Outdoor pig production offers substantial welfare benefits over indoor systems but faces its own welfare challenges including thermal stress and biosecurity pressures.
Outdoor pigs in summer without adequate shade and wallowing areas suffer acute heat stress as they cannot sweat and rely entirely on wallowing and shade for thermoregulation. Piglets born outdoors in wet cold winters face hypothermia mortality without adequate hut bedding and protection. Outdoor conditions with poor drainage cause mud accumulation causing joint infections and respiratory problems. Despite these challenges, outdoor systems generally provide substantially better welfare for the behaviourally motivated rooting, foraging, and social behaviours pigs are strongly driven to express.