Stocking density directly affects broiler welfare. Research consistently shows welfare improvements at lower densities, informing standards debates between industry and advocates.
Stocking density is among the most important determinants of broiler welfare in commercial production. At high densities, birds cannot perform locomotor behaviors, compete more intensely for resources, are exposed to higher ammonia from accumulated litter, and have less opportunity to move away from aggressive interactions. Research shows consistent welfare improvement as density decreases, with threshold effects at key density levels. The EU's 33 kg per square meter legal maximum still allows significant crowding — at slaughter weight a 2.2 kg bird needs only the area of a sheet of paper under this standard. Higher-welfare certification schemes specifying lower densities are the primary market mechanism driving density reduction below the legal maximum.