Keel bone fractures affect the majority of hens in cage-free systems, causing chronic pain. Addressing this hidden welfare crisis requires both housing design and genetic improvements.
Keel bone fractures represent a welfare crisis that has emerged with the shift to cage-free aviaries, systems that were designed and mandated to improve hen welfare. The irony that cage-free systems, while improving freedom of movement, have created a new and widespread welfare problem illustrates the complexity of welfare trade-offs in system transitions. Hens with fractured keel bones experience chronic pain that persists for the remainder of their productive lives, as healing in commercial laying systems is rarely complete. The solution requires both engineering improvements in aviary design and genetic selection for keel bone strength. Consumer, industry, and regulatory actors who pushed for cage-free transitions have a responsibility to ensure that these new systems genuinely deliver better welfare rather than simply exchanging one form of compromise for another.