Abstract
Methane (CH4) is a greenhouse gas which contributes significantly to global warming and a significant proportion of atmospheric methane is produced by livestock. Livestock contribute 18% of global greenhouse gas (GHG) emissions. Apart from enteric emission, decomposition of livestock manure under anaerobic conditions is also a source of methane. The later condition arises in confined management system. There is difficulty in disposing off the excreta and wastes produced on a large scale; they are stored in large pits which provide suitable environment for CH4 production. Another green house gas is nitrous oxide (N2O), released during the nitrification-denitrification of nitrogen contained in livestock waste. Cattle and feedlots are responsible for 26% of N2O emissions from anthropogenic sources. Being greenhouse gases, their large scale emission is detrimental to the environmental safety. So, different strategies are emerging to either subside their emission from faeces and animal wastes or to use them effectively for energy saving purposes.
Key words: Global warming, manure, methane, nitrous oxide.
