笼养肉鸡生长过程NH3、N2 O、CH4和CO2的排放

为确定规模化笼养肉鸡生产过程NH3、N2O、CH4和CO2的排放因子,并探讨不同生长阶段排放特征,本研究选择山东某商业化肉鸡养殖场,利用INNOVA 1312多气体分析仪-连续采样测试系统和风机风量现场测定系统(FANS),对肉鸡舍NH3、N2O、CH4和CO2的排放进行为期42 d的测定,确定了肉鸡整个生产过程气体的平均排放因子和累积排放因子.结果表明,整个肉鸡生产过程中NH3排放因子呈现出先升高后降低的趋势,变化范围在8.5～342.1 mg·(d·bird)-1,平均为137.9mg·(d·bird)-148.6 g·(d.AU)-1],CH4和CO2排放因子随着日龄的增加而增大,CH4排放因子的变化范围在19.5～351.9mg·(d·bird)-1之间,平均为154.5 mg·(d·bird)-154.4 g·(d.AU)-1],CO2的排放因子在2.2～152.9 g·(d·bird)-1之间变化,平均为65.9 g·(d·bird)-123.2 kg·(d.AU)-1],整个生产过程没有监测到N2O的排放;肉鸡的NH3累计排放因子为(5.65±1.02)g·(bird·life cycle)-1,第1阶段(0～17 d)、第2阶段(18～27 d)和第3生长阶段(28～42 d)氨气排放占总排放的比例分别为33.6%、36.4%和29.9%,第2阶段的NH3累计排放因子显著高于第1和第3生长阶段;CH4和CO2的累计排放因子分别为(6.30±0.16)g·(bird·life cycle)-1和(2.68±0.18)kg·(bird·life cycle)-1,第3阶段的CH4和CO2累计排放因子显著大于1和2阶段,占总排放量的50%以上.研究结果为控制气体排放提供了数据基础.

NH3, N2 O, CH4 and CO2 Emissions from Growing Process of Caged Broilers

To obtain Ammonia and greenhouse gas (GHG) emission factors of caged broilers, ammonia (NH₃), methane (CH₄), nitrous oxide (N₂ O) and carbon dioxide (CO₂) emissions of broilers aged 0 d to 42 days were monitored in caged broilers production systems located in Shandong province. Gas concentrations of incoming and exhaust air streams were measured by using INNOVA 1312 multi-gas monitor with multi-channel samplers. Building ventilation rates were determined by on site FANS (Fan Assessment Numeration System) measurement systems. The NH₃ emission factors showed a trend of increase at the beginning and then decreased with the broiler ages. The NH₃ emission rates were 8.5 to 342.1 mg·(d·bird)^-1 and the average daily emission rate was 137.9 mg·(d·bird)^-1 48.6 g·(d·AU)^-1] over the 42-d period. The GHGs emission rates were 19.5-351.9 mg·(d·bird)^-1 with an average of 154.5 mg·(d·bird)^-1 54.4 g·(d·AU)^-1] for CH₄, and 2.2-152.9 g·(d·bird)^-1 with an average of 65.9 g·(d·bird)^-1 23.2 kg·(d·AU)^-1] for CO₂. No emission of N₂ O was observed. The CH₄ and CO₂ emission rates increased with the increase of broilers ages. The total NH₃ emission over the 42 d growing period averaged (5.65±1.02) g·(bird·life cycle)^-1. The NH₃ emission contribution in different growth phase to the total emission were 33.6% in growth phase 1 (0-17 day, GP1), 36.4% in GP2 (18-27 days), and 29.9% in GP3 (28-42 days), respectively. The NH₃ emission in GP2 was significantly higher than emission in GP1 and GP3. CH₄ and CO₂ cumulative emission rates were (6.30±0.16) g·(bird^-1·life cycle)^-1 and (2.68±0.18) kg·(bird·life cycle)^-1, respectively. The cumulative emission rates of CH₄ and CO₂ in GP3 were significantly higher than emission rates in GP2 and in GP1, accounting for 50% of total emissions. The results of this study could provide the data support for mitigation of gas emission from broilers production.