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Author Álvarez, I.; Royo, L.J.; Pérez-Pardal, L.; Fernández, I.; Lorenzo, L.; Goyache, F. url  doi
openurl 
  Title Assessing diversity losses due to selection for coat colour in the endangered bay-Asturcón pony using microsatellites Type Journal Article
  Year Publication Livestock Science Abbreviated Journal Livest Sci  
  Volume In Press, Corrected Proof Issue Pages  
  Keywords Conservation; MC1r; Asip; Gene diversity; Allelic richness  
  Abstract The bay-Asturcón pony (A21) population recovery started recently. A total of 297 samples (180 from founder individuals) belonging to the A21 population were genotyped for: a) a set of 15 microsatellites; and b) the presence of the two recessive chestnut alleles reported in the literature (e and ea) on the MC1r gene (locus Extension) and the deletion on the ASIP gene (locus Agouti) associated with recessive black coat in horses. The extent to which the genetic variability of the A21 population could be affected by selection strategies aimed at decreasing the frequency of the chestnut allele was quantified in terms of gene diversity and allelic richness. The possible genetic impact of a controlled introgression of A21 offspring into the black-coated Asturcón (A20) population was also assessed using 261 available A20 genotypes. The wild alleles for the Extension and Agouti loci (E and A, respectively) were the most frequent (77.8% and 59.4%) in the A21 population. Both the e and ea recessive chestnut alleles were identified with frequencies of 21.2% and 1.0%. As expected, the contribution to overall diversity of the founder subpopulation was always higher than that of the A21 offspring subpopulation. Total contribution of the offspring subpopulation to overall allelic richness was negative (- 1.84%), showing that all their alleles were present in the founder subpopulation. Although favourable, the chestnut carrier individuals had poor contributions to overall gene diversity and tended to have negative contributions to allelic richness. The elimination of the chestnut carrier A21 individuals would not affect genetic variability to a significant extent. Therefore, efforts for preserving the genetic variability in the A21 population could focus on a careful planning of matings between individuals free of the recessive chestnut alleles. The expected influence of a controlled introgression of A21 offspring on the genetic variability of the A20 population was always favourable. The gene diversity of the introgressed population was higher than that of the original A20 population for both gene diversity (GDT = -1.2% ± 0.04%) and, particularly, allelic richness (CT = 4.9% ± 0.27%). Very limited gene flow may increase the number of alleles of the A20 population but also would yield a balance of the allelic frequencies at a population level. Therefore, a common breeding policy for the two Asturcón pony populations may ensure the viability of this prominent genetic resource.  
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  ISSN 1871-1413 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5174  
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Author Thiruvenkadan, A.K.; Kandasamy, N.; Panneerselvam, S. url  doi
openurl 
  Title Coat colour inheritance in horses Type Journal Article
  Year 2008 Publication Livestock Science Abbreviated Journal  
  Volume 117 Issue 2-3 Pages 109-129  
  Keywords Horse; Coat colour; Melanogenesis; Genetic control; Molecular genetics  
  Abstract The colours of the horses have long been a subject of interest to owners and breeders of horses as well as to scientists. Though, the colour of horses has little to do with its performance, it is a primary means of identification and also the first indicator of questionable parentage. Probably the ancestral colour of the horse was a black-based pattern that provided camouflage protection against predators. Horse colours are mostly controlled by genes at 12 different loci. The three basic colours of horses are black, bay and chestnut. The genetic control of the basic colours of horses resides at two genetic loci, namely Extension (E) and Agouti (A) loci. Among the basic colours bay is dominant to black and both are epistatic to chestnut. Dilution of basic colours of horses as a result of four colour dilution genes such as cream dilution, dun, silver dapple and champagne resulted in extensive array of possible colours of horses. The most widespread and familiar of the horse colour dilution gene is the one that produces the golden body colour and are called as palomino or buckskin based on the colour of the points. The grey coat colour is due to the presence of dominant gene (G) at the grey locus. Grey is epistatic to all coat colour genes except white and a grey horse must have at least one grey parent. Roan is due to a dominant gene (Rn) at roan locus and this combines with any base colour to produce the various shades of roan pattern. White coat is due to a single dominant gene (W) and it is epistatic to the genes controlling all other colours. White marking in the face and legs are due to genetic and non-genetic factors. Several genes are involved in producing white markings. During recent years, comparative genomics and whole genome scanning have been used to develop DNA tests for different variety of horse colours. Molecular genetic studies on coat colour in horses helped in identification of the genes and mutation responsible for coat colour variants. In future, this will be applied to breeding programmes to reduce the incidence of diseases and to increase the efficiency of race horse population.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1871-1413 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 4776  
