Cleaner cow burps may save world
New feed can cut the methane gas that they emit.
First, let’s get one thing straight. Despite what you may have heard, it is cow burps, not cow flatulence, that are the real climate change problem.
Here’s how it works: Cows digest their food in four-part stomachs, including a “rumen,” which is a site that allows for fermentation — a process that gives off a lot of carbon dioxide and methane gas, as microorganisms aid in the process of digestion. That gas has to get out of the cow’s body somehow — hence, burps. “Approximately 132 to 264 gallons of ruminal gas produced by fermentation are belched each day,” notes the Penn State College of Agricultural Sciences.
And because we have so many cows — where would human civilization be without them? — this really adds up. Indeed, according to the EPA, so-called “enteric fermentation” in cows and other ruminant animals, like sheep and goats, contributed 26 percent of the country’s total emissions of methane, a hard-hitting greenhouse gas with much greater short-term warming consequences than carbon dioxide does (though the latter packs a far greater long-term punch).
Globally, meanwhile, methane emissions from livestock are an even bigger problem. Overall, the livestock supply chain emits 44 percent of the globe’s human-caused methane, according to the U.N.’s Food and Agriculture Organization — and a large slice of that comes from cattle’s methane burps. So anything you could do to cut down on cow belching would, literally, help save the planet.
The ideas for how to do this have been numerous — and sometimes hilarious. We’ve heard about cow backpacks, for instance, to capture methane and put it to use. And there are also more mundane solutions like simple “husbandry,” says Johan Kuylenstierna, policy director of the Stockholm Environment Institute.
“You could reduce emission intensities — i.e. emissions per kg meat or milk, by about 30 percent if people in a given region adopted the good practices of the top 10 percent of farmers that have the lowest methane emissions,” Kuylenstierna says by e-mail, citing the FAO. This includes keeping animals healthier, giving them better diets, and managing their reproduction to lower their overall emissions.
But one fundamental way of fixing the problem involves trying to change the chemistry of what’s happening in cows’ rumens — after all, methane emissions represent lost food energy that could have gone towards cow growth or milk production. For some time now, the Dutch life sciences and materials company DSM has been pursuing such a solution, which it appropriately calls its “Clean Cow” project.
The company has created a powder that can be added to cow feed that, it says, can reduce emissions with no negative effects on the animal. And now, newly published science backs this idea up.
DSM worked with a top dairy sciences researcher who focuses on methane emissions, Alexander Hristov of Penn State University, to study the clean cow technology — what they more technically called a “methane inhibitor.” And they got promising results.
Hristov and colleagues, including several researchers from DSM, designed and carried out a trial in which 48 cows, receiving varying amounts of the inhibitor in their feed, were observed over 12 weeks.
The research found that the inhibitor cut methane emissions in dairy cows by 30 percent.
“The present experiment is, to our knowledge, the first to document this effect using a methane inhibitor with potential for widespread use in the livestock industries,” notes the study. It was just published in an influential scientific journal, the Proceedings of the National Academy of Sciences.