Bayesian inference of genetic parameters for reproductive traits in Sistani native cows using Gibbs sampling

This study was undertaken to estimate the genetic parameters for some reproduction traits in Sistani beef cattle. The data set consisted of 1489 records of number of insemination, calving, and insemination dates in different calving was used. Reproduction traits including calving interval (CI), gestation length (GL), days open (DO), calving to first service (CTFS), first service to conception (FSTC), conception rate (CR), pregnancy rate (PR), and number of insemination per conception (NSPC) have been evaluated. The variance components for traits were estimated using of different single-trait animal models analyzed via Gibbs and correlations between traits were estimated using the best multi-trait animal models. After convergence, the posterior mean of heritability for CI, GL, DO, CTFS, FSTS, CR, PR and NSPC in the best model were estimated as 0.032, 0.113, 0.096, 0.002, 0.012, 0.082, 0.023, and 0.123, respectively. The highest and lowest genetic correlations were found for CI×CR (-0.999) and CTFS×NSPC (0.001), respectively. The results showed that the additive genetic for the most of reproduction traits in Sistani beef cattle was low so doing selection for these traits would make slow progression. However, the estimated heritability of GL, DO, and NSPC and also genetic correlation of these traits with CI, CR and PR may suggest that selection for these traits in Sistani beef cattle could be an effective way to make genetic improvement.