Keel bone fractures affect the majority of laying hens in enriched colony and barn systems. They cause chronic pain that is rarely detected or treated, representing one of the most significant ongoing welfare deficits in egg production.
Keel bone fractures represent one of the most underappreciated welfare crises in commercial egg production. The prevalence is extraordinary — the majority of hens in non-cage systems are likely living with painful skeletal injuries. The chronic nature of the pain is well-evidenced by pharmacological choice tests showing hens preferentially access analgesic-containing water when they have keel bone damage. Because the injuries are invisible during life and welfare inspection focuses on observable behaviours, the scale of the problem has been largely invisible to consumers and retailers. Cage-free and barn systems — often promoted as welfare improvements over conventional cages — may actually have higher keel bone fracture rates due to falls from heights and perch collisions. Addressing keel bone welfare requires selective breeding for bone strength, perch design improvements, and the development of on-farm detection methods.