印度養牛產業之腸道發酵甲烷排放減量潛力與成本分析

Abstract

The purpose of this study is to find alternative rations to help the Indian cattle and buffalo sector reduce enteric methane emissions. We suggested a practical and low-cost method, in which the composition of rations used in 2010 was adjusted to attain emissions reductions. In this research, we analyzed enteric emissions and feed costs. We used the GLEAM-i model to calculate enteric emissions, which is based on the IPCC Tier 2 approach. The GHG calculations with the GLEAM-i model are detailed and comprehensive. Enteric emissions are associated with energy requirements. The energy requirements of cattle and buffalo are based on their live weight, gender, and function (to produce milk or meat or to provide labor). We identified 16 groups of bovines according to their different energy requirements. For each group, we imposed six scenarios of alternative rations that aimed to reduce enteric emissions. Among the six scenarios, the proportion of feed materials of higher digestibility is increased, thus replacing those of lower digestibility. Combining the mitigation potential and feed costs of the alternative rations, Scenario 6 presents the best choice, followed by Scenarios 5, 4, 3, 2, and then 1. Scenario 6 could attain a 1.5% reduction of enteric emissions (8.7 million t -eq/year) and a 13% reduction in the feed costs ($3,828 USD/year) from the 2010 benchmark. In the short term, Scenario 6 would be the best choice for India to cut enteric emissions without adding significant financial burden. The relatively more costly Scenarios 1–5 could be feasible when India achieves better economic viability.