Keel bone fractures affect a majority of laying hens in cage-free systems. This widespread and painful condition has emerged as a major welfare challenge in modern egg production.
Keel bone fractures represent an unexpected welfare consequence of the transition from battery cages to cage-free laying systems. While cage-free housing better meets hens behavioural needs for perching, foraging, and dust bathing, the active environment has revealed a hidden weakness: modern high-production hens have bones poorly adapted to the physical demands of climbing and falling from perches. Research is actively investigating solutions including genetics for stronger bones, perch design that reduces collision injuries, and nutritional programmes supporting bone mineralisation. This situation demonstrates that welfare improvement is ongoing: solving one problem sometimes reveals others.