Keel bone fractures affect 50-80% of laying hens in aviary systems; this painful chronic condition represents a major welfare failure.
Keel bone fractures have emerged as one of the most significant welfare problems identified in the transition from battery cages to cage-free aviary systems. The injury causes chronic pain that affects movement, feeding, and social behavior. Breeding for stronger bones, improved perch design, and nutrition management can reduce fracture rates, but current commercial systems have high rates of this preventable welfare harm.