Keel bone fractures affect the majority of hens in cage-free systems and cause chronic pain. This emerging welfare issue requires urgent attention as producers transition away from battery cages.
Keel bone fractures represent one of the most significant emerging welfare problems in the transition from battery cages to cage-free systems. The irony is painful: cage-free systems dramatically improve behavioral freedom but introduce a new source of chronic suffering in the form of bone fractures from falls and collisions. A hen with a fractured keel bone lives with chronic pain that affects every movement and behavior. The fracture rates observed in commercial aviaries — often exceeding 50% of all hens — mean this is not a rare event but a near-universal welfare outcome in many cage-free systems. Addressing keel bone fractures through ramp design, perch modification, lighting management, and breed selection is essential to ensuring that cage-free transitions genuinely improve hen welfare rather than trading one problem for another.