Farm Animal Welfare

Pig Group Housing Aggression Management

Regrouping pigs causes aggression as animals establish new social hierarchies. Management strategies reduce injury and welfare costs of mixing.

Key Facts

Regrouping unfamiliar pigs triggers intense fighting as dominance hierarchy is established
Mixing at weaning and transfer between production stages causes significant welfare harm
Providing hiding structures, visual barriers, and multiple feeding points reduces aggression
At-weaning mixing versus post-weaning mixing produces different aggression patterns
Genetic selection for reduced aggression is a promising long-term approach to this welfare challenge

Welfare Considerations

Pig aggression during regrouping is one of the most welfare-significant events in commercial pig production. The injuries sustained and fear experienced during hierarchy establishment cause real suffering. Management strategies can substantially reduce the severity and duration of aggression, and reducing the frequency of regrouping events is itself a welfare improvement.

What You Can Do

Support pig farming systems that minimize regrouping events through stable group management
Choose higher-welfare pork from systems with aggressive management mitigation strategies
Advocate for research funding into genetic selection for reduced pig aggression
Support farmer training programs on low-aggression pig regrouping practices