|
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
| 