Keel bone fractures affect the majority of laying hens in many systems, causing chronic pain and representing one of the most prevalent welfare problems in commercial egg production.
Keel bone fractures are the single most prevalent welfare problem in laying hens globally. The keel bone is the sternum, and fractures cause chronic pain that affects feeding, movement, and rest. Many hens live with untreated fractures for months. The high prevalence across systems - including free-range and aviary - indicates this is a systemic problem requiring genetic and management solutions, not just system change alone.