Perch design in laying hen housing significantly affects welfare, with inappropriate perch shape and height contributing to keel bone fractures and foot problems.
Perch design is a welfare detail that has received significant scientific attention because of its connection to keel bone fracture — the most prevalent welfare problem in laying hens. Hens dismounting from high round perches frequently collide with the keel bone against the perch, causing the fractures that affect the majority of hens in many commercial systems. Perch design modifications — flatter profiles, lower heights, horizontal rather than angled approaches — reduce fracture risk. The cumulative welfare benefit of these design changes, multiplied across billions of laying hens, is substantial. This illustrates how welfare science applied at the design stage of housing systems prevents suffering at scale.