Lameness affects up to 30% of commercial broiler chickens, causing chronic pain that is rarely treated because of the difficulties of identifying and treating pain in individual birds at commercial scale.
Broiler lameness is simultaneously one of the most significant welfare problems in the poultry industry and one of the clearest demonstrations that animal welfare and productivity are connected. Lame chickens suffer chronic pain that affects every movement — they show preference for analgesic-containing food in preference tests, demonstrating that the pain is motivationally relevant. The causes of lameness — rapid skeletal growth outpacing structural development, hard concrete floors, poor litter quality — are all amenable to management intervention. The economic costs of lameness — mortality, feed conversion, carcass condemnation — provide financial incentives for improvement that should align with welfare improvement but rarely do in practice.