Farm Animal Welfare

Pig Aggression Group Housing Management

Mixing unfamiliar pigs in group housing triggers aggression that causes injury and stress, requiring evidence-based management strategies to minimise fighting welfare impacts.

Key Facts

Social hierarchy in pigs is established through fighting when unfamiliar animals are mixed
Injuries from fighting include ear wounds, flank bites, and occasionally serious injury
Mixing at night reduces fighting duration compared to daytime mixing
Providing hiding barriers reduces injurious fighting by allowing retreat
Stable established groups show significantly less aggression than newly mixed groups

Welfare Considerations

Pig aggression during social mixing is a predictable welfare event that evidence-based management can substantially reduce. Minimising the frequency of regrouping, mixing at appropriate times, providing environmental complexity, and prompt identification of injured pigs are practical interventions that reduce welfare harm.

What You Can Do

Support pig farming practices that minimise unnecessary social regrouping
Learn about evidence-based mixing strategies that reduce fighting welfare impacts
Advocate for aggression monitoring as a component of pig group housing welfare standards