Mitigation strategies for reducing enteric methane in grazing dairy systems

Authors: Soder, Kathy; BRITO, ANDRE - University Of New Hampshire

Submitted to: American Dairy Science Association Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 3/12/2022
Publication Date: 6/12/2022
Citation: Soder, K.J., Brito, A.F. 2022. Mitigation strategies for reducing enteric methane in grazing dairy systems[abstract]. American Dairy Science Association Abstracts. Pg 1.

Interpretive Summary: No Interpretive Summary is required for this Abstract Only. JLB.

Technical Abstract: Reducing emissions of greenhouse gases (GHG) in livestock production is a global priority to mitigate climate change. Methane is an important GHG with a global warming potential 28 times greater than carbon dioxide. Enteric methane emissions accounts for approximately 6% of global total GHG emissions from agriculture and represent loss of dietary energy, thus contributing to reduced livestock production efficiency. Ruminant grazing systems have been targeted as a particular source of GHG emissions, primarily due to decreased forage quality and digestibility and reduced system efficiency that frequently result in increased enteric methane production. Compared to confinement operations, grazing systems provide additional challenges due to lack of control of diet quality and difficulty in quantifying dry matter intake and methane emissions of grazing dairy cattle, although emerging technologies are making GHG data collection less cumbersome and more accurate. These challenges have limited data collection on enteric methane emissions and mitigation strategies in grazing environments. This presentation will cover current animal and forage management strategies to mitigate enteric methane emissions in grazing dairy systems, including improving forage quality for greater digestibility and animal production, utilizing forages with beneficial secondary/bioactive compounds, increasing forage diversity, genetic selection, greater understanding of the ruminal microbiome, strategic supplementation and methane inhibitors. While numerous feeding and management strategies show promise in reducing enteric methane emissions, limitations such as economics, commercial availability, method of delivery, or milk market constraints (e.g., grassfed or organic) have restricted widespread adoption in dairy grazing systems. Additionally, current research has failed to consider the impact of many of these inputs on the entire milk production system, such as management considerations for producing high-quality forage, costs of growing, processing, and transporting supplements, and potential effects of higher milk yield on herd fertility and health.