Characterisation and selection of gilts with improved performance of progeny: Final Report APL Project 2014/458

Abstract

It was the aim of this research project to investigate the effects of sow and birth-litter characteristics on performance of progeny and to evaluate genotype by parity interactions in order to identify management and selection strategies that provide better support for gilts and their progeny. The analyses for this project involved extensive data sets from three herds. The combined data included about 320,000 growth, backfat and muscle depth records, 10,000 feed intake records, 2,000 repeated weight measurements and 1,000 immune parameters. Information about litter and dam characteristics included number born alive, average piglet birth weight, number of piglets weaned, lactation lengths (or weaning age of the piglet), weight and fat depth of sows at testing shortly before selection. Analyses were performed separately for each herd to evaluate significance of litter and sow characteristics for performance traits of progeny. Genotype by parity interactions were evaluated by defining progeny growth as a separate trait for progeny from the first five parities of sows. Progeny growth was affected by sow parity in all herds. However, the magnitude of the birth-parity effect on progeny growth was variable between herds, between time periods and between sow parities. Growth rate of gilt progeny was reduced by -35 to -2 g/day in comparison to growth rate of progeny from multiparous dams. Farmers should evaluate their own data to establish which group of sows need better support in order to improve progeny growth. Some herds may also need to focus on supporting older sows and their litters in order to improve growth in progeny from older sows.