Emission factors of greenhouse gases from layer and broiler barns in Cameroon

摘要

Limited information is available in the literature on greenhouse gas (GHG) quantification from livestock production systems in Africa. Therefore, this project was carried out to generate baseline emission factors of methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2) from broiler and layer barns with building design typical of Cameroon. Emissions were measured from two broiler barns during the entire production cycles and a layer barn for a limited period using flux chambers. Methane emission factors from the broiler barns with mud and cement floors were 0.96 +/- 1.04 and 0.36 +/- 0.17 mg bird(-1) hr(-1) respectively, and 0.76 +/- 0.56 mg bird(-1) hr(-1) from the layer barn with cement floor. Nitrous oxide emission from the broiler barns with mud and cement floors were 12.94 +/- 10.11 and 1.68 +/- 1.02 mg bird(-1) hr(-1) respectively, and 0.21 +/- 0.28 mg bird(-1) hr-1 from the layer barn. Carbon dioxide emission factors from the broiler barns with mud and cement floors were 9327 +/- 3508 and 25526 +/- 6904 mg bird(-1) hr(-1) respectively, and 8942 +/- 36756 mg bird(-1) hr(-1) from the layer barn. When scaled per livestock unit (LU), where 1 LU is 500 kg bird weight, CH4 emissions were 0.16 +/- 0.17 and 0.06 +/- 0.03g LU-1 hr(-1) from the broiler barns, and 0.19 +/- 0.14g LU-1 hr(-1) from the layer barn. Nitrous oxide emissions were 2.16 +/- 1.69 and 0.28 +/- 0.17 g LU-1 hr(-1) from the broiler barns, and 0.05 +/- 0.07 g LU-1 hr(-1) from the layer barn. Broilers reared in management systems with wood shavings on mud floor had relatively high CH4 and N2O emissions compared to broilers on wood shavings and cement floor, with the contrary observed for CO2. The emissions N2O were significantly higher from broiler barns compared to layer barns. Emissions were higher in the mornings compared to later periods of the day. Given the observed results, GHG emission mitigation strategies need to be customised for each building design and management system.