February 13, 2014 | 1
Apparently cows are terrorists too. Last month, journalists reported—in what can only be described as a “chicken-run” scenario of cows plotting their big escape—that a herd of dairy cows in central Germany caused an explosion in their housing facility.
Police failed to thwart the plan, as the explosion seemed to be caused by flatulence. Yes, cow farts. According to reporters, static electricity ignited the accumulated methane gas that cows had released through their farts. This was an ingenious plan because methane is a color-less and odor-less gas, making it difficult to detect prior to the explosion. It can only be assumed that the 90 cows in the barn frantically rubbed against one another to create the spark “herd” around the world.
Not cow farts?
The reports, of course, were wrong. The main culprit of this methane whodunit was not the farts. One of the earliest studies looking at methane production in ruminants found that the majority of methane production occurs in the rumen, and that is the piece of the puzzle the reporters missed. All animals classified as ruminants—cattle, sheep, goats, etc.—have a rumen with bacteria responsible for breaking down food. During the break-down process, also called enteric fermentation (say that three times fast), methane is emitted. You might think that what happens in the rumen is released through the cow’s rear door. Not so. 95% of methane in cows is released via eructation. NOT farting.
Eructation (like the word flatulence) is simply a less-offensive way of saying burping. Apparently reporters got a little confused between a cow’s head and a cow’s butt. Easily done. I guess. Although many journalists attributed the explosion to both burping and farting, that really isn’t fair to the cow’s butt, since the main perpetrator is really the cow’s mouth.
A cow burp suit
How do we know all of this? Many methods have been developed to measure methane excretion via burping, but my favorite is the “cow backpack.” Dairy cows are fitted with small gas chambers on their backs, while tubes catch emissions from the nose and mouth. (Is the cow back-pack a formidable competitor for the dog fart suit? Only you can decide).
The problem with tooting
Why are cow burps, and to a much lesser extent cow farts, a problem (aside from the fact that they make for a very rude house guest)? According to the Food and Agricultural Organization of the United Nations, the release of methane gas that occurs during these “rude” habits, combined with decomposition of animal manure, account for 18% of global greenhouse gas (GHG) emissions. Ouch. It should be noted that there has been considerable debate about this figure since the release of this report in 2006, but the general concern remains. Cattle, by far, are the worst offenders among ruminants, as 6% of their ingested energy is lost via burped methane.
I understand if you feel tricked by the media. Who can bypass a BuzzFeed headline, 90 Cows Exploded A Barn in Germany With Their Farts? But now you know the whole story, and which end of the cow to fear.
This guest post was written by Priya Motupalli, a final year PhD candidate at Harper Adams University in the UK and is studying applied dairy cow behaviour and welfare. Her research focuses on dairy cattle preference for pasture, and the welfare and production implications of allowing farm animals to have control over their own environment. Priya’s recent award for excellence in scientific communication was featured in the industry news section of Meat Management Magazine. Her previous guest posts on Dog Spies have compared dog and cow welfare, see below.
Motupalli P (2011) Cow Spies. Dog Spies. Blogger
Motupalli P (2013) “Moooove over, I need to stretch out,” said the cow. Dog Spies. Blogger
Hecht J (2013) Dog Farts Part 1: What Are Dog Farts Made Of? Scientific American
Hecht J (2013) Dog Farts Part 2: How to Make Dog Farts Less Stinky. Dog Spies. Scientific American
Johnson KA and Johnson DE (1995) Methane Emissions From Cattle. Journal of Animal Science. 73: 2483-2492.
Murray RM, Bryant AM and Leng RA (1976) Rates of production of methane in the rumen and large intestine of sheep. Br J Nutr 36: 1-14.
Thorpe A (2009) Enteric fermentation and ruminant eructation: the role (and control?) of methane in the climate change debate. Climatic Change 93: 407-431.
Photos: ‘I’m gassy and I know it‘ used with permission: Tyler Gildin and Elite Daily. Cow backpack via Harper Adams commons website. Eructos de las vacas contribuyen al efecto invernadero, Hernán Kirsten, Flickr Creative Commons License