If the theme song used by Burger King in a recent ad campaign is cartoonish and hokey, the story behind the campaign is even less believable, livestock nutrition experts say.
Some experts say the company’s claims that lemongrass can substantially reduce the amount of methane emitted by cattle are misguided and based on inconclusive research.
Why it matters: Feed additives and other methane-reducing strategies do show promise. Burger King’s most recent claims about lemongrass, however, are not backed by rigorous data.
Burger King has since backtracked on the ad, which depicts a young person singing a twangy song about cattle farts and enforces old stereotypes about farmers – and their gas.
The piece is specifically about how a pilot project aims to reduce methane emissions from cow farts using lemongrass as a feed additive.
There are numerous inaccuracies in the ad, including that cow gas is the big climate villain, when eructation or burps from cows are where most methane is released.
To help reduce the climactic impacts of greenhouse gases derived from ruminant digestion, reports the company, the Burger King brand has “partnered with top scientists to develop and test a new diet for cows, which according to initial study results, on average reduces up to 33 per cent of cows’ daily methane emissions per day during the last three to four months of their lives.
“Starting on July 14, select Burger King restaurants in Miami, New York, Austin, Portland, and Los Angeles will offer the Reduced Methane Emissions Beef Whopper sandwich, made with beef sourced from cows that emit reduced methane, while supplies last.”
The company’s official statement goes on to say it has made its findings and processes public to encourage other suppliers, farmers and food brands to adopt its lemongrass solution.
Data on lemongrass sparse
Burger King’s lemongrass claims are based on two studies from the University of California-Davis and from Autonomous University of the State of Mexico. However, findings from the former have yet to be published, and findings from the latter have not been replicated.
What is lemongrass? Lemongrass is a perennial herb often cultivated for culinary use. It is usually grown as an annual and is propagated from saved stems. In California, lemongrass is planted in March. Burger King claims adding 100 grams of dried lemongrass leaves to a cows’ daily diet makes a significant difference in methane excretion.
Dr. Ermias Kebreab, head researcher for the U.C. Davis project, responded to Burger King’s video by saying their study did not find a 33 per cent reduction in methane emissions, as was the case for his Mexican counterparts.
“Turns out Fresno-sourced lemongrass was not quite the same as Mexican,” said Kebreab via Twitter. U.C Davis also pushed back with a response letter on their website.
Data aside, the video advertisement’s fart-specific focus is misguided, says Claudia Wagner-Riddle, professor in the School of Environmental Sciences at the University of Guelph and authority in carbon cycling in food systems.
In reality, the vast majority of greenhouse gas emissions from cattle come from burps, the rumination process, and manure, meaning bovine flatulence is comparatively not a factor. While she says such a distinction may not matter to the general public, it does contribute to scientific misunderstanding.
Taking the information at face-value is itself problematic since the lemongrass additive is only being used during the finishing stage of beef production — while the majority of emissions are released prior to the feedlot.
“You need to consider the life cycle and how that lemongrass is produced… some of our work on dairy shows 40 per cent of life cycle emissions are due to rumination, another 40 per cent is from feed production,” says Wagner-Riddle, adding the viability of lemongrass production in different areas could pose challenges in itself.
“I definitely think it’s premature to make such a claim. Where is that lemongrass going to come from? Is it coming from places where you’re deforesting to plant lemongrass?
“I think the message of trying to source beef from producers who are reducing their carbon footprint is good, but right now they are only offering it in three places. The question is how feeding lemongrass, if it actually works, would be implemented at a large scale and its implications. There is no silver bullet at the moment. If there was it would have already been implemented.”
Katherine Wood, assistant professor of ruminant nutrition and physiology in the University of Guelph’s Department of Animal Biosciences, describes this kind of ruminant nutrition research as very “in-vogue” globally.
Within Canada, she says, researchers across the country are working on a wide range of methane-reducing techniques — from feed additives to genetic variations and breeding more digestible forages.
“In lemongrass the theory is it’s a tannin-based response. There’s a long list of things that people think might have this effect. There’s lots and lots of different plants being investigated for this,” says Wood.
Like other feed additives, she says, it is possible lemongrass does have some effect on belched methane levels. But with inconclusive results from U.C. Davis, not to mention the inherent variability in study conditions and how measurements are taken, it’s hard to draw concrete conclusions.
“It’s very difficult to make a claim like this without peer review and getting repeated results in a variety of different scenarios. That’s one of the reasons why we haven’t seen one of these kinds of compounds make an impact on the market,” she says.