Genetic estimates of growth traits in a small Yak population using Bayesian approach.

In India, yak is a prized germplasm for tribal highlanders due to its economical and ecological importance. However, over the years, a decline has been observed in the yak population of the country. This could be majorly attributed to the pastoral nature of the occupation, as a result of which, selection and genetic improvement of the population is not possible. This study was conducted in one of the very few organized yak farms of the country where accurate data and pedigree records of Arunachali yak breed are being maintained. However, due to the small herd size of the farm, Bayesian approach was used to estimate the genetic parameters for growth traits. A total of 880 individuals born between the years 1988 to 2021 were considered in this study and body growth was measured in the form of birth weight (BWT), body weight at 6, 12, 18, 24, 30 and 36 months (BW6M, BW12M, BW18M, BW24M, BW30M and BW36M). Non-genetic factors significantly affecting the above traits were identified and the final model was tried for genetic parameter estimation using BLUPF90 family of programs. The posterior genetic estimates of heritability were moderate to high for all the traits except BW18M. BW6M showed the highest heritability values (h2 = 0.565 ± 0.151) and also was highly and positively correlated with all the subsequent body weight traits. Hence, BW6M could be an ideal criterion for selection of growth traits in Arunachali yak, particularly females.