wageningen : Wageningen Environmental Research (Wageningen Environmental Research rapport 2837) - 27
    dierlijke meststoffen - stikstof - fosfor - nabij infrarood spectroscopie - referentienormen - analyse - betrouwbaarheid - analytische methoden - animal manures - nitrogen - phosphorus - near infrared spectroscopy - reference standards - analysis - reliability - analytical methods
    Sustainable development of agriculture: contribution of farm-level assessment tools
    Olde, Evelien de - \ 2017
    Wageningen University. Promotor(en): I.J.M. de Boer, co-promotor(en): E.A.M. Bokkers; F.W. Oudshoorn. - Wageningen : Wageningen University - ISBN 9789463430685 - 152
    sustainable agriculture - sustainability - sustainability indicators - sustainability criteria - assessment - tools - reliability - validity - farming systems - duurzame landbouw - duurzaamheid (sustainability) - duurzaamheidsindicatoren - duurzaamheidscriteria - beoordeling - gereedschappen - betrouwbaarheid - geldigheid - bedrijfssystemen

    Current environmental, economic and social challenges urge agriculture to change to more sustainable modes of production. Insight in the impact of a system or a potential innovation on sustainability could support decision makers in identifying actions towards sustainable development. Over the past decade, therefore, a large number of tools have been developed to assess sustainability performance at farm level. Several concerns, however, have been raised whether assessment results provide reliable and valid conclusions about the sustainability performance of farms, and whether these conclusions can be implemented in practice. To evaluate the contribution of farm-level assessment tools to sustainable development of agriculture, this thesis analyzed current approaches to assessing sustainability. One of these approaches is the sustainability assessment tool RISE 2.0, which was used to assess the sustainability performance of 37 organic farms in Denmark. Analysis of the assessment results showed the impact of decisions, made during the development of a tool (e.g. selection of themes, indicators, reference values, scoring and aggregation method), on the assessment results. This emphasizes the importance of transparency in sustainability assessment tools to understand assessment results and identify actions to improve. Subsequently, a comparison of sustainability assessment tools in practice was made to gain insight into practical requirements, procedures and relevance perceived by farmers. Of 48 indicator-based sustainability assessment tools, only four tools (RISE, SAFA, PG and IDEA) complied to the selection criteria and were applied to assess the sustainability performance of five Danish farms. Characteristics including data requirements, assessment time, complexity, transparency and output accuracy varied between tools. Critical factors in farmers’ perception of tool relevance were context specificity, user-friendliness, complexity of the tool, language use, and a match between value judgements of tool developers and farmers. Farmers, moreover, indicated that implementing conclusions derived from sustainability assessments is challenging given the complex organization of agricultural systems. A more in-depth analysis of the four tools revealed a high diversity in selected indicators, themes, reference values, and scoring and aggregation methods. This results in different conclusions on the sustainability performance of farms, which does not only cause confusion but also affects the trust in, and reliability and implementation of, sustainability assessments. Variability in tools is caused by different perspectives on how to assess sustainability and is related to differences in context, priorities and value judgements of tool developers. These differences also play a role in the prioritization of criteria for indicator selection. To explore whether sustainability experts agreed on which criteria are most important in the selection of indicators and indicators sets for sustainability assessments, two ranking surveys were carried out. Both surveys showed a lack of consensus amongst experts about how best to measure agricultural sustainability. This thesis revealed variability in approaches to assess sustainability at farm level. This makes current assessment tools less suitable for functions that require a high reliability and validity, such as certification. Instead, current assessment tools present a useful starting point for discussion, reflection and learning on sustainable development of farming. To enhance the contribution of tools towards sustainable development of agriculture, more attention should be paid to increasing reliability and validity of tools, and improving transparency, harmonization, participation and implementation of assessments.

