Laying Hen Keel Bone Fractures | Animal Welfare Hub

Keel bone fractures are among the most prevalent and painful injuries in laying hens. Understanding the causes and solutions is essential for improving welfare in egg production.

Key Facts

Studies find keel bone fractures in 50-80% of laying hens in commercial systems.
The keel bone (sternum) is the site of major flight muscle attachment and is vulnerable to collisions.
Fractures cause chronic pain and reduce hens' ability to perch, forage, and compete for resources.
Aviary and free-range systems reduce bone density problems from inactivity but can increase collision risk.
Genetic selection for high egg production has made hens more susceptible to bone weakness.
Pain assessment tools show fractured hens have altered gait, posture, and behavior consistent with pain.

Welfare Considerations

Keel bone fractures represent one of the most significant unresolved welfare problems in the egg industry. Despite affecting the majority of hens in most production systems, they have historically received little attention. These fractures cause chronic, often undiagnosed pain affecting feeding, perching, and social behavior. Solutions are complex: cage systems prevent activity-related fractures but cause other severe welfare problems; aviary systems improve mobility but may increase collision risk. Progress requires selective breeding for bone strength, thoughtful aviary design, and systematic fracture monitoring in all systems.

What You Can Do

Choose egg products from suppliers who actively monitor and report keel bone fracture rates.
Support research into genetic selection for stronger bones in laying hens.
Advocate for keel bone fracture assessment to be included in egg certification schemes.
Encourage retailers to demand welfare data from egg suppliers including fracture prevalence.
Reduce egg consumption or switch to plant-based alternatives to reduce demand-side pressure.