Bart J Ducro

Bart J Ducro
Wageningen University & Research | WUR · Animal Breeding and Genomics Centre

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171
Publications
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Publications

Publications (171)
Article
In the past, small population sizes and unequal ancestor contributions have resulted in high inbreeding rates (Δ F ) in the Friesian horse. Two decades ago, the studbook implemented a mating quota and started publishing individual kinships and reduced Δ F below 1% per generation. However, since then, the breeding population size has decreased and t...
Article
Breeding is a promising greenhouse gas (GHG) mitigation option for the dairy sector that offers potential permanent and cumulative effects. However, there is limited understanding of how genetic traits affect GHG emissions from the dairy production chain and how breeding indices could be used to find a balance between GHG emissions and farm profit....
Article
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This research paper addresses the problem that, thus far, there is no method available to predict herd resilience for farms that do not use automated milking systems (AMS). Recently, a methodology was developed to estimate both individual cow as well as herd resilience using daily milk yield observations at individual cow level from farms with AMS....
Article
Full-text available
Background: Nitrate leaching to groundwater and surface water and ammonia volatilization from dairy farms have negative impacts on the environment. Meanwhile, the increasing demand for dairy products will result in more pollution if N losses are not controlled. Therefore, a more efficient, and environmentally friendly production system is needed,...
Conference Paper
Full-text available
Dairy farming may have negative impacts on the environment, such as ammonia emissions to air and nitrate leaching to water. By selecting more efficient cows, the amount of nitrogen excreted per cow and consequently the adverse environmental impacts will be reduced. The aim of this study was to predict nitrogen use efficiency (NUE) of individual dai...
Preprint
Full-text available
Background Nitrate leaching to groundwater and surface water and ammonia volatilization from dairy farms have negative impacts on the environment. Meanwhile, the increasing demand for dairy products will result in more pollution if N losses are not controlled. Therefore, a more efficient, and environmentally friendly production system is needed, in...
Article
Osteochondrosis (OC) is an important skeletal disease causing profound welfare concerns in horses. Although numerous studies have explored the genetics underlying OC in various breeds, the Belgian Warmblood (BW) remains unstudied despite having a concerning prevalence of 32.0%. As a result, this study aimed to conduct genome-wide association (GWA)...
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Full-text available
Reliable prediction of lifetime resilience early in life can contribute to improved management decisions of dairy farmers. Several studies have shown that time series sensor data can be used to predict lifetime resilience rankings. However, such predictions generally require the translation of sensor data into biologically meaningful sensor feature...
Article
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Background The effect of heat stress on livestock production is a worldwide issue. Animal performance is influenced by exposure to harsh environmental conditions potentially causing genotype-by-environment interactions (G × E), especially in highproducing animals. In this context, the main objectives of this study were to (1) detect the time period...
Preprint
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Background: The effect of heat stress on livestock production is a worldwide issue, where animal performance is influenced by exposure to high environmental temperatures, indicating the existence of possible genotype-by-environment interactions (G´E). The main objectives of this study were to (1) detect the time periods in which heifer fertility tr...
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Appropriate evaluation of BW and gain during rearing is required for optimal extended laying performance in laying hens. The objective of this study was to compare monophasic, diphasic, and triphasic Gompertz and logistic models describing BW and gain in individually fed free-run laying hens and to study the variation between individuals in shape p...
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Cow survival is a complex trait that combines traits like milk production, fertility, health and environmental factors such as farm management. This complexity makes survival difficult to predict accurately. This is probably the reason why few studies attempted to address this problem and no studies are published that use ensemble methods for this...
Article
Advances in technology and improved data collection have increased the availability of genomic estimated breeding values (gEBV) and phenotypic information on dairy farms. This information could be used for the prediction of complex traits such as survival, which can in turn be used in replacement heifer management. In this study, we investigated wh...
Article
Full-text available
Abstract Background Copy Number Variation (CNV) is a common form of genetic variation underlying animal evolution and phenotypic diversity across a wide range of species. In the mammalian genome, high frequency of CNV differentiation between breeds may be candidates for population-specific selection. However, CNV differentiation, selection and its...
Preprint
Full-text available
Background Copy Number Variation (CNV) is a common form of genetic variation underlying animal evolution and phenotypic diversity across a wide range of species. In the mammalian genome, high frequency of CNV differentiation between breeds may be candidates for population-specific selection. However, CNV differentiation, selection and its populatio...
