Keel bone fractures affect the majority of laying hens in some studies, causing chronic pain that significantly compromises welfare; this is an emerging priority in poultry welfare science.
Keel bone fractures represent an unexpected welfare crisis in systems that are welfare improvements over cages. The shift to enriched and free-range housing, which allows hens to fly and use perches, has exposed a previously unrecognised vulnerability in keel bone integrity. A hen with a fractured keel experiences chronic pain that affects every movement — perching, wing spreading, and even lying down. The fracture prevalence across populations represents a huge number of individual animals in chronic discomfort across the laying period. Solutions exist: padded perches, reduced drop heights, and breeding selection for stronger keel bone structure — but they require investment and have not yet been widely adopted.