Abstract:

In previous work, we theoretically derived expressions for an upper and lower bound of the correlation between purebred and crossbred performance (r_pc), using only variance components of the parental purebred lines. In the current study, we validated these expressions in real data of pigs by comparing predicted bounds of r_pc with the estimated r_pc. We compared three methods to approximate the required variance components. The results suggest that the most useful method is to use ordinary REML estimates. If confirmed in other datasets, this approach may help breeders to predict the value of r_pc based only on parental line information, or to determine the relative contributions of genotype by genotype and genotype by environment interactions to the value of r_pc. We therefore advise studies estimating r_pc with genotype data to also estimate and report genetic variance components within and between the parental lines, estimated as described in this study.