Records 1 - 20 / 341
Zo kies je een gezonde en sociale hond
Ruis, M.A.W. - \ 2019
Wageningen : Wageningen University & Research - 21 p.
animal welfare - pets - dogs - animal behaviour - animal housing - animal health - animal nutrition - animal breeding
Deze interactieve brochure van Platform Fairfok geeft een overzicht van beschikbare informatie, diensten of producten van organisaties die zich actief inzetten voor de gezonde en sociale hond in Nederland.
Learn how to set up a breeding programme | WURcast
Komen, J. - \ 2019
Wageningen : WURcast
animal breeding - animal breeding methods - breeding programmes
Animal breeding: the concept of inbreeding | WURcast
Bijma, P. - \ 2019
Wageningen : Centre for Genetic Resources and Animal Breeding and Genomics Group, Wageningen University and Research Centre
inbreeding - animal breeding - alleles
Inbreeding is the result of mating two related individuals. Related individuals are more alike genetically than non-related individuals because they share alleles.
Hoe kies je de beste stieren voor je bedrijf?
Hoving, A.H. ; Ducro, B.J. - \ 2019
Wageningen : Centre for Genetic Resources, the Netherlands (CGN), Wageningen University & Research
animal breeding - dairy cattle - genetics - teaching materials - intermediate vocational training - animal welfare - animal production - animal health
Docentenhandleiding bij lesmateriaal ‘Hoe kies je de beste stieren voor je bedrijf?’ Powerpoint ‘Hoe kies je de beste stieren voor je bedrijf?’ Excel file ‘Een selectie van de stierenkaart’.
Prospects of whole-genome sequence data in animal and plant breeding
Binsbergen, Rianne van - \ 2017
Wageningen University. Promotor(en): R.F. Veerkamp; F.A. Eeuwijk, co-promotor(en): M.P.L. Calus. - Wageningen : Wageningen University - ISBN 9789463431903 - 220
next generation sequencing - dna sequencing - quantitative trait loci - cattle - genomics - solanum lycopersicum - animal breeding - plant breeding - next generation sequencing - dna-sequencing - loci voor kwantitatief kenmerk - rundvee - genomica - solanum lycopersicum - dierveredeling - plantenveredeling
The rapid decrease in costs of DNA sequencing implies that whole-genome sequence data will be widely available in the coming few years. Whole-genome sequence data includes all base-pairs on the genome that show variation in the sequenced population. Consequently, it is assumed that the causal mutations (e.g. quantitative trait loci; QTL) are included, which allows testing a given trait directly for association with a QTL, and might lead to discovery of new QTL or higher accuracies in genomic predictions compared to currently available marker panels. The main aim of this thesis was to investigate the benefits of using whole-genome sequence data in breeding of animals and plants compared to currently available marker panels. First the potential and benefits of using whole-genome sequence data were studied in (dairy) cattle. Accuracy of genotype imputation to whole-genome sequence data was generally high, depending on the used marker panel. In contrast to the expectations, genomic prediction showed no advantage of using whole-genome sequence data compared to a high density marker panel. Thereafter, the use of whole-genome sequence data for QTL detection in tomato (S. Lycopersicum) was studied. In a recombinant inbred line (RIL) population, more QTL were found when using sequence data compared to a marker panel, while increasing marker density was not expected to provide additional power to detect QTL. Next to the RIL population, also in an association panel it was shown that, even with limited imputation accuracy, the power of a genome-wide association study can be improved by using whole-genome sequence data. For successful application of whole-genome sequence data in animals or plants, genotype imputation will remain important to obtain accurate sequence data for all individuals in a cost effective way. Sequence data will increase the power of QTL detection in RIL populations, association panels or outbred populations. Added value of whole-genome sequence data in genomic prediction will be limited, unless more information is known about the biological background of traits and functional annotations of DNA. Also statistical models that incorporate this information and that can efficiently handle large datasets have to be developed.
