A review: Enteric methane emissions and animal performance in dairy and beef cattle production: enumerating the opportunities and impact of reducing emissions

Authors: MIN, BYENG - Tuskegee University; LEE, SEUL - Jeollabuk-Do Center; Miller, Daniel; CHEN, RUI - Tuskegee University

Submitted to: Animal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/7/2022
Publication Date: 4/7/2022
Citation: Min, B.R., Lee, S., Miller, D.N., Chen, R. 2022. A review: Enteric methane emissions and animal performance in dairy and beef cattle production: enumerating the opportunities and impact of reducing emissions. Animal. 12(8):948. https://doi.org/10.3390/ani12080948.
DOI: https://doi.org/10.3390/ani12080948

Interpretive Summary: Enteric methane (CH4) emissions produced by microbial fermentation in the rumen result in greenhouse gas (GHG) emission into the atmosphere. Increasing production efficiency and improving feed efficiency can lower emissions. This review compiles information from peer-reviewed studies to analyze relationships between CH4 emissions and measures of production [milk, energy corrected milk (ECM), average daily gain (ADG], consumption [dry matter intake (DMI) and gross energy intake (GEI)], and rumen function [fermentation profiles (volatile fatty acids, hydrogen), and microflora activities] in beef and dairy cattle. There was a significant positive correlation (P < 0.001) between dairy cattle CH4 emissions and DMI (R2 = 0.44), milk production (R2 = 0.37; P < 0.001), ECM (R2 = 0.46), GEI (R2 = 0.50), and acetate/propionate ratio (R2 = 0.45). For beef cattle, CH4 emissions were significantly and positively correlated (P < 0.05-0.001) with DMI (R2 = 0.37) and GEI (R2 = 0.74). Accordingly, the ADG (R2 = 0.19; P < 0.01) and acetate/proprionate ratio (R2 = 0.15; P < 0.05) were significantly associated with CH4 emission in beef steers. This information may lead to cost-effective methods to reduce enteric CH4 production from cattle. Our study concluded that enteric CH4 emissions per unit of ECM, GEI, and ADG, as well as rumen fermentation profiles, had great potential for estimating enteric CH4 emissions.

Technical Abstract: Enteric methane (CH4) emissions produced by microbial fermentation in the rumen result in losses from greenhouse gases (GHG) into the atmosphere. The GHG emissions reduction from the livestock industry can attain by increasing production efficiency and improving feed efficiency, by lowering the emission intensity of production, or by combining the two. In this work, we compiled information from peer-reviewed studies to analyze CH4 emissions calculated per unit of milk production, energy corrected milk (ECM), average daily gain (ADG), dry matter intake (DMI), gross energy intake (GEI), rumen fermentation profiles (volatile fatty acids [VFA], hydrogen [H2]), and microflora activities in the rumen of beef and dairy cattle. There was a positive and significant correlation (P < 0.001) between dairy cattle CH4 emissions and DMI (R2 = 0.44), milk production (R2 = 0.37; P < 0.001), ECM (R2 = 0.46), GEI (R2 = 0.50), and acetate/propionate (A/P) ratio (R2 = 0.45). For beef cattle, CH4 emissions were significantly and positively correlated (P < 0.05-0.001) with DMI (R2 = 0.37) and GEI (R2 = 0.74). Accordingly, the ADG (R2 = 0.19; P < 0.01) and A/P ratio (R2 = 0.15; P < 0.05) were significantly associated with CH4 emission in beef steers. This information may lead to cost-effective methods to reduce enteric CH4 production from cattle. Our study concluded that enteric CH4 emissions per unit of ECM, GEI, and ADG, as well as rumen fermentation profiles, had great potential for estimating enteric CH4 emissions.