Bayesian estimates of genetic parameters and genetic trends for morphometric traits and their relationship with yearling weight in Moghani sheep

Abstract

This study was conducted to estimate variance components, genetic parameters and genetic trends for morphometric traits and their relationship with yearling weight in Moghani sheep. The data set and pedigree information of Moghani sheep were obtained from the breeding station of Moghani sheep (in Ardebil province, Iran) and comprised 2387 lamb records for morphometric traits during 1994 to 2012. Traits considered were height at withers (HW), height at rump (HR), body length (BL), heart girth (HG), leg circumference (LC) and yearling weight (YW). Four different animal models were fitted, differentiated by including or excluding maternal effects, with covariance between maternal and direct genetic effects were implemented by Gibbs sampling methodology. Selection of the best model of analysis for each trait was based on Akaike’s information criterion (AIC). Posterior mean estimates of direct heritabilities for BL, HW, HR, LC, HG and YW were 0.34, 0.037, 0.47, 0.073, 0.065 and 0.17, respectively. Estimates of direct genetic correlation between morphometric traits varied from −0.21 (between BL–LC) to 0.67 (between LC–HG). Estimates of direct genetic correlation between morphometric traits and YW were positive and varied from 0.08 (between HW–YW) to 0.52 (between HG–YW). Estimates of direct genetic trends for BL, HW, HR, LC and HG were significant (p