Crossbreeding in Swine: Genetic Effects on Pig Growth and Carcass Merit

Abstract

The effects of offspring heterosis, maternal heterosis and breed composition on individual pig performance and carcass merit were estimated with data from purebred, single cross, paternal backcross (single cross sires) and maternal backcross (single cross dams) pigs produced from matings among the Chester White, Duroc, Hampshire and Yorkshire breeds. Offspring heterosis was important for all weight traits, with highly significant estimates ranging from 3.5% (birth weight) to 10.5% (154-d weight). Maternal heterosis was small for most traits except 21-d weight (4.9%, P<.01). General combining ability was a highly significant source of variation for 154-d weight and all carcass traits except yield. Significant differences among maternal ability estimates indicated that this factor was an important source of variation for all traits except marbling and color. Breed of maternal grandparent was a significant source of variation in 154-d litter weight and longissimus muscle area and was highly significant for the remaining traits. Specific combining ability was an important source of variation for birth weight, marbling and color. The residual purebred effect was an important source of variation for backfat and color. Copyright © 1982. American Society of Animal Science. Copyright 1982 by American Society of Animal Science.