Inside Bovaer: How a Feed Additive is Reducing Methane Emissions in Dairy and Cattle
Tackling Livestock's Biggest Climate Challenge: Methane Emissions
Enteric methane is the largest single contributor to the dairy sector’s emissions. Depending on the production system, it can represent between 40% and 60% of the total carbon footprint per liter of milk or kilogram of meat.
Alejandro Vergara, CEO of ODOS, sat down with Dennis Rijnders, VP Global Sales & Business Development, Bovaer at DSM, to explore the science, strategy, and field adoption of one of the most targeted climate tools in livestock: Bovaer. The conversation began by acknowledging the scale of the problem.
Bovaer is a feed supplement for cows designed to reduce methane emissions at the source. It targets a specific biochemical process in the cow’s rumen, where methane is produced as a byproduct of digestion. By inhibiting a key enzyme used by archaea microbes, Bovaer interrupts the formation of methane without affecting animal health or productivity. This makes it one of the few methane reduction tools that can be integrated into existing feed systems with no disruption to daily farm operations.
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Why DSM Succeeded Where 40 Years of Research Failed
The idea for Bovaer was born out of DSM’s internal innovation program focused on climate challenges. Researchers were asked to explore breakthrough solutions in food and nutrition. Among them were two young scientists who took on a challenge many considered too complex: reducing enteric methane from ruminants.
The team focused on the biochemistry inside the cow’s rumen, where archaea microbes convert hydrogen and carbon dioxide into methane. Unlike past efforts that aimed at broad rumen manipulation, DSM’s approach was precise. They identified the final step in the methane pathway, an enzyme unique to these microbes, and asked a simple but powerful question: What if we could block just that one step?
“They thought, hey, if we inhibit this enzyme, then we can come up with a very effective solution that will have minimal impact on the rumen of the cow and on the cow itself,” Rijnders explained. “And they quite quickly were able to find the solution.”
DSM succeeded where others had stalled because of its deep in-house expertise in enzyme chemistry, animal nutrition, and safety science. The result was the molecule 3-NOP, now known as Bovaer. Early trials in Spain demonstrated clear methane reductions in sheep. The team expanded testing across dairy and beef systems in various countries.
“They saw the product always worked,” Rijnders said.
From Lab to Farm: Making It Practical for Farmers
Scientific results mean little if the product is not usable on real farms. Bovaer was developed with that in mind. Farmers do not apply it manually. Instead, it is delivered through standard feed systems. DSM works directly with feed suppliers and nutritionists to incorporate the correct dose, typically 12 to 15 grams per cow per day, into mineral or protein concentrates. The dose is tailored to each farm’s ration, and once adjusted, requires no daily changes unless the feed plan is altered.
As Rijnders explained: “We want to make it as easy as possible. The product is integrated into existing feed routines. The farmer makes a phone call to the feed supplier. That’s it.”
What About Grazing Systems?
To work effectively, Bovaer needs to be ingested daily. In housed systems or farms with total mixed rations (TMR), this is straightforward: cows receive a consistent diet every day, making Bovaer delivery both easy and reliable.
But grazing systems complicate this. When cows are outside for much of the day, eating grass rather than controlled feed, it becomes harder to ensure a consistent daily dose. This raises the question: can Bovaer still be effective when cows are only partially or occasionally consuming mixed rations?
Partial grazing is common across Europe, especially in spring and summer. In these systems, cows often spend around six hours per day outdoors and the rest indoors. DSM conducted trials in Belgium and the Netherlands to test Bovaer’s efficacy under these conditions. The results were promising. “We see that if you do that partial grazing of about 6 hours, you actually don’t lose any methane reduction,” Rijnders explained. The reason: Bovaer temporarily inhibits the specific enzyme responsible for methane formation. Even when cows go out to graze, the inhibition effect persists throughout the day.
