Methane Emissions

The digestion of kangaroos emits less methane!

Greenhouse Effect

Methane is a molecule that causes the Greenhouse's Effect increase in a negative way. Molecules such as methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O) are really bad for the atmosphere layer, therefore they provoke the bouncing of more UV-rays and radiated heat.

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Today, around 20% of the methane emissions come from ruminants. Ruminants are mammals and herbivores (deer, giraffe, moose, sheep, goat, cattle, cows) that eat a lot of grass and plant-based food. Due to the fact that ruminants need to digest a lot of cellulose they have a four or three chambered stomach, not four different stomachs! For instance the cows have a four chambered stomach; it's in a way similar to the human heart.

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Digestive System and its process.

The digestive system of ruminants is made up of the esophagus, reticulum, omasum, abomasum, rumen, and the large and small intestines.

Ruminants need a different way of digesting food in comparisson to humans, because they mostly eat food rich in cellulose. The food first goes to the rumen and then back to the mouth in order to be broken down further with the help of saliva. Afterwards it goes all through the reticulum, omasum, and abomasum and then to the intestines.

Pseudo-ruminants lack the rumen, therefore they have a three chambered stomach. But they have the cecum in the beginning of their large intestine with symbiotic microorganisms that break down cellulose.


It is known that cows, deer, etc. release more methane to the environment than kangaroos. That is why it is believed that kangaroos have a different intestinal composition. "If you consider the absolute volume of methane per body size, kangaroos produce about as much as horses or ostriches -- i.e. significantly less than cows," explains Marcus Clauss from the University of Zurich.

Moreover, the researchers discovered that the amount of methane per food intake can vary in the space of a few days. "If the animals eat less, i.e. the food remains in their foregut for longer and the bacteria have more time to digest, they produce more methane per food intake," says Adam Munn from the University of Wollongong.

"If we want to reduce methane production in cows, the question is whether they can be bred so that parts of the food don't remain in the rumen for as long..." The researchers conclude that differences between species are more down to the conditions that the intestinal bacteria are exposed to than the exact type of these bacteria. Under normal conditions, kangaroos digest more rapidly than cows.


University of Zurich. (2015, November 5). Faster digestion in kangaroos reduces methane emissions. ScienceDaily. Retrieved February 9, 2016 from

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