The cage-free transition in egg production replaces conventional battery cages with alternative housing systems that have their own welfare implications. Understanding which systems best meet hen needs guides advocacy and purchasing.
The cage-free transition illustrates that welfare improvements are not binary and that better does not mean good. Cage-free systems genuinely improve welfare outcomes across multiple dimensions compared to battery cages: hens can walk, spread wings, use nest boxes, and perform more natural behavior. But cage-free introduces new welfare challenges: multi-tier aviary systems cause keel bone fractures from falls that affect the majority of hens in some studies. Feather pecking in large groups is harder to manage than in small cage groups. Disease transmission in higher-density barn systems can be problematic. The welfare hierarchy - outdoor free-range with good management best, followed by aviary cage-free, followed by enriched cages, followed by battery cages worst - reflects genuine but imperfect gradations.