Milk progesterone measures to improve genomic selection for fertility in dairy cows
Tenghe, Amabel Manyu Mefru - \ 2017
Wageningen University. Promotor(en): R.F. Veerkamp; B. Berglund, co-promotor(en): D. J. de Koning; A.C. Bouwman. - Wageningen : Wageningen University - ISBN 9789463431330 - 179
dairy cows - fertility - progesterone - milk - genomics - genetic improvement - heritability - genetic parameters - dairy performance - reproductive traits - animal genetics - animal breeding - dairy farming - melkkoeien - vruchtbaarheid - progesteron - melk - genomica - genetische verbetering - heritability - genetische parameters - melkresultaten - voortplantingskenmerken - diergenetica - dierveredeling - melkveehouderij
Improved reproductive performance has a substantial benefit for the overall profitability of dairy cattle farming by decreasing insemination and veterinary treatment costs, shortening calving intervals, and lowering the rate of involuntary culling. Unfortunately, the low heritability of classical fertility traits derived from calving and insemination data makes genetic improvement by traditional animal breeding slow. Therefore, there is an interest in finding novel measures of fertility that have a higher heritability or using genomic information to aid genetic selection for fertility. The overall objective of this thesis was to explore the use of milk progesterone (P4) records and genomic information to improve selection for fertility in dairy cows. In a first step, the use of in-line milk progesterone records to define endocrine fertility traits was investigated, and genetic parameters estimated. Several defined endocrine fertility traits were heritable, and showed a reasonable repeatability. Also, the genetic correlation of milk production traits with endocrine fertility traits were considerably lower than the correlations of milk production with classical fertility traits. In the next step 17 quantitative trait loci (QTL) associated with endocrine fertility traits, were identified on Bos taurus autosomes (BTA) 2, 3, 8, 12, 15, 17, 23, and 25 in a genome-wide association study with single nucleotide polymorphisms. Further, fine-mapping of target regions on BTA 2 and 3, identified several associated variants and potential candidate genes underlying endocrine fertility traits. Subsequently, the optimal use of endocrine fertility traits in genomic evaluations was investigated; using empirical and theoretical predictions for single-trait models, I showed that endocrine fertility traits have more predictive ability than classical fertility traits. The accuracy of genomic prediction was also substantially improved when endocrine and classical fertility traits were combined in multi-trait genomic prediction. Finally, using deterministic predictions, the potential accuracy of multi-trait genomic selection when combining a cow training population measured for the endocrine trait commencement of luteal activity (C-LA), with a training population of bulls with daughter observations for a classical fertility trait was investigated. Results showed that for prediction of fertility, there is no benefit of investing in a cow training population when the breeding goal is based on classical fertility traits. However, when considering a more biological breeding goal for fertility like C-LA, accuracy is substantially improved when endocrine traits are available from a limited number of farms.
Selection for pure- and crossbred performance in Charolais
Vallée-Dassonneville, Amélie - \ 2017
Wageningen University. Promotor(en): Johan van Arendonk; Henk Bovenhuis. - Wageningen : Wageningen University - ISBN 9789463430180 - 151
charolais - cattle - animal breeding - crossbreeding - crossbreds - selection - beef cattle - genomes - genetic parameters - charolais - rundvee - dierveredeling - kruisingsfokkerij - kruising - selectie - vleesvee - genomen - genetische parameters
Two categories of beef production exist; i.e. (i) purebred animals from a beef sire and a beef dam and (ii) crossbred animals from a beef sire and a dairy dam.
For the purebred beef production, there is a growing interest to include behavior and type traits in the breeding goal. Heritabilities for behavior traits, estimated using subjective data scored by farmers, range from 0.02 to 0.19. Heritabilities for type traits range from 0.02 to 0.35. Results show that there are good opportunities to implement selection for behavior traits using a simple on-farm recording system to allow collection of large data set, and for type traits in Charolais. A genome-wide association study detected 16 genomic regions with small effect on behavior and type traits. This suggests that behavior and type traits are influenced by many genes each explaining a small part of the genetic variance.
