Influence of Sire and Line of Breeding on Sow Productivity

Abstract

A study was made to determine the effects of line of breeding and sire on sow productivity. Traits studied were numbers of pigs farrowed and weaned per litter and litter weights at farrowing and 56 days. Overall line averages were significantly different for some traits; however, when lines were compared on a within season basis relative production was very inconsistent. In no comparison was one line better than the one with which it was compared in all seasons for any one trait. There was little indication that genetic differences between sire progeny groups for sow productivity could be detected with any consistency when sires were represented by small numbers of daughters. The negative regression of the productivity of the sire's purebred daughters on his crossbred daughters might be caused by overdominance, but the regression coefficients were small and not significant and may therefore have been chance variations. Copyright © . .