Economic Weights for Maternal Pig Traits in Australia Motivate Genetic Improvement for Robustness

A new model was developed to provide Australian pig breeders with an ability to estimate economic values and economic weights of key traits in a way that was more flexible and relevant to pig producers. Economic weights were converted using a genetic standard deviation scalar so that the relative contributions of each trait to the overall maternal breeding objective could be made. Number of piglets born alive had the greatest contribution (30.9%) to the maternal index followed by daily gain (maternal) (20.5%) and sow mature weight (13.6%). Other traits considered in the maternal breeding objective were pre-weaning survival (13.2%), sow longevity (11.3%), gilt age at puberty (7.9%), and piglet survival at birth (2.6%). The emphasis on growth rates in pigs has led to heavier sow mature weights and associated economic and animal welfare costs. Inclusion of the mature weight trait into the maternal index will allow farmers to assess the trade-off between their desired rates of progress in pig growth traits and that of sow mature weight.