The amount of space provided to pigs in commercial systems directly affects their ability to perform natural behaviours, their stress levels, and the prevalence of aggression and injury.
Space is foundational to pig welfare. Insufficient space prevents normal lying behaviour, increases competition and aggression, and creates environments where avoiding social conflict is impossible. Pigs in very tight space allowances cannot simultaneously lie, stand, feed, and drink without constant disruption. Higher space allowances reduce these stressors significantly. The economic cost of additional space is real but modest when viewed against the welfare benefit. Regulatory minimum space allowances in most countries lag significantly behind what welfare science suggests is adequate.