Laying hens produce eggs at rates far exceeding wild ancestors, depleting calcium reserves and causing severe osteoporosis. Bone fractures affect the majority of commercial laying hens and cause chronic pain.
Laying hen osteoporosis is one of the most widespread and serious welfare problems in animal agriculture. The majority of commercially farmed hens live with bone fractures for months, causing chronic pain that affects their ability to compete for food, water, and nest space. The underlying cause — extreme egg production rates — is a product of selective breeding that prioritizes productivity over physiological sustainability. Slower-laying breeds show substantially better bone health. Calcium supplementation and perch design improvements reduce but do not eliminate fracture incidence. Breeding programs targeting bone density alongside egg output offer the most sustainable long-term welfare improvement.