    Updating the reference population to achieve constant genomic prediction reliability across generations
    Pszczola, M. ; Calus, M.P.L. - \ 2016
    Animal 10 (2016)6. - ISSN 1751-7311 - p. 1018 - 1024.
    dairy cattle - reference population - relationships - reliability

    The reliability of genomic breeding values (DGV) decays over generations. To keep the DGV reliability at a constant level, the reference population (RP) has to be continuously updated with animals from new generations. Updating RP may be challenging due to economic reasons, especially for novel traits involving expensive phenotyping. Therefore, the goal of this study was to investigate a minimal RP update size to keep the reliability at a constant level across generations. We used a simulated dataset resembling a dairy cattle population. The trait of interest was not included itself in the selection index, but it was affected by selection pressure by being correlated with an index trait that represented the overall breeding goal. The heritability of the index trait was assumed to be 0.25 and for the novel trait the heritability equalled 0.2. The genetic correlation between the two traits was 0.25. The initial RP (n=2000) was composed of cows only with a single observation per animal. Reliability of DGV using the initial RP was computed by evaluating contemporary animals. Thereafter, the RP was used to evaluate animals which were one generation younger from the reference individuals. The drop in the reliability when evaluating younger animals was then assessed and the RP was updated to re-gain the initial reliability. The update animals were contemporaries of evaluated animals (EVA). The RP was updated in batches of 100 animals/update. First, the animals most closely related to the EVA were chosen to update RP. The results showed that, approximately, 600 animals were needed every generation to maintain the DGV reliability at a constant level across generations. The sum of squared relationships between RP and EVA and the sum of off-diagonal coefficients of the inverse of the genomic relationship matrix for RP, separately explained 31% and 34%, respectively, of the variation in the reliability across generations. Combined, these parameters explained 53% of the variation in the reliability across generations. Thus, for an optimal RP update an algorithm considering both relationships between reference and evaluated animals, as well as relationships among reference animals, is required.

    Parametric estimation of P(X >Y) for normal distributions in the context of probabilistic environmental risk assessment.
    Jacobs, R. ; Bekker, A.A. ; Voet, H. van der; Braak, C.J.F. ter - \ 2015
    PeerJ 3 (2015). - ISSN 2167-8359
    species sensitivity distributions - stress-strength model - confidence-intervals - reliability - less - inference
    Estimating the risk, P(X > Y), in probabilistic environmental risk assessment of nanoparticles is a problem when confronted by potentially small risks and small sample sizes of the exposure concentration X and/or the effect concentration Y. This is illustrated in the motivating case study of aquatic risk assessment of nano-Ag. A non-parametric estimator based on data alone is not sufficient as it is limited by sample size. In this paper, we investigate the maximum gain possible when making strong parametric assumptions as opposed to making no parametric assumptions at all. We compare maximum likelihood and Bayesian estimators with the non-parametric estimator and study the influence of sample size and risk on the (interval) estimators via simulation. We found that the parametric estimators enable us to estimate and bound the risk for smaller sample sizes and small risks. Also, the Bayesian estimator outperforms the maximum likelihood estimators in terms of coverage and interval lengths and is, therefore, preferred in our motivating case study.
    Proficiency test for aflatoxin in pig feed
    Elbers, I.J.W. ; Nijs, W.C.M. de - \ 2015
    Wageningen : RIKILT Wageningen UR (RIKILT report 2015.010) - 27
    aflatoxinen - varkensvoeding - vergelijkend warenonderzoek - laboratoria - betrouwbaarheid - evaluatie - aflatoxins - pig feeding - comparative testing - laboratories - reliability - evaluation
    Proficiency testing is conducted to provide laboratories with a powerful tool to evaluate and demonstrate the reliability of the data that are produced. Next to validation and accreditation, proficiency testing is an important requirement of the EU Additional Measures Directive 93/99/EEC [1] and is required by ISO 17025:2005 [2]. The aim of this proficiency test was to give laboratories the possibility to evaluate or demonstrate their competence for the analysis of aflatoxins in pig feed.
