INFLUENCE OF LITTER QUALITY AND QUANTITY ON AMMONIA EMISSIONS IN BROILER CHICKEN PRODUCTION

摘要

Broiler production has developed significantly in recent years. Broilers are raised in Finland in enclosed, heated buildings on a litter-on-concrete floor. Due to developments in breeding, feeding, medicine, and technology and a general concern for hygienic conditions, the time required to raise one lot of broiler chickens has decreased to 35 - 37 days. This intensive schedule requires accuracy throughout the production chain. Litter placed on the floor for manure recovery is one of the materials necessary in broiler production. The properties of litter material have effects on nutrient and liquid retention but also on emission of ammonia into the broiler house atmosphere. In warm broiler house conditions, the high nitrogen content of manure is a substantial cause for ammonia volatilization, especially in the second part of the raising period. A high ammonia concentration in the air of the production house is a risk to avian and human health, can be harmful to the growth of the chickens, and places a load on the environmental that should be minimized. In Finland, a measurement technique designed for broiler house conditions has been developed: a specific sensor can be placed at bird height, and results can be monitored continuously. This system can measure levels of NH_3, CO_2, and RH, as well as inside and outside temperature. The heating and ventilation are computer-controlled in modern broiler houses. Peat as an acidic material has an outstanding ammonia-binding capacity compared to, e.g., wood shavings or sawdust. If the pH of the manure/litter mixture is acidic, the ammonium nitrate originating from the manure stays in the mixture, but if the pH reaches highly alkaline levels, ammonia starts to volatilize strongly into the air. This presentation deals with a study of the quality and quantity of litter in relation to ammonia emissions. The results, determined via a novel technique, are described and discussed.