A genetic study of piglet growth and survival

The study analysed 954 Yorkshire sows from a research station in Sweden. Th e heritability for mean piglet weight at 3 weeks was 0.30 and the heritabil ity for number dead up to 3 weeks was 0.09. Correlations showed that when t he number of piglets born into a litter increased, it followed that each pi glet weighed less at 3 weeks of age (genetic correlation - 0.1). The higher the litter size at birth, the more piglets died, and if many piglets died in a litter, growth was low in the surviving piglets. The genetic correlati on between mean birth weight and mean weight at 3 weeks was estimated to be 0.6.