Environmentalists are now becoming very concerned about issues related to air pollutants especially ammonia emissions from the broiler industry. Ammonia produced by broiler farms not only has a detrimental effect on the health and productivity of broiler chickens, but also has a severe influence on the environment. The ammonia emissions from broiler chicken houses can be effectively reduced by lowering the protein content of the feed, although broiler growth performance can suffer as a result. To improve protein digestibility and utilization in broiler chickens, enzymes can be used as feed additives. Hence, enzymes can avoid feeding with excessive protein content to broilers. Due to its ability to improve digestion and retention of N in the body, enzymes especially protease can reduce N excretion through excreta so that it has an impact on reducing ammonia emissions from broiler chicken houses. This present review provides an overview of the role of enzymes in reducing ammonia emissions from broiler farms. The mechanism of how enzymes reduce ammonia emissions from broiler farms is also discussed in this review. پرونده مقاله