New questions about high-protein cattle feed

By Jonathan Martin
Seattle Times staff reporter

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Although the practice was partially banned in 1997 to decrease the risk of mad-cow disease, farmers and ranchers can still buy feed containing the granular meal of rendered chickens or hogs. Such high-protein additives can halve the three years it takes to fatten beef cattle fed with just grain or double the milk output of dairy cows.

But turning herbivores into carnivores carries a stigma, even among Americans who demand cheap groceries. Doug McGreevy, a feed supplier for Whatcom, Skagit and Snohomish county beef and dairy farms, said his company switched to higher-cost soy protein additives in the mid-1990s to avoid consumer worry.

"Our customers make milk for the table, and they don't want a mother concerned about what's there on her table," said McGreevy, of Elenbaas Co., in Sumas, Whatcom County.

A confirmed case of mad-cow disease at a Central Washington dairy has prompted new questions about what's included in cattle feed.

What is in cattle feed? Cattle feed consists primarily of roughage — such as hay or silage — mixed with a grain, such as corn, barley or wheat. A high-protein supplement usually made from soybeans or rendered animal parts — typically chickens or pigs — is then added. Baking soda can be included to reduce acidity. A high-producing dairy cow can consume 40 pounds of food a day. It costs about $3.85 a day to feed the average cow. Source: Feed suppliers; Colorado State University

Milk and beef cattle can develop the disease by eating food containing protein supplements from infected cows or sheep. Humans, in turn, can develop a variant of mad-cow disease by eating certain products from a sick cow.

Investigators are trying to determine if the Yakima County cow that tested positive for mad-cow disease last week ate contaminated feed at some point.

According to the book "Mad Cow U.S.A.," renderers in the 1980s began marketing high-protein feed made from otherwise worthless animal waste, which can be up to 45 percent of an animal's total weight. About 44,000 tons of animal waste are produced each week by meat processors, grocers and restaurants, according to the National Renderers Association.

But an outbreak of mad-cow disease in Great Britain — possibly spread by cows eating ground-up byproducts from infected sheep — prompted the United States in 1997 to ban cow and sheep meal in cattle feed. It is still legal in the United States to feed that meal to pigs, poultry and pets. Processed chicken and pig parts also can be fed to cows and sheep.

Marian Nestle, author of "Safe Food: Bacteria, Biotechnology, and Bioterrorism," said the practice is driven by a quest for more profitable farming, not by consumer safety.

"(Cattle) were very good at turning completely inedible grasses into meat that could be consumed by people," she said. "What we've done is change that process and in the course of doing that, we've messed around with nature — with consequences in this case."

While the risks of using cattle and sheep products in cattle feed are well-documented, the U.S. Department of Agriculture said there is no public health risk in other animal-byproduct feed.

But a 2002 report by the General Accounting Office, the investigative arm of Congress, said cattle feed could be contaminated when rendering plants and feed manufacturers process ruminants — sheep and cows — and other types of animals.

The Food and Drug Administration is considering a new regulation prohibiting renderers and feed plants from processing both types of animals.

Paul Morley, a veterinarian with Colorado State University, said it is critical for farmers to supplement cattle feed with a protein source.

Grass-fed beef cattle in South America take three years to reach "finished" weight, while U.S. cattle receiving protein supplements finish in about 1-½ years and weigh 200-300 pounds more, he said.

Morley said that while most U.S. farmers use soybeans as a protein supplement, there is no evidence that rendered chicken or pig meal is unsafe.

Jonathan Martin: 206-464-2605

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