High ammonia concentrations in poorly ventilated poultry sheds cause respiratory damage, eye irritation, and chronic suffering in millions of birds.
Ammonia is a persistent welfare hazard in intensive poultry production that is often overlooked because birds cannot communicate their discomfort and eye damage develops gradually. At the concentrations regularly found in inadequately ventilated sheds, birds experience continuous mucosal irritation, impaired vision from keratoconjunctivitis, and increased susceptibility to respiratory pathogens. Chronic low-level exposure causes irreversible airway damage that reduces lifespan and productivity. Good ventilation design and litter management can keep ammonia concentrations below welfare-relevant thresholds, but economic pressure to reduce energy costs on ventilation means many sheds operate at harmful concentrations.