Measuring methane in the rumen under different production systems as a predictor of methane emissions

The objectives of this project were to:

• evaluate the utility of the intra-ruminal device to sense changes in methane, carbon dioxide and hydrogen concentration under varying feeding conditions in ruminants
• determine the ability of the intra-ruminal device to identify high and low methane emitting ruminants that have been previously ranked on respiration chamber measurements
• determine the performance of the intra-ruminal device including analysis of variability, repeatability and verification of total emission of emissions measured
• identification of key issues facing the future development of the device including use under commercial conditions as a device for monitoring and verification of methane emissions from ruminants.

Key findings

The gas-sensing devices have provided the first continuous record of physiological data relating fermentation gases in the rumen and effects of diet and feeding events. This has provided a fundamental basis for understanding the mechanisms which might contribute to a low and high methane phenotype.

In addition, the monitoring of fermentation gases provides an index of rate and extent of fermentation which may assist in identifying animals that have more efficient and productive rumens.

For the device to be able to estimate methane production rate from rumen methane concentration, constant release of a marker gas in the rumen is required. This would enable to device to be used to assess methane abatement methodologies and genetic selection programs.