Estimation of Variance Components and Genetic Trend for the Race Performance in Turkish Arabian horse

In this study, variance components and genetic trends were estimated for Turkish Arabic race performance characteristics. For this purpose, 8,321 horses riding in Turkey between 1990 and 2016 was evaluated as the result of 35929 races. The variance components were estimated with REML, the breeding values were estimated with BLUP Animal model with MTDFREML. Distance, sex, track type, age, race year and city effects on the best race time and race speed are significant. For the best models, the heritability () for the best race time and speed was estimated to be 0.05 and 0.07, respectively. The repeatability (r) for the same traits was estimated to be 0.06 and 0.07, respectively. Heritability for the total earning, mean earnings per start per year and rank ratio were estimated 0.12, 0.18 and 0.84, respectively. According to these results, it can be said that it is difficult to obtain genetic progress with selection for the best race time and speed in this population. However, genetic progress can be achieved quite well for the rank ratio, while there is limited progress for earning characteristics. It was seen that the genetic trend estimated for the stallions and mares was fluctuating and the reliability in the selection decreased.