New research suggests feeding cattle diets less high in grain would solve much of the need for antibiotics, an issue which has limited U.S. beef export opportunities.

Diets of starchy, high-calorie grain trigger disorders in cattle that must be treated with antibiotics and other drugs, new research from USDA and Cornell University suggests. In typical commercial beef production, steers are fed a 90-100-percent grain diet for several weeks in feedlots prior to slaughter so that tender, tasty fat marbling is added to the muscle.

According to James Russell, USDA researcher working at Cornell, an all-grain diet is not natural to cattle. As ruminant animals, cattle are designed to consume and digest huge quantities of high-cellulose, low-nutrition grass. That's why they have four stomachs. "When you feed cattle 90 or 100-percent grain, it creates an acidosis in the rumen (stomach) and the rumen wall becomes ulcerated," he said.

Bacteria migrate through the ulcers and infect the liver, where they cause abscesses.

At least 13 percent of the animals in feedlots have liver abscesses, some as big as your thumb, which means the livers have to be discarded as unfit for human consumption.

If They Didn't Give Antibiotics, About 75 Percent Of The Animals' Livers Would Be Abscessed

Cattle producers and feedlot managers give cattle antibiotics to suppress the bacteria. Subtherapeutic doses of certain antibiotics, plus hormones, also stimulate growth by increasing feed conversion efficiency.

However, the practice of giving cattle antibiotics and hormones has come under attack from environmental and animal-welfare organizations, which claim over-abundance of antibiotics in the environment leads to the development of antibiotic-resistant pathogens causing disease in humans that resists traditional antibiotic therapies.

Imports of beef from hormone-treated cattle was banned by the European Union in the mid-'80s. This eliminated a valuable export market for the US beef industry. Though the industry has challenged the so-called "hormone ban" several times in court and has won, the ban remains in place.

Russell said high-grain diets may cause other problems in cattle, such as bloating. He estimates that approximately 3 of every 1,000 cattle in feedlots die of grain-related disorders.

The fatty, starchy grain causes food to move slowly and sluggishly through a steer's digestive system, building up high levels of acid in the rumen.

About half the bicarbonate soda produced in the United States -- a common home treatment for stomach problems in humans -- is fed to cattle to help neutralize the acid in the rumen.

Beef producers also give cattle lime to calm their stomachs. Other estimates suggest that more than half the antibiotics manufactured in the United States are fed to livestock.

According to Russell, cattle are healthiest when they eat grass, hay, and other high-fiber feeds.

The high cellulose content of these feeds stimulates the gut to work properly and limits the production of acid in the rumen. Animals gain weight without the risk of developing liver abscesses.

However, grass and hay are low in nutrition, requiring months before cattle gain enough weight to be commercially marketable.

Russell said he does not oppose feeding cattle grain. He is looking for alternative ways to fatten cattle economically without causing them health problems.

"If we switched all the cattle from grain to hay, the supply of hay in the United States would not be enough to make up for the deficit," he said.

He believes these health problems could be controlled when cattle are given more time for grazing before they eat weight-gain-stimulating high-fat grain diets. He also suggested changing the diet in feedlots to about 60 percent grain and 40 percent hay or grass.

Gary Weber, spokesman for the National Cattlemen's Beef Association, called it "a challenge" to raise cattle economically. "We fully support any research that will help us produce beef more efficiently."

Reuters May 22, 2001