Bone disease is one of the most significant and poorly recognized sources of chronic suffering in laying hens, affecting the majority of commercial egg-producing chickens.
Bone disease in laying hens represents a chronic welfare crisis affecting the majority of the world's 8 billion laying hens. The biological cause is clear: extreme selective pressure for egg production has created birds whose calcium metabolism is fundamentally compromised, with egg production prioritized over skeletal maintenance. Keel bone fractures cause pain comparable to rib fractures in humans, affecting birds' ability to move, rest, and access resources. The transition to cage-free systems, while positive for behavioral freedom, has created an unexpected increase in keel bone fractures from falls and collisions. Addressing this requires genetic selection for bone strength alongside production traits — a shift that requires consumer and regulatory pressure.