The space available to broiler chickens profoundly affects welfare outcomes. Evidence supports significantly lower stocking densities than current commercial norms.
Stocking density is one of the most directly controllable determinants of broiler welfare. At high densities — the norm in standard commercial production — birds cannot move freely, are exposed to higher ammonia concentrations from accumulated litter, have difficulty accessing food and water resources, and experience greater heat stress. The evidence for welfare improvement at lower densities is consistent across multiple welfare indicators. The economic incentive to maximise birds per square metre is clear; counteracting this requires both market pressure through welfare certification and regulatory minimum standards.