Agricultural producers are under constant pressure to minimize the impact their management practices have on the environment. Although most environmental concerns related to animal agriculture have focused on water quality during the past two decades, air quality issues have become an increasing concern. Odors have been the main air quality concern related to agricultural animal production. However, ammonia emissions from livestock and poultry operations have recently received significant attention. New air quality standards that cover ammonia emissions in the United States were adopted in 1997. These regulations will have a significant impact on the future of animal production operations. The purpose of this publication is to provide an overview of ammonia production associated with animal agriculture and to explain why it is receiving greater attention from those concerned with environmental quality.

Nitrogen (N) and phosphorus (P) are the two nutrients that cause the most concern with respect to environmental pollution from animal manure. Generally, higher concentrations of N and P in the ration result in their greater excretion in urine (N) and feces (N and P). Overfeeding these nutrients can be a significant problem, particularly if nutrient levels accumulate in the soil and contaminate water sources through leaching or surface runoff. Nitrogen can also volatilize as ammonia and pose a potential environmental problem with air emission standards, which are currently under review.