Keel bone fractures are a widespread and underappreciated welfare problem in commercial laying hens — affecting the majority of birds in many cage-free systems and causing chronic pain throughout the laying period.
Keel bone fractures represent a serious welfare problem that is largely invisible to consumers and often to farmers themselves. Hens with keel bone fractures experience ongoing pain with every movement and breath — the keel bone is essential to flight muscle attachment and respiratory function. The prevalence (affecting the majority of birds in many systems) means that the total welfare burden is extremely large. The policy challenge is that keel bone fractures are more prevalent in cage-free systems — the system touted as higher welfare — than in enriched cages. This does not mean cage-free is worse overall, but it does mean that keel bone fracture prevention must be addressed through breed selection, barn design, and management within cage-free systems to achieve genuinely better welfare.