Reduce enteric fermentation emissions from ruminant animals
Reduce enteric fermentation emissions from ruminant animals by improving feed quality, animal productivity, and using dietary additives
Methane emissions represent 17.3% (1) of total global GHG emissions. However, methane is a particularly potent GHG, trapping 84 times more heat than carbon dioxide in the first two decades following its release into the air (2).
Figure 1: FOLU “Growing Better: Ten critical transitions to transform Food and Land Use", pag. 87 (3)
Ruminants are responsible for 30% of global methane emissions. Enteric fermentation is the digestive process of cattle, sheep, and other ruminants that releases methane (CH4), a potent GHG, as a byproduct. Enteric methane is a Short-Lived Climate Pollutant (SLCP), parts of which stay in the atmosphere for many hundreds to thousands of years. Enteric fermentation is the main source of emissions from cattle. Related emissions amount to 1.1 gigatons, representing 46% and 43% of the total emissions in dairy and beef supply chains, respectively (4). Factors such as feed quality, animal size, and environmental temperature impact the amount of methane produced.
When tackling enteric methane, the aim is to increase the efficiency of digestion and nutrition without resulting in trade-offs for productivity. This can be done in multiple ways:
Increasing feed quality: Switching to a dairy cattle feed that increases dietary oils (cottonseed) was found to reduce CH4 emissions by ~12% and increased milk yield by ~15%, thereby sustainably enhancing food security by ensuring stability of dairy supply, and reducing emission intensity (5). Improving cattle feed can reduce carbon dioxide equivalent emissions by 4.42-15.05 gigatons by 2050 (6). Improving feed quality can be achieved through improved grassland management, improved pasture species, forage mix, and greater use of supplements, preferably locally available.
2. Using dietary additives: Additives such as3-nitrooxypropan (3-NOP) prevent methane formation in the cow’s rumen (or other ruminant livestock) during the digestive process (7). The additives can be natural feed supplements like garlic, or kelp – feeding one type of seaweed at 3% of the total diet has been shown to reduce CH4 emissions by as much as 80% from cattle (8).
Figure 2: Methane Reductions from Feed Additives (9)
3. Improving animal productivity:
Reducing the ratio of animals dedicated to reproduction to animals dedicated to production, thereby reducing the methane emitted from non-producing animals.
Improving animal performance by breeding for low-emission animals. There is emerging evidence that animal breeding can lead to a microbiome that produces less CH4: research found that CH4 can be reduced by 7% to 17% per generation (10).
Improving the reproductive efficiency and extending the reproductive life of the animal improves lifetime performance per animal and reduces methane emissions per unit of animal product.
Animal nutrition and input providers can support shifting diets of ruminants through dietary additives. For example, DSM has developed Bovaer, a methane-reducing feed additive for cattle. The first large-scale on-farm use of Bovaer was rolled out in March 2023 at 158 dairy farms in the Netherlands by Royal FrieslandCampina, DSM, and feed supplier Agrifirm. The six-month program, which started in 2022, confirmed that Bovaer can be introduced at scale without affecting animal health, milk production, or milk composition, hence supporting the quick adoption of Bovaer by the dairy sector to reduce GHG emissions (11).
Food processors and manufacturers can work with producers to reduce methane emissions. For example, Danone has set a target of 30% absolute reduction in methane emissions by 2030 (in alignment with the Global Methane Pledge). If met, this target is projected to remove 1.2 million tons of carbon dioxide equivalent of methane emissions by 2030.
The company works with farmers and other partners to implement several levers to reduce methane emissions in their production:
Better herd and feed management: Improving animal health and welfare, ensuring a high-quality diet composition, achieving better feed efficiency to improve yield and reduce enteric methane emissions per liter of milk.
Breakthrough methane inhibitors: Investing in innovative solutions such as feed additives which can, for instance, directly prevent micro-organisms’ production of methane in the rumen (12).
Targeted emissions sources
Scope 1 (Biogenic), Category 1 Direct GHG emissions (for producers)
Scope 3, Category 1 purchased goods and services (for offtakers, manufacturers, retailers)
Under modelled global net anthropogenic CO2 emission pathways, it was found that among agricultural measures, the largest potential for non-CO2 reductions is reduced enteric fermentation from better feed and animal management (CH4 reduced by 0.1-1.2 GtCO2e p.a) (13).
New market opportunities For input providers, there is a new market opportunity to offer enteric emission reducing feed. For producers, there is also a positive business case for improving animal productivity, thus leading to greater production efficiency.
Additional revenue While the higher quality feedstuff is more expensive than conventional feeds, the cost was found to be offset by the additional revenue from increased milk yield, modeled as an increase of USD $8.53 per kilogram of protein of animal-sourced product (14).
Act instead of react In 2021, 150 nations signed on to the Global Methane Pledge (GMP), a global voluntary commitment toward a collective reduction in global methane emissions by at least 30% of 2020 levels by 2030. In May 2023, agriculture and environment ministers and ambassadors from 13 countries, including the United States, issued a commitment to reduce methane emissions in agriculture (15). In addition to meeting climate goals, reducing methane emissions presents an opportunity for companies to place themselves ahead of national regulatory requirements.
