Genomic mating allocation model with dominance to maximize overall genetic merit in Landrace pigs

D. Gonzalez-Dieguez et al., 69th Annual meeting of the european federation of animal science (EAAP), Dubrovnik, Croatie, 27-31 août 2018

Mating allocation strategies that account for dominance can be of interest for maximizing the overall genetic merit of future offspring. In a genomic context, accounting for dominance effects in genetic evaluations is easier than in a classical pedigree-based context. The objective of the present study was to evaluate, in terms of genetic gain, the efficiency of a genomic mating allocation model accounting for dominance in a Landrace pig population. Genetic variance components were estimated for three traits (age at 100 kg, backfat depth and average piglets weight per litter) using an additive and dominance GBLUP model with inbreeding. The estimated additive and dominance genetic variances were used to obtain additive and dominant SNP effects using a BLUP-SNP model. Then, additive breeding values (BV) and total genetic values (TGV, those including dominance) were predicted for the offspring of all possible matings between 40 boars and around 1,500 sows (the number of available sows depended on the trait). Following a traditional breeding scheme, the best matings resulting from 40 boars and 600 sows, were selected based either on BV or TGV using linear programming. The expected genetic gain was calculated as the difference between the mean BV (or the mean TGV) of selected matings and the mean BV (or the mean TGV) of all possible matings. Results show that, for the analysed traits, mating allocation is a feasible and a potential strategy to improve the productive performance of the offspring (i.e. to improve their TGV) without compromising the additive genetic gain in this Landrace pig population.