Methane Emissions in Ruminants: Perspectives on Measurement and Estimation Methods

Abstract

This paper is an introduction to the methods used to measure and estimate ruminant methane emission. An understanding of these methods is very important in order to plan experiments, understand and interpret experimental results, and compare them with findings of other studies. In this review, the principles as well as the merits and demerits of known methods used in quantifying enteric methane emission from ruminants are compared. The methods include the chambers, sulphur hexafluoride (SF₆) technique and the in vitro gas production technique. Newer methods such as the carbon dioxide (CO₂) are also discussed. Method of choice for estimating enteric methane emission will depend on aim, equipment, knowledge, time and money available. This paper will therefore be useful for expanding the knowledge base of researchers, farm planners, and policymakers as they work to develop and maintain sustainable environmental conditions for livestock farming system.