The two main dairy breeds mated to Charolais sires for crossbred beef production in France are Montbéliard and Holstein. The genetic correlation between the same trait measured on Montbéliard x Charolais and on Holstein x Charolais was 0.99 for muscular development, 0.96 for birth weight; and 0.91 for calving difficulty, 0.80 for height, and 0.70 for bone thinness. Thus, for these last three traits, results show evidence for re-ranking of Charolais sires depending on whether they are mated to Montbéliard or Holstein cows. When using genomic prediction, the Montbéliard x Charolais and Holstein x Charolais populations could be combined into a single reference population to increase size and accuracy of genomic prediction. Results indicate that the higher the genetic correlation is between the two crossbred populations, the higher the gain in accuracy is achieved when combining the two populations into a single reference.
The selection of Charolais sires to produce purebred or crossbred animals is made through distinct breeding programs. An alternative could be to combine selection into one breeding program. Decision for combining or keeping breeding programs separate is determined by the correlation between the breeding objectives, the selection intensity, the difference in level of genetic merit, the accuracy of selection, and the recent implementation of genomic evaluation. Considering all parameters and based on estimations for selection on birth weight, I recommend combining both breeding programs because this will lead to higher genetic gain, and might simplify operating organization and reduce associated costs.
Genetische analyse van de Stabij
Doekes, H.P. ; Oldenbroek, J.K. ; Windig, J.J. - \ 2016
Zeldzaam huisdier 41 (2016)1. - ISSN 0929-905X - p. 18 - 19.
zeldzame rassen - genetische analyse - hondenrassen - friese stabij - dierveredeling - rare breeds - genetic analysis - dog breeds - frisian stabyhoun - animal breeding
De Stabij is een van de negen oorspronkelijke Nederlandse hondenrassen die een belangrijke rol vervullen in het Fairfok-programma van de Raad van Beheer voor de Kynologie. De SZH ondersteunt dat programma door de rasverenigingen van kennis en advies te voorzien en heeft met het CGN een genetische analyse gemaakt van het Stabijras.
Genetische analyse van het Markiesje
Doekes, H.P. ; Oldenbroek, J.K. ; Windig, J.J. - \ 2016
Zeldzaam huisdier 41 (2016)2. - ISSN 0929-905X - p. 20 - 21.
hondenrassen - zeldzame rassen - genetische analyse - dierveredeling - stamboeken - dog breeds - rare breeds - genetic analysis - animal breeding - herdbooks
Het Markiesje is een van de negen oorspronkelijke Nederlandse hondenrassen. Het vervult een belangrijke rol in het Fairfok-programma. De SZH ondersteunt dat programma door de rasverenigingen van kennis en advies te voorzien.
Leerstoelgroep Filosofie en Dier-ethiek Wageningen; '10.000 liter per koe is onethisch'
Gremmen, Bart - \ 2016
animal welfare - animal ethics - animal production - dairy cattle - cattle - animal breeding - animal health
De melkveehouderij krijgt geregeld als kritiek dat ze dieronvriendelijk en onethisch werkt. Neem de kalf-bij-de-koediscussie. Het dier wordt steeds meer vermenselijkt, met als gevolg scheve veronderstellingen over dierethiek. Wageningse professor Bart Gremmen: „Het eten van dierlijke producten gaat altijd gepaard met dierenleed.”
‘Inteelt zie je niet altijd, maar kost wel geld’ : onderzoeker Nauta overweegt studieclub fokkerij op te zetten
Windig, Jack - \ 2016
inbreeding - inbreeding depression - goat keeping - animal breeding - farm management
Fokken, wat is dat?
