Estimation of genetic and phenotypic correlations of the conformation traits with the racing performance traits of Iranian Arab horse

Iran is the origin and rise of the Arabian horse. Each year, the breed originality of the new born horses will be confirmed and registered by the World Arabian Horse Organization (WAHO) through the DNA test. The aim of this study was to unbiased estimation of phenotypic and genetic correlations of the conformation traits with the racing performance traits of the Iranian Arab horse through designing the appropriate statistical models. In a randomized sampling, six important traits were recorded, including withers height, body length, hind cannon circumference, fore cannon circumference, thorax girth and chest depth. The best racing time in distance of 1250 meters, the best racing time in distance of 1750 meters, and the best place in distance of 1250 meters were recorded by reviewing the horse racing films. To estimate the genetic correlations, the multi-trait animal model and derivative free-restricted maximum likelihood and DFREML software were used. The highest and the lowest genetic correlations were estimated for the thorax girth with the best place in distance of 1250 meters (-0.70±0.08) and the fore cannon circumference with the best racing time in distance of 1250 meters (0.06±0.00), respectively. Generally, high genetic correlation was estimated for the body conformation and performance traits. Therefore, at the young age, conformation traits can be used for the selection of the reproductive and appropriated horses for the racing and then reduced the generation interval and increased the genetic progress.