Keel bone fractures affect the majority of laying hens in many housing systems, causing chronic pain that is one of the most significant and underrecognized welfare problems in egg production.
Keel bone fractures represent a hidden welfare crisis in laying hen production. The prevalence is extraordinarily high - the majority of hens in many commercial systems have experienced fractures - yet the condition is rarely discussed outside specialist veterinary and welfare circles. Fractures cause chronic pain indicated by altered posture, reduced activity, and changes in resource use. The transition from cages to cage-free systems was intended to improve welfare, but aviary systems with high perches and large flock sizes have increased keel bone fracture rates. Solutions require system redesign, perch material improvements, and genetic selection for skeletal strength.