High ammonia concentrations in broiler sheds are a chronic and largely preventable welfare problem, causing respiratory damage, eye lesions, and behavioral suppression in millions of birds.
Ammonia welfare is invisible in the way that most air quality problems are — chronic, pervasive, and affecting behavior and health in ways that accumulate gradually rather than dramatically. A broiler house at 50 ppm ammonia does not look obviously different from one at 15 ppm; the birds appear to be living the same life. But the chronic irritation, respiratory compromise, and eye damage are accumulating with each hour of exposure. Because the welfare harm is invisible and diffuse, it receives less public attention than more dramatic welfare failures. Yet it affects billions of birds annually and is largely preventable through management practices that are well understood and economically feasible. The gap between knowing how to prevent it and actually preventing it is primarily one of regulation and enforcement.