greg@brahms.berkeley.edu (Greg Kuperberg) (07/01/90)
This question came up in ca.environment. I understand that cows produce a lot of methane because they ruminate. However, there is disagreement as to which exit the methane uses. Someone in ca.environment said it was definitely the front end, while an old article in the Economist about air pollution definitely indicated it was the rear end. Is there an authority on the matter here? Please send a copy of your reply by e-mail. Thanks in advance. ----------------------------------------------------------- The Tail Gunner "A well-regulated militia being necessary to the security of a free state, the right of the people to keep and bear arms shall not be infringed."
sbishop@desire.wright.edu (07/02/90)
In article <1990Jun30.191814.13908@agate.berkeley.edu>, greg@brahms.berkeley.edu (Greg Kuperberg) writes: > This question came up in ca.environment. I understand that cows > produce a lot of methane because they ruminate. However, there is > disagreement as to which exit the methane uses. Someone in > ca.environment said it was definitely the front end, while an old > article in the Economist about air pollution definitely indicated it > was the rear end. > > Is there an authority on the matter here? Please send a copy of your > reply by e-mail. Thanks in advance. > ----------------------------------------------------------- > The Tail Gunner > > "A well-regulated militia being necessary to the security of a free state, > the right of the people to keep and bear arms shall not be infringed." Giggle, giggle, I'm sorry but as a farmer's daughter I thought this was hilarious. Anyone who has spent any time around cows KNOWS that the rear smells much worse than the front! I don't think the methane comes from the ruminant. It comes from the MANURE! Somehow the idea of cows belching methane just doesn't get it. When you burb can you light the resulting gas? Why don't some of you city types go spend some time around cows? This reminds me of the guy in MISC.RURAL who seriously asked about pollution of ground water when someone described their pigs wallowing in the stream that wandered through their pasture. Farm land is disapearing at an alarming rate. All these city dwellers are moving out into the farm land then they get angry because their neighbor has GASP! HORROR! farm animals! WALKING AROUND NUDE! And CHOKE! having SEX! Sorry!!! Just came back from a confrontation with a neighbor who thought that my horses were an attractive nuisance because I complained about her precious little darling brats sneaking into my barn at night. Then there is their nasty German Shepherd who terrorizes the neighborhood because they 'think it's mean to keep a big dog confined'. Now if I can just get my hands on the mutt he will end up in the dog pound.....
larry@kitty.UUCP (Larry Lippman) (07/03/90)
In article <720.268e3e5c@desire.wright.edu>, sbishop@desire.wright.edu writes: > > This question came up in ca.environment. I understand that cows > > produce a lot of methane because they ruminate. However, there is > > disagreement as to which exit the methane uses. Someone in > > ca.environment said it was definitely the front end, while an old > > article in the Economist about air pollution definitely indicated it > > was the rear end. > > Giggle, giggle, I'm sorry but as a farmer's daughter I thought this was > hilarious. Anyone who has spent any time around cows KNOWS that the rear > smells much worse than the front! I find the incorrect information in your reply just as hilarious; I can believe that you are a "farmer's daughter" since it is painfully obvious that you are neither a "veterinarian's daughter" nor a "chemist's daughter". :-) As an initial point of information, methane is essentially odorless and tastless - whatever anyone claims to "smell" around a cow is NOT methane! The vast majority of methane is not only produced in the rumen, but is eliminated through eructation. The "Economist" article referred to by the original poster is incorrect as to the principal exit mechanism for methane in cows. Cows eructate at a rate of 1 to 3 times per minute; any observant person who has been around cows should realize that. An immense amount of microbial activity occurs in the rumen, with such activity being responsible for the digestion of at least 75% of all ingested solids. A typical composition of rumen gas is 65% carbon dioxide, 25% methane, with the balance being nitrogen, oxygen, hydrogen and hydrogen sulfide. It is the hydrogen sulfide which is primarily responsible for the odor of "cow breath" and, for that matter, "cow pies" :-). These rumen gases are produced by both bacterial metabolism and the action of salivary bicarbonate (releases carbon dioxide). Cow feces smells worse because not only is hydrogen sulfide still present, but so are indole and methyl indole (skatole), which result from subsequent digestion in the small and large intestines. > I don't think the methane comes from the > ruminant. It comes from MANURE! Somehow the idea of cows belching methane > just doesn't get it. Sorry, but what you state is simply not true. You don't have to take my word for this, however; just consult any textbook on veterinary physiology, such as the classic "Duke's Physiology of Domestic Animals". > When you burp can you light the resulting gas? People don't burp methane, but *cows* do. However, the presence of 65% carbon dioxide in rumen gas goes a long way towards quenching any attempt at ignition. It is possible to collect cow feces and extract the methane for ignition; this is particularly facilitated since methane is lighter than air, while carbon dioxide (also produced by feces) is heavier than air. > Why don't some of you city types go spend some time around cows? I have, thank you; I have lived in a rural area with my own large (and small) animals for the past 19 years. Larry Lippman @ Recognition Research Corp. "Have you hugged your cat today?" {boulder||decvax||rutgers||watmath}!acsu.buffalo.edu!kitty!larry VOICE: 716/688-1231 || FAX: 716/741-9635 {utzoo||uunet}!/ \aerion!larry
eoph12@castle.ed.ac.uk (I F Gow) (07/03/90)
Cows do indeed produce methane, due to the fermentation taking place in their stomachs. This methane is released by "belching" and thus comes out the front - the idea of this being a hazard to the environment was around when I did microbiol about 10 years ago. Maybe a real microbiologist somewhere can illuminate? Iain