Genetic Analyses of Sow Longevity Traits, Age at First Farrowing and First-Litter Characteristics

Sow longevity is a vital trait in the pig production sector because of its economic and welfare importance. However, this trait is recorded late in a sow’s life and early selection criteria associated with sow longevity are beneficial for genetic improvement of sow longevity. The aim of this study was to estimate genetic parameters of sow longevity and other sow reproduction traits. Data included 14,284 purebred sows recorded from 1996 to 2016 in 7 commercial herds across Australia. Traits describing sow longevity included the number of maximum parities reached, length of productive lifetime in days, total number of piglets born alive per sow over her lifetime, and stayability from parity 1 to parity 4. Further traits considered were number of piglets born alive (litter size) and average piglet birth weight (both recorded in the first litter), and age at first farrowing. Sow longevity traits were genetically the same traits and had low heritabilities (0.07 to 0.13). Genetic correlations were lowly negative between sow longevity and age at first farrowing (-0.13 to -0.22), and between sow longevity and average piglet birth weight (-0.19 to -0.26). First litter size had positive genetic correlations with sow longevity traits (0.49 to 0.65). This study showed favourable genetic correlations of the traits first litter size and age at first farrowing with sow longevity, suggesting that these two traits could be suitable genetic indicators for sow longevity.