Preprint
Full-text available
Background Copy Number Variation (CNV) is a common form of genetic variation underlying animal evolution and phenotypic diversity across a wide range of species. In the mammalian genome, high frequency of CNV differentiation between breeds may be candidates for population-specific selection. However, CNV differentiation, selection and its populatio...
Article
Full-text available
In pig production, efficiency is benefiting from uniform growth in pens resulting in single deliveries from a pen of possibly all animals in the targeted weight range. Abnormalities, like pneumonia or aberrant growth, reduce production efficiency as it reduces the uniformity and might cause multiple deliveries per batch and pigs delivered with a lo...
Article
Equine insect bite hypersensitivity (IBH) is a pruritic skin allergy caused primarily by biting midges, Culicoides spp. IBH susceptibility has polygenic inheritance and occurs at high frequencies in several horse breeds worldwide, causing increased costs and reduced welfare of affected horses. The aim of this study was to identify and validate sing...
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Full-text available
Insect bite hypersensitivity (IBH), which is a cutaneous allergic reaction to antigens from Culicoides spp., is the most prevalent skin disorder in horses. Misdiagnosis is possible, as IBH is usually diagnosed based on clinical signs. Our study is the first to employ IgE levels against several recombinant Culicoides spp. allergens as an objective,...
Article
In this study, we compared multiple logistic regression, a linear method, to naive Bayes and random forest, 2 nonlinear machine-learning methods. We used all 3 methods to predict individual survival to second lactation in dairy heifers. The data set used for prediction contained 6,847 heifers born between January 2012 and June 2013, and had known s...
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Full-text available
The spectrum of modern horse populations encompasses populations with a long history of development in isolation and relatively recently formed types. To increase our understanding of the evolutionary history and provide information on how to optimally conserve or improve these populations with varying development and background for the future, we...
Preprint
Full-text available
Background Copy Number Variation (CNV) is a common form of genetic variation underlying animal evolution and phenotypic diversity across a wide range of species. In the mammalian genome, high frequency of CNV differentiation between breeds may be candidates for population-specific selection. However, CNV differentiation, selection and its populatio...
Article
Full-text available
Muscle grading of livestock is a primary component of valuation in the meat industry. In pigs, the muscularity of a live animal is traditionally estimated by visual and tactile inspection from an experienced assessor. In addition to being a time consuming process, scoring of this kind suffers from inconsistencies inherent to the subjectivity of hum...
Article
Udder conformation is an important trait in dairy cattle breeding because of its relation to milk production (Short and Lawlor, 1992), udder health (Samoré and Groen, 2006) and longevity (Vollema et al., 2000). Breeding values for udder conformation are usually estimated based on udder traits scored by classifiers which show substantial heritabilit...
Conference Paper
Copy Number Variants (CNVs −gain or loss of genomic material) are a common form of genetic variation underlying phenotypic diversity across a wide range of species. It has previously been hypothesized that high frequency CNV differentiation between breeds may be linked to population-specific selection; and highly inbred populations may also accumul...
Book
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’.
Article
Full-text available
Background: Many common and relevant diseases affecting equine welfare have yet to be tested regarding structural variants such as copy number variations (CNVs). CNVs make up a substantial proportion of total genetic variability in populations of many species, resulting in more sequence differences between individuals than SNPs. Associations betwe...
Article
The weight of a pig and the rate of its growth are key elements in pig production. In particular, predicting future growth is extremely useful, since it can help in determining feed costs, pen space requirements, and the age at which a pig reaches a desired slaughter weight. However, making these predictions is challenging, due to the natural varia...
Conference Paper
Full-text available
Automatic Milking Systems (AMS) provide data to derive phenotypes comparable with the current set of phenotypes used for breeding value estimation, but AMS are also a source for novel phenotypes as a base for new breeding values. In this general overview possible applications of data from AMS in breeding are discussed. Cartesian teat coordinates me...
Conference Paper
Full-text available
Automatic Milking Systems (AMS) provide data to derive phenotypes comparable with the current set of phenotypes used for breeding value estimation, but AMS are also a source for novel phenotypes as a base for new breeding values. In this general overview possible applications of data from AMS in breeding are discussed. Cartesian teat coordinates me...
