Measurement of ammonia and nitrous oxide concentrations and estimation of the emission rates from gestation pig buildings

Measurements of ammonia and nitrous oxide concentrations were taken from gestation pig buildings in Beijing for one year from 2004 to 2005. The NH₃ and N₂O emission flux per pig was estimated based on ventilation rates which were calculated by application of carbon dioxide mass balance method. The NH₃ and N₂O concentration and emission flux varied seasonally. Mean NH₃ and N₂O concentration values were 11.64±4.36 and (1.17±0.2)mg／m³ in November, 3.31±2.67 and (0.6±0.02)mg／m³ in July, and NH₃ and N₂O emission rate from pig building varied from 107.18 to 424.42mg／h, and 3.85 to 35.93 mg／h per animal respectively.