This isn't "new" news. It has been widely reported in the media for at least a decade.
GROSS: If you're just joining us, my guest is Michael Pollan. He's the author of the book "The Botany of Desire: A Plants-Eye View of the World." But his new piece in this past Sunday's New York Times isn't about plants; it's about livestock and how the industrial steak is made in the United States.
Now you say that the livestock, after about six months, aren't fed grass. They're not fed hay. They're fed corn. Why are they fed corn instead of grass?
Mr. POLLAN: Basically because corn is the cheapest and most portable thing you can feed a cow. You know, we grow vast quantities of corn in this country, about 10 billion bushels a year. And it's very cheap because it's subsidized by the government. It costs the feedlot about $2.25 a bushel, which is over 50 pounds of corn, to buy it. And it would cost the farmer more than that to grow it, if not for subsidies. So you have this feed that is very, very cheap. It's the cheapest source of calories you can give the animal. And also it's very portable compared to hay. If you were feeding an equivalent amount of hay, the sheer bulk of it would overwhelm you.
So corn, you know at this feedlot, at the mill, I saw every single hour another tractor-trailer would pull up and disgorge 25 more tons of corn. You know, without corn, without this--and soybeans, too, to a lesser extent--this incredibly compact and portable feed, you could never have this urbanization of livestock. It is what allows you to gather together up to 100,000 cattle or millions of chickens, and now fish and pigs, in these small animal cities and feed them efficiently. You could not do it on their natural food.
GROSS: What fattens a steer quicker, corn or grass?
Mr. POLLAN: Corn by far. It's simply a richer food. It has more food energy in it. It's full of starch. And that is the other reason we give them corn. You know, it's all about speed. I asked the ranchers that I was working with, the Blairs, and they said, well, they were four generations in the cattle business, and their grandfather would bring beef cows to slaughter at four or five years, and then their fathers at two to three years. And they're doing it at 14 to 16 months. And what allows you to go from 80 pounds calf to 1,250 pounds steer is vast quantities of corn and antibiotics and growth hormones. So the combination of the corn and the pharmaceuticals allows you to speed up this process. Also, to some extent, the genetics. They've improved the genetics. We're gradually creating an animal that can digest corn efficiently.
GROSS: OK. Before we get to the pharmaceuticals, let's talk a little bit about corn some more. How does the corn affect the cow's digestive system, a digestive system that was really made for grass?
Mr. POLLAN: Yeah. You know, this was a bit of a revelation to me because this phrase corn-fed beef has been around so long that we just take it for granted that this is some kind of old-fashioned virtue. But it's neither that old or that virtuous, as it turns out. These animals, in nature or, you know, when grazing, encounter very, very little grain. I mean, grain is essentially the seed of grasses. So when the bluestem that they're eating and the Western wheat grass they're eating flowers and puts on seed, they get a little bit of grain, but very, very little. And now suddenly they're given this incredibly rich diet. As one of the feedlot managers put it to me, it's like feeding them Snickers bars all day long. It's a very rich food, although they don't appear to like it quite as much as Snickers bars. But it wreaks havoc on a digestive system that has evolved to do something quite miraculous, which is digest grass.
You know, that, for me, is the underlying insanity of this system. We have this animal, a ruminant--there's a class of animals; it includes cows, but also sheep and deer and several others--that has this unique ability to digest grass. We can't do it. If you consume grass you will not be able to digest it. So they can take this sort of substandard land that can only grow grass because it's too dry or too hilly or the soil is too thin, and because they have this digestive organ, this rumen, which is essentially a 45-gallon fermentation tank in which a resident population of bacteria goes to work on the grass and turns it into protein, they can make good use of this incredibly common solar-generated food source. So we've taken the solar system--you know, 'cause the grass is fed on sunlight and water. It's this miracle of photosynthesis, which is, when you think about it, the only free lunch in nature. And so they take this free lunch and can make very high-quality food out of it. But rather than use that system, we move to another kind of system, which is feeding them corn.
