High ammonia concentrations in poultry houses cause respiratory irritation, eye damage, and chronic discomfort — ventilation management is a direct welfare intervention with measurable effects.
Ammonia irritates the respiratory tract and eyes of birds at concentrations that are chronic in many commercial houses. Eye lesions indicate exposure that compromises vision and quality of life. Footpad dermatitis from wet ammonia-rich litter causes pain and lameness. Winter management trade-offs between warmth and ventilation are a genuine welfare challenge. Litter management, stocking density, and ventilation design all affect ammonia levels and thus bird welfare.