Global Progress on Ending Caged Layer Hen Housing
Battery cages — small wire enclosures housing 4-8 hens with approximately 67-116 cm² of space per bird — have been the dominant global egg production system for decades. This space allocation is less than a sheet of A4 paper per hen. Birds cannot spread their wings, dust bathe, perch, or engage in most natural behaviors. Battery cages cause severe welfare impairment through chronic restriction of movement, behavioral frustration, and the inability to express normal hen behavior. Their replacement is one of the most impactful welfare improvements achievable in modern animal agriculture given the enormous number of hens involved.
The EU banned conventional battery cages in 2012 (under Directive 1999/74/EC), replacing them with the requirement for enriched colony cages providing more space, nest boxes, perches, and litter. Enriched cages are significantly better than battery cages but still restrict natural behavior substantially. The EU's Farm to Fork Strategy proposed extending the cage ban to all cage systems (enriched cages, rabbit cages, broiler breeder cages) by 2027, though implementation timelines have been subject to political negotiation.
The US has no federal ban on battery cages. However, California's Proposition 12 — enacted 2018, implemented from 2022 — requires all eggs sold in California to come from cage-free systems, effectively setting a cage-free standard for eggs entering the world's fifth-largest economy. Similar state-level mandates in Massachusetts, Colorado, Nevada, and other states are creating a patchwork of cage-free requirements that represent significant national progress.
Cage-free does not mean problem-free. Cage-free aviary and barn systems provide significant welfare improvements (freedom to move, perch, dust bathe, lay in nests) but face challenges including feather pecking, disease transmission in larger flocks, and social stress in very large groups. Best practice cage-free systems combine appropriate stocking density, perch provision, nest boxes, litter management, and beak trimming reduction with good stockmanship.
Battery cage reform has progressed substantially but remains incomplete globally. Key 2025 developments include: continued expansion of cage-free sourcing by major food companies; EU progress toward complete cage elimination; US state-level mandate expansion; and growing advocacy pressure on Asian and Latin American markets. The trajectory is clearly toward cage elimination, but the pace — particularly in high-volume Asian markets — determines how many billions of hen-years of welfare improvement will be achieved in the near term.