ONLINE ONLY - Additive and dominance genetic variance of fertility by method R and preconditioned conjugate gradient

The objectives of this study were threefold: 1) estimation of additive and dominance genetic variances for fertility traits for Austrian Simmental and Brown Swiss dairy cattle; 2) use of method R and the preconditioned conjug ate gradient compared to solving for method R by second-order Jacobi iterat ion; and 3) study of the impact of inclusion of parental subclass effects o n solutions for other random effects. Dominance variances were modeled for the inseminated cow and ranged from 0.32 to 1.36% of total variance. These values were similar to values for additive effects, which were approximatel y 1% of total variance. Convergence was clearly improved with preconditione d conjugate gradient and number of extrapolations reduced. Variance for per manent environment under a model without dominance could be split into a ne w estimate of permanent environmental variance and parental subclass varian ce. Solutions for parental subclass dominance effects were approximately pr oportional to permanent environment effects, but highly dependent on the nu mber of animals contributing dominance relationships, especially full-sibs and three-quarter-sibs. For animals with a lot of dominance information (fu ll-sibs, three-quarter-sibs, cousins), permanent environment and parental s ubclass dominance effects were nearly independent. Changes in additive effe cts were negligible, probably because both variances for parental subclass dominance effects and additive genetic effects were very small compared wit h residual variance.