Ultrasound is commonly used by doctors to check on the health of a
human fetus or to scan a patient's organs. Ultrasound has also been
used to study fetuses in livestock. But now, Agricultural
Research Service and Iowa State University scientists have found
that scanning a live cow with ultrasound can determine its fat and marbling
qualities just as well as measurements taken on the carcass can.
Ultrasound is delivered via a small, noninvasive, hand-held probe that
emits sound waves. These sound waves are turned into images that are
displayed on a monitor so researchers can see inside the body. Trained
technicians use the same machine as obstetricians do, but it has been
modified for livestock use. The probe is placed on the animal's back
(the part used in rib-eye steak) to see how lean and muscular the animal
is as well as how much marbling it has. Marblingthe little pieces
of fat in the middle of steaksadds flavor.
The research on using ultrasound to determine carcass quality was conducted
cooperatively by Iowa State University and ARS scientists using steers
produced and evaluated at ARS' Roman L. Hruska U.S. Meat Animal Research
Center (MARC) in Clay Center, Nebraska. Ultrasound evaluations and data
analyses were conducted by Scott Greiner, now an extension agent at
Virginia Tech University, at Iowa State University in the early 1990s.
But researchers have been using ultrasound on livestock since the 1950s.
Producers want ways to know whether the cattle they breed will produce
quality beef, but they usually know this only when the animal has been
While scanning each animal may take only a few minutes, research leader
Larry V. Cundiff says this technology will be used mainly by producers
of breeding stock. "It can be used to identify and select superior
breeding stock for production of progeny with high levels of marbling
and relatively low levels of fat trim," Cundiff says.
The researchers at MARC and Iowa State developed equations to see how
accurate ultrasound is in determining quality beef. Greiner states,
"With ultrasound, the predicted composition of the live animal
closely matches the composition seen in the carcass."
The Angus breed of cattle is the most popular one on which to use the
technology, but ultrasound can be used on all breeds. "The industry
has widely and rapidly adopted ultrasound use," Greiner says. Each
ultrasoundwhich includes the machine, probe, computer hardware
and software, and other suppliescosts between $20,000 and $25,000,
he says.By David Elstein, Agricultural
Research Service Information Staff.
This research is part of Food Animal Production, an ARS National
Program (#101) described on the World Wide Web at www.nps.ars.usda.gov.
Larry V. Cundiff
is with the USDA-ARS Roman L. Hruska U.S.
Meat Animal Research Center, P.O. Box 166, Clay Center, NE 68933-0166;
phone (402) 762-4171, fax (402) 762-4173.
"Ultrasound Helps Producers Find Ideal Cattle" was
published in the April
2003 issue of Agricultural Research magazine.