Oldenbroek, Kor - \ 2016
animal welfare - pets - dogs - animal health - animal behaviour - animal breeding - genetics
Genomic selection in egg-laying chickens
Heidaritabar, M. - \ 2016
Wageningen University. Promotor(en): Martien Groenen, co-promotor(en): John Bastiaansen. - Wageningen : Wageningen University - ISBN 9789462576704 - 220
hens - genomics - genetic variation - selective breeding - quantitative traits - breeding value - animal genetics - animal breeding - hennen - genomica - genetische variatie - selectief fokken - kwantitatieve kenmerken - fokwaarde - diergenetica - dierveredeling
Heidaritabar, M. (2016). Genomic selection in egg-laying chickens. PhD thesis, Wageningen University, the Netherlands
In recent years, prediction of genetic values with DNA markers, or genomic selection (GS), has become a very intense field of research. Many initial studies on GS have focused on the accuracy of predicting the genetic values with different genomic prediction methods. In this thesis, I assessed several aspects of GS. I started with evaluating results of GS against results of traditional pedigree-based selection (BLUP) in data from a selection experiment that applied both methods side by side. The impact of traditional selection and GS on the overall genome variation as well as the overlap between regions selected by GS and the genomic regions predicted to affect the traits were assessed. The impact of selection on genome variation was assessed by measuring changes in allele frequencies that allowed the identification of regions in the genome where changes must be due to selection. These frequency changes were shown to be larger than what could be expected from random fluctuations, indicating that selection is really affecting the allele frequencies and that this effect is stronger in GS compared with BLUP. Next, concordance was tested between the selected regions and regions that affect the traits, as detected by a genome-wide association study. Results showed a low concordance overall between the associated regions and the selected regions. However, markers in associated regions did show larger changes in allele frequencies compared with the average changes across the genome. The selection experiment was performed using a medium density of DNA markers (60K). I subsequently explored the potential benefits of whole-genome sequence data for GS by comparing prediction accuracy from imputed sequence data with the accuracy obtained from the 60K genotypes. Before sequencing, the selection of key animals that should be sequenced to maximize imputation accuracy was assessed with the original 60K genotypes. The accuracy of genotype imputation from lower density panels using a small number of selected key animals as reference was compared with a scenario where random animals were used as the reference population. Even with a very small number of animals as reference, reasonable imputation accuracy could be obtained. Moreover, selecting key animals as reference considerably improved imputation accuracy of rare alleles compared with a set of random reference animals. While imputation from a small reference set was successful, imputation to whole-genome sequence data hardly improved genomic prediction accuracy compared with the predictions based on 60K genotypes. Using only those markers from the whole-genome sequence that are more likely to affect the phenotype was expected to remove noise from the data, but resulted in slightly lower prediction accuracy compared with the complete genome sequence. Finally, I evaluated the inclusion of dominance effects besides additive effects in GS models. The proportion of variance due to additive and dominance effects were estimated for egg production and egg quality traits of a purebred line of layers. The proportion of dominance variance to the total phenotypic variance ranged from 0 to 0.05 across traits. Also, the impact of fitting dominance besides additive effects on prediction accuracy was investigated, but was not found to improve accuracy of genomic prediction of breeding values.
Breeding against infectious diseases in animals
Rashidi, H. - \ 2016
Wageningen University. Promotor(en): Johan van Arendonk, co-promotor(en): Herman Mulder; P.K. Mathur. - Wageningen University - ISBN 9789462576452 - 179
livestock - infectious diseases - animal breeding - selective breeding - disease resistance - tolerance - genetic variation - breeding value - genetic correlation - traits - genomics - animal genetics - vee - infectieziekten - dierveredeling - selectief fokken - ziekteresistentie - tolerantie - genetische variatie - fokwaarde - genetische correlatie - kenmerken - genomica - diergenetica
Infectious diseases in farm animals are of major concern because of animal welfare, production costs, and public health. Farms undergo huge economic losses due to infectious disease. The costs of infections in farm animals are mainly due to production losses, treatment of infected animals, and disease control strategies. Control strategies, however, are not always successful. Selective breeding for the animals that can mount a defence against infection could therefore be a promising approach. Defensive ability of an animal has two main mechanisms: resistance (ability to control the pathogen burden) and tolerance (ability to maintain performance when pathogen burden increases). When it is difficult to distinguish between resistance and tolerance, defensive ability is measured as resilience that is the ability to maintain performance during a disease outbreak regardless of pathogen burden. Studies have focused on the genetics of resistance and resilience with little known about the genetics of tolerance and its relationship with resistance and resilience. The objectives of this thesis were to: 1) estimate the genetic variation in resistance, tolerance, and resilience to infection in order to assess the amenability of these traits for selective breeding in farm animals, 2) estimate the genetic correlation between resistance, tolerance and resilience and 3) detect genomic regions associated with resistance, tolerance, and resilience.
