High ammonia concentrations in poultry houses cause chronic respiratory damage and eye irritation in laying hens, representing a pervasive and largely invisible welfare problem in commercial production.
Ammonia exposure in poultry houses causes chronic suffering that is invisible to consumers but measurable in the birds. Eye inflammation from ammonia exposure ranges from mild irritation to keratoconjunctivitis causing corneal damage and pain. Respiratory damage from prolonged exposure impairs breathing and increases susceptibility to respiratory disease. Hens cannot move away from the ammonia source when housed in enclosed facilities. The solutions — adequate ventilation, low stocking density, dry litter maintenance — are technically straightforward but require consistent management attention and investment that is not always prioritized in high-throughput commercial operations.