Osteoporosis is endemic in commercial laying hens, driven by the enormous calcium demands of continuous egg production and inadequate exercise in intensive systems.
Osteoporosis in laying hens is a consequence of a fundamental biological conflict: the hen must produce calcium-shelled eggs at a rate that exceeds her dietary calcium intake, drawing on skeletal reserves. Over a production cycle, this depletion is measurable and significant. Hens with severe osteoporosis fracture vertebrae and long bones during normal movement, causing pain that is often undetected. The intervention is straightforward in principle — exercise builds and maintains bone density, and calcium supplementation helps — but delivering adequate exercise in intensive systems is logistically challenging. Higher welfare systems that provide outdoor access consistently achieve better bone health outcomes than their confined equivalents.