In chapter 2, we studied the variation among sows in response to porcine reproductive and respiratory syndrome (PRRS). First a statistical method was developed to detect PRRS outbreaks based on reproduction records of sows. The method showed a high sensitivity (78%) for disease phases. Then the variation of sows in response to PRRS was quantified using 2 models on the traits number of piglets born alive (NBA) and number of piglets born dead (LOSS): 1) bivariate model considering the trait in healthy and disease phases as different traits, and 2) reaction norm model modelling the response of sows as a linear regression of the trait on herd-year-week estimates of NBA. Trait correlations between healthy and disease phases deviated from unity (0.57±0.13 – 0.87±0.18). The repeatabilities ranged from 0.07±0.027 to 0.16±0.005. The reaction norm model had higher predictive ability in disease phase compared to the bivariate model.
In chapter 3 we studied 1) the genetic variation in resistance and tolerance of sheep to gastrointestinal nematode infection and 2) the genetic correlation between resistance and tolerance. Sire models on faecal nematode egg count (FEC), IgA, and pepsinogen were used to study the genetic variation in resistance. Heritability for resistance traits ranged from 0.19±0.10 to 0.59±0.20. A random regression model was used to study the reaction norm of sheep body weight on FEC as an estimate of tolerance to nematode infection. We observed a significant genetic variance in tolerance (P<0.05). Finally a bivariate model was used to study the genetic correlation between resistance and tolerance. We observed a negative genetic correlation (-0.63±0.25) between resistance and tolerance.
In chapter 4, we studied the response to selection in resistance and tolerance when using estimated breeding values for resilience. We used Monte Carlo simulation to generate 100 half-sib families with known breeding values for resistance (pathogen burden) and tolerance. We used selection index theory to predict response to selection for resistance and tolerance: 1) when pathogen burden is known and selection is based on true breeding values for resistance and tolerance and 2) when pathogen burden is unknown and selection is based on estimated breeding values for resilience. Using EBV for resilience in absence of records for pathogen burden resulted in favourable responses in resistance and tolerance to infections, with more emphasis on tolerance than on resistance. However, more genetic gain in resistance and tolerance could be achieved when pathogen burden was known.
In chapter 5 we studied genomics regions associated with resistance, resilience, and tolerance to PRRS. Resistance was modelled as sire effect on area under the PRRS viremia curve up to 14 days post infection (AUC14). Resilience was modelled as sire effects on daily growth of pigs up to 28 days post infection (ADG28). Tolerance was modelled as the sire effect on the regression of ADG28 on AUC14. We identified a major genomics region on chromosome 4 associated with resistance and resilience to PRRS. We also identified genomics regions on chromosome 1 associated with tolerance to PRRS.
In the general discussion (chapter 6) I discussed: 1) response to infection as a special case of genotype by environment interaction, 2) random regression model as a statistical tool for studying response to disease, 3) advantages and requirements of random regression models, and 4) selective breeding of farm animals for resistance, tolerance, and resilience to infections. I concluded that random regression is a powerful approach to estimate response to infection in animals. If the adequate amount of data is available random regression model could estimate breeding values of animals more accurately compared to other models. I also concluded that before including resistance and tolerance into breeding programs, breeders should make sure about the added values of including these traits on genetic progress. Selective breeding for resilience could be a pragmatic approach to simultaneously improve resistance and tolerance.
