Farm Animals

Pig Regrouping Aggression: Managing Social Stress at Mixing

Mixing unfamiliar pigs causes intense aggression with welfare consequences that persist for days after regrouping.

Key Facts

Pigs establish dominance hierarchies through fighting when unfamiliar groups meet
Regrouping aggression causes injuries including lacerations and ear damage
Strategies including smell masking, mixing at night, and adequate space reduce fighting
Keeping litter mates together from birth significantly reduces lifetime aggression

Welfare Considerations

The acute pain and stress of regrouping is preventable. Farm management practices that minimise mixing events, provide escape routes, and use sensory strategies to reduce recognition reduce suffering significantly.

What You Can Do

Support pig welfare standards that limit unnecessary regrouping events
Choose pork certified under schemes with social group stability requirements
Advocate for farm welfare protocols that include regrouping management plans