How to Calculate Enteric Methane Reductions Under VM0041

VM0041 is the Verra methodology for crediting reductions in enteric methane, the methane that cattle, sheep, goats and other ruminants release mainly by belching and breathing. Its full title is Methodology for the Reduction of Enteric Methane Emissions from Ruminants through the Use of Feed Ingredients. This guide explains how the calculation works, which data you need on the farm and what a verifier will look for. It describes the logic and names the parameters; for the exact equations, tables and default values, always work from the official VM0041 document on verra.org.

A note on naming: VM0041 is sometimes confused with VM0051, but VM0051 is Verra’s rice cultivation methodology. If your project is about livestock diets, VM0041 is the one that applies. For rice, see our rice methane credits guide.

VM0041 at a glance

• Current version: v2.0, approved 21 December 2021 and listed as active by Verra. Version 1.0 (developed by Mootral SA) was active from November 2019 to November 2021.
• Sectoral scope: 15, livestock and manure management. Globally applicable.
• What it credits: reductions only, from feed ingredients that suppress or inhibit methanogenesis in the rumen.
• Revision under way: Verra consulted on a draft v3.0 from 8 October to 7 November 2025, with changes to additionality, applicability, boundary, quantification and monitoring intended to align VM0041 with the ICVCM Core Carbon Principles (Verra announcement). As of our check, v2.0 is still the version in force.
• CCP status: VM0041 v2.0 appears in the enteric methane category of the ICVCM assessment tracker, but it has no CCP-approved decision yet. Credits under it cannot carry the CCP label today.
• CORSIA: the VCS Program is eligible for CORSIA, and Verra lists VM0041 among eligible methodologies for the 2024-2026 first phase. Each unit still needs the CORSIA label, which for 2021+ vintages requires a host-country authorization and corresponding adjustment (Verra CORSIA page).

Applicability conditions

Before any math, a project has to pass the applicability test. Under v2.0, in short:

• The animals are ruminants and are fed an ingredient that reduces enteric methane by acting on methanogens or on the rumen environment.
• The ingredient complies with feed and food rules in every jurisdiction where it is consumed (the strictest rule wins), has no negative effect on animal health, and is used according to the manufacturer’s instructions, including dose per kilogram of dry matter intake.
• Gains from other strategies, such as better productivity or general nutrition changes, cannot be claimed.
• The ingredient must be traceable from the manufacturer to on-farm consumption.
• There must be evidence that manure emissions do not rise. If they do, manure methane and nitrous oxide are accounted for as project emissions.
• Existing farms need reliable historical records (feed intake, diet composition) for each animal group: at least two years for the direct-measurement baseline and three years for the IPCC model baseline. Farms without records can use regional statistical averages.

Additionality uses an activity method: the project shows regulatory surplus and meets all applicability conditions, which together work as the positive list.

How baseline emissions are determined

The baseline is business as usual: the same herd on its normal diet, without the ingredient. Emissions are calculated per farm and per animal group (animals grouped by type, weight, production phase or feeding regime), then converted to tCO2e using the global warming potential of methane. The methodology offers three options for the enteric emission factor, chosen per group according to the data you have:

1. Direct measurement. Methane per head per day is measured on site with respiration chambers or automated head-chamber systems that take repeated spot samples. The result is multiplied by the average head count and the days each animal spent in the group. A control group that does not receive the ingredient can provide the baseline during the project. Once set, this production factor stays fixed for the crediting period.
2. IPCC Tier 2 model. The factor is built from gross energy intake (dry matter intake multiplied by the energy density of the diet), the methane conversion factor Ym (the share of gross energy lost as methane), the energy content of methane, head count and days. The document gives default energy densities and guidance on Ym by animal group.
3. Default emission factors. Where data for the Tier 2 model are missing, national or regional per-head factors, or those listed in the methodology’s appendix, are applied to head count and days.

How project emissions are determined

Project emissions start from the same group emission factor, reduced by the emission reduction factor (ERF) of the ingredient. To that you add emissions from manufacturing and transporting the ingredient (grid electricity and fossil fuel used per kilogram produced, plus transport distance and mode), unless they are shown to be de minimis, and any statistically significant increase in manure emissions.

There are two ways to set the ERF:

• Meta-analysis: a reduction percentage derived from at least three peer-reviewed studies in journals indexed in the Science Citation Index Expanded. The project’s conditions (animal type, dry matter intake, fibre, housing) must fall within the range covered by the studies; meta-regression can adjust for some differences.
• Direct measurement: methane is measured on animals receiving the ingredient during the first monitoring period and compared with the baseline factor. The result can be reused for the crediting period while feeding regime and animal profile stay the same.

Leakage is set to zero in v2.0. Net reductions are the sum, across farms, of baseline emissions minus project emissions.

Data and monitoring you will need

• Head count per animal group and the start and end dates of ingredient feeding.
• Dry matter intake, diet energy density or fat content, fibre (NDF) and the Ym used.
• Methane measurements and protocols, if you use direct measurement.
• Feeding records that follow the manufacturer’s dosing instructions, plus invoices or delivery receipts with batch numbers proving the amount purchased.
• Manufacturer data on energy and fuel use per kilogram of ingredient, and transport distances.
• Calibration records for any measurement equipment. Monitoring data must be archived electronically for at least two years after the first verification.

Reporting

The monitoring report presents, for each farm and animal group, the option chosen for the baseline and for the ERF, the parameter values and their sources, the calculated baseline and project emissions, and the evidence trail for dosing. The validation and verification body will reconcile purchased ingredient against animals and days claimed, so mismatches there are the fastest way to lose credits.

Common mistakes

• Citing VM0051 or another methodology in the project documents. VM0051 covers rice.
• Using a meta-analysis ERF for a diet or animal type outside the range of the underlying studies.
• Claiming animals that did not receive the full dose for the full period, or lacking batch-level proof of purchase.
• Mixing animal groups with very different diets in one average, which hides changes in intake.
• Ignoring manure effects when the ingredient changes digestibility.
• Assuming a CCP label. VM0041 is still under ICVCM assessment.

Why it matters for Brazil

Brazil had 234.3 million head of cattle at the end of 2025, according to IBGE’s Municipal Livestock Survey released in September 2026 (Agência Gov). That scale makes enteric methane a natural target. The practical hurdle is dosing: VM0041 requires proof that each animal received the ingredient as instructed, which is simpler in feedlots and dairies with controlled rations than on extensive pasture. Brazil’s regulated market does not impose obligations on primary agricultural production, so these projects sit in the voluntary market; see our SBCE explainer.

FAQ

Is VM0041 the same as VM0051?

No. VM0041 covers enteric methane from ruminants through feed ingredients. VM0051 covers methane from rice cultivation.

Which feed ingredients qualify?

Since v2.0, any ingredient approved for animal use with scientific evidence of efficacy, such as 3-nitrooxypropanol or seaweed-based products, provided it meets all applicability conditions.

Can grazing herds use VM0041?

In principle yes, but the project must trace and document that grazing animals actually consumed the ingredient at the instructed dose.

Do VM0041 credits carry the CCP label?

Not yet. The methodology is listed under ICVCM assessment, and Verra’s v3.0 revision targets CCP alignment.

Verified on 13/10/2026 against the Verra methodology page, the ICVCM assessment tracker and Verra’s CORSIA page.

Track status changes for this and other methodologies in our Methodology Watch. Related reading: VM0041 explained, what CCP labels mean for buyers and VM0051 for rice, explained.