Group housing is better for pig welfare than individual stalls, but aggression during mixing remains a major welfare challenge requiring active management.
The transition from individual gestation stalls to group housing is one of the most significant welfare improvements in pig farming — but it requires careful management to avoid replacing one harm with another. When unfamiliar pigs are mixed, fierce aggression for social dominance can cause serious injuries. Evidence-based strategies — providing deep straw for distraction, ensuring adequate feeder space, using visual barriers, and minimizing mixing frequency — substantially reduce but do not eliminate aggression. Group housing with good management represents a significant net welfare improvement over stall confinement.