Why has an additive called Bovaer sparked controversy online?

Some UK social media users have been pouring milk down their sinks and toilets in protest at the trial of a new feed additive that claims to significantly reduce the emission of methane gas in dairy cows.

Arla Foods, a Danish-Swedish company which owns the UK’s biggest dairy cooperative, announced last week that 30 of its farms across the country would test the additive, named Bovaer.

The company says Bovaer - which is added in small quantities to cow feed - could reduce cow methane emissions by between 30-45%.

It has been approved for use by UK regulators, and several major supermarkets will stock milk produced by cattle eating feed with the additive.

Methane is a much more potent greenhouse gas than carbon dioxide and is helping drive climate change.

Cows produce it when their stomachs are breaking down hard fibres like grass for digestion. This fermentation process creates methane gas which is then mostly belched out again.

Bovaer works to suppress the enzymes in a cow’s stomach that create the gas. The National Farmers Union (NFU) says when the additive is used as recommended it breaks down in the cow’s digestive system and as such is not found in milk or meat.

According to DSM-Firmenich, the additive is available for sale in 68 countries around the world.

As part of its trial, Arla Foods is working with some of the UK’s largest supermarkets, including Tesco, Morrisons and Aldi, who will stock products produced by cows which have eaten the additive.

Since Arla announced the trial, Bovaer has been subjected to a huge range of claims online.

Among those raising concerns has been Reform UK MP Rupert Lowe, who said on X that he had asked the Department for Environment Food and Rural Affairs to carry out an urgent review of the additive.

Meanwhile, some dairy farmers have said they will not use the feed, citing concerns over some of the compounds used to make the additive.

Bovaer is made using silicon dioxide, propylene glycol and organic compound 3-nitrooxypropanol (known as 3-NOP).

Some of those posting online have alleged that Microsoft founder Bill Gates is involved in the development of Bovaer, a claim which the additive's developer flatly denies.

In a strongly worded statement on 2 December, DSM-Firmenich said it had “fully developed” Bovaer and emphasised that the company had “no other investors”.

“Bill Gates is not involved in the development of Bovaer,” the statement added.

The US-based billionaire has instead invested in a rival start-up, Rumin8, which develops a similar methane reducing product.

Mr Gates has long been the subject of multiple conspiracy theories - the most extreme of which claim that he is part of an effort to depopulate the world.

Some online activists have sought to link Bovaer to such claims, pointing to a past approval letter from US regulator the FDA which found that the additive could lead to male infertility.

However, the letter was referring to precautions that must be taken when handling the product in its pure form - rather than when it is added to animal feed.

Debates about Bovaer appear to have started to spread almost immediately after Arla announced its planned trial on 26 November.

Its post on X announcing its partnership with Tesco, Lidl and Morrisons has nearly 6 million views and attracted thousands of comments as of 3 December.

Users with a history of spreading conspiracy theories latched onto the trial within hours. Some of those posting have in the past shared anti-vaccine and climate-change denying content.

Other users, however, appear to be sharing posts about the additive out of genuine concern.

According to the social media analysis firm Brandwatch, mentions of Bovaer on X rose from virtually zero to over 71,000 in the days after the trial was announced.

Meanwhile, on TikTok clips attacking the product have received up to 1.8m views each.

Some of the most popular have seen users disposing of packets of Arla's Lurpak butter and pouring cartons of milk away, with one captioned: “Not in my house.”

The National Farmers Union says 15 years of trials have proved there is no risk to consumers or animals - that Bovaer breaks down in a cow's digestive system and is not present in milk or meat.

Graphics by Christine Jeavans.