Cows are among the most numerous mammals on Earth (thanks to us) and as a result these placid bovines have a significant role in contributing to climate change (again owing to us). Forests have been felled to make way for grazing grounds and growing cattle feed, too, leaves a large carbon footprint.
Then there is this: the animals directly contribute to climate change by releasing large amounts of methane, a potent greenhouse gas, through their burps and, well, farts. Methane traps a whopping 84 times more heat than carbon dioxide over a period of two decades. “Methane pollution causes one quarter of the global warming that we’re experiencing right now,” Fred Krupp of the Environmental Defense Fund, has noted.
But what if we could get cows to produce less methane by tweaking their diet? A team of researchers at the University of the Sunshine Coast in Australia say they have an answer for just that kind of dietary tweak in the form of a pink seaweed. If every cow in Australia was fed on this nutritious puffy seaweed, Australia’s methane emissions would be lower by 10%, they say.
The seaweed, called Asparagopsis taxiformis, is abundant off the coast of Queensland and is generally much to the cows’ liking. “Seaweed is something that cows are known to eat. They will actually wander down to the beach and have a bit of a nibble,” says Associate Professor Nick Paul, who leads the research team.
“When added to cow feed at less than 2 percent of the dry matter, this particular seaweed completely knocks out methane production,” Paul adds. “It contains chemicals that reduce the microbes in the cows’ stomachs that cause them to burp when they eat grass.”
Paul and his team analyzed 20 different species of tropical macroalgae to see which of them might work best at reducing the amount of methane produced by cows. Asparagopsis taxiformis proved to be the one by inhibiting 98.9% of the ungulates’ methane production after 72 hours.
The scientists are now working on a way to grow plenty of the seaweed in large outdoor aquaculture tanks so as to mix it into the diet of more and more cattle in Australia and elsewhere.
“We know the chemical composition of Asparagopsis and we know the chemical compounds that actually reduce methane production in cows, so now we want to maximise the concentration of that chemical so we can use less seaweed for the same effect,” says Ana Wegner, a scientist working on the project.