Pigs are highly susceptible to heat stress because they cannot sweat effectively. Climate change is making heat stress an increasingly critical welfare issue in global pig production.
Heat stress is a serious and growing welfare problem for farmed pigs globally. Unlike cattle and poultry, pigs are particularly vulnerable because of their poor thermoregulatory capacity. During heat stress, pigs show reduced movement, increased respiratory rate, and eventually collapse if temperatures are extreme. Outdoor pigs without shade or wallow facilities suffer most acutely. Indoor intensive systems can provide cooling but many fail to do so adequately during heat waves. The welfare impact of climate-driven heat stress on pig farming will intensify without proactive management.