A simulation study to evaluate different strategies of genomic selection in Italian heavy pigs

Pig breeding selection schemes have been designed to maximize their effectiveness dealing with specific biological features of this species (e.g. short generation interval, large litter size, etc.) and with the limited reproduction technologies available (e.g. reduced number of semen doses per boar). The introduction of genomic selection in pig breeding could provide additional advantages to the current schemes, further improving their efficiencies and overcoming some limits of the already established selection strategies. Simulations studies can give preliminary information on the impacts and effects of genomic selection on pig breeding. A few studies have already simulated different scenarios for the introduction of genomic selection in North European pig breeding systems. However, the Italian heavy pig breeding industry has specific peculiarities that should be considered in a simulation analysis. To this aim, we used the software QMSim to simulate a structurated pig population with a genome marked with 60K bi-allelic single nucleotide polymorphisms. The population was selected over 25 generations based on BLUP breeding values for a trait with heritability of 0.40. Different genotyping strategies and methods of predicting genomic breeding values were considered and compared. The introduction of genomic evaluations might increase the accuracy levels both in young piglets and in selected reproducers and the choice of male candidate would be more accurate. Nevertheless the evaluation of the return on investment in the Italian heavy pig breeding industry would determine the implementation of genomic selection in practice