Space allowance is one of the most studied variables in pig welfare science. Evidence shows clear welfare benefits from increased space, but regulatory standards often fall well below scientifically recommended thresholds.
Space allowance affects pig welfare through multiple pathways. Insufficient space prevents simultaneous lying down by all pigs — a basic welfare requirement — and increases competition for resources including feed, water, and comfortable resting areas. Crowding elevates baseline cortisol and increases aggression frequency and severity. Tail biting, a serious welfare and production problem, is fundamentally an indicator of a system operating below the threshold needed for normal behaviour expression. Providing 20-30% more space than legal minimums, alongside straw bedding and rooting enrichment, dramatically reduces tail biting incidence and eliminates most of the welfare pressure that currently drives routine tail docking. Producers who have transitioned to higher-space systems with enrichment consistently report reduced mortality and veterinary costs alongside welfare improvements. The regulatory floor is genuinely a floor — welfare science recommends substantially more space for finishing pigs to express normal activity budgets.