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 reproductive traits in sistani beef cattle. the data set consisted of 1489 records of the number of insemination, calving, and insemination dates in different calving events. reproductive traits, including the 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 inseminations per conception (nspc) were evaluated. variance components for traits were estimated using different single-trait animal models analyzed by gibbs sampling, and correlations between traits were esti-mated using the best multi-trait animal models. after convergence, the posterior mean of heritabili-ties 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) interactions, respectively. the results showed that additive genetic for most reproductive traits in sistani beef cattle was low; therefore, selection for these traits would make slow genetic progress. however, the estimated heritability of gl, do, and nspc, and the genetic correlations of these traits with ci, cr and pr suggested that selection for these traits in sistani beef cattle may enhance genetic progress in fertility.