Osteoporosis is endemic in commercial egg-laying hens and is a significant welfare problem. The intensive calcium demands of egg production deplete structural bone, causing fractures and pain.
Hens with osteoporosis and keel bone fractures live with chronic pain that affects their ability to access resources and express natural behaviours. The welfare scale of this problem is enormous given the global laying hen population. Providing exercise opportunities - especially perching and wing flapping - is the most evidence-based intervention to maintain bone strength throughout the laying period.