Duenk Genomic Selection Review: Optimizing genomic selection for crossbred performance by model improvement and data collection

By Caitlin Vonderohe

Crossbreeding, genetically crossing purebred lines to improve the performance of the progeny, is widely practiced in pig and poultry production. However, this practice is made more challenging because the selection practices occur on purebred lines, but the performance improvements are measured in the crossbred offspring. The genetic correlation between purebred and crossbred performance can be predicted, meaning a breeding value can be calculated for crossbred animals. A recent review by Duenk et al. in the Journal of Animal Science, “Optimizing genomic selection for crossbred performance by model improvement and data collection” focused on strategies to use crossbred performance to predict breeding value of purebred animals to be used in production. 

The review first explored predictive modeling strategies for crossbred performance based on studies that used a purebred reference population. Studies that used a dominance selection model, rather than an additive model showed short term improvements in crossbred performance. Other purebred-focused studies showed that including the effect of production environment improved the accuracy of genetic prediction. The authors then focused on studies that used data collected on crossbred animals to predict breeding value. Phenotyping crossbred animals, rather than purebred animals improved accuracy of the estimated breeding value for crossbred performance and the benefits of genotyping crossbred animals increases as the number purebred animals included in the reference population decreased. Inclusion of crossbred instead of purebred animals in a study population can greatly improve the response to selection in production animals. The authors finally discussed studies that assessed the utility of breed origin of alleles can also improve selection practices. 

Overall, this review presented an assessment of multitude of strategies to improve genetic selection purebred animals for crossbred production.