How inadequate water access causes significant welfare harm in farmed pigs and what adequate provision requires.
Water access for farmed pigs has both physical and behavioral welfare dimensions. Beyond basic hydration, pigs have strong behavioral motivations to interact with water for wallowing and rooting — behaviors that regulate body temperature and provide enrichment. Systems that provide insufficient drinkers create competitive exclusion dynamics where subordinate pigs cannot access water adequately. In hot weather, the absence of wallowing water is a significant welfare problem — pigs cannot sweat and depend on behavioral thermoregulation that requires water access. Adequate water welfare requires not just physical availability but sufficient provision points and appropriate water forms for behavioral expression.