Outdoor access for pigs provides welfare benefits that indoor systems cannot fully replicate. Evidence from outdoor and extensive pig systems informs higher-welfare approaches.
Outdoor access provides welfare benefits to pigs that are fundamental to their nature: rooting in natural substrates satisfies their most intensively motivated foraging behaviour; wallowing provides thermoregulation and skin care; access to varied terrain allows exploration and environmental complexity. Pigs in outdoor systems consistently show lower rates of stereotypic behaviour, aggression, and tail biting than housed counterparts. The welfare case for outdoor access is supported by both the theoretical argument from pig natural history and empirical evidence from welfare outcome comparisons. The practical challenges of parasite management, weather, and production economics are real but not insurmountable.