Ammonia produced by decomposing poultry litter is a major but often invisible welfare threat in broiler and laying hen houses. Even at sub-lethal concentrations, ammonia causes eye damage, respiratory illness, and pain.
Ammonia is a pervasive but underappreciated welfare hazard in commercial poultry production. Unlike visible injuries, ammonia damage is cumulative and often detected only when disease has already taken hold. Chickens exposed to chronic low-level ammonia develop progressively worsening eye conditions — their eyes are the primary organ damaged at concentrations that may not immediately affect respiration. Hens and broilers unable to see clearly cannot navigate to feed and water effectively, creating a compounding welfare impact on nutrition and social interaction. The interaction between ammonia and respiratory disease is a significant mortality driver in intensive flocks. Importantly, ammonia levels are manageable through good husbandry: ventilation design, litter moisture management, and appropriate stocking density all affect peak concentrations. The same interventions that improve litter welfare and reduce footpad disease also reduce ammonia — making litter management one of the highest-leverage welfare interventions available to poultry producers.