Cold stress in piglets and growing pigs causes significant welfare harm through hypothermia, reduced growth, and increased disease susceptibility, particularly in outdoor and poorly insulated systems.
Cold stress in pigs represents a welfare challenge concentrated most severely in the neonatal period. Newborn piglets emerge into a farrowing environment that may be 20°C cooler than the uterine environment, and without rapid access to colostrum and supplemental heat, they can become hypothermic within hours. Shivering, huddling, weakness, and failure to suckle are warning signs. Heat lamp placement, heated mats, and draft exclusion are critical in the first days. In older growing pigs, chronic cold stress is a subtler welfare problem — animals show increased aggression as they compete for warm lying areas, and tail biting risk increases with cold, wet conditions. Deep straw bedding provides significant thermal benefit and also satisfies rooting motivation. Monitoring pig posture — pigs that huddle persistently are cold — is a simple welfare indicator that requires daily observation.