Kangaroos may not be such low-emission marsupials as some previously thought, the researchers find.
In a paper – published Wednesday in the Journal of Experimental Biology – Dr. Adam Munn, a zoologist at the University of Wollongong’s School of Biological Sciences in Australia and his colleagues wrote that, although cows and sheep produce more greenhouse gasses than kangaroos, it seems as though Australia’s iconic marsupials are not that special after all.
Dr. Munn said that although kangaroos are low-methane, they are not any lower than other non-ruminant herbivores.
According to the Food and Agriculture Organization of the United Nations, livestock is responsible for about 14.5 percent of all greenhouse gas emissions across the globe. Of those gasses, 44 percent consist of methane.
The fermentation digestive process of ruminants, accounts for approximately 39 percent of all the livestock greenhouse gas emissions.
It is unclear whether scientist can use “the microbial population from the gut of kangaroos and if they could be transplanted into sheep and cattle to try and reduce the methane emissions from those animals,” Dr. Munn said.
However, those microbes may not help that much because the lower methane emissions may actually be linked to the way in which kangaroos digest their food, rather than what microbes reside in their guts, Dr. Munn and his colleagues suggest.
In cows and sheep, the food first goes to the rumen (a big vat) and then a lengthy digestion process begins. The food leaves the big vat once it is broken into tiny particles, when fluid and food particles move together through the gut, Dr. Munn explained.
In kangaroos, the food particles stay in the foregut while the fluids move along. The process is a lot faster, which means that microbes do not have time to move to their adult stage as quickly as in cows or sheep.
To find this, the researchers conducted a study in which they placed individual kangaroos in separate chambers in which there was an in-and-out flow of air that was being monitored and analysed. The kangaroos were given two meals that had different sizes. According to the findings, kangaroos produced more methane when they ate less food.
Scientists say that this shift probably occurred because when more food was packed into the kangaroos’ foreguts, more fluid was forced out, which means that the microbes had a lot less time to mature and generate methane.
Image Source: environment