Laying Hen Keel Bone Fractures: A Pervasive Welfare Failure

Keel bone fractures affect the majority of laying hens in both cage-free and enriched cage systems, causing chronic pain and representing one of the most widespread welfare problems in egg production.

Key Facts

Keel bone fracture prevalence exceeds 50% in most commercial laying hen housing systems studied
Fractures occur primarily when hens collide with perches, housing structures, or other birds during flight
Hens with keel fractures show behavioral indicators of chronic pain including reduced activity
Selective breeding for lighter bones to improve egg production contributes to fracture susceptibility
Neither cage-free nor furnished cage systems have consistently demonstrated lower fracture rates

Welfare Considerations

Keel bone fractures represent a systemic welfare failure that crosses housing system boundaries. The shift from battery cages to cage-free was expected to improve this welfare measure, but the evidence is mixed: greater freedom of movement in cage-free systems may actually increase collision risk. Perch design, pop-hole dimensions, and lighting management all influence fracture rates. Breeding programs that select for stronger bones alongside production traits offer the most durable solution. Until such breeds are widely available, housing and management optimization reduces but does not eliminate the problem.

What You Can Do

Choose eggs from producers committed to keel bone fracture reduction programs
Support poultry welfare research focusing on bone health in laying hens
Advocate for keel bone fracture rates to be included in welfare certification criteria
Reduce egg consumption or choose plant-based alternatives to lower overall demand