May 1, 2002 -- Steven Davis says he didn't set out to start a fight, but found one when he began attacking one of the most sacred beliefs of the vegetarian community.

One of the reasons most commonly cited by vegetarians for giving up meat is the conviction that other animals have a right to life as well as humans. But when Davis began setting up a course on animal ethics for the animal science department at Oregon State University four years ago, he reached a rather surprising conclusion.

Nobody's hands are free from the blood of other animals, not even vegetarians, he concluded. Millions of animals are killed every year, Davis says, to prepare land for growing crops, "like corn, soybean, wheat and barley, the staples of a vegan diet."

Smaller Victims

The animals in this case are mice and moles and rabbits and other creatures that are run over by tractors, or lose their habitat to make way for farming, so they are not as "visible" as cattle, he says.

And that, Davis says, gives rise to a fundamental question: "What is it that makes it OK to kill animals of the field so that we can eat [vegetables or fruits] but not pigs or chickens or cows?"

Any disruption of the land, whether it be to farm or to build subdivisions, reduces the amount of land left for other animals, resulting in the deaths of many. And Davis, a professor of animal science at Oregon State who grew up on a farm, says as a child he saw animals killed by the routine operation of farm machinery, so there's no way to have a bloodless farm.

"If they say they don't want to kill an animal so they can eat, I think their conclusion is misguided because they are killing animals so that they can eat that vegetarian diet," Davis says. "Those animals happen to be a little bit invisible. They are not as obvious to the man on the street as killing a steer in the slaughterhouse. But nonetheless, it's still going on."

Ever since he revealed his conclusions, Davis' e-mail box has been jammed with responses, much of it from vegetarians, and not all of it friendly. Most of it, though, has been "quite decent," he says, because vegetarians tend to be well-educated, sensitive and thoughtful folks.

One-Time Kill vs. Continuous Slaughter

"This is something we've been aware of for a long time," admits Jack Norris, president of Vegan Outreach in Davis, Calif., an organization that is dedicated to spreading the gospel of vegetarianism. (Norris is a vegan, by the way, which is even more restrictive then vegetarianism in that it rejects all animal products, including milk and other dairy products.)

It's obvious that some animals die when their land is taken away for farming, Norris says, "but you take it away only once." It doesn't lead to the continuous slaughter of animals for human consumption, he contends, because once the land is turned into a farm, there aren't that many animals around to kill.

Davis admits he doesn't really know how many animals are lost each year to agriculture, but he suspects it runs in the millions. Not many farmers do a before-and-after survey, so the best data are really just estimates.

But it's clear that many are killed to put meat and dairy products on our tables, and Norris and others are just as concerned over the suffering of those animals prior to slaughter as they are over the deaths themselves.

Citing numerous studies by federal agencies, as well as news organizations, Norris says in most cases it's tough being a farm animal. That's especially true for pigs and chickens.

Female breeding pigs are restricted to pens so small they can't even turn around, he says. Five to 10 chickens often are housed in cages "about the size of your typical microwave oven," he says.

And federal government statistics reveal that cows have been fed so much growth hormone that they boosted their milk production from an average 2.3 tons of milk per year for each cow in 1940 to 8.4 tons by 1997.

Norris says that has led to all kinds of diseases and sicknesses among cows.

Lay Off Chickens and Pigs?

Davis and Norris agree on one point. No system is perfect, and what's needed here is far more dialogue among growers, consumers and vegetarians.

Davis believes the death toll among all animals could be reduced if ranchers concentrated on raising cattle instead of pigs and chickens and let those cattle revert to foraging in open fields that could be shared with other animals.

Citing U.S. Department of Agriculture statistics, Davis says of the 8.4 billion animals killed each year for food in the United States, 8 billion are poultry and only 41 million are cows, calves, sheep and lambs. So he figures you could double the number of cattle killed each year, and lay off the chickens, and consequently save about 7.5 billion animals.

But just letting cattle roam freely doesn't solve the problem either, Norris says, because other animals like coyotes and wolves would still likely be killed (just as they are today) to protect the cattle. And he still can't stand the thought of all those hamburgers.

It's not a perfect world, Davis counters, but perhaps with a lot more thought and cooperation, a better alternative might be found. But unless someone comes up with a brilliant idea, whether you eat meat or just fruit and vegetables, you're going to have to share somewhat in the bloodletting.

It might do more good, of course, if all of us just ate a little less of everything.

Lee Dye’s column appears weekly on ABCNEWS.com. A former science writer for the Los Angeles Times, he now lives in Juneau, Alaska.