Estimating parameters growth traits of chinese simmental
Data from 1980 to 2000 were collected from six national Chinese Simmental farms,and genetic parameters of growth traits were estimated by using animal models and MTDFREML. The analyses showed that the heritabilities of birth weight, weaning weight, yearling weight, 18-month weight and mature cow weight were 0.32,0.11,0.27,0.36 and 0.47 respectively. Direct-maternal genetic correlations of growth traits were from (-0.39) to -0.99,while direct genetic correlations were significant between two closer growth traits.The result showed yearling weight was a good early select criterion,while the direct and maternal additive gentic correlations between yearling and 18-month weight,mature cow weight were significant.