    Impact of QTL properties on the accuracy of multi-breed genomic prediction
    Wientjes, Y.C.J. ; Calus, M.P.L. ; Goddard, M.E. ; Hayes, B.J. - \ 2015
    Genetics, Selection, Evolution 47 (2015). - ISSN 0999-193X
    dairy-cattle populations - residual feed-intake - complex traits - linkage disequilibrium - genotype imputation - data sets - selection - values - animals - reliability
    Background - Although simulation studies show that combining multiple breeds in one reference population increases accuracy of genomic prediction, this is not always confirmed in empirical studies. This discrepancy might be due to the assumptions on quantitative trait loci (QTL) properties applied in simulation studies, including number of QTL, spectrum of QTL allele frequencies across breeds, and distribution of allele substitution effects. We investigated the effects of QTL properties and of including a random across- and within-breed animal effect in a genomic best linear unbiased prediction (GBLUP) model on accuracy of multi-breed genomic prediction using genotypes of Holstein-Friesian and Jersey cows. Methods - Genotypes of three classes of variants obtained from whole-genome sequence data, with moderately low, very low or extremely low average minor allele frequencies (MAF), were imputed in 3000 Holstein-Friesian and 3000 Jersey cows that had real high-density genotypes. Phenotypes of traits controlled by QTL with different properties were simulated by sampling 100 or 1000 QTL from one class of variants and their allele substitution effects either randomly from a gamma distribution, or computed such that each QTL explained the same variance, i.e. rare alleles had a large effect. Genomic breeding values for 1000 selection candidates per breed were estimated using GBLUP modelsincluding a random across- and a within-breed animal effect. Results - For all three classes of QTL allele frequency spectra, accuracies of genomic prediction were not affected by the addition of 2000 individuals of the other breed to a reference population of the same breed as the selection candidates. Accuracies of both single- and multi-breed genomic prediction decreased as MAF of QTL decreased, especially when rare alleles had a large effect. Accuracies of genomic prediction were similar for the models with and without a random within-breed animal effect, probably because of insufficient power to separate across- and within-breed animal effects. Conclusions - Accuracy of both single- and multi-breed genomic prediction depends on the properties of the QTL that underlie the trait. As QTL MAF decreased, accuracy decreased, especially when rare alleles had a large effect. This demonstrates that QTL properties are key parameters that determine the accuracy of genomic prediction.
    Evaluation of research methods to study domestic food preparation
    Bongoni, R. ; Verkerk, R. ; Dekker, M. ; Steenbekkers, B. - \ 2015
    British Food Journal 117 (2015)1. - ISSN 0007-070X - p. 7 - 21.
    brassica vegetables - handling behaviors - cooking methods - health - questionnaire - reliability - attributes - products
    Purpose – Domestic preparation practices influence the sensory properties and nutritional composition of food products. Information on the variability in actual domestic preparation practices is needed to assess the influence of applied conditions on the sensory and nutritional quality of food. The collection of such information requires a reliable, valid and practical research method. The paper aims to discuss these issues. Design/methodology/approach – Direct in-home observations, observations in a model-kitchen using cameras, and a self-reporting questionnaire were evaluated for reliability and validity, to study domestic food preparation practices by consumers. Broccoli preparation practices by Dutch consumers were checked by these three methods in this research paper. Findings – All three research methods were found to be test-retest, inter-observer, parallel-form reliable; and face, content and concurrent valid. However, the self-reporting questionnaire is the most practical research method that can be administered on a large number of respondents in a short time to capture the wide variations in preparation practices. Originality/value – Consumers can be assisted on domestic food preparation practices that reach their sensory preferences (e.g. texture, colour) as well as have health benefits on consumption. Keywords Reliability, Validity, Consistency in behaviour, Food preparation, Observation (through cameras), Self-reporting questionnaire Paper type Research paper
    Comparison of locomotion scoring for dairy cows by experienced and inexperienced raters using live or video observation methods.
    Schlageter-Tello, A. ; Bokkers, E.A.M. ; Groot Koerkamp, P.W.G. ; Hertem, T. van; Viazzi, S. ; Romanini, C.E.B. ; Halachmi, I. ; Bahr, C. ; Berckmans, D. ; Lokhorst, K. - \ 2015
    Animal Welfare 24 (2015). - ISSN 0962-7286 - p. 69 - 79.
