Study of factors affecting the body conformation traits of Iranian Turkoman horses

The Iranian Turkoman horse is considered one of the major categories of Iranian native horses. The aim of this research was to study the genetic and nongenetic factors affecting body conformation traits in Iranian Turkoman horses. For this, measurements were performed on body conformation traits of 121 horses. To study the effect of nongenetic factors, the Lsmeans procedure was used. Variance components and heritability were estimated by restricted maximum likelihood method (REML) and AI-REML convergence algorithm. The standard deviation was estimated to be 7.04 cm for croup depth and 2.08 cm for chest width, and the coefficient of variation was estimated to be 11.27% for croup length and 2.58% for withers height. Sex had a significant effect on head-neck circumference (P<0.05), withers height (P<0.05), chest width (P<0.05), and croup height (P<0.05). Province had a significant effect on withers height (P<0.05) and croup depth (P<0.05). The lowest and highest heritability estimates were for head-neck circumference (0.12 ± 0.06) and neck-body circumference (0.33 ± 0.09), respectively. The lowest and highest additive genetic variance estimates were for head length (0.64) and pelvis width (18.34), respectively. Generally, the medium to high estimated heritability for the traits in this study indicate that genetic improvement would be possible in these traits.