Stocking density — the amount of space available per pig — is one of the most powerful determinants of welfare outcomes in commercial pig farming. Understanding minimum requirements and their welfare rationale helps consumers make informed choices.
Stocking density is a fundamental determinant of pig welfare that interacts with virtually every other welfare factor. When pigs have insufficient space, all the social, locomotor, and comfort behaviours that characterise good welfare become more difficult: lying down requires compromise, feeding requires competition, moving without disturbing others is impossible. Below the critical welfare threshold, pigs respond with increased aggression, stereotypic behaviour, and redirected activities including tail biting. Litter quality degrades faster at higher densities as manure output exceeds the capacity of the bedding to absorb it — creating wet, ammonia-rich conditions that cause footpad disease and respiratory damage. The economic pressure to maximise animals per unit of building space is the driver of high stocking densities; the welfare cost is borne entirely by the animals. Consumer willingness to pay modest price premiums for certified lower-density pork is the market mechanism that can make reduced density commercially viable.