Keel bone fractures affect 50-80% of laying hens in modern production systems, causing chronic pain that significantly impairs welfare while remaining largely invisible to consumers and farmers.
Keel bone fractures represent one of the most significant and underappreciated welfare problems in modern egg production. The transition from battery cages to aviary systems — motivated by welfare concerns — has inadvertently created a new welfare problem at enormous scale: the majority of laying hens in aviary systems suffer fractures that cause chronic pain affecting their behavior and wellbeing throughout their productive lives. The problem is tractable: genetic selection, perch design modification, and management practices that reduce collision risk all reduce fracture rates. However, progress requires that keel bone health is prioritized as a welfare outcome metric in certification standards, triggering producer attention and investment. Consumers, retailers, and certification bodies that include keel bone fracture monitoring in welfare assessment create the incentive for this improvement.