Scottish Agricultural College researchers conducted a study that found pig aggression to be a genetic trait that can impact welfare, carcass value and meat quality.

The SAC-led study was part of the pan-European SABRE project, which focuses on genomics for sustainable animal breeding. The study analyzed tissue from pigs at the commercial farm of pig breeder PIC, to identify genes linked with aggression, stress and meat quality, and how they interact. Researchers from SAC’s Animal and Veterinary Sciences Research Group found that pigs with aggressive personalities cause more fighting and experience more stress when mixed in unfamiliar groups.


“The mixing of pigs into new groups commonly occurs pre-slaughter," said SAC Behavioral Scientist Dr. Rick D’Eath. "Increased fighting presents an obvious welfare concern and can also reduce carcass value when scratched or damaged areas have to be discarded. In addition, the pigs we studied which experienced stress prior to slaughter had less acidic meat post-slaughter, which can reduce its eating quality."

According to D'Eath, reducing pig aggression, particularly pre-slaughter, could bring welfare and financial benefits while reducing waste and improving meat quality. "Producers, hauliers and slaughterhouses could work together to avoid the mixing of pigs in unfamiliar groups before slaughter, such as by ensuring that farm groups of pigs are penned separately on the truck and at lairage," said D'Eath. "In the longer term, the study also opens the way for tackling the issue of pig aggression using genetic selection.”