AMMONIA EMISSIONS FROM BROILER HOUSING FACILITY: INFLUENCE OF LITTER PROPERTIES AND VENTILATION

At present, the European Union regulations allow to keep broiler chickens on litter covered floors only. Properties of litter (litter temperature, litter age) with ventilation rate are therefore important parameters influencing ammonia (NH3) concentrations and emissions in broiler houses. Litter temperature, litter age, and ventilation rate were measured in commercial grow-out facility with deep litter, designed for 25,000 broilers, during 6 consecutive flocks. Birds were housed from hatching to 40 days of age. Litter temperature and litter age positively correlated (P<0.001) with production of ammonia gas. The amount of ammonia emissions increased with increasing litter age (P<0.001), as a consequence of which both the ammonia concentration and ventilation rate (P<0.001) also increased. The lowest concentrations of NH3 were observed during summer, although ammonia emissions tended to be higher in summer months due to higher ventilation rates. The elevated levels of ammonia in winter were attributed to the lower ventilation rates during cold weather. From the ammonia emission data, it can be concluded that during the grow-out period of broilers kept on renewed litter there is an average loss of 6.18 g ammonia per bird and/or 0.043 kg of ammonia per bird yearly. Increasing litter temperature during grow-out periods is a process, which could be controlled to prevent excessive ammonia volatilization from housing.