Medicinal herbs as a potential strategy to decrease methane production by rumen microbiota: a systematic evaluation...

Area of Science:

• Agricultural Science
• Microbiology
• Environmental Science

Background:

• Ruminant livestock production is a significant source of methane (CH4) emissions, contributing to environmental concerns.
• Current methods for mitigating ruminant methane are often limited in effectiveness or practicality.
• Medicinal herbs possess bioactive compounds with potential antimicrobial properties that may reduce methane production.

Purpose of the Study:

• To screen a wide range of medicinal herbs for their in vitro efficacy in reducing methane production by rumen microbiota.
• To identify specific herbs and their active components that can lower methane emissions.
• To investigate the impact of effective herb extracts on rumen microbial populations and fermentation.

Main Methods:

• In vitro assessment of CH4 production inhibition using extracts from 100 medicinal herbs.
• Identification of key compounds in the most effective herb extract (Perilla frutescens seeds).
• Analysis of rumen microbial community shifts (methanogens, bacteria, fungi, protozoa) and volatile fatty acid profiles.

Main Results:

• Extracts from 12 medicinal herbs demonstrated CH4 reduction, with Perilla frutescens seed extract showing the highest efficacy.
• P. frutescens seed extract altered rumen fermentation by increasing specific bacteria (e.g., Ruminobacter) and decreasing key methanogens (Methanobrevibacter millerae).
• Certain bacterial groups were positively correlated with CH4 production, while volatile fatty acid concentrations remained unaffected.

Conclusions:

• Medicinal herbs, especially Perilla frutescens seeds, show promise as a practical strategy for mitigating ruminant methane emissions.
• The CH4 reduction is linked to specific shifts in the rumen microbial ecosystem.
• Further research into these herbs could lead to sustainable solutions for reducing the environmental impact of livestock.