Keel bone fractures affect the majority of laying hens in commercial systems, causing chronic pain that profoundly impairs quality of life for billions of birds worldwide.
Keel bone fractures represent one of the most prevalent yet underrecognised welfare problems in modern egg production. Unlike visible conditions such as feather pecking or foot disease, fractures are internal and cannot be detected by visual flock inspection. Hens with painful fractures cannot signal their suffering — they continue to lay eggs while experiencing chronic pain with every breath. The scale is staggering: with global laying hen populations in the billions, the number of individual birds suffering from keel fracture pain at any given time is enormous. Solving this problem requires genetic selection for better bone mineralisation, perch design that reduces impact forces, and housing systems that minimise collision risk.