The welfare comparison between enriched colony cages and cage-free aviary systems for laying hens is genuinely complex, with each system having distinct welfare advantages and risks that inform policy debates.
The welfare comparison between enriched cages and cage-free systems defies simple summary, which is often used by advocates of each system to support their preferred position. Cage-free systems allow hens to express more natural behaviours including flying, perching at height, foraging in litter, and dust bathing — behaviours that are strongly motivated and contribute to positive welfare states. However, the physical risks of aviary systems including keel fractures, smothering, and disease spread are real and require skilled management to minimise. Enriched cages reduce some physical risks but fundamentally cannot provide the space and substrate for full behavioural expression. The weight of welfare science evidence supports the conclusion that well-managed cage-free systems with environmental complexity provide better welfare than enriched cages, but this advantage depends entirely on management quality. Poor cage-free management may produce worse outcomes than well-managed enriched cages.