Methane Inhibiting Feed Additives Report, Nov 2021

The inclusion of feed additives in livestock diets or supplements is a routine global nutritional management practice. Consequently, the existing commercial feed additive marketing and delivery pathways will be able to deliver rapid market penetration of feed additives specifically developed to reduce enteric methane emissions. So, the delivery path is clear, but are the methane mitigating additives available, effective, and are there any constraints or risks associated with their use?

To answer these questions an assessment of the ten leading classes of compounds being studied for methane mitigation efficacy in ruminants was made. The assessment is provided as a concise resource that can serve as an evidence base to guide investment and management decisions by all actors in the livestock additive supply chain.

Key findings of the 10 reviewed additive groups

• Only two additives (3-Nitrooxypropanol) and dried Asparagopsis (red algae) have routinely delivered over 20% mitigation of enteric methane by the consuming ruminants. Dietary nitrate is the third most effective additive and can safely deliver 10% or more mitigation when consumed. The other classes of additive cannot be expected to deliver 10% mitigation when fed.
• Two major constraints for all reviewed additives achieving substantial global impact on livestock emissions in the immediate future, include:
  • Insufficient evidence to show any of these additives will increased production while decreasing methane output.
  • Almost all studies relied on additives mixed into a total mixed ration. There is almost no evidence of the efficacy of administering additives as a supplement, as in rangeland systems.
• Further research is needed to establish a business case for on-farm use of these additives.
• A small survey of the actors in the feed additive pipeline from the manufacturers through feed millers to livestock managers, shows:
  • A poor understanding of the efficacy and co-benefits of potential additives.
  • All livestock managers recognized they need more information on additives.
  • No additive manufacturers identified the grazing industry as a high priority market for a methane mitigating product.

Click on the download link to read the full report.