    ensure high repeatability - training-program - milk-production - weighted kappa - holstein cows - risk-factors - lameness - cattle - agreement - reliability
    Lameness is considered a major problem in dairy production. Lameness is commonly detected with locomotion scores assigned to cows under farm conditions, but raters are often trained and assessed for reliability and agreement by using video recordings. The aim of this study was to evaluate intra- and inter-rater reliability and agreement of experienced and inexperienced raters for locomotion scoring performed live and from video, and to calculate the influence of raters and the method of observation (live or video) on the probability of classifying a cow as lame. Using a five-level locomotion score, cows were scored twice live and twice from video by three experienced and two inexperienced raters for three weeks. Every week different cows were scored. Intra- and inter-rater reliability (expressed as weighted kappa, ¿w)) and agreement (expressed as percentage of agreement, PA) for live/live, live/video and video/video comparisons were determined. A logistic regression was performed to estimate the influence of the rater and method of observation on the probability of classifying a cow as lame in live and video observation. Experienced raters had higher values for intra-rater reliability and agreement for video/video than for live/live and live/video comparison. Inexperienced raters, however, did not differ for intra- and inter-rater reliability and agreement for live/live, live/video and video/video comparisons. The logistic regression indicated that raters were responsible for the main effect and the method of observation (live or from video) had a minor effect on the probability for classifying a cow as lame (locomotion score =3). In conclusion, under the present experimental conditions, experienced raters performed better than unexperienced raters when locomotion scoring was done from video. Since video observation did not show any important influence in the probability of classifying a cow as lame, video observation seems to be an acceptable method for locomotion scoring and lameness assessment in dairy cows.
    Homo erectus at Trinil on Java used shells for tool production and engraving
    Joordens, J.C.A. ; d’Errico, F. ; Wesselingh, F.P. ; Munro, S. ; Vos, J. de; Wallinga, J. ; Ankjaergaard, C. ; Reimann, T. ; Wijbrans, J.R. ; Kuiper, K.F. ; Mücher, H.J. ; Coqueugniot, H. ; Prié, V. ; Joosten, I. ; Os, B. van; Schulp, A.S. ; Panuel, M. ; Haas, V. van der; Lustenhouwer, W. ; Reijmer, J.J.G. ; Roebroeks, W. - \ 2015
    Nature 518 (2015). - ISSN 0028-0836 - p. 228 - 231.
    quartz osl ages - luminescence signals - south-africa - indonesia - sediments - reliability - sangiran - record - rates
    The manufacture of geometric engravings is generally interpreted as indicative of modern cognition and behaviour1. Key questions in the debate on the origin of such behaviour are whether this innovation is restricted to Homo sapiens, and whether it has a uniquely African origin1. Here we report on a fossil freshwater shell assemblage from the Hauptknochenschicht (‘main bone layer’) of Trinil (Java, Indonesia), the type locality of Homo erectus discovered by Eugène Dubois in 1891 (refs 2 and 3). In the Dubois collection (in the Naturalis museum, Leiden, The Netherlands) we found evidence for freshwater shellfish consumption by hominins, one unambiguous shell tool, and a shell with a geometric engraving. We dated sediment contained in the shells with 40Ar/39Ar and luminescence dating methods, obtaining a maximum age of 0.54 ± 0.10 million years and a minimum age of 0.43 ± 0.05 million years. This implies that the Trinil Hauptknochenschicht is younger than previously estimated. Together, our data indicate that the engraving was made by Homo erectus, and that it is considerably older than the oldest geometric engravings described so far4, 5. Although it is at present not possible to assess the function or meaning of the engraved shell, this discovery suggests that engraving abstract patterns was in the realm of Asian Homo erectus cognition and neuromotor control.
    Prevalence and potential influencing factors of non-nutritive oral behaviors of veal calves on commercial farms
    Leruste, H. ; Brscic, M. ; Cozzi, G. ; Kemp, B. ; Wolthuis-Fillerup, M. ; Lensink, B.J. ; Bokkers, E.A.M. ; Reenen, C.G. van - \ 2014
    Journal of Dairy Science 97 (2014)11. - ISSN 0022-0302 - p. 7021 - 7030.
