Bill Gates-Backed Rumin8 Develops Synthetic Feed Additives to Cut Cattle Methane

Funding and development

Breakthrough Energy Ventures led Rumin8’s $12m Phase 2 seed financing, announced in January 2023. The funding was allocated to commercial trials in Australia, New Zealand, Brazil and the United States, as well as product development and pilot manufacturing.

Rumin8 is attempting to reproduce naturally occurring compounds with anti-methanogenic properties in synthetic form. Its stated aim is to create feed additives with consistent composition that can be produced at scale and used in different livestock systems. The investment supports commercial development; it does not establish that the products have broad regulatory approval or are already being used widely on farms.

How the additive is intended to work

Cattle produce methane through enteric fermentation. Microorganisms in the rumen break down fibrous plant material and generate hydrogen and other compounds. Methanogenic archaea use hydrogen to form methane, which cattle release mainly by belching.

Rumin8 is studying synthetic bromoform as the active compound. Bromoform interacts with vitamin B12 and inhibits a step in the biochemical pathway used by methane-producing microorganisms. The substance is volatile, however, so the company is developing formulations intended to improve its stabilisation and delivery.

Methane remains in the atmosphere for less time than carbon dioxide but has a stronger warming effect over a 20-year period. Livestock’s environmental footprint also includes feed production, manure management and land use. The Food and Agriculture Organization of the United Nations identifies enteric fermentation and manure management as important sources of agricultural methane.

Results from animal studies

Two studies published in 2025 reported different results for synthetic bromoform. Research in Translational Animal Science involved 24 Angus beef steers and compared oil and powder formulations under controlled conditions. The oil-based product lowered methane production and methane yield by about 95%. The researchers reported no significant changes in the measured production indicators or rumen-environment variables. The powder product did not produce a significant reduction at the lower dose tested.

A study in Animal Nutrition examined 16 Hereford–Friesian heifers grazing on fresh pasture. It reported methane-yield reductions of 16% at 300mg a day and 24% at 500mg a day, compared with a control group. The researchers found no treatment effect on feed intake and detected no bromoform accumulation in muscle or fat under the conditions examined.

The findings differed according to the formulation, dose, animal type and feeding system. Controlled trials do not by themselves establish performance on commercial farms. Further work identified in the research includes assessment of long-term safety, animal-health effects, food-safety issues and economic feasibility.

Practical and regulatory considerations

Administering a measured additive is more straightforward in feedlots, where cattle receive controlled quantities of feed, than in grazing systems. Other factors include manufacturing costs, distribution, regulatory approval and farmers’ willingness to adopt the products.

Animal nutrition, health, genetics and farm management are among the other approaches used to address livestock emissions. Rumin8’s technology is being developed as one intervention within that broader set of measures, with current studies showing reductions under some experimental conditions and variation between products and farming systems.