Improved contractual agreements Cattle and dairy producers implementing initiatives to reduce their on-farm (Scope 1) emissions may receive a more attractive contractual agreement from offtakers for a lower-emission product. By purchasing a lower-emission product, the offtaker would be able to claim the reduction in their Scope 3, Category 1 emissions. Climate-smart producers will be able to strike more attractive contractual agreements.
Modelling by Project Drawdown found that conventional cattle management operating costs are USD $9.48 per kilogram of protein from animal-sourced products, and USD $13.38 per kilogram of protein for improved cattle feed quality.
Academic research evaluating the cost-effectiveness of three feeding strategies found that reducing the maturity stage of grass and grass silage was the most cost-effective (€57/t of CO2e), followed by supplementation of dietary nitrate (€241/t of CO2e) and supplementation of an extruded linseed product (€2,594/t of CO2e). Supplementation of nitrate resulted in the largest reduction in GHG emissions, but reducing the maturity stage of grass and grass silage resulted in lower costs and better cost-effectiveness. This latter strategy, therefore, was found to be most promising for application in practice (16).
Indicative abatement cost
In the agriculture sector, the average cost per ton of methane reduced is $830 (17).
Impact beyond climate and business
When using seaweed-based feed additives, beyond reducing methane emissions, seaweed farming increases carbon sequestration in oceans and reduces ocean acidification.
Beyond reducing emission intensity, increasing feed quality also improves milk yield, thereby sustainably enhancing food security by ensuring stability of dairy supply.
By improving animal productivity, producers secure greater socioeconomic benefits.
An additional benefit to increased productivity is fewer animals are needed to meet the demand for milk, thus reducing the pressure on land and water.
Mitigation measures often increase productivity and animals’ live weight (pre-slaughter weight), which often leads to increases in overall emissions, but lower emissions per kilogram of product.
Improved feed and feed supplements can be costly and unaffordable to many low-income farmers in developing countries.
Feed can be an additional source of emissions, especially if associated with land-use change, such as soy (18).
Typical business profile
This solution applies to companies with beef and dairy in their supply chain, including input providers, farmers and producers, traders, manufacturers and processors, and retailers. Companies can play a critical role in reducing global enteric emissions by creating incentives and by investing in technologies that are tailored to the needs and concerns of farmers and ranchers. By investing in the reduction of enteric emissions in their supply chain, companies in the beef and dairy sector can reduce their Scope 3 emissions significantly per kilogram of product.
Below are some typical steps a company aiming to reduce its enteric fermentation emissions can engage in:
Assess emissions: Conduct a comprehensive assessment to understand your emissions and environmental footprint
Identify emissions hotspots: Identify which suppliers represent a large portion of your Scope 3 emissions and select those your company will engage with
Set internal emission reduction strategy: Develop a Scope 3 emissions reduction strategy and associated supplier engagement plan
Implement supplier engagement plan: Contact suppliers to discuss their emission reduction plans (if any), introduce your Scope 3 emissions reduction strategy, discuss any improvement requirements, and establish next steps
Buy-in from an array of internal and external stakeholders is needed to efficiently reduce enteric fermentation emissions, for example:
Executive Management: To set decarbonization goals specific to methane emissions and integrate these into procurement requirements; approve investment in improved feed and additives, and in a novel animal productivity strategy
Finance & Accounting: To align budget availability amid a new enteric emissions reduction strategy
Procurement: To implement a roadmap for engaging producers with new procurement requirements
Farmers: To introduce an improved feeding regime and feed additives, and implement an animal productivity strategy
Government: To set enteric fermentation emissions reduction targets for the agri-food sector; support the roll-out of policies that offer incentives for companies actively reducing enteric fermentation emissions in their supply chain; support research and development into cost-effective enteric fermentation emissions reduction
Key parameters to consider
Solution maturity: While quantitative evidence that increasing feed quality and improving animal productivity reduces enteric fermentation emissions is fairly recent, these techniques have always been used by producers to optimize cattle for their specific needs. Both optimal feed-mix and productivity improvement plans will differ depending on the herd species. The use of methane inhibitors such as feed additives is a novel solution, but with significant academic research proving its efficacy (19).
Technical constraints or pre-requisites: The uptake of dietary additives depends on further technical improvements to drive greater cost parity.
Geographical specificities: The feasibility of these feeding strategies will depend on the type of production system, associated costs, market availability, and localized social acceptance (20).
Implementation and operations tips
While awareness of the need to reduce enteric emissions is on the rise, barriers to adopting solutions remain – the most significant being cost. In a survey by the Environmental Defense Fund, only 30% of farmer respondents reported that they would be willing to adopt an enteric solution if they had to bear the cost (21). Private and public stakeholders should develop systems of incentives that will bear the cost of enteric solutions so they are financially feasible for producers to incorporate into their operations.