Laying Hen Osteoporosis: Bone Welfare in Egg Production

Key Facts

• Laying hens mobilize calcium from their bones to produce eggshell calcium, causing progressive structural bone loss
• Keel bone fractures affect 50-80% of commercial hens in conventional systems, causing chronic pain
• Cage systems prevent exercise needed to maintain cortical bone mass, accelerating osteoporosis
• Free-range and organic hens with exercise access have significantly lower fracture prevalence
• Breed selection for high egg production has been identified as contributing to skeletal fragility

Welfare Considerations

Laying hen osteoporosis and keel fractures represent one of the most widespread but poorly recognized welfare problems in animal agriculture. A keel bone fracture causes acute pain at the moment of injury, followed by chronic pain during healing — which may take months or never fully resolve. The prevalence is staggering: in conventional cages, the majority of hens fracture their keel. Free-range and aviary systems with ample space reduce fracture risk but do not eliminate it. Welfare improvements require a combination of system design changes, exercise opportunities, and breed selection for bone health.

What You Can Do

• Choose free-range or organic eggs — hens have significantly better bone health with exercise access
• Advocate for banning conventional cages in all remaining countries that permit them
• Support research into laying hen breed selection for keel bone strength and fracture resistance
• Engage with supermarket and retailer commitments to 100% cage-free eggs
• Share information about keel bone fracture prevalence with consumers to drive informed purchasing