Bayesian estimates of genetic changes for body weight traits of Moghani sheep using Gibbs sampling.

The objective of the present study was to estimate genetic changes of body weight at different ages in Moghani sheep. Traits included were birth weight (BW, n = 4,208), 3-month weight (3MW, n = 4,175), 6-month weight (6MW, n = 3,138), 9-month weight (9MW, n = 2,244), and yearling weight (YW, n = 1,342). Data and pedigree information used in this study were collected at the Breeding Station of Moghani sheep during 1989-2005. The analysis was carried out for five traits, using the MTGSAM program. Breeding values of individual animals were obtained from a multivariate animal model analysis and genetic trends were obtained by regressing the means of predicted breeding values on year of birth for each trait. Direct genetic trends were positive and significant (P < 0.05) for BW, 3MW, 6MW, 9MW, and YW and were 1.63, 69.20, 79.38, 66.83, and 110.22 g/year, respectively. Also, maternal genetic trends for BW, 3MW, 6MW, 9MW, and YW were positive and significant (P < 0.05) and were 2.36, 49.18, 37.33, 17.73, and 9.67 g/year, respectively. The results showed that improvement of body weights of Moghani sheep seems feasible in selection programs.