Conference Paper
Full-text available
Genotype data from 9 horse populations sampled in the Netherlands with about 20 horses per population were analysed to quantify genetic relationships and diversity and to increase our understanding of their evolutionary history. Level of inbreeding was low in populations that allowed introgression like the royal Dutch sport horse (KWPN) population....
Article
Due to uncertainty about survival and future performance of replacement heifers, many farmers rear a surplus of heifers. By predicting survival at an early age, uncertainty about heifer survival could be reduced, and fewer replacement heifers would be needed. A dataset of 1907 Holstein heifers born between 2012 and 2013 with 50 genomic breeding val...
Article
Full-text available
Automatic Milking Systems (AMS) provide data to derive phenotypes comparable with the current set of phenotypes used for breeding value estimation, but AMS are also a source for novel phenotypes as a base for new breeding values. In this general overview possible applications of data from AMS in breeding are discussed. Cartesian teat coordinates me...
Article
Full-text available
Background Most Friesian horses reach their anaerobic threshold during a standardized exercise test (SET) which requires lower intensity exercise than daily routine training. Aim: to study strengths and weaknesses of an alternative SET-protocol. Two different SETs (SETA and SETB) were applied during a 2 month training period of 9 young Friesian dre...
Article
Full-text available
Background Inbreeding and population bottlenecks in the ancestry of Friesian horses has led to health issues such as dwarfism. The limbs of dwarfs are short and the ribs are protruding inwards at the costochondral junction, while the head and back appear normal. A striking feature of the condition is the flexor tendon laxity that leads to hyperexte...
Article
Sport performance in dressage and show jumping are two important traits in the breeding goals of many studbooks. To determine the optimum selection scheme for jumping and dressage, knowledge is needed on the genetic correlation between both disciplines and between traits measured early in life and performance in competition in each discipline. This...
Article
Full-text available
Most breeding companies evaluate economically important traits in males and females as a single trait, assuming genetic correlation of 1 between phenotypes measured in both sexes. This assumption may not be true because genes may be differently expressed in males and females. We estimated genetic correlations between males and females for growth an...
Article
Full-text available
Most breeding companies evaluate economically important traits in males and females as a single trait, assuming genetic correlation of 1 between phenotypes measured in both sexes. This assumption may not be true because genes may be differently expressed in males and females. We estimated genetic correlations between males and females for growth an...
Article
In males with cryptorchidism, one or both testes do not descend into the scrotum thereby affecting among other things fertility. Testis size has been suggested to contribute to cryptorchidism. Therefore, the aim of our study was to estimate genetic parameters of cryptorchidism and testis size in Friesian colts. Data on cryptorchidism (0/1, n = 1,32...
Article
Most Warmblood horse studbooks aim to improve the performance in dressage and show jumping. The Dutch Royal Warmblood Studbook (KWPN) includes the highest score achieved in competition by a horse to evaluate its genetic ability of performance. However, the records collected during competition are associated with some aspects that might affect the q...
Article
Full-text available
While susceptibility to hypersensitive reactions is a common problem amongst humans and animals alike, the population structure of certain animal species and breeds provides a more advantageous route to better understanding the biology underpinning these conditions. The current study uses Exmoor ponies, a highly inbred breed of horse known to frequ...
Article
Full-text available
Background: Hydrocephalus in Friesian horses is a developmental disorder that often results in stillbirth of affected foals and dystocia in dams. The occurrence is probably related to a founder effect and inbreeding in the population. The aim of our study was to find genomic associations, to investigate the mode of inheritance, to allow a DNA test...
Article
Full-text available
Insect bite hypersensitivity (IBH) is the most common allergic skin disease in horses and is caused by biting midges, mainly of the genus Culicoides. The disease predominantly comprises a type I hypersensitivity reaction, causing severe itching and discomfort that reduce the welfare and commercial value of the horse. It is a multifactorial disorder...
Article
Recent studies on data from the Dutch Warmblood Studbook (KWPN) have shown that the ongoing specialization of horses for either dressage (DH) or show jumping (JH) has led to a decreasing genetic relationship between the two subpopulations. The aim of this study was to analyse the effect of the specialization process on the genetic parameters of tra...
