Measurement and analysis of methane concentration and flux emitted from finishing pig house

Methane(CH₄) emissions from animal breeding has become a concern. The concentration and emissions per animal species are affected by animal characteristics, housing type and manure collection management as well as the climate. To investigate CH₄ emissions from finishing pigs appropriate for China management method and climate situation, the CH₄ concentration and related information were measured in Beijing during 2004～2005, six data collection periods, 72～80 hours each were scheduled through one year and four measurement seasons. The emission per pig was estimated based on ventilation rates which was calculated by application of carbon dioxide mass balance method. The CH₄ concentration and emissions varied diurnally and seasonally. Mean CH₄ concentration values were (22.68±10.52)mg/m³ in January, (2.68±0.68)mg/m³ in July. Mean methane concentration was lower between 9:00 am～17：00 pm, which was greatly related to temperature and ventilation rate. CH₄ emission from pig house varied between 68.10～207.01 mg/h per animal or 436～1185 mg/h (500 kg) live weight.