    immune-responses - housing systems - dairy calves - risk-factors - welfare - sucking - intersucking - stereotypies - reliability - indicators
    Veal calves raised under intensive conditions may express non-nutritive oral behaviors. When expressed in an abnormal way, these behaviors can be a sign of mental suffering and reduced welfare due to a mismatch between environmental or management features and animals' needs. The aims of this study were to estimate the prevalence of non-nutritive oral behaviors in a large sample of veal farms in Europe and to determine the potential influencing factors present at farm level. Data were collected on 157 commercial veal farms in the 3 main veal-producing countries in Europe (the Netherlands, France, and Italy). Observations of 3 non-nutritive oral behaviors (manipulating substrates, tongue rolling, and manipulating a penmate) were performed when calves were aged 14 wk, and the prevalence of these behaviors was calculated. Information on management practices and characteristics of the building and equipment were collected on all farms to assess potential influencing factors for each of the 3 behaviors. Odds ratios and 95% confidence intervals were calculated to evaluate the effect of each individual factor within a generalized linear model. The mean percentage of calves per farm performing manipulating substrates was 11.0 ± 0.46%, performing tongue rolling 2.8 ± 0.18%, and manipulating a penmate 2.7 ± 0.09%, with a high range between farms. Allowing more space for calves than the legal minimum requirement of 1.8 m2/calf and housing them in groups of >10 calves/pen reduced the incidences of manipulating substrates and tongue rolling. Incidence of manipulating substrates was lower for calves fed maize silage compared with calves fed cereal grain, pellets, or muesli. A higher risk of tongue rolling was found when baby-boxes (i.e., single housing during the first 5 to 8 wk) were not used. Risk of calves manipulating a penmate was higher for calves of milk- or meat-type breeds compared with dual-purpose breeds and for calves fed with 280 to 380 kg compared with those fed >380 kg of milk powder in total for the fattening period. The study allowed assessment of multiple factors across farms that showed variety in terms of conditions and level of non-nutritive oral behaviors. Identification of the factors influencing non-nutritive oral behavior is helpful to define potential actions that could be taken on farms to improve the welfare of calves and reduce the prevalence of these behaviors.
    Proficiency test for tropane alkaloids in food en feed
    Pereboom-de Fauw, D.P.K.H. ; Elbers, I.J.W. ; Mulder, P.P.J. ; Nijs, W.C.M. de - \ 2014
    Wageningen : RIKILT Wageningen UR (RIKILT report 2014.008) - 35
    voer - voedsel - voedselproducten - geldigheid - betrouwbaarheid - laboratoriummethoden - graansoorten - voedselconsumptie - voedselveiligheid - tropaanalkaloïden - feeds - food - food products - validity - reliability - laboratory methods - cereals - food consumption - food safety - tropane alkaloids
    Proficiency testing is conducted to provide laboratories with a powerful tool to evaluate and demonstrate the reliability of the data that are produced. Next to validation and accreditation, proficiency testing is an important requirement of the EU Additional Measures Directive 93/99/EEC [1] and is required by ISO 17025:200. The proficiency test for tropane alkaloids was organized by RIKILT, Wageningen UR in accordance with ISO 17043. The primary goal of this study was to provide laboratories with the opportunity to implement a method in their laboratory and to evaluate or demonstrate their performance regarding quantitative analysis of tropane alkaloids in cereals intended for human consumption and in animal feed.
    Rapport : bemonsteren en analyseren van dierlijke mest op een vrachtauto
    Zedde, H.J. van de; Kekem, C. van; Boer, E.P.J. - \ 2014
    Wageningen : Wageningen UR - Food & Biobased Research (Rapport / Wageningen UR Food & Biobased Research 1432) - ISBN 9789461737014 - 47
    dierlijke meststoffen - analyse - bemonsteren - nabij infrarood spectroscopie - analytische methoden - trucks - betrouwbaarheid - animal manures - analysis - sampling - near infrared spectroscopy - analytical methods - trucks - reliability
    Dierlijke mest is uitermate lastig materiaal om te analyseren met NabijInfraRood Spectroscopie (NIRS), want het is donker materiaal, hoofdzakelijk bestaand uit vocht en het is niet homogeen qua samenstelling. Toch wordt in literatuur beschreven, en ook in eerder onderzoek onder gecontroleerde omstandigheden aangetoond, dat stikstof- en fosfaatgehaltes in dierlijke mest kan worden gemeten met behulp van NIR spectroscopie met acceptabele niveaus qua betrouwbaarheid. De doelstellingen van het in dit rapport beschreven project waren: - Kan met Nabij Infrarood Spectroscopie bij belading en tijdens het lossen van mesttransport vrachtwagens een analyse van stikstof en fosfaat worden gerealiseerd die zich qua betrouwbaarheid ten minste kan meten met de huidige laboratorium-analyses? - Is de Nabij Infrarood Spectroscopie geschikt om toe te passen op voertuigniveau waarbij behoud van de betrouwbaarheid van analysen een voorwaarde is? - Is de Nabij Infrarood Spectroscopie een techniek die qua kosten en handhaving op grotere schaal in de praktijk toegepast kan worden?
