Stories tagged cows

Jul
13
2010

Brown gold!: This is actually the solid byproduct of a manure-to-methane operation. As you can see, it holds no fear for the owner of this bare hand.
Brown gold!: This is actually the solid byproduct of a manure-to-methane operation. As you can see, it holds no fear for the owner of this bare hand.Courtesy kqedquest
We’ve talked about the delights of cow feces before on Science Buzz, but mid-July always puts me in the mind of “brown gold” (coincidentally, the last occasion it came up was exactly four years ago today), and any time there’s talk of turning an animal into a fuel source, I get excited. (Remember that fuel cell that ran on the tears of lab monkeys? Like that.) Why not take another look?

So here you are: another wonderful story of cows trying their best to please us, before they make the ultimate gift of allowing their bodies to be processed into hamburgers and gelatin and cool jackets.

Poop jokes aside (j/k—that’s impossible), it is a pretty interesting story. The smell you detect coming from cattle farms is, of course, largely from the tens of thousands of gallons of poop the cattle produce every day. The decomposing feces release lots of stinky methane. (Or, to be more precise, the methane itself isn’t smelly. The bad smell comes from other chemicals, like methanethiol, produced by poop-eating bacteria along with the methane.)

Aside from being, you know, gross, all of that poop is pretty bad for the environment. The methane is released into the atmosphere, where it traps heat and contributes to global warming (methane is 20 to 50 times more potent than carbon dioxide as a greenhouse gas), and the poop itself is spread onto fields as fertilizer. Re-using the poop as fertilizer is mostly a good idea, but not all of it gets absorbed into the soil, and lots of it ends up getting washed away into rivers, lakes, and streams, where it pollutes the water.

Some farms have managed to address all of these problems, and make money while doing it.

Instead of spreading the manure onto fields right away, the farms funnel all the poop into swimming pool-sized holding tanks, where it is mixed around and just sort of stewed for a few weeks. All of the methane gas produced by bacteria as it breaks down the manure is captured in tanks. What’s left is a fluffy, more or less sterile, solid that can be used as bedding for the animals, or mixed in with soil, and a liquid fertilizer that can be spread onto fields.

The methane can then be used on-site to generate electricity, either by burning it in a generator, or using it in a fuel cell. (The methane is broken apart and combined with oxygen from the air to produce electricity, water, and carbon dioxide.) A large farm will produce enough electricity to power itself and several hundred other houses. (The extra electricity is just put back into the power grid and sold to the power company.)

Whether the methane is burned or used in a fuel cell, the process still creates carbon dioxide. However, CO2 isn’t nearly as bad as methane when it comes to trapping heat, and because the original source of the carbon was from plant-based feed, the process can be considered “carbon-neutral.” (Although one might argue that the fossil fuels involved in other steps of the cattle farming process could offset this. But let’s leave that be for now. It’s complicated.)

The downside is that setting up an operation to capture and process manure, and to generate power by burning it is expensive—it took about 2.2 million dollars to do it at the farm covered in the article, with about a third of that coming from grants. Still, the byproducts (electricity, fertilizer, soil/bedding) are profitable enough that the system could pay for itself over the course of a few years.

It’s amazing, eh? Out of a cow’s butt we get soft, clean bedding, liquid fertilizer, and electricity, all without the bad smell. What a world.

Aug
27
2008

Cow pointing north: Maybe THIS is why you always see animals on weather vanes
Cow pointing north: Maybe THIS is why you always see animals on weather vanesCourtesy Leo Reynolds
Researchers in Germany used Google Earth to examine hundreds of aerial images of cattle herds at rest and found that 2 out of 3 cows tended to align their bodies north-south. It seems that no one has really ever noticed this before, which is a little shocking. On the other hand it's nice to know that science still has some basic observations left to be made.

At first I was a bit skeptical. As a kid I'd heard that you could tell if it was going to rain depending on whether cows were laying down or not, which is a silly tale for sure...so maybe this was a similar situation? How would cows sense the Earth's magnetic field anyways? Actually, lots of animals can sense the earth's magnetic field:

Most of this research is still under-way and new discoveries may give us different explanations about how animals sense the Earth's magnetic field. Yet, it is certain that all varieties of creatures, cows included, seem to be able to sense the Earth's weak yet significant magnetic field.

What about you? Can you feel North?

Sep
24
2007

Running on empty: photo by corypina on flickr.com
Running on empty: photo by corypina on flickr.com
Citing concern over Creutzfeldt-Jakob, or Mad Cow, disease spreading from northern Europe, the U.S. has imposed a blanket ban on all sperm imports from countries exposed to the disease. "We still have a little bit left, but not much," said Claus Rodgaard, manager of a Danish-based sperm bank with offices in the U.S.

Some blame faulty policy for the shortage. There is no evidence that Mad Cow disease can be transmitted by sperm, but government authorities insist on maintaining the ban.

The shortage has only highlighted our country’s already much-discussed reliance on foreign sperm. Scientists are hard at work developing a domestically produced alternative, but even the most optimistic estimates place the release of such a substitute decades into the future. A handful of prominent politicians have proposed looking to Alaska, which is reputed to have significant sperm reserves, although some argue that the process of tapping this source would place too much of a strain on the local wildlife.

For the time being, officials are urging the public to adopt many of the same conservation measures developed during the sperm shortage of the 1970s, and the national Ad Council is already planning a relaunch of its controversial “Got Gametes?” campaign.

Jul
12
2007

Excuse me: British scientists are looking for less gassy diet options for cows to reduce their burps. Cows belch 25 to 50 gallons of methane a day, which contributes to global warming. (flickr photo courtesy of Denmar)
Excuse me: British scientists are looking for less gassy diet options for cows to reduce their burps. Cows belch 25 to 50 gallons of methane a day, which contributes to global warming. (flickr photo courtesy of Denmar)
Don’t you just hate it when cows burp?

Scientists working on global warming and climate change hate it just as much as we do and are doing something about it. They’re working on developing new diets for cows that will cut back on their burps and the amount of methane they’re expelling into the atmosphere.

The average cow belches out 25 to 50 gallons of methane each day. Methane is a greenhouse gas that contributes to the growing carbon dioxide levels in the atmosphere that fuel global warming.

So what’s a polite, green-friendly cow to eat these days and reduce global warming? Scientists in Great Britain are proposing simpler digestibles like legumes – such as clover and alfalfa – could reduce cows’ belching significantly. The researchers also say that more grasses could be bred that would be easier for cows to process.

There’s good news for the very impolite cows. The scientists have also determined that methane is released into the air through cow burps, not the gas emissions they make from the other end of their body. They don’t have to strike baked beans from their diet!