Osteoporosis and bone fractures are among the most serious and widespread welfare problems in laying hens. Understanding the bone health crisis in commercial egg production reveals the hidden welfare costs of high egg production.
Laying hen bone health represents one of the most pervasive and underappreciated welfare problems in animal agriculture. The calcium demands of continuous egg production deplete bone density over a hen's laying life, leaving her bones brittle and prone to fracture. Keel bone fractures — largely invisible to casual observation — cause chronic pain that affects movement, perching, and feeding behavior. The transition from cages to cage-free systems was expected to improve bone health through increased physical activity; instead, research shows keel bone fracture rates may be higher in cage-free systems due to falls and collisions. This is not an argument against cage-free housing, but a demonstration that system transitions require ongoing welfare research and management improvement rather than the assumption that one change solves all problems.