Keel bone fractures affect the majority of laying hens in most housing systems, causing chronic pain and representing one of the most widespread welfare failures in egg production.
Keel bone fractures represent one of the most numerically significant welfare problems in food animal production. With billions of laying hens worldwide and fracture rates often exceeding 50%, the absolute number of affected birds experiencing chronic pain is staggering. The fractures are painful — hens with keel fractures show altered movement, reluctance to perch, and reduced feed access — yet because birds continue laying, the condition is frequently invisible to producers and consumers. No housing system has fully solved the problem; even free-range systems have high fracture rates from collision with environmental features. Selective breeding for bone strength alongside production traits is the most promising long-term solution.