    Right-hand-side updating for fast computing of genomic breeding values
    Calus, M.P.L. - \ 2014
    Genetics, Selection, Evolution 46 (2014). - ISSN 0999-193X - 24 p.
    genetic value - prediction - selection - accuracy - reliability - algorithm - cattle
    Since both the number of SNPs (single nucleotide polymorphisms) used in genomic prediction and the number of individuals used in training datasets are rapidly increasing, there is an increasing need to improve the efficiency of genomic prediction models in terms of computing time and memory (RAM) required.
    Quantifying the development of agreement among experts in Delphi studies
    Meijering, J.V. ; Kampen, J.K. ; Tobi, H. - \ 2013
    Technological Forecasting and Social Change 80 (2013)8. - ISSN 0040-1625 - p. 1607 - 1614.
    coefficient-alpha - kappa-coefficient - methodology - consensus - lessons - requirements - reliability - prevalence - management - accuracy
    Delphi studies are often conducted with the aim of achieving consensus or agreement among experts. However, many Delphi studies fail to offer a concise interpretation of the meaning of consensus or agreement. Whereas several statistical operationalizations of agreement exist, hardly any of these indices is used in Delphi studies. In this study, computer simulations were used to study different indices of agreement within different Delphi scenarios. A distinction was made between the indices of consensus (Demoivre index), agreement indices (e.g., Cohen's kappa and generalizations thereof), and association indices (e.g., Cronbach's alpha, intraclass correlation coefficient). Delphi scenarios were created by varying the number of objects, the number of experts, the distribution of object ratings, and the degree to which agreement increased between subsequent rounds. Each scenario consisted of three rounds and was replicated 1000 times. The simulation study showed that in the same data, different indices suggest different levels of agreement, and also, different levels of change of agreement between rounds. In applied Delphi studies, researchers should be more transparent regarding their choice of agreement index and report the value of the chosen index within every round as to provide insight into how the suggested agreement level has developed across rounds
    Allured or alarmed: Counteractive control responses to food temptations in the brain
    Smeets, P.A.M. ; Kroese, F.M. ; Evers, C. ; Ridder, D.T.D. de - \ 2013
    Behavioural Brain Research 248 (2013). - ISSN 0166-4328 - p. 41 - 45.
    self-regulatory-success - menstrual-cycle phase - primary visual-cortex - attentional control - inhibitory control - goal activation - fmri - metaanalysis - reliability - validity
    Typically, it is believed that palatable, high caloric foods signal reward and trigger indulgent responses. However, Counteractive Control Theory suggests that, to the extent that people are concerned about their weight, a confrontation with palatable foods should also trigger ‘alarm bell responses’ which promote successful self-control. Our study is the first to investigate such counteractive control processes in the brain employing functional magnetic resonance imaging (fMRI) in a sample of successful self-regulators. Indeed, besides the traditional finding that foods elicit heightened attention as witnessed by greater activation of primary visual cortex, we found that viewing palatable foods elicited brain activation in areas associated with self-regulation. Crucially, brain activation in self-regulation areas was related to diet importance. Thus, our results are the first to show that food cues not only evoke hedonic brain responses; in successful self-regulators they also trigger alarm bell responses, which may reflect the neural processes underlying successful self-control.
    Assessment time of the Welfare Quality protocol for dairy cattle
    Vries, M. de; Engel, B. ; Uijl, I. ; Schaik, G. van; Dijkstra, T. ; Boer, I.J.M. de; Bokkers, E.A.M. - \ 2013
    Animal Welfare 22 (2013)1. - ISSN 0962-7286 - p. 85 - 93.
