Minimum space allowances for farmed animals are among the most important welfare standards, directly affecting animals' ability to move, lie down, and perform natural behaviours.
Stocking density is one of the most powerfully welfare-relevant parameters in livestock farming, yet minimum legal standards remain substantially below what many species need to express normal behaviour. A broiler at 33-42kg/m2 has approximately the floor space of an A4 sheet of paper. Sows in group housing at minimum legal space allowances cannot avoid more dominant individuals. Space requirements must be considered in the context of the full housing environment, but inadequate minimum space is a baseline welfare failure.