Breeding cows to burp less will reduce methane in atmosphere, Adelaide Uni research shows
You’ve heard about cows’ farts increasing greenhouse gas, right? That’s not quite true — burps are the problem. But research may have the answer.
Breeding polite cows that burp less is the secret to reducing the amount of greenhouse gas they produce, scientists say.
Adelaide researchers are part of an international team that has found genetics plays a big role in the composition of a cow’s gut and how much methane they produce.
One of the project’s leaders, University of Adelaide Professor John Williams, said it showed cattle could be bred to produce less methane.
And the key is what comes out of a cow’s mouth, instead of the other end. “Most methane, 99 per cent, comes out of the mouth rather than the rear end, which is a popular misconception,” Prof Williams said.
“So they are belching rather than farting.”
The researchers analysed the “microbiome” of 1000 cows alongside other measurements, such as food intake, milk production and methane emissions.
They found the types and number of methane-producing microbes in the rumen, the first stomach in a cow’s digestive system, varied between animals.
Prof Williams said it was clear livestock breeders would be able to select those animals with fewer methane-producing microbes, leading to less emissions.
He said the next step was convincing farmers.
“My guess is that without legislation or strong social pressures, farmers would be much more inclined to select for quality of beef or quantity of production than reducing methane gas in their genetic criteria.”
He said the pay off could be using the gut analysis to breed cows that may also be better able to process their food, saving energy and creating less waste.
“If we can actually increase efficiency and reduce greenhouse emissions then we have a win-win.
“We can produce more food and do less harm to the planet.”
In Australia, the agriculture industry produces the equivalent of about 84 million tonnes of carbon dioxide each year, or 15 per cent of the country’s total greenhouse gas emissions.
Most of this is methane from cattle and sheep, the equivalent of 55 million tonnes of carbon dioxide.
Prof Williams said the methane was produced in the rumen when certain microbes broke down the cow’s fibrous food, such as grass and grain.
A single cow on average produces between 70 and 120kg of methane a year.
There are about 1.5 billion cattle worldwide.
The research, published in the journal Science Advances, involved dairy cows.
However, researchers said the findings should also apply to beef cattle.
The study was part of a project called RuminOmics.
It was led by the University of Aberdeen and the Parco Tecnologico Padano in Italy, where Prof Williams used to work, plus researchers in Israel, Europe and the US.