Estimation of Non-Additive Genetic Variances in Three Synthetic Lines of Beef Cattle Using an Animal Model

摘要: Dominance and additive x genetic variances were estimated for birth weaning traits of calves from three synthetic lines beef cattle differing in mature size. Data consisted 3,992 2,877 records small-, medium-, large-framed each two research herds located at Rhodes McNay, IA, respectively. Variance components separately by herd line weight (BWT), hip height (BH), 205-d (WW), (WH) derivative-free REML with an animal model. Model 1 included fixed effects year, sex, age dam. Random direct (a) maternal (m) covariance (a,m), permanent environmental, residual. 2 also dominance (d) model 3 plus (a:a) effects. In general, only slight changes occurred other variance estimates when day was 2. However, large obtained 4 out 24 analyses associated reductions variances. Direct (maternal) heritability averaged across herd-line combinations .53(.11), .42(.04), .27(.12), .35(.04) BWT, BH, WW, WH, Corresponding (a,m) as fractions phenotypic (sigma p2) .00, .01, .06, For environmental 2, average sigma p2 .03, .05, .02, BW, explained, on average, 18, 26, 28, 11% total Most the negligible, except one data set where relative this component high (.21 to .45). These results suggest that most non-additive studied is accounted