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Evaluation and optimization of GreenFeed Emission Monitoring units for livestock – Department of Agriculture Ref No 01200.047

Project start date: 17 September 2012
Project end date: 11 December 2015
Publication date: 01 August 2015
Project status: Completed
Livestock species: Sheep, Lamb, Grassfed cattle, Grainfed cattle
Relevant regions: National
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​GreenFeed Emission Monitoring (GEM) Units are a commercially developed measurement system that allows estimation of daily enteric methane production (DMP) from cattle based on averaging multiple short term (3-6min) measures of methane emission.

GEMs were developed in 2010 but had been little tested. This project was responsible for validating the accuracy of DMP estimation by GEM, for developing guidelines on the number of samples that are required to establish emission reduction and the emission phenotype of an individual.

In addition, the project led to the development of a commercial sheep GEM unit.

No differences between GEM and respiration chamber determined DMP were detected, so confirming the accuracy of the units, with units being used to demonstrate effects of nitrate and of animal genotype on DMP in research trials and demonstration sites.

The GEM unit has commercial application in

  1. phenotyping cattle (and potentially sheep) for their methane phenotype as part of a genetic improvement program;
  2. verifying on-farm mitigation; and
  3. underpinning inventory estimate estimates is used in the field for prolonged periods.

There is need for evaluation of potential GEM impacts on grazing behaviour and emissions in more extensive environments to provide assurance that the process of being measured does not interfere with the natural behaviour and emission of the animals studied.

More information

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Primary researcher: University of New England