How does a hole in a cow’s body help scientists to reduce global warming?

The source of air pollutants, whose relevancy is often not appreciated, is grazing cattle. Actually, the amount of methane released by a cow can be compared to the pollution generated by a car, being about 200-500 liters daily. Taking into account transportation of animal products and feed production, livestock constitutes even higher environmental burden due to greenhouse gases emission, surpassing transport.

How do cows generate methane?

In order to understand the process of methane production and its subsequent release by cows, the focus has to be laid on an unusual mechanism of food digestion harnessed by these animals, jointly called ruminants. Instead of one stomach, there are four of them in the digestive tract of cows. The second striking difference between human and cow's digestion mechanism is the ability to digest cellulose. We, as humans, cannot eat paper or grass since we are deprived of necessary enzymes digesting bonds linking glucose units in cellulose chains. In case of ruminants, in turn, there are special, symbiotic microorganisms which fulfill the role of cellulose digestion. That is why grass, the main ingredient of cow diet, can be ingested by them.

When a cow swallows a bite of grass, it is transported to the rumen, the first of the animal's stomachs. After grass is partially digested by microorganisms, it travels in the reverse direction, reaches the mouth and is chewed once again. Unfortunately to our climate, there is a by-product of anaerobic cellulose fermentation generated by some of these symbiotic microorganisms, namely methane, which can be treated as a waste compound.

How can the amount of greenhouse gases be reduced?

In order to examine the process of methane generation in cow's stomach, a rather unusual technique can be applied. Sometimes, for research purposes, so-called cow fistulation is performed. The aim of this operation is to create a permanent hole in the body of a cow, leading directly to its rumen. To prevent the hole from closing, an additional element, called cannula, is introduced, which is simply a rubber ring with a lid that can be opened to access the stomach. According to scientists dealing with cannulated cows, this artificially applied element makes no difference to animals, neither inhibiting life processes nor generating pain.

Thanks to cannulas, researchers have an opportunity to scrutinise the process of specific pasture digestion. Cows are allowed to graze, then a sample of digesting material is taken through a cannula and analysed. In this way, the digestion process can be examined in case of different animal feeds and, by the modification of their content, the most optimal one can be chosen. Going further, thanks to the provision of specific pasture composition or by the addition of specific additives inhibiting the production of methane during fermentation process, the amount of greenhouse gases can be significantly reduced, giving hope for more environmentally friendly cattle breeding.

by Jakub Chrustowicz

Sources:

http://en.wikipedia.org/wiki/Livestock's_Long_Shadow

http://www.un.org/apps/news/story.asp?newsID=20772&CR1=warning#.UUxr6ByLiSo

http://science.howstuffworks.com/zoology/mammals/methane-cow.htm

http://en.wikipedia.org/wiki/Cannulated_cow

http://awp.diaart.org/dunning/cowstomach.html

http://www.abc.net.au/science/articles/2010/09/28/3023670.htm

http://www.umb.no/iha-etn/article/fistula-cows-with-holes-in-their-stomachs/