Now corn, you might argue, well, that's a solar system to because, you know, the corn grows, is a kind of grass, and it grows out in the sun. But, in fact, to get the kind of harvest of corn we get and the surpluses, you have to apply vast quantities of fertilizer, which is a fossil fuel. It's ammonium nitrate. And we began doing this after World War II. It made corn grow incredibly well. We get 130 bushels of corn off an acre where a hundred years ago we got 20. And all of that fertilizer is made from oil. And, in fact, it takes 1.2 gallons of oil to grow a bushel of corn. So I realized I was looking at a different kind of system. We had gone from a solar system to a fossil fuel system. And this strikes me as a kind of crazy thing.
GROSS: Let's get back to the cow's stomach.
Mr. POLLAN: Yeah.
GROSS: So the cow now is eating corn instead of eating grass. Its stomach is made for digesting grass and turning it into protein. How does the cow's digestive system handle corn?
Mr. POLLAN: Well, very poorly. It'll go kablooey if it's not done very gradually. And I talked to people who said that most cows, most beef cattle getting a heavy diet of corn--and again, they can tolerate some of it, but when you crank it up to 70, 80, 90 percent grain, their stomachs go haywire. They suffer from a range of different phenomenon, one of which is bloat.
You know, the rumen, this organ, is always producing copious amounts of gas, and these are expelled during rumination, you know, when the animal kind of chews its cud. It regurgitates this bolus of grass and in the process releases all this greenhouse gas, essentially methane and things because when you're digesting grass much gas is produced. But when they're eating corn, this layer of slime forms over the mass in the rumen, and it doesn't allow the gas to escape. So what happens is the rumen begins to expand like a balloon until it's pressing up against the lungs of the animal. And if nothing is done to release the pressure of that gas, the animal suffocates. It can't breathe anymore. So what do they do? Well, if it gets to that point, they force a hose down the esophagus of the animal, and that releases the gas, and they very quickly put them back on hay for a little while.
So that's one of the things that can go wrong. Well, perhaps the most dramatic. But a whole other range of problems are created because the corn acidifies the rumen. The rumen has basically a neutral pH when it's healthy and getting grass, and that's very significant for a lot of reasons. But you feed it corn and it gets a lot more acidic. And the rumen can't deal with acids, and what happens is the acids gradually eat away at the wall of the rumen, creating little lesions or ulcers through which bacteria can pass. And the bacteria get into the bloodstream and travel down to the liver, which collects all such impurities, and infects the liver. And that is why more than 13 percent of the animals slaughtered in this country are found to have abscessed livers that have to be thrown away and is a sign of disease.
But this low-level sickness, acidosis or even subacute acidosis, as they call it, afflicts many, many--probably the majority--of feedlot calves, and it leaves them vulnerable to all sorts of other diseases. Their immune systems are compromised. So they get this, you know, horrifying list of feedlot diseases. You know, we have these diseases of civilization, you know, heart disease and such things. Well, they have their own diseases of civilization: feedlot polio, abscessed livers, rumenitis, all these kinds of things that cows in nature simply don't get.
GROSS: Is this where the antibiotics come in?
Mr. POLLAN: Yeah. The only way you can keep a cow alive getting this much corn would be with antibiotics. And they get large quantities of antibiotics with their feed every day. They get rumensin, which is technically an ionophore. It's a kind of antibiotic that helps with the bloat and the acidosis. And then they get tylosin, which is in the erythromycin family. And that antibiotic cuts down on the incidence of liver disease, and without that, they would all have liver disease probably.
So, you know, when people debate antibiotics in livestock, which is a very, you know, important issue, and it's before the Congress right now, they make this easy distinction between feeding animals antibiotics to promote growth, which is done in the chicken industry and the pig industry, and then feeding them when they're sick, which even the public health advocates against using antibiotics in livestock say, 'Of course it's fine. You must treat sick animals.' But where do you put the beef calf who is clearly getting these antibiotics to cure him? On the other hand, he wouldn't be sick if we weren't feeding him what we feed him? So it kind of confounds the usual distinction. If you took away these antibiotics, everything would have to change.
Wednesday, January 30, 2008
Isn't Corn Just another Grass?
Well, of course it is. And aren't the stomachs of cattle evolved to eat grass? Yes they are. So what is wrong with feeding corn to cattle? Nothing, according to an anonymous responder to this post. But here is what Michael Pollan, author of An Omnivore's Dilemma, had to say about corn-fed cattle in an interview a few years ago with Terry Gross on NPR's Fresh Air: