Gaseous Ammonia Emission from Poultry Facilities in Taiwan

Four representative broiler and laying hen houses in the central and southern Taiwan were sampled to investigate their ammonia concentrations and emissions. Generally, ammonia concentrations in hen cages and around the exhausting outlets of sealed houses ranged from 1 to 9 ppm and 0.5 to 12.5 ppm, respectively. Notably, ammonia concentrations from manure disposal sites were as high as 500 ppm at 10 cm above the manure surface. Moisture spraying was occasionally used for prevention of ammonia effluent from sealed houses, and ammonia removal efficiencies were 30%-50%. Mechanical rapid composting systems are effective for manure digestion, and bioscrubbers attached to acid wet scrubbers are recommended because they are highly efficient for ammonia removal. Emission rates of 0.24 and 0.42 kg NH3/hen/year were emitted from the houses of broiler and laying hens, respectively, in summer. However, in winter, the emission rates were 0.15 and 0.19 kg NH3/hen/year from the broiler and laying hen houses, respectively. Further, average ammonia emission rates for a broiler raising stock (8 weeks) were 36.9 g NH3/broiler in summer and 23.1 g NH3/broiler in winter. Ammonia emission rates from henhouses in winter were only 45%-63% of those in summer.