Osteoporosis and bone fractures affect the majority of laying hens toward the end of their laying cycle, causing significant pain that is often invisible to producers and consumers.
Keel bone fractures are a silent epidemic of suffering in commercial laying hen production. The majority of hens in cage-free systems — the welfare-preferred alternative to caged systems — develop keel bone fractures during their laying period. This creates a troubling paradox: the welfare improvement of cage-free housing has inadvertently introduced a new welfare problem from increased movement and collision risk. The fractures cause chronic pain that is difficult to observe directly, contributing to their neglect in welfare assessment. Solutions exist — perch redesign, pullet bone development programs, and selective breeding for bone strength — but implementation requires deliberate welfare investment that is not currently standard in even certified higher-welfare operations. Keel bone welfare is emerging as one of the most important unresolved welfare challenges in egg production.