Fully pasture-based systems, like those dominant in Ireland, are more complex. Without regular access to mixed feed, maintaining daily intake is harder. In trials with Teagasc, DSM tested a twice-daily feeding approach and saw methane reductions of 10–13%. While this is below the 30% average seen in housed systems, it still represents meaningful progress. “We are actively looking for and developing further applications for that,” Rijnders added. “We hope that once we are a little bit later in the year, we can give you some positive messages on this.”
DSM is now exploring new delivery mechanisms tailored to full grazing systems, including alternative dosing formats and more flexible feed strategies.
Can Bovaer Go Beyond 30% Reduction?
The often-quoted 30% methane reduction is not a fixed number; it’s a conservative average based on numerous global trials across different farm systems. The actual reduction depends on both the diet and the dosage. In energy-rich diets, such as those based on corn silage, the effect is significantly stronger.
“We’ve seen at the 60 PPM dose that we got 44 to 50% methane reduction,” Rijnders said, referring to trial results from Italy where corn silage was the dominant feed. These diets are more efficient at generating hydrogen in the rumen, which directly impacts how much methane can be mitigated. In contrast, grass silage diets typically lead to more modest reductions, as they generate less hydrogen for methane-forming microbes to use.
To help farmers and stakeholders make precise projections, DSM developed a meta-analysis tool that calculates expected methane reductions based on individual feed compositions. “That is a very solid science,” Rijnders emphasized. This tool is already being used in discussions with cooperatives, buyers, and verification platforms to ensure that reductions are both measurable and diet-specific.
By aligning Bovaer dosing with ration types and using validated science to forecast results, DSM ensures that methane reductions can be accurately reported and tailored to regional feed systems.
Why Certification Matters
Getting Bovaer approved as a feed additive wasn’t just a regulatory step; it was a strategic choice. “It is definitely not easy to get an ingredient being fed to animals,” Dennis Rijnders explained. DSM chose to go beyond the minimum requirements, filing under the European feed additive category for products with a positive environmental impact.
“We said quite early on, we are developing this product to, in the end, help farmers and the dairy and the beef sector reduce their enteric methane emissions,” he said. That required ensuring that every claim made about Bovaer’s environmental benefit could stand up to the highest level of scrutiny.
The European Food Safety Authority (EFSA) assessed the product for animal safety, consumer safety, environmental safety, and overall impact. “Going through the regulatory approval process is the best guarantee for farmers, for consumers, for the industry,” Rijnders emphasized. While the EU does not certify environmental claims directly, this approval allows Bovaer to be marketed with a verified methane reduction claim, something that sets it apart from unregulated alternatives.
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What Is The Price of Methane Emission Reductions Through Bovaer?
Yes, Bovaer comes with a cost, around €50 to €100 per cow per year. But as Dennis Rijnders pointed out, that cost must be weighed against the far greater costs already being felt across agriculture due to climate change.
“Farmers, they are probably the first to truly experience the impact of climate change. Droughts, floods, fires, it’s all happening. It’s not far away anymore,” he said. “It is in Spain, in the Netherlands, in Ireland, in the UK. It’s happening.”
And the economic consequences are only growing. “At some point in time, the insurance company is just not going to insure farmers anymore if this continues to happen,” Rijnders warned. “So I think there is also certainly something of self-interest here for farmers.”
But the burden doesn’t lie with farmers alone. Dairy companies, retailers, and buyers of livestock ingredients are stepping up. “They have made their commitments when it comes to science-based targets initiatives,” he explained. “They’re part of national programs to reduce their emissions.”
In parallel, governments are beginning to support methane reduction directly. “In Europe, there are a couple of examples where, in Denmark, there’s a subsidy available. In Flanders, there’s a subsidy available. In Slovenia, there’s a subsidy available,” Rijnders noted. Other countries are also considering policy tools to accelerate decarbonization in line with commitments like the Paris Agreement and Global Methane Pledge.
The momentum is growing. And as Rijnders summed it up: “Products that reduce absolute methane are extremely powerful because methane is such a powerful greenhouse gas. They make big reductions happen in an immediate and direct way.”