Technical note: Validation of the GreenFeed system for measuring enteric gas emissions from cattle

Citation

McGinn, S.M., Coulombe, J.F., Beauchemin, K.A. (2021). Technical note: Validation of the GreenFeed system for measuring enteric gas emissions from cattle. Journal of Animal Science, [online] 99(3), http://dx.doi.org/10.1093/jas/skab046

Plain language summary

There are knowledge gaps in animal agriculture on how to best mitigate greenhouse gas emissions while maintaining animal productivity. One reason for these gaps is the uncertainties associated with methods used to derive emission rates. This study compared emission rates of methane (CH4) and carbon dioxide (CO2) from a commercially-available GreenFeed (GF) system to those of a mass flow controller (MFC) that released known quantities of both gases over time (i.e., emission rate) used in 1) in an open environment with low background concentrations to simulate a pasture setting, and 2) a respiration chamber (RC) representing a barn with potentially higher background concentrations. Differences between the GF and the other measurement systems were ≤ 2% for CH4 and ≤ 3% for CO2. We conclude that the GF system has the potential to accurately estimate enteric CH4 and CO2 emission rates of cattle when influencing factors are properly managed.

Abstract

There are knowledge gaps in animal agriculture on how to best mitigate greenhouse gas emissions while maintaining animal productivity. One reason for these gaps is the uncertainties associated with methods used to derive emission rates. This study compared emission rates of methane (CH4) and carbon dioxide (CO2) measured by a commercially available GreenFeed (GF) system with those from (1) a mass flow controller (MFC) that released known quantities of gas over time (i.e., emission rate) and (2) a respiration chamber (RC). The GF and MFC differed by only 1% for CH4 (P = 0.726) and 3% for CO2 (P = 0.013). The difference between the GF and RC was 1% (P = 0.019) for CH4 and 2% for CO2 (P = 0.007). Further investigation revealed that the difference in emission rate for CO2 was due to a small systematic offset error indicating a correction factor could be applied. We conclude that the GF system accurately estimated enteric CH4 and CO2 emission rates of cattle over a short measurement period, but additional factors would need to be considered in determining the 24-hr emission rate of an animal.

Publication date

2021-03-01

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