Space allowance is one of the most important determinants of pig welfare in intensive systems. Research consistently shows that higher stocking densities increase aggression, reduce resting space, and impair welfare across multiple indicators.
Overcrowding in pig systems creates a cascade of welfare problems: competition for limited resources generates chronic stress, reduced lying space forces pigs to rest on top of each other causing discomfort, and the frustration of confined animals redirects into harmful behaviours including tail and ear biting. Research clearly shows that providing even modest additional space beyond legal minimums significantly reduces these problems. The economic argument against higher space allowances is real but must be weighed against the substantial welfare cost of minimum-standard crowding.