Kangaroos could help reduce methane emissions from cattle

Baby kangaroo feces could provide an unlikely solution to cow-produced methane, according to a new study from Washington State University.

Methane is the second largest greenhouse gas contributor and is 30 times more potent than carbon dioxide. More than half of the methane released into the atmosphere is thought to come from the agricultural sector. Ruminant animals, such as cattle and goats, are the most significant contributors.

Using a cow stomach simulator, the researchers discovered that methane production can be inhibited by a microbial culture developed from baby kangaroo feces.

“Methane emissions from cows are a major contributor to greenhouse gases, and at the same time, people like to eat red meat,” said study co-author Birgitte Ahring.

To reduce methane, researchers have tried changing cows’ diets and developing vaccines, but there are too many varieties of the methane-producing bacteria. These interventions can also negatively affect biological processes.

The WSU researchers had previously designed an artificial rumen, the largest stomach compartment, to simulate cow digestion. Ahring said that among the enzymes that are able to break down natural materials, rumens have “amazing abilities.”

Ahring learned that kangaroos have acetic acid-producing, instead of methane-producing, bacteria in their foregut. The specialized acetic acid-producing process only occurred in baby kangaroos – not in adults. Unlike methane, acetic acid benefits cows by supporting muscle growth. 

After reducing the methane-producing bacteria in their reactor with a specialized chemical, the acetic acid bacteria were able to replace the methane-producing microbes for several months.

“It is a very good culture. I have no doubt it is promising,” Ahring said. “It could be really interesting to see if that culture could run for an extended period of time, so we would only have to inhibit the methane production from time to time. Then, it could actually be a practice.”

The research is published in the journal Biocatalysis and Agricultural Biotechnology.

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By Katherine Bucko, Earth.com Staff Writer

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