Pig housing design profoundly affects welfare across all production stages—from farrowing crates to finishing accommodation. Evidence-based housing standards balance animal behaviour needs with practical production and biosecurity requirements.
Pigs are intelligent, active animals requiring adequate space for natural behaviour expression: rooting, exploration, social interaction, resting, and thermoregulation. EU minimum space requirements (Directive 2008/120/EC) provide legal floors but welfare science indicates higher space allowances deliver meaningfully better welfare outcomes. Research shows that below approximately 1 m² per finishing pig (25-100 kg), aggression, lesion rates, and stress biomarkers increase substantially.
Rooting is a fundamental behavioural need for pigs—they spend up to 50% of their time rooting in natural conditions. Provision of manipulable substrate (straw, hay, compost, wood shavings) satisfies this need and significantly reduces tail biting, ear biting, and flank biting behaviour that results from thwarted rooting motivation. EU law requires pigs have access to manipulable material; bare concrete slatted floors that provide no substrate are a fundamental welfare failure for this species.
Pigs cannot sweat and rely on behavioural thermoregulation (mud wallowing, shade-seeking). In commercial housing, temperature management through ventilation, cooling systems (sprinklers, wet floors), and insulation maintains thermal comfort. Insufficient cooling in summer causes heat stress—elevated cortisol, reduced feed intake, increased water consumption, lethargy, and in severe cases heat stroke. Creep areas with supplementary heating for piglets prevent neonatal hypothermia.
Concrete slatted flooring, while facilitating manure removal, causes foot lesions, shoulder injuries, and lameness at high rates compared to straw-bedded solid floors. Rubber mats on concrete significantly reduce foot lesion prevalence. Deep straw bedding provides cushioning, allows rooting and nesting behaviour, and reduces lameness. The welfare trade-off between manure management efficiency and foot comfort must weigh animal welfare appropriately.
Pigs are social animals that establish stable hierarchies within familiar groups. Regrouping unfamiliar pigs causes serious aggression during hierarchy re-establishment—bite wounds, stress, and sometimes death. Minimising regrouping events, introducing pigs in familiar groups, and providing adequate space for subordinate animals to avoid dominant pigs reduces regrouping welfare costs. Stable groups throughout the production cycle are a key welfare principle in pig production.