Keel bone fractures affect the majority of laying hens in non-cage systems and represent one of the most significant unresolved welfare problems in egg production.
Keel bone fractures represent a major unresolved welfare paradox in egg production. Non-cage systems, widely seen as more humane than battery cages, have dramatically higher fracture rates than the cages they replaced. This is because hens in barns and free-range systems use elevated perches, and the collisions and falls associated with perch use cause keel bone injury. This does not mean cages are preferable - cage systems create their own severe welfare problems - but it highlights that welfare improvements are rarely simple. Solutions being researched include better perch design, lighting management to prevent panic flights, genetic selection for bone strength, and early-life interventions. Addressing keel bone fractures is essential to realising the welfare potential of non-cage systems.