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Author Kavar, T.; Dovc, P. url  doi
openurl 
  Title Domestication of the horse: Genetic relationships between domestic and wild horses Type Journal Article
  Year 2008 Publication Livestock Science Abbreviated Journal  
  Volume 116 Issue 1-3 Pages 1-14  
  Keywords Equus caballus; Domestication; Mitochondrial DNA (mtDNA); Y chromosome markers  
  Abstract To date, a large amount of equine genetic data has been obtained regarding (i) extant domestic horses of various breeds from all over the world, (ii) ancient domestic horses, (iii) the extant Przewalski's wild horse, and (iv) the late Pleistocene wild horse from Eurasia and North America. Here, a review of mtDNA and Y chromosome marker analyses is presented in the context of horse domestication. High matrilineal (mtDNA) diversity, which can be found in both extant and ancient (domestic and wild) horses, has suggested that a high number of wild (and tamed) mares were domesticated. Alternatively, Y chromosome marker analysis revealed a single haplotype in all domestic horses analyzed; interestingly even a small population of extant Przewalski's wild horses showed two different Y chromosome haplotypes. It seems that an extreme male population bottleneck occurred due to domestication, while reduction in the female population was only moderate, leaving about 100 distinct haplotypes. For this reason, we speculate that domestication might have started when the appropriate stallion was found or was obtained by selection. Perhaps it had some unusual but special characteristics which could have accelerated the process of domestication. We doubt that only a single Y chromosome haplotype will be found in present-day domestic horses if there are no important differences between the founder stallion/s and the other stallions that were not included in the domestication. In the Eneolithic, tamed and wild mares have probably been spread all over Eurasia, although the number of animals was most likely very low and the populations were limited to a restricted area (e.g., taming centers). Only two subspecies of wild horses (Tarpan and Przewalski's wild horse) have survived up to recently. During the further process of domestication, mares (tamed or wild) were preferentially crossed to stallions having more desirable characteristics. We assume that mares from different regions varied in their morphology due to adaptation to their local environmental conditions. These data might explain rapid expansion of horse populations, as well as their rapid differentiation into various phenotypes during the early phase of domestication.  
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  Series Volume Series Issue Edition  
  ISSN 1871-1413 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 4771  
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Author Puppe, B.; Langbein, J.; Bauer, J.; Hoy, S. url  doi
openurl 
  Title A comparative view on social hierarchy formation at different stages of pig production using sociometric measures Type Journal Article
  Year 2008 Publication Livestock Science Abbreviated Journal  
  Volume 113 Issue 2-3 Pages 155-162  
  Keywords Pig; Dominance; Sociometric measures; Social hierarchy; Ontogeny  
  Abstract A standardised and comprehensive approach to describe dominance relationships in gregarious farm animals quantitatively was recently developed, incorporating a combination of appropriate sociometric measures. The present study applied this approach to a comparative analysis of the social hierarchies within 57 groups of domestic pigs at different age/production stages with a total of 496 animals. Unacquainted pigs were grouped to three age categories which correspond to the typical production stages: weaned pigs (PIG28, 12 groups), growing pigs (PIG80, 16 groups), and reproductive sows (SOW, 29 groups). Based on observed agonistic interactions, sociometric values were calculated both at the dyadic and at the group level and may be considered as preliminary reference values for further studies. As indicated by the respective values of the Kendall index (PIG28: 0.66, tested as significant in 69.0% of the observed groups; PIG80: 0.71, 87.5%; SOW: 0.61, 69.0%), and the improved Landau index (PIG28: 0.70, 75.0%; PIG80: 0.72, 93.7%; SOW: 0.71, 72.4%), a social organisation towards a quasi-linear social hierarchy was predominantly developed throughout all age/production categories. However, compared to weaned and growing pigs, sows were characterised by significant differences concerning establishment (fewer agonistic interactions) and kind (more unknown dyads, fewer two-way and significant dyads, higher directional consistency index) of their social hierarchy. It seems that sows have effectively adapted their agonistic behaviour towards pen-mates to regulate social dominance relationships, whereas younger pigs frequently display agonistic interactions also to gain additional experience on social cues (e.g. the fighting ability of an opponent). Hence, it is concluded that the effective experience of socialisation during sensitive periods may increase the social skills of pigs which in turn can improve their welfare and health, e.g. by adjusted aggressive behaviour. The consideration of comparable and standardised sociometric measures in livestock breeding may help to improve husbandry conditions.  
