[NH3, N2O, CH4 and CO2 emissions from growing process of caged broilers].

ABSTRACT

To obtain Ammonia and greenhouse gas (GHG) emission factors of caged broilers, ammonia (NH3), methane (CH4), nitrous oxide (N2O) 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 x (d x bird)(-1) and the average daily emission rate was 137.9 mg x (d x bird)(-1) [48.6 g x (d x AU)(-1)] over the 42-d period. The GHGs emission rates were 19.5-351.9 mg x (d x bird)(-1) with an average of 154.5 mg x (d x bird)(-1) [54.4 g x (d x AU)(-1)] for CH4, and 2.2- 152.9 g x (d x bird)(-10 with an average of 65.9 g x (d x bird)(-1) [23.2 kg x (d x AU)(-1)] for CO2. No emission of N2O 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 x (bird x 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 x (bird(-1) x life cycle)(-1) and (2.68 +/- 0.18) kg x (bird x 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.