Enteric Methane Mitigation

Developing Feed Additives to Reduce Methane Emissions

Methane is a climate pollutant that contributes to global warming (IPCC 2023), and methane emissions from enteric fermentation and manure are a primary global source (Saunois et al. 2020). Livestock production needs to adopt practical dietary approaches that effectively reduce ruminal methane emissions without compromising milk or beef production efficiency, animal health or human food safety. Feed additives will also need to undergo rigorous safety and efficacy testing to receive approval by the FDA to claim methane mitigation potential.

The use of feed additives has the potential to lower methane emissions from livestock and slow the progression of climate change in the short term. Feed additives that lower rumen methane production fit two classifications:

Rumen modifiers: Compounds that modify the rumen microbial ecosystem, which include medium-chain and unsaturated fatty acids, plant-extracts such as essential oils, tannins, saponins, ionophores, or nitrate with methane-reducing efficacy generally being <30%.
Direct inhibitors: Inhibit enzymes of ruminal methanogenesis, which include 3-nitroxypropanol [3-NOP], halogen-containing seaweed, or synthetic bromoform. These inhibitors can reduce methane production 30% to 95% depending on type, dose and duration of use.

Our Focus

Our team of scientists leverage the Cornell Dairy Research Facility, climate-controlled respiration chambers, GreenFeed methane monitoring units, and a wide array of laboratory methodologies to address critical gaps in knowledge surrounding feed additives. We embrace a three-pronged approach.

Enhancing Energy Use

By defining energy use in cattle fed a methane-reducing feed additive using indirect calorimetry, we can expand our understanding of hydrogen and nutrient use in cows experiencing methane mitigation. Our work aims to address how energy use changes in the cow experiencing different planes of nutrition or physiological states. If a feed additive reduces methane energy, we identify strategic approaches to enhance energy use for growth, lactation, or overall health of the animal.

Methane Mitigation

Investigating the effects of feed additives on enteric methane emissions over extended periods of time helps determine whether microbial adaptation develops. Our research informs how feed additives interact with host genetics and diet nutrient composition. We explore the biological underpinnings as to why some cows respond to feed additives while others don’t. This work will provide farmers and nutritionists with strategies to enhance the duration and magnitude of methane mitigation under different management scenarios.

Animal and Human Food Safety

By working with the Cornell Animal Health Diagnostic Center to confirm that a feed additive does not impair animal health, we are prioritizing animal and human food safety. We are working to ensure that residues of human food—for example, bromoform or iodine—do not accumulate in meat or milk. In partnership with the department of food science, we are exploring the effects of feed additives on the chemical, physical and sensory characteristics of dairy foods.