Keel bone fractures affect the majority of laying hens in cage-free systems and represent one of the most significant unresolved welfare problems in egg production globally.
Keel bone fractures represent a genuine welfare crisis in cage-free egg systems that is obscured by focusing only on the improvements from battery cage elimination. The majority of hens in cage-free aviaries have fractured keels, causing chronic pain that affects their ability to move, compete for resources, and access food and water. Fractures cause discomfort measurable through altered movement and reduced willingness to use affected wings. The existence of this problem in systems promoted as high welfare represents a significant failure to address welfare comprehensively. Genetic selection for keel bone strength and changes to aviary design can reduce fracture rates but neither solution is yet widely deployed. The welfare community has a responsibility to address this problem in cage-free systems rather than assuming that elimination of conventional cages resolves laying hen welfare.