Dietary mitigation of enteric methane emissions from ruminants: A review of plant tannin mitigation options

Authors: Min, Byeng Ryel; SOLAIMAN, SANDRA - Tuskegee University; Waldrip, Heidi; Parker, David; Todd, Richard; Brauer, David

Submitted to: Animal Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/27/2020
Publication Date: 9/17/2020
Publication URL: https://handle.nal.usda.gov/10113/7014277
Citation: Min, B., Solaiman, S., Waldrip, H., Parker, D.B., Todd, R.W., Brauer, D.K. 2020. Dietary mitigation of enteric methane emissions from ruminants: A review of plant tannin mitigation options. Animal Nutrition. 6(3):231-246. https://doi.org/10.1016/j.aninu.2020.05.002.
DOI: https://doi.org/10.1016/j.aninu.2020.05.002

Interpretive Summary: The effect of methane (CH4) on global warming is gaining attention because, as a greenhouse gas, it has a global warming potential 28 times that of carbon dioxide. There have been few studies to summarize greenhouse gas emissions associated with plant tannins, rumen microbiota activities, feed efficiency, and dietary intervention. Scientists from USDA-ARS at Bushland, TX, and Tuskegee University, Tuskegee, AL, analyzed how the dietary tannins and other dietary interventions affect greenhouse gas emissions and rumen microbial activities. Our meta-analysis concluded that tannin-rich diet suppressed methanogenesis via anti-methanogenic activity. This data will be used to update greenhouse gas emission strategies for feedlot beef cattle and dairy cattle.

Technical Abstract: The livestock industry is a source of global greenhouse gas (GHG) emissions including methane (CH4) gas through animal production activities. The potential to manipulate the rumen microbiome and meet sustainable ruminant production systems through animal genetic selections and introduction of dietary interventions has recently progressed towards promising new technologies. Feed conversion efficiency (FCE) and residual feed intake (RFI) of ruminants directly affect the profitability, efficiency, and sustainability of livestock production. Although, CH4 production is crucial for rumen homeostasis, enteric CH4 emissions from ruminant animals has generated a great deal of attention because of the influence that GHG emissions have on global climate change. Therefore, GHG reduction strategies should be established that increase ruminant production efficiency, while minimizing loss of CH4 from cattle, sheep and goats. Alternatively, CH4 emissions may be efficiently mitigated via systematic intervention of the natural rumen microbiota by a combination of improved feed efficiency strategies and other chemical means. Although some CH4 abatement strategies have shown efficacy in vivo, more research is required to make any of these approaches pertinent to modern animal production systems. The current review aimed to understand how rumen microbiota and anti-methanogenic compounds (e.g., plant tannins) alter host responses and CH4 emissions. Thus, this review provides information relevant to understanding the impact of tannins on methanogenesis via feed additives that may provide a cost-effective means to reduce enteric CH4 production and the influence of ruminant animals on global GHG emissions.