Why does a kangaroo expel less methane than a cow? Researchers from the University of Zurich and Australia decide to investigate – and discovered that the emission of this climate-damaging gas in kangaroos is linked to how long food is digested.
Animals produce methane during the digestion process – some more than others. Currently, around 20 percent of the world’s methane emissions stem from ruminants. If this gas is released into the atmosphere, it aggravates the greenhouse effect and aids global warming.
Previous studies revealed that ruminants, which include cows and sheep, release more methane into the environment than kangaroos, for instance – even though the latter also possess a foregut, where bacteria break down the plant fibers and produce methane (much like in a cow’s rumen).
Exactly why kangaroos produce less methane, however, remained a mystery. The belief was that a different intestinal flora composition to a cow’s was responsible.
Researchers from the University of Zurich, ETH Zurich and the University of Wollongong in Australia have now studied the previous assumptions from a different angle. The team measured how much methane kangaroos emit per food intake.
“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. “If the gas production is correlated with the amount of food ingested, however, the amount of methane is higher and therefore closer to the ruminants again. In other words, the digestion process itself in kangaroos is not all that different to a cow’s.”
Different conditions for bacteria
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.
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.
“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,” say the researchers, who published their study within the scope of a project on methane production in wild animals that was funded by the Swiss National Science Foundation.
Vendl C, Clauss M, Stewart M, Leggett K, Hummel J, Kreuzer M, Munn A (2015) Decreasing methane yield with increasing food intake keeps daily methane emissions constant in two foregut fermenting marsupials, the western grey and red kangaroos. Journal of Experimental Biology (in press). November 4, 2015. Doi 10.1242/jeb.128165
Melanie Nyfeler | Universität Zürich
Preservation of floodplains is flood protection
27.09.2017 | Technische Universität München
Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
It's possible to produce hydrogen to power fuel cells by extracting the gas from seawater, but the electricity required to do it makes the process costly. UCF...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
17.10.2017 | Life Sciences
17.10.2017 | Physics and Astronomy
17.10.2017 | Life Sciences