What Is the Methane-Reducing Additive Bovaer, and Why Is It Going Viral?

Cows graze in a field at a dairy farm in Petaluma, Calif., on April 26, 2024. Justin Sullivan/Getty Images

The cattle feed supplement, Bovaer, has gone viral in recent weeks with warnings major supermarkets are stocking products connected with the substance.

Savvy dairy producers responded quickly trying to capitalise on the movement, reassuring customers while publicly announcing on social media they did not use the additive.

But what is Bovaer and why has it caused such a stir?

What Does Bovaer Do?

In late November, Arla Foods, which owns the UK’s biggest dairy co-operative, announced on X it was trialling Bovaer, a cattle feed supplement that aims to reduce methane production in cattle.

According to the developer, the Swiss-based company DSM-Firmenich, the supplement suppresses an enzyme that combines hydrogen and carbon dioxide, so that less methane is produced in the cow rumen when microbes digest food.

Methane is a greenhouse gas, and according to the United Nations’ Environment Programme is 80 times more potent than carbon dioxide at global warming. The initiative aims to reduce methane production in attempts to limit global warming to 1.5 degrees Celsius.

Which Supermarkets Are Stocking It and Why?

Arla Foods said it was working alongside European supermarket giants Morrisons, Aldi, and Tesco to trial the supplement across 30 British farms.

In the announcement, Arla Foods reiterated research suggesting that Bovaer could “reduce [methane] emissions from cows by ~27 percent,” but questions remained over the long-term effectiveness of the supplement, and the impact on animal and consumer health.

In Australia, Bovaer has been backed by supermarket giant Coles and its “Coles Finest” certified carbon neutral beef supplier Warren Barnett.

Coles group began using the additive in 2022. Dr. Steve Wiedemann, principal scientist and managing director of Integrity Ag and Environment, worked with Coles and expressed willingness to expand its use.

“Bovaer is a highly effective product with strong research supporting mitigation rates of at least 50 percent, and up to as high as 85 percent in the diets being used to finish cattle in the Coles Finest certified carbon neutral beef program. I’m confident this product can deliver lower emissions and I’m looking forward to seeing its use expanded throughout the Coles supply chain over time,” said Dr. Wiedemann.

The Online Community Responds

The announcement was met with backlash from consumers across social media platforms, with many shoppers threatening to boycott the three supermarkets (Morrisons, Aldi, and Tesco) and Arla brands, especially Lurpak, a large Danish butter brand stocked globally.

As part of the response, TikTok videos emerged with people pouring jugs of milk down the toilet, down the drain, and some throwing tubs of butter in the bin.

Critics argued Bovaer contained “toxic chemicals,” that it could be dangerous for consumption, and cause reproductive issues. In particular, there has been a focus on the active ingredient, 3-nitrooxypropanol (3-NOP).

One user on X, formerly Twitter, cited a safety and efficacy study by the European Food Safety Authority (EFSA) from 2021 with the following extract for adverse effects in rats: “Treatment with 500 mg 3-NOP/kg bw per day caused adverse effects in the testes and epididymides characterised by severe reduction of the spermatogenesis.”

Dairy Producers, Farmers Capitalise on Movement

A swathe of Aussie dairy companies moved quickly to publish social media posts distancing themselves from the cattle feed additive.

Norco Milk, Gippsland Jersey, and Maleny Dairies released public statements stating they do not use Bovaer.

Norco Milk stated product quality and safety was of critical importance for their company, whilst Gippsland Jersey condemned the use of the supplement.

“At Gippsland Jersey, we pride ourselves on producing Australia’s Best REAL Milk—real, natural, and free from ANY additives. We are true purists when it comes to milk!” Gippsland wrote on Facebook.

“Here’s why: No MRNA. No Bovaer. Just wholesome, award-winning Jersey milk from farmers who care deeply about their cows, their land, and your health.

“We believe in keeping farming transparent, ethical, and sustainable.”

Even butcheries, like the Queensland-based large format Super Butcher, released a public statement on their website outlining to customers the brands of beef which do not use the additive.

Meanwhile, Patrick Holden, an advisor to King Charles and founder of the Sustainable Food Trust, told the Telegraph that Arla had “resorted to feed additives to maintain positive PR for their dairy-farming industry.”

“Feeding cows potions to reduce emissions is a classic case of the dairy industry, and I use that word advisedly, treating the symptoms rather than the cause of the problem.”

Arla Responds

In response to the social media backlash, both Arla and DSM-Firmenich released public statements.

DSM-Firmenich reiterated that Bovaer had been approved and considered safe by the UK and EU Food Safety Authorities.

The company also mentioned the supplement was included in cow feed at a ratio of one gram per 20 kilograms of feed; the supplement is fully metabolised by the cow, so it is not present in milk or beef, thus does not reach consumers.

The company emphasised the extensive scientific evidence for the safety and effectiveness of Bovaer.

They cited over “130 on-farm trials in 20 countries and over 80 peer-reviewed scientific studies,” where it was “proven safe for consumer, farmer, and animal, having no impact on milk production or reproduction.”

The public statement from Arla Foods restated these key facts, reassuring consumers the supplement has undergone extensive testing and is safe for cows and humans.

What Do the Experts Say?

Professor Alastair Hay, from the University of Leeds (in the UK), commented on the controversy in a post on the Science Media Centre.

“The level of detection was 5 ug (micrograms) per kg of milk. Theoretical studies indicate that levels of 3-NOP possible in milk at the dosing levels proposed are some 100 times less than would occur at the dose accepted by the FSA as safe,” he said.

“In cancer studies in rodents, the chemical was noted to be associated with some benign changes in mesenchymal cells in a few male animals tested.”

Mesenchymal cells are found in many tissues and can be converted into other forms of tissue such as connective tissue, lymphatic tissue, bone, or cartilage.

“However, there is a safety factor of some 170 between the dose at which some benign tumours were seen in rodents, and the dose of the additive considered safe by the FSA,” he added.

Ian Musgrave, senior lecturer in pharmacology at the University of Adelaide, emphasised the dosage used in cows would not cause harm.

He noted that “3-NOP was not lethal at the doses used in safety studies, up to 600 mg 3-NOP per kg of body weight. At 100 mg per kg of body weight in rats, it had no adverse effects,” he wrote in The Conversation.

“Research in rats and cows found that doses of 300–500 mg per kg of body weight resulted in ovarian and testicular shrinkage. To put that in perspective, to achieve the same exposure in humans, a 70 kg human would need to consume 21–35 grams (around 2 tablespoons) of pure 3-NOP a day every day for weeks on end to see this effect.”

Senator Says More Scrutiny is Needed

Meanwhile, on Dec. 11, Senator Gerard Rennick posted a response he received from the Australian Pesticides and Veterinary Medicines Authority (APVMA) in which the regulator stated it can only regulate products that meet the definition of a veterinary medicine under section 5 of the Agricultural and Veterinary Chemical Codes Act.

Under the Act, a veterinary chemical product is a vitamin, a mineral substance, or an additive that is used to treat an animal’s disease, alleviate an animal’s injury, or one that modifies an animal’s physiology in respect to its natural development.

“Feed supplements intended solely for the reduction of methane do not meet this requirement,” the letter states.

Additionally, the APVMA website states that it does regulate feed medications, supplements, and additives “unless they have been specifically excluded in the Agvet Code Regulations.”

Rennick said: “I would have thought Bovaer was at least a supplement or additive?”