The primary objective of this study was to assess the influence of animal feed composition on greenhouse gas emissions from pig manure on three farms through the use of the Intergovernmental Panel on Climate Change (IPCC) methodology, which measures the digestibility, gross energy and ash content of feed to determine volatile solids content in manure. The farms in this study were purposively sampled based on good farm management and record keeping systems. The data that formed this study was collected over a period of three months (one month on each farm).

The digestibility (DE) values in feed for farms in Lusaka, Chongwe and Choma districts were 48.7%, 55.1% and 50.3% for growing pigs, while those for adults pigs were 63.6%, 69.1% and 66.0%. The gross energy (GE) values in feed for these farms were 22.68MJ/day, 23.23MJ/day and 16.92MJ/day in growing pigs, while that for adult pigs were 37.8MJ/day, 38.72MJ/day and 28.2MJ/day, respectively. The Ash content values in both feed and manure for growing and adult pigs for these farms were 8.14%, 9.37% and 9.64%. The volatile solids (VS) values in manure for the these farms were 0.58 kg dm/day, 0.51 kg dm/day and 0.41 kg dm/day in growing pigs, while that for adult pigs were 0.69, 0.59 and 0.47 kg dm/day, respectively. These results seem to suggest that feeds with low digestibility, low ash content and high energy contents excrete high amounts of volatile solids which is a function of methane (CH4) emissions from pig manure. One approach for reducing CH4 emissions from pig manure can be by increasing the digestibility of feed by modifying feed using feed additives or supplements. This would result in larger portion of energy in the pig feed being directed towards creation of useful products (pork), rather than CH4 emissions from manure.