Pigs are uniquely dependent on wallowing for thermoregulation as they cannot sweat, making wallow provision in outdoor and semi-intensive systems a fundamental welfare requirement.
Wallow provision for pigs is not an optional enrichment but a fundamental welfare requirement for a species that cannot sweat. Pigs kept in warm conditions without access to wallowing cannot effectively regulate body temperature and experience heat stress that causes physiological distress and welfare harm. Outdoor systems without muddy wallows - which can occur in dry summer conditions if wallow sites are not maintained - leave pigs without their primary cooling mechanism. Practical wallow provision requires active management including water supply to wallow areas in dry conditions. Consumer purchasing of outdoor pig products should seek certification that includes wallow provision requirements.