Multi-population genomic prediction
Wientjes, Y.C.J. - \ 2016
Wageningen University. Promotor(en): Roel Veerkamp; Mario Calus. - Wageningen : Wageningen University - ISBN 9789462576193 - 267
cum laude - dairy cattle - genomics - prediction - quantitative trait loci - genetic improvement - breeding value - selective breeding - animal breeding - animal genetics - melkvee - genomica - voorspelling - loci voor kwantitatief kenmerk - genetische verbetering - fokwaarde - selectief fokken - dierveredeling - diergenetica
Cum laude graduation
Hereditary disorders in pedigree dogs and look-a-likes
Zeeland, C.W.M. Van; Beerda, B. - \ 2015
Wageningen UR, Wetenschapswinkel (Rapport / Wetenschapswinkel Wageningen UR 317) - ISBN 9789461738882 - 51
dogs - dog breeds - genetic disorders - pedigree - disease prevalence - animal breeding - animal welfare - animal health - pets - honden - hondenrassen - genetische stoornissen - stamboom - ziekteprevalentie - dierveredeling - dierenwelzijn - diergezondheid - gezelschapsdieren
Selectie en genetische variatie in een fokprogramma
Oldenbroek, Kor ; Maurice - Van Eijndhoven, Myrthe - \ 2015
Zeldzaam huisdier 40 (2015)4. - ISSN 0929-905X - p. 14 - 17.
dierveredeling - veredelingsprogramma's - genetische variatie - selectie - zeldzame rassen - heritability - inteelt - verwantschap - groninger paard - animal breeding - breeding programmes - genetic variation - selection - rare breeds - heritability - inbreeding - kinship - groningen horse
In drie voorgaande artikelen in deze serie zijn achtereenvolgens het fokdoel, de registratie van gegevens en de basisprincipes van de erfelijkheid besproken. In dit laatste artikel wordt het belang van genetische variatie en de selectie van ouderdieren besproken. Twee belangrijke elementen in het fokprogramma van een zeldzaam ras.
Fokkerij nieuwe strategie zonder quotum
Veerkamp, Roel - \ 2015
animal breeding - cattle - breeding aims - animal breeding methods - selection - mating - animal genetics
Handboek melkveehouderij 2015/16
Remmelink, G.J. ; Middelkoop, J.C. van; Ouweltjes, W. ; Wemmenhove, H. - \ 2015
Wageningen : Wageningen UR Livestock Research (Handboek / Wageningen UR Livestock Research 30) - 386
melkvee - melkveehouderij - bodemeigenschappen - bemesting - graslandbeheer - voedergrassen - voedergewassen - rundveevoeding - dierveredeling - diergezondheid - melkproductie - landbouwbedrijfsgebouwen - nederland - handboeken - dairy cattle - dairy farming - soil properties - fertilizer application - grassland management - fodder grasses - fodder crops - cattle feeding - animal breeding - animal health - milk production - farm buildings - netherlands - handbooks
Natuurlijke antilichamen als voorspeller zieke koe
Knaap, J. van der; Poel, J.J. van der - \ 2015
Veeteelt 32 (2015)15. - ISSN 0168-7565 - p. 10 - 12.
melkveehouderij - dierveredeling - natuurlijke antilichamen - diergezondheid - fokwaarde - dairy farming - animal breeding - natural antibodies - animal health - breeding value
De aanwezigheid van natuurlijke antilichamen, de zogenaamde NAbs, kan sterk verschillen per koe. Door de erfelijkheidsgraad van NAbs is het mogelijk om erop te fokken, zo blijkt uit het project Weerbaar Vee. De uitkomsten bieden perspectief om de gezondheid te verbeteren, maar de uitvoering lijkt nog niet prakijkrijp.