Laying Hen Keel Bone Fractures: A Major Welfare Crisis

Keel bone fractures affect 50-80% of laying hens in commercial systems, causing chronic pain that is only recently being recognized as a major welfare issue.

Key Facts

The keel bone is the central ridge of the sternum in birds, analogous to the human breastbone
Prevalence of keel bone fractures ranges from 50-80% in both cage-free and colony cage systems
Fractures occur from falls, collisions with equipment, and landing on perches in cage-free systems
Fractures cause pain demonstrated by behavioral changes and response to analgesics
Genetic selection for egg production has reduced bone density contributing to fracture susceptibility
Current cage-free transition campaigns may worsen keel bone welfare without targeted interventions

Welfare Considerations

Keel bone fractures represent a massive and underappreciated welfare crisis in laying hen production. The majority of hens in all commercial housing systems — including welfare-certified cage-free systems — suffer fractures that cause chronic pain. The irony of the cage-free transition is that while it improves behavioral freedom, multi-tier aviary systems have higher fracture rates than enriched colony cages due to fall distances. Solutions require multiple approaches: genetic selection for stronger bones, perch design changes, litter management to reduce collision risks, and monitoring programs. The scale of this problem affecting hundreds of millions of hens globally demands urgent attention from industry, regulators, and welfare researchers.

What You Can Do

Support research specifically addressing keel bone fracture prevention in laying hens
Advocate for keel bone fracture rates as a mandatory welfare metric in laying hen audits
Choose eggs from farms that demonstrate efforts to reduce keel bone fractures
Engage with welfare certification schemes to include keel bone welfare in their standards
Support genetic research into bone density and fracture resistance in laying hen breeds