Posta, J., Mezei, A., & Mihók, S. (2012). Genetic evaluation of competition years, as a kind of measurement of durability in Hungarian show-jumping horses. In K. Krueger (Ed.), Proceedings of the 2. International Equine Science Meeting (Vol. in press). Wald: Xenophon Publishing.
Abstract: The aim of the study was to investigate the possibilities to use “number of years in competition” as a measure of durability in the genetic evaluation of Hungarian show-jumping horses. Competition results recorder between 1996 and 2009 in show-jumping competitions were used to estimate genetic parameters for number of years in competition. The results were collected by the Show-jumping Group of the Hungarian Horse Breeder’s Society. For estimation of genetic parameters for number of years in competition different linear mixed models were tested. In the first model, sex and birth year were taken into account as fixed effects. In the second model, an adjustment was made for age at first result in competition. The model fit was compared based on their determination coefficient. Variance components were estimated with VCE-6 software package. The determination coefficients of the models were 0.09 and 0.20, while the estimated heritability for number of years in competition was 0.27 and 0.23, respectively.
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Mezei, A., Posta, J., & Mihók, S. (2012). Analysis of eventing competition results of Hungarian Sporthorses. In K. Krueger (Ed.), Proceedings of the 2. International Equine Science Meeting (Vol. in press). Wald: Xenophon Publishing.
Abstract: The aim of the study was to evaluate the Hungarian Sporthorse population based on eventing competition performance. The database contained the results of 792 horses and 449 riders between 1996 and 2006. The eventing results were gathered from Hungary and other European countries. Blom transformed ranks were used to measure competition performance. Sporthorses competed in fourteen categories but only the easiest category (category ’A’) contained enough result to handle it as a single category (model I.). The other 13 categories were handled together based on professional reasons in a different model (model II.). In model III., all records were analysed together and the results were weighted according to the difficulty of the category. The competition results were classified into eight groups, each group had a weight (0-7) and it was multiplied by a constant 3, and the result of this formula was added to the original Blom score. The linear mixed models included fixed effects for age, sex, breeder, owner, location, year and random effects for animal and rider. The model II. contained one more fix effect for difficulty of the competition level. The distribution of number of horses and number of starts by sex were heterogeneous (P<0.05). For category ’A’ mares and geldings appeared in higher proportion, despite this fact ratio of stallions is greater in higher competition levels. Considering the goodness of fit in each model, model fitting to the weighted Blom scores was the best R2=0.82. In model III. every fix effects (age, sex, breeder, owner, location, year) were significant. Random effects for animal and rider were not significant, but form professional point of view they need to be included in the model. The variance components estimated for the weighted Blom scores were the highest also (0.52 rider effect, 0.09 animal effect), the animal x rider interaction effect was zero. The variance proportion of rider effect exceeded the variance proportion of animal effect in each model. Breeding values of eventing performance were predicted using model III. The reliability of the estimated breeding values was acceptable for only a few stallions. To improve the reliability of breeding values, more progenies should be used in eventing competitions (as a kind of progeny test) and more competition records needed (as a kind of own performance test).
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