Farm Animals

Pig Aggression at Regrouping and Management

Regrouping unfamiliar pigs causes intense aggression as hierarchies are established, with welfare consequences that management strategies can significantly mitigate.

Key Facts

Regrouping fights establish dominance hierarchies through biting and chasing
Fight wounds are common, with facial, ear, and flank injuries most prevalent
Regrouping is necessary when pigs move between production stages
Techniques including regrouping in darkness or using aggression-reducing sprays reduce fighting
Static groups (no changes) have better welfare than frequently re-mixed groups

Welfare Considerations

Regrouping aggression causes acute pain from bite wounds and prolonged stress during hierarchy establishment. This is an unavoidable feature of commercial pig management unless static groups are maintained throughout production. Minimising the frequency of mixing and using evidence-based mitigation reduces welfare impact.

What You Can Do

Support farms using static group management to minimise regrouping stress
Advocate for welfare guidelines that specify regrouping mitigation techniques
Choose pork from farms with transparent group management and welfare policies