Article
Full-text available
Natural antibody (NAb) levels and survival rates were evaluated in 4 breeds of laying hens in Ethiopia: indigenous, improved indigenous, exotic layer, and crossbred. Titers of NAb isotypes IgG and IgM binding keyhole limpet hemocyanin (KLH) in serum were measured at 20, 26, 35, and 45 wk age. Repeated-measure ANOVA showed that IgG and IgM levels va...
Article
Full-text available
To improve the health status (resilience) of dairy cows, levels of natural antibodies (NAb) might be useful. The objective of the present study was to compare levels and to estimate genetic parameters for NAb measured in milk and plasma samples. Titers of NAb IgM and IgG isotype-binding keyhole limpet hemocyanin of 2,919 cows, in both plasma and mi...
Article
Megaesophagus appears to be more common in Friesian horses than in other breeds. A prevalence of approximately 2% was observed among Friesian horses presented to the Wolvega Equine Clinic and the Utrecht University Equine Clinic. In this study, morphologic changes in the esophagi of Friesian horses with megaesophagus were compared with those of 6 c...
Conference Paper
Full-text available
Abstract Text: During the last decades, a process of specialisation into show jumping (JH) and dressage (DH) has been taking place in the Dutch Warmblood studbook (KWPN). The objectives of this paper were to describe the evolution of the connectedness between JH and DH over the last 15 years and to analyse the change in genetic parameters for some...
Conference Paper
Full-text available
Abstract Text: Dwarfism is a well-known developmental genetic disorder that, in horses, predominantly has been reported in the Friesian breed, possibly related to their relatively small gene pool. A GWAS of 50k genotypes from 19 cases and 65 controls, partly paternal half-sibs, confirmed an association with a highly significant region on ECA14 (loc...
Conference Paper
Abstract Text: ABSTRACT: The pedigree structure of the Friesian horse breed was analysed with the purpose to characterise inbreeding with special emphasis on the recent period in which measures to reduce inbreeding were taken. Measures taken consisted of a mating quota to breeding stallions and calculating individual kinship coefficients with a r...
Conference Paper
Abstract Text: To improve resilience of dairy cows, parameters like levels of natural antibodies (NAbs) can be used. The present study aimed to identify differences between levels of NAbs in milk- and blood from dairy cows, and subsequently estimate genetic parameters for NAb immunoglobulin isotypes IgM and IgG. Titres of NAb binding Keyhole Limpet...
Conference Paper
Full-text available
Abstract Text: With completion of the horse genome sequence in 2007, the potential of close international collaboration of researchers was impressively demonstrated, and an important step for genomic research in horses was taken. Since then, several European scientists have significantly contributed to the development of tools and strategies for us...
Conference Paper
Abstract Text: Egg shell quality is important for commercial egg production. The objective of this study was to identify single nucleotide polymorphisms (SNPs) that are significantly associated with egg shell strength using either own phenotype or deregressed estimated breeding values (DEBV) in brown-egg laying chickens. In this study egg shell s...
Article
During the last decades, the breeding practice within the Dutch Warmblood studbook (KWPN) has resulted in an increasing specialisation of horses into show-jumping (JH) and dressage (DH). The objective of this study was to describe the effect of the specialisation on the connectedness between the subpopulations of JH and DH horses registered by KWPN...
Article
Training horses improves athletic capabilities by inducing skeletal muscle-specific and systemic adaptations. However, rest is required to recover from exercise or else overtraining may occur and affect performance and welfare. Biomarkers would be useful to identify early chronic overtraining in animals. The objective of the current study was to in...
Article
The aim of the study was to analyse the pedigree information of Thoroughbred horses which were participating in gallop races between 1998 and 2010 in Hungary. Among the 3043 individuals of the reference population there were imported animals from foreign countries (e.g. Germany, England or Ireland) and horses that were born in Hungary. The number o...
Article
Culicoides spp. of the Obsoletus complex belong to the most important species of midge, involved in causing insect bite hypersensitivity (IBH) in horses in The Netherlands. The aim of the current study was to evaluate seven different Obsoletus complex-derived recombinant allergens (Cul o 1 – Cul o 7) and to compare these with Obsoletus complex whol...
Article
Equine osteochondrosis is a developmental joint disease that is a significant source of morbidity affecting multiple breeds of horse. The genetic variants underlying osteochondrosis susceptibility have not been established. Here, we describe the results of a genome-wide association study of osteochondrosis using 90 cases and 111 controls from a pop...