
Genetic Testing Helps
Single Out Leanness GeneBy Ben Hardin June 22, 1999Genetic testing of cattle may soon help
breeders plan sure-bet matings to make production more efficient and ensure
consumers get lean but tender steaks. The key to this approach, according to Agricultural Research Service scientists,
involves raising cattle with just one copy of a gene called inactive myostatin.
Before birth, a calf with no copies of the inactive form produces a protein
that limits the animal's potential to produce lean beef. ARS scientists at the Roman L. Hruska U.S. Meat Animal Research Center
(MARC), Clay Center, Neb., found that carcasses from cattle with one inactive
myostatin gene typically yield about 7 percent more edible lean beef than those
from cattle without the gene. And the untrimmed carcasses have 14 percent less
overall fat. A calf with two copies of inactive myostatin is extremely muscular in the
hind quarters. That condition, called "double muscling," is
undesirable because birth assistance is often needed. So the goal would be to