Feeding cows red seaweed poised to turn the tide on dairy and meat’s methane emissions

03 Apr 2023 --- The market for methane-suppressing products is anticipated to heat up as governments around the world move toward rolling out policies targeted at boosting their uptake. Cows in the UK could be given “methane blockers” to cut climate emissions, according to the government’s recently published Net Zero Strategy, while researchers have discovered lactating cows that are fed a diet of seaweed oil may emit significantly less of the environmentally degrading gas.

“We anticipate entry of high efficacy methane suppressing products to the UK market from 2025 and will explore the role of industry and government to maximize uptake of such products for suitable cattle farm systems at pace, through a phased approach,” says the Net Zero Growth Plan report.

“This will include the ambition to mandate the introduction of products with proven safety and efficacy in compound feeds for cattle as soon as practically possible in England.”

Britain’s 9.4 million cattle produce 14% of human-related emissions, mostly from belching.

Britain’s 9.4 million cattle produce 14% of human-related emissions, mostly from belching.

Meanwhile, the National Farmers’ Union states that feeding cattle methane-suppressing products could be useful but more investigations need to happen with regards the impact they will have on the efficiency of the diet.

One paper published in the recent March edition of the journal Animal Feed Science and Technology, supports that the particular method of feeding cows canola oil steeped with Asparagopsis armata effectively slashed methane emissions by 39-44% without affecting cow milk yield or dry matter intake.

Notably, the seaweed oil did not affect milk yield or quality. While it was found to increase the amount of bromoform in cow milk, these levels were at “safe concentrations” for humans to consume.

Growing interest in methane blockers
Investigations into bromoform have not stunted agri-food research into seaweed as a feed supplement. FutureFeed, an offshoot of CSIRO, currently holds the intellectual property rights to Asparagopsis armata as a feed additive.

Studies have been examining more seaweed varieties for their potential to reduce methane in ruminants. 

Researchers writing in Fronteirs last April found that the Asparagopsis taxiformis is one type commonly known to be effective.

They found that Asparagopsis taxiformis reduced methane concentrations by 95.1% compared to the control treatment, but it also decreased fiber degradation and volatile fatty acid-producing (VFA) bacteria activity, which could negatively impact animal performance.

Cracking down on bromoform
But while the variety of edible seaweed types deemed suitable for this application is broadening through new studies, contrasting research warns that a particular compound – bromoform – present in some seaweed varieties might cause potential toxicity considerations.

Bromoform is deemed both a hero and villain in the origin story of methane production. The substance counteracts the formation of methane in the cow’s rumen, highlight scientists in a statement from Wageningen Livestock Research in the Netherlands.Varieties of seaweed have been found to reduce methane emissions in cattle and other livestock.“Bromoform inhibits the formation of methane in the cow’s rumen, it's also toxic,” says Wouter Muizelaar, researcher at Wageningen Livestock Research.

However, the acute (short-term) effects from inhalation or ingestion of high levels of bromoform in humans and animals consist of nervous system effects such as the slowing down of brain functions, and injury to the liver and kidney, according to the US Environmental Protection Agency.

Non-seaweed methane blockers gains traction
The activity of using methane blockers on farms continues to gather pace. Last month, Royal FrieslandCampina, DSM, and feed supplier Agrifirm incorporated the solution Bovaer into the regular farming activities of 158 dairy farms in the Netherlands.

Bovaer is advertised as the world’s first large-scale on-farm use of the methane-reducing feed additive for cattle.

The six month program, which started in 2022 and involved more than 20,000 cows, confirmed that Bovaer can easily be introduced at scale “without affecting animal health, milk production or milk composition.”

The project reports a decrease of 10,000 tons of CO2e in methane emissions (an average of 28% less enteric methane emissions). 

By Benjamin Ferrer