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Berkeleyan

Prof has a beef with McDonald’s antibiotics announcement

| 23 July 2003

 



Common antibiotics used to control infections in corn-fed cattle — but at what cost?


On June 19, fast-food titan McDonald’s announced it would ask its meat suppliers to stop using antibiotics to promote livestock growth, and to cut back on antibiotics used on animals for other purposes. Close to 25 million pounds of antibiotics are fed to livestock every year — almost eight times the amount given to humans to treat disease, according to the Union of Concerned Scientists. The unregulated, widespread use of antibiotics in animals has led to bacteria that are resistant to older drugs such as penicillin and tetracycline, making them less effective in treating sick humans.

The McDonald’s move was hailed by consumer, environmental, and animal-health advocates alike as a step toward healthier meat production. In this excerpt from a conversation with the campus NewsCenter’s Bonnie Azab Powell, Michael Pollan, the Knight Professor of Journalism at the Graduate School of Journalism, is asked whether he agrees with that assessment. Pollan, a renowned science journalist, wrote “Power Steer,” an influential New York Times Magazine cover story in 2002 that followed a steer from birth through the feedlot to slaughter. He spoke to the NewsCenter from Connecticut as his family packed for the move to Berkeley, where he will resume teaching this fall.

First of all, explain why meat suppliers use such large quantities of antibiotics.
There are two reasons for using antibiotics in factory farming. One is to keep the animals healthy in a situation that would tend to make them sick, where there is severe overcrowding, high stress, and very unsanitary conditions. So if you’re going to grow them indoors, or even on feedlots in close confinement, you have to give them antibiotics to keep them healthy.

The other reason is that small quantities of antibiotics promote faster growth in many species, particularly chickens and pigs, for reasons that scientists don’t actually understand. What McDonald’s has done is say that they will favor suppliers that are not using antibiotics for growth promotion. Now they didn’t say anything about the other use of antibiotics. So it makes me wonder just how revolutionary this will be.

I think the policy is that suppliers can still use antibiotics to treat sick animals and to prevent disease outbreaks.
“Prevent disease outbreaks” is key. In that sentence is the license to continue including antibiotics in the feed every day. The other question that comes to mind: If you’re using antibiotics both for growth promotion and to control disease, how do you know which is which? Could someone engage in the same practice with a different justification, which would leave the whole issue of antibiotics pretty much unchanged? Yes.

The antibiotics issue is a very tricky one. Poultry suppliers pledged last year to cut down on antibiotics use. The last information I saw on that was that after declining a bit, the numbers are trending back up again. Perhaps it’s harder to cut back than they thought. The thing about antibiotics is that they’re not just chemicals that people are using and they can stop using. It’s part of a whole system. If you could segregate out the growth promotion, you could say, “We’ll all grow our meat a little more slowly, it’ll be a little more expensive as a result, but we can elect to stop.” But using antibiotics to prevent outbreaks of disease is one of the linchpins of the whole system. And if you take away that linchpin, it’s arguable whether the system can survive. Feedlots depend on antibiotics.

So let’s talk about beef, because that’s where factory farming seems to be most dependent on antibiotics. Why are they used, if not for growth promotion?
One thing to remember is that the antibiotics used in beef tend not to be the ones that compete with human antibiotics. Chicken is where they were apparently using Cipro and other antibiotics that we depend on. In the case of beef cattle, they use them because if you have a feeding system that’s dependent on diets very high in corn, up to 80 or 90 percent corn, you just can’t do that without antibiotics. You would have to back way off and give the cattle more roughage, more hay and grass.

Why does a corn diet require antibiotics?
Corn is a very different, much starchier ration than cows have evolved to digest. The marvelous things about ruminants, which is what cows are, is that they can digest grass, which we can’t do. They can because they have this complicated digestive system. Specifically, they have a rumen, which is a fermentation tank in which bacteria go to work breaking down cellulose and turning it into protein that they then digest. This is their boon to the food chain. It’s a nice system, where the sun feeds the grass and the grass feeds the cows and the cows feed us. It’s solar, sustainable, and in its way,
elegant.

But it’s slow, by the standards of contemporary agriculture, and it takes a lot of space. So if you want to speed up the process, you give them richer food. The cheapest, richest food around is corn. The price of corn is artificially lower than the cost of producing it, because of government subsidies and the fact that there’s an oversupply. But if you want to feed them on corn, which makes them grow a lot faster and gives them fattier marbled beef, which tastes good, you have to accustom them to this diet slowly, [because] corn acidifies their gut. The cow’s stomach is not accustomed to this acid the way our digestive system is — we’re designed to have this very acidic system that kill everything and breaks things down through acids. They’re not. As it acidifies, it eats away at the lining of the stomach walls, and lets some of the bacteria get into the bloodstream, where it lodges in the liver and causes abscesses. So farmers use antibiotics to control that infection process.

And that’s why we rarely eat beef liver anymore?
Yes. I’ve heard that 30 to 40 percent of the livers found at slaughter have to be thrown out because they have abscesses. They’re diseased. I’ve talked to vets who’ve said, “We don’t know how long they could live on this kind of diet, but it’s not indefinitely.” These animals are slaughtered at 14 to 16 months old. Whether they could even live two or three years is an open question … on that diet, that is. Put them back on grass and they could live to a ripe old age.

This whole system of keeping the animals in confinement and giving them an incredibly rich diet to grow them very quickly and get them to slaughter at 14 months depends on antibiotics. As much as McDonald’s might like to, the industry can’t simply throw away that crutch without rethinking everything. So there’s a structural issue with antibiotics that I’m not sure is being addressed here. It’s not just a matter of taking away one drug, but of looking at the whole system, looking at the diet, the confinement. I don’t know that the industry is prepared to go that far.

To read the full text of the NewsCenter’s conversation with Michael Pollan, visit www.berkeley.edu/news/media/releases/2003/07/01_pollan.shtml