Aviary systems for laying hens allow natural behaviours like perching and dust bathing, but introduce specific welfare challenges including injurious pecking, keel bone fractures, and air quality problems.
Aviary systems represent a welfare improvement over caged systems in allowing expression of natural behaviours, but create new welfare challenges not present in cages. The high prevalence of keel bone fractures in particular is a significant welfare concern requiring attention to perch height, landing platforms, and light management. Breeding lines with lower fracture susceptibility and better aviary design are key research priorities.