Estimates of Additive and Non-Additive Genetic Variances with Varying Levels of Inbreeding

In this study, two populations with varying percentages of animals in full-sib families were simulated. For each population, two combinations of additive and dominance genetic variances of different relative magnitudes were considered thereby creating 4 sub-populations. For each sub-population, a further 3 populations (11, 12,13) were created with varying degree of inbreeding level (0, 0.02 and 0.05) resulting in a total of 12 populations. Constant residual variance was used in all populations. Variance components were estimated using the tilde-hat approximation to REML based on sire-dam model. Both additive and dominance genetic variances were estimated with high degree of accuracy and the level of inbreeding did not seem to result in changes in the magnitudes of the genetic variances. At low levels of inbreeding, accounting for inbreeding in genetic evaluations may not be necessary.