Individual gestation stalls (crates) measure approximately 0.6m × 2.2m — barely larger than the sow herself. They prevent turning, rooting, and normal social behavior for the entire 16-week pregnancy. Sows may spend 3-5 years cycling through gestation crates in industrial systems.
Confined sows show significantly higher rates of stereotypic bar-biting, repetitive nosing of the crate floor, and depression-like behavioral inactivity. Bone and muscle deterioration from immobility causes lameness. Cardiovascular and urinary tract health are compromised. The scientific consensus across welfare science is that prolonged confinement in gestation crates severely compromises sow welfare.
The EU banned gestation crates after 4 weeks of pregnancy in 2013 (Directive 2001/88/EC). The UK phased them out in 1999. New Zealand banned them in 2015. Nine US states have passed ballot measures or legislation banning gestation crates. Major food companies including McDonald's, Walmart, and Compass Group have made supply chain commitments.
Group housing allows sows to turn, walk, root, and interact socially. Welfare outcomes in well-managed group housing are significantly better than gestation crates. Electronic sow feeding (ESF) systems allow individual feeding in group settings, reducing competition and ensuring adequate nutrition.
Converting from crate to group housing requires infrastructure investment and management skill development. Aggression during initial group formation causes injuries if not managed correctly. Research on group size, space allowance, and introduction protocols guides welfare-positive implementation.
While gestation crate phase-out has broad consensus, farrowing crates (used around birth) remain contested. Welfare risks to piglets (crushing) are cited for retention, while sow welfare advocates push for free farrowing systems. Free farrowing pen designs that protect piglets while allowing sow movement are being adopted in progressive markets.