Maternal genetic effects for lifetime growth should be considered more in pig breeding

Abstract

Maternal genetic effects are potential breeding objective traits. Growth (LADG) and backfat (BF) at 93.9 kg body weight were recorded for 163,139 pigs in 10 herds from 2000 until 2012. Proportions of variances due to direct genetic, maternal genetic and common litter effects were 0.16, 0.03 and 0.11 for LADG and 0.28, 0.01 and 0.05 for BF, respectively. Multiple weight measurements were recorded on 896 pigs in 2013 at weaning, five, nine, 12 and 17 weeks in one herd. These individual growth traits were regressed on direct and maternal effects of LADG from the first analyses. Regression coefficients for direct or maternal genetic effects indicated that selection for these genetic effects will influence growth in a similar pattern. Whether selection for maternal genetic effects of LADG favors higher pre-weaning growth followed by a reduction in growth shortly after weaning should be explored.