    lying behavior - cows - reliability - lameness - imputation - indicator - agreement - variables - system
    The Welfare Quality® (WQ) protocols are increasingly used for assessing welfare of farm animals. These protocols are time consuming (about one day per farm) and, therefore, costly. Our aim was to assess the scope for reduction of on-farm assessment time of the WQ protocol for dairy cattle. Seven trained observers quantified animal-based indicators of the WQ protocol in 181 loose-housed and 13 tied Dutch dairy herds (herd size from 10 to 211 cows). Four assessment methods were used: avoidance distance at the feeding rack (ADF, 44 min); qualitative behaviour assessment (QBA, 25 min); behavioural observations (BO, 150 min); and clinical observations (CO, 132 min). To simulate reduction of on-farm assessment time, a set of WQ indicators belonging to one assessment method was omitted from the protocol. Observed values of omitted indicators were replaced by predictions based on WQ indicators of the remaining three assessment methods, resources checklist, and interview, thus mimicking the performance of the full WQ protocol. Agreement between predicted and observed values of WQ indicators, however, was low for ADF, moderate for QBA, slight to moderate for BO, and poor to moderate for CO. It was concluded that replacing animal-based WQ indicators by predictions based on remaining WQ indicators shows little scope for reduction of onfarm assessment time of the Welfare Quality® protocol for dairy cattle. Other ways to reduce on-farm assessment time of the WQ protocol for dairy cattle, such as the use of additional data or automated monitoring systems, should be investigated.
    The 40-item Monell Extended Sniffin' Sticks Identification Test (MONEX-40)
    Freiherr, J. ; Gordon, A.R. ; Alden, E.C. ; Ponting, A.L. ; Hernandez, M. ; Boesveldt, S. ; Lundstrom, J.N. - \ 2012
    Journal of Neuroscience Methods 205 (2012)1. - ISSN 0165-0270 - p. 10 - 16.
    odor-identification - olfactory function - normative data - discrimination - reliability - performance - dysfunction - thresholds - university - version
    Background Most existing olfactory identification (ID) tests have the primary aim of diagnosing clinical olfactory dysfunction, thereby rendering them sub-optimal for experimental settings where the aim is to detect differences in healthy subjects’ odor ID abilities. Materials and methods We have developed an extended version of the olfactory ID subtest of the Sniffin’ Sticks test battery to better assess the variability in ID scores and thereby olfactory abilities of healthy, adult individuals. Twenty-four odorants, corresponding cue labels, and distractor labels were added to the existing 16-item Sniffin’ Sticks ID test to create the 40-item Monell Extended Sniffin’ Sticks Identification Test (MONEX-40). The MONEX-40 was administered to 259 healthy young subjects, of which 72 were retested on an average of 212 days (SD 112 days) later. Results The added odor items demonstrated good validity, as shown by a significant correlation of the results with the original 16-item ID test. In addition, the MONEX-40 achieved a significant test–retest and split-half reliability. Conclusions Taken together, these results suggest that the MONEX-40 is a reliable method for experimental assessment of odor ID ability in healthy, young individuals. Moreover, its use of a wider range of odors allows the experimenter to present subsets of the MONEX-40 within the same experiment while maintaining statistical power.
    Evaluation of on-farm veal calves' responses to unfamiliar humans and potential influencing factors
    Leruste, H. ; Bokkers, E.A.M. ; Heutinck, L.F.M. ; Wolthuis-Fillerup, M. ; Werf, J.T.N. van der; Brscic, M. ; Cozzi, G. ; Engel, B. ; Reenen, C.G. van; Lensink, B.J. - \ 2012
    Animal 6 (2012)12. - ISSN 1751-7311 - p. 2003 - 2010.
    human-animal interactions - commercial dairy-cows - human contact - test-retest - behavior - cattle - pigs - reliability - management - welfare
    The human–animal relationship is an important component of the welfare of farm animals and for this reason animal responsiveness tests to humans are included in on-farm welfare assessment schemes that provide indicators for this. However, apart from the behaviour of stockpersons towards their animals, other factors may also influence animals’ reactivity to humans as observed through behavioural tests, which can add a further layer of complexity to the interpretation of test results. Knowledge of these factors may help a better interpretation of differences from one farm to another in the outcome of human–animal relationship tests, and may provide clues for improving the relationship between animals and humans. The main objective of this study was to identify whether management or environmental factors could influence the outcome of human–animal relationship tests in veal calves. Two tests were performed when calves were aged 14.9 ± 1.6 (SD) weeks in 148 veal farms: the voluntary approach of an unfamiliar human standing at the feeding fence and the reaction towards an unfamiliar human who entered the home pen and tried to touch each calf in a standardised way (Calf Escape Test (CET) – score 0 to 4). Questionnaires were filled in and interviews with the stockpersons were performed in order to obtain information on stockpersons, management, animal and building characteristics. The latency to touch an unfamiliar human at the feeding fence was significantly correlated with the CET scores. Total number of calves on the farm, space allowance, breed, environmental enrichment, stockperson's experience and season of observation influenced the percentage of calves that scored 0 in CET (i.e. calves that could not be approached). Type of milk distribution, type of breed and number of calves per stockperson influenced the percentage of calves that scored 4 in CET (i.e. calves could be touched). For both CET0 and CET4, the level of self-reported contacts by the stockperson (analysed only on the French subset of 36 farms) did not influence the results. This paper concludes that according to the tests conducted on veal calves on commercial farms, factors such as milk distribution method, breed of the calves or the level of experience of stockpersons with veal farming can have an impact on the results of tests focusing on human–animal relationships.
