安格斯牛18月龄体尺体重性状遗传参数分析OA北大核心CSTPCD

The study was to analyze the effects of different animal models on the estimation of genetic parameters of growth traits in Angus cattle at 18 months of age in Ningxia,and to screen out the best animal models for estimating genetic parameters of growth traits.In this study,six animal models were distinguished using the inclusion or exclusion of maternal genetic effects,maternal permanent environmental effects and the presence or absence of covariance between maternal and direct genetic effects,and the genetic parameters of 18-month-old growth traits in Angus cattle were estimated using the constrained maximum likelihood method(AI-REML)with the help of the DMU_AI module of DMU software.The best animal model for genetic parameter estimation was determined using the Akaike Information Criterion(AIC)and Likelihood Ratio Test(LRT).The results showed that:1)Model 4 was the best model for estimating body weight(BW),crucifixion height(CH)and shin circumference(SC)in Angus cows at 18 months of age,and the direct heritability of the above three traits estimated by this model was 0.42,0.29 and 0.22,respectively.Maternal heritability was 0.11,0.14 and 0.05,respectively,and total heritability was 0.23,0.12 and 0.11,respectively.2)Model 6 was the best model for estimating body height(BH),body length(BL)and chest circumference(CC)in 18-month-old Angus cows,and the estimated direct heritability for these traits was 0.42,0.29 and 0.22,respectively,and the estimated direct heritability for the above three traits was 0.11,0.14 and 0.05,respectively.The estimated direct heritability of these traits was 0.48,0.48 and 0.64,the maternal heritability was 0.02,0.12 and 0.08,and the total heritability was 0.33,0.18 and 0.34,respectively.In summary,considering the covariance and maternal effects between direct genetic effects and maternal genetic effects,and maternal effects allows for more accurate and unbiased prediction of the target trait.This study provides a theoretical basis for accelerating genetic progress in Angus cattle.