What it is
3-nitrooxypropanol (3-NOP), sold as Bovaer by dsm-firmenich and licensed with Elanco in North America, inhibits a rumen enzyme in the last step of methane making. Peer-reviewed trials and the companies’ dossiers support on the order of a 30 percent drop in enteric methane for lactating dairy cows at labeled doses. The EU authorized it in 2022. In May 2024 the U.S. FDA finished its review and allowed marketing under enforcement discretion.
Problem it targets
Cattle are a large source of methane, a short-lived but strong greenhouse gas. Feed additives, breeding, and better health can cut that flow while herds still exist. They do not erase land use or nitrous oxide.
How it works
The additive is mixed into the total mixed ration at grams-per-cow-per-day scale. It must be fed daily. Effect size depends on diet. It is not a vaccine and not a genetic rewrite of the animal.
Status and players
dsm-firmenich (developer); Elanco (North American commercialization); dairy cooperatives testing carbon-inset payments. Other methane tools (asparagopsis seaweed, 3-NOP rivals) are in parallel trials.
Risks and limits
Cost versus milk price; public distrust; and the temptation to call a 30 percent cut “climate-neutral beef.” Leakage if herds grow. Seaweed additives have their own bromine and supply questions — this card is about 3-NOP, not every feed claim.
Sources
EU authorization of 3-NOP (2022); Elanco / FDA CVM review completion, 28 May 2024 (~30% methane reduction claim in company and dossier materials); dsm-firmenich Bovaer science pages; peer-reviewed 3-NOP meta-analyses.