    The impact of climate change on the critical weather conditions at Schiphol airport (Impact)
    Jacobs, A.J.M. ; Barkmeijer, J. ; Siebesma, A.P. ; Plas, E.V. van der; Wichers Schreur, B.G.J. ; Roozekrans, J.N. ; Holtslag, A.A.M. ; Steeneveld, G.J. ; Ronda, R.J. ; Roode, S.R. de - \ 2012
    Utrecht/Wageningen : Knowledge for Climate Programme Office (Knowledge for Climate KfC 53/2012) - ISBN 9789490070571 - 76
    luchthavens - betrouwbaarheid - weersgegevens - klimaat - modellen - weersvoorspelling - haarlemmermeer - airports - reliability - weather data - climate - models - weather forecasting - haarlemmermeer
    Schiphol is van groot belang voor de economische positie van Nederland. De luchthaven is erg gevoelig voor kritieke weersomstandigheden zoals mist, intensieve neerslag en hevige wind. Als gevolg van klimaatverandering verwachten we dat ook de variabiliteit van het weer op de luchthaven en de frequentie en intensiteit van kritieke weersomstandigheden zullen veranderen, maar een precieze kwantificering daarvan ontbreekt. De belangrijkste doelstelling van dit project is daarom het verstrekken en demonstreren van het volgende generatie weer‐ en klimaatmodel HARMONIE. Dit is een nieuw model dat beter geschikt lijkt om het effect van klimaatverandering op lokale kritieke weersomstandigheden op de luchthaven te kwantificeren en te begrijpen. Bovendien zal kennis uit dit project worden gebruikt om de kwaliteit van onze huidige en toekomstige weersvoorspellingen te verbeteren. In dit project wordt het potentieel van het HARMONIE model, om meer gedetailleerdere en nauwkeurigere weersvoorspellingen voor luchthaven Schiphol te leveren dan ons huidige operationele weermodel HIRLAM, nagegaan in het huidige klimaat.
    Validity of a short questionnaire to assess physical activity in 10 European countries
    Feskens, E.J.M. - \ 2012
    European Journal of Epidemiology 27 (2012)1. - ISSN 0393-2990 - p. 15 - 25.
    activity energy-expenditure - combined heart-rate - cancer - accelerometry - repeatability - adults - reliability - actiheart - accuracy - sensor
    To accurately examine associations of physical activity (PA) with disease outcomes, a valid method of assessing free-living activity is required. We examined the validity of a brief PA questionnaire (PAQ) used in the European Prospective Investigation into Cancer and Nutrition (EPIC). PA energy expenditure (PAEE) and time spent in moderate and vigorous physical activity (MVPA) was measured in 1,941 healthy individuals from 10 European countries using individually-calibrated combined heart-rate and movement sensing. Participants also completed the short EPIC-PAQ, which refers to past year’s activity. Pearson (r) and Spearman (s) correlation coefficients were calculated for each country, and random effects meta-analysis was used to calculate the combined correlation across countries to estimate the validity of two previously- and one newly-derived ordered, categorical PA indices (“Cambridge index”, “total PA index”, and “recreational index”) that categorized individuals as inactive, moderately inactive, moderately active, or active. The strongest associations with PAEE and MVPA were observed for the Cambridge index (r = 0.33 and r = 0.25, respectively). No significant heterogeneity by country was observed for this index (I2 = 36.3%, P = 0.12; I2 = 0.0%, P = 0.85), whereas heterogeneity was suggested for other indices (I2 > 48%, P <0.05, I2 > 47%, P <0.05). PAEE increased linearly across self-reported PA categories (P for trend
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