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  Notes Approved no  
  Call Number Serial 2139  
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Author Ducro, B.J.; Koenen, E.P.C.; van Tartwijk, J.M.F.M.; van Arendonk, J.A.M. url  openurl
  Title Genetic relations of First Stallion Inspection traits with dressage and show-jumping performance in competition of Dutch Warmblood horses Type Journal Article
  Year 2007 Publication Livestock Science Abbreviated Journal  
  Volume 107 Issue 1 Pages 81-85  
  Keywords Riding horse; Heritability; Stallion inspection; Dressage; Show-jumping  
  Abstract Genetic parameters for traits evaluated at the First Stallion Inspection (FSI) and genetic correlations with dressage and show-jumping performance in competition were estimated. Data comprised 2361 stallions with FSI-observations from 1994 through 1999. Genetic analyses were performed using univariate and bivariate animal models. Heritability estimates of the FSI-traits ranged from 0.25 to 0.61. FSI-traits related to gaits showed strong genetic correlations (above 0.70) and FSI-traits related to free jumping had correlations close to unity. Competition results of 23,897 horses with performance in dressage and 22,811 horses with performance in show-jumping were linked to the FSI data to estimate the genetic relationship with performance in competition. Heritability estimates for dressage and show-jumping were 0.14. Genetic correlation between FSI-gaits and dressage in competition were positive, ranging from 0.37 to 0.72. Genetic correlation between FSI-jumping traits and show-jumping were all above 0.80. FSI-jumping traits showed negative correlations with dressage (about – 0.48). FSI-gait traits showed negative correlations with show-jumping, except for canter. It is concluded that selection at First Stallion Inspection comprises an important component of the stallion selection program, because FSI-traits have good genetic relationships with performance in competition and, due to the number of animals involved, relative high selection intensities can be achieved.  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ user @ Serial 3948  
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Author Ducro, B.J.; Koenen, E.P.C.; van Tartwijk, J.M.F.M.; Bovenhuis, H. url  openurl
  Title Genetic relations of movement and free-jumping traits with dressage and show-jumping performance in competition of Dutch Warmblood horses Type Journal Article
  Year 2007 Publication Livestock Science Abbreviated Journal  
  Volume 107 Issue 2-3 Pages 227-234  
  Keywords Horse; Heritability; Movement; Free-jumping; Dressage  
  Abstract Genetic parameters for traits evaluated at the studbook entry inspection and genetic correlations with dressage and show-jumping performance in competition were estimated. Data comprised 36,649 Warmblood horses that entered the studbook between 1992 and 2002. The genetic analyses were performed using univariate and bivariate animal models. Heritabilities of the studbook entry traits were estimated in the range 0.15-0.40. The movement traits showed moderate to strong mutual genetic correlations, whereas the genetic correlations of movement traits with free-jumping traits were weak to moderate. The free-jumping traits showed strong to very strong mutual genetic correlations. Competition results of 33,459 horses with performance in dressage and 30,474 horse with performance in show-jumping were linked to the studbook entry data to estimate the genetic relationship with performance in competition. Heritability estimates for dressage and show jumping were 0.14. Genetic correlations of the movement traits with dressage were moderate to strong, and with show-jumping weak to moderate. Genetic correlations of the free-jumping traits with dressage were weak to moderate and unfavourable. The free-jumping traits were genetically strong to very strong correlated to show-jumping. It was concluded that a selection of the traits evaluated at the studbook entry inspection will favourably contribute to estimation of breeding values for sport performance.  
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  Series Editor Series Title Abbreviated Series Title  
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  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ user @ Serial 3947  
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Author Thoren Hellsten, E.; Viklund, A.; Koenen, E.P.C.; Ricard, A.; Bruns, E.; Philipsson, J. url  doi
openurl 
  Title Review of genetic parameters estimated at stallion and young horse performance tests and their correlations with later results in dressage and show-jumping competition Type Journal Article
  Year 2006 Publication Livestock Science Abbreviated Journal  
  Volume 103 Issue 1-2 Pages 1-12  
  Keywords Genetic parameters; Sport horse; Performance test; Competition; Dressage; Show-jumping  
  Abstract Results from performance tests and competitions of young horses are used by major European warmblood horse breeding associations for genetic evaluations. The aim of this review was to compare genetic parameters for various tests of young horses to assess their efficiency in selection for dressage and show-jumping. Improved understanding of genetic information across countries is also necessary, as foreign trade with semen is rapidly increasing. The review is based on inquiries to European breed associations and on (17) scientific publications available, which have analysed genetic parameters of young horse data and/or relationships between young and mature horse results in sport. Despite differences in testing methods of young horses, results for major horse populations were in good agreement. Specially designed young horse performance tests, including stallion tests, showed high heritabilities and high genetic correlations with later competition results. We recommend that test results are encouraged to be used across countries for genetic evaluation of imported stallions and semen. Short station tests are generally preferred when selecting stallions for both dressage and jumping traits, whereas competition data may be used when selecting for only one discipline. We also recommend that extensive field testing of young horses is encouraged and should include both genders.  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ user @ Serial 3951  
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Author Lewczuk, D.; Sloniewski, K.; Reklewski, Z. url  openurl
  Title Repeatability of the horse's jumping parameters with and without the rider Type Journal Article
  Year 2006 Publication Livestock Science Abbreviated Journal  
  Volume 99 Issue 2-3 Pages 125-130  
  Keywords Via; Jumping; Linear parameters; Stallion's test  
  Abstract The total number of 4323 jumps with and without the rider of 141 young stallions were filmed and measured using video image analysis. Horses were filmed on the doublebarre fence (100, 110 and 120 cm) with the same width of 90 cm. The style of jump was characterised by measurements of taking off and landing distances, as well as some measurements of the silhouette of the horse over the obstacle. The repeatability was 0.40-0.58 for distances of the jump's length, 0.37-0.56 for bascule's measurements and about 0.20 for legs' lifting above the fence. Traits measured under the rider and on the highest fences were more repeatable.  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ user @ Serial 3969  
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Author Górecka-Bruzda, A.; Chruszczewski, M.H.; Jezierski, T.; Murphy, J. url  doi
openurl 
  Title Behaviour-related traits of Polish sport horse stallions participating in 100-day performance tests Type Journal Article
  Year Publication Livestock Science Abbreviated Journal Livest Sci  
  Volume In Press, Corrected Proof Issue Pages  
  Keywords Horse; 100-day performance tests; Behaviour; Temperament; Factor Analysis  
  Abstract Sport horse studbooks frequently use performance tests to identify, evaluate and approve stallions for future breeding programmes. The aim of this study was to analyse behaviour-related traits of Polish Warmblood stallions participating in studbook 100-day performance tests. Both relatedness and differences of traits and their contribution to overall variability were analysed. Three-year-old stallions (n = 374) participated in 100-day performance test programmes at two Polish training stations from 2004 to 2008. Traits including character, temperament and trainability (trainer rated), free-jumping, jumping under the rider, walk, trot and canter (independently rated by both trainer and the selection jury) and jumping ability, dressage-ability and rideability (rated by the independent test rider) were subjected to Factor Analysis (FA) with varimax rotation. The FA produced three factors [Cooperation (Cp), Jumping Potential (JP) and Dressage Potential (DP)] with eigenvalues > 1, which accounted for 64.6% of the total variance of the traits examined. After rotation, the factors represented Cp: 23.2.0%, JP: 21.5% and DP: 19.8% of variance respectively. The traits of character, temperament, trainability, jumping under the rider, rideability, dressage and jumping abilities had high loadings on the second factor (Cp) and thereafter, the assessment of all behaviour-related traits contributed to the general evaluation with approximately one-fifth of total variability. The findings may indicate that successful sport careers for any horse may be much more closely associated with willingness to cooperate with the rider and riding and handling behaviour, than to the horse's actual physical performance potential. It would appear that only so-called sport-suitable performance of the horse is being selected for in performance tests (during jumping and dressage suitability testing). This approach may be short-sighted and inadequate with serious implications for horse under-performance in leisure activities notwithstanding general horse welfare within the disciplines of equitation.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1871-1413 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5281  
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Author Dubois, C.; Manfredi, E.; Ricard, A. doi  openurl
  Title Optimization of breeding schemes for sport horses Type Journal Article
  Year 2008 Publication Livestock Science Abbreviated Journal  
  Volume 118 Issue 1-2 Pages 99-112  
  Keywords Breeding scheme; Horse; Jumping; Optimization; Genetic trend, Multistage selection  
  Abstract A selection scheme for jumping sport horses is modelled with four stages of selection for males and one stage for females. The selection objective included three traits: conformation and gaits (CG, weighted 20%), competition jumping (CJ, weighted 60%) and a third trait (TT, weighted 20%) such as sperm quality or orthopaedic status. The first selection stage is based on knowledge of the pedigree with the aim of selecting horses suitable for CG test (at 3 years old) and CJ test (at 5 years old). The second stage includes the horse's own performance with respect to CG and CJ with the aim of selecting horses suitable for the TT test. The third stage is the selection of a limited number of males who are allowed to reproduce. The fourth stage (at 12 years old) takes into account the results of the horse's progeny. Females are selected in one step, whatever the number of performances measured at 5 years old. The annual genetic response was 9.4% genetic standard deviation of the objective, 2.6% for CG, 9.0% for CJ and 1.5% for TT. Results showed that selection by progeny testing did not contribute much to genetic response (12% of progeny issued from proven sires), the female pathway represented 26% of genetic response, TT was difficult to improve when the genetic correlation was unfavourable (- 0.6% genetic standard deviation for - 0.20 genetic correlation), and should consequently be directed towards the use of molecular markers. When compared with a selection scheme involving a station test, genetic response was the same if the breeding values used for selection before entering the station test took into account the results of the relatives for CJ and CG. This revealed the importance of an extensive performance test (like for competition performance) when designing breeding schemes for sport horses.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1871-1413 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 4759  
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