UCSB Science Line
 Do rats fart more or less than cows? Question Date: 2018-05-01 Answer 1: Scientists can tackle questions like yours in a few general ways. In empirical studies, scientists look for answers by measuring the variables of interest. To answer your question empirically, researchers would have to put rats in chambers and measure their output of methane (and similar gases). That would be pretty pricey and I doubt anyone would get funding for it. Another issue is the variation in rat diets. Rats are generalists. They’ll eat anything from peperoni pizza to peanut butter. Since different foods have different abilities to produce flatulence, it would be difficult to come up with one answer. Research on cow gas production is interesting enough to get funded. Cow digestive systems are basically big fermentation tanks. So how would one measure bovine gas output? This clip shows one system in action: This system collects gas that can be analyzed later to determine which gases are being emitted. Most of the gas that comes from the far end of the digestive tract is carbon dioxide. Like any mammal, cows also expel carbon dioxide when they breathe. But they also burp up a lot of methane. So the methane production has to be measured at the cow’s mouth. Total gas production for one or a few cows can be measured empirically. But how do scientists know the amount of gas emitted by all cows? Often scientists have to use estimates and models. For example, they could take data from a few cows, find an average, then multiply that by the total number of cows on Earth. But they need to estimate the total number of cows, it’s not as though every cow has a license. Plus, different cows are different sizes and eating different foods. According to one source ( cow farts problem ), “livestock pushed about 119.1 million tons of methane into the air in 2011 alone.” A different team of scientists might have slightly different estimates or assumptions and arrive at a different total, even using the same base data. That doesn’t mean that models are useless though. They are usually critical in determining the highest and lowest likely values. Even though there are many, many rats on earth, they do not have a digestive system based on eating low-quality food, fermenting it, burping up cud (partially digested food and bacteria), then fermenting it some more. So I’m going to say that cows produce a lot more gas. Notice that I arrived at this conclusion by reasoning and applying what is known about the species. That is another way to get reasonable answers in science; using facts and logic to reach a conclusion. If you wanted to estimate the total number of rats on earth, how would you do it? Thanks for asking. Answer 2: There is not necessarily a straightforward answer to this question - it depends on what the rats eat. Cows are known to fart frequently because of their diet and the structure of their digestive tract. They are large herbivores with many stomachs and a large quantity of (harmless) bacteria that produce gas . Rats, on the other hand, are omnivores, but depending on the types of food a particular rat eats and how much it eats, it may also fart often. However, rat guts may not contain as much of the gas-producing bacteria as cow guts do. In general, cows probably fart more, but the specifics have not been studied! Answer 3: The following chart will be interesting to read: here Answer 4: Cows are huge compared to rats, so it's hard to picture that rats fart more. Also, I can't find anything about rats farting a lot, and I found a lot about cows farting a lot. I googled about 'flatulence' in cows and rats instead of 'fart' and got some nice hits: MEASUREMENT OF HYDROGEN PRODUCTION IN THE RAT HAS POTENTIAL FOR A PREDICTIVE BIOASSAY FOR FLATULENCE IN MAN. read here This is an interesting article that I found for you to read, it is about howseaweed in cow feed reduces methane emissions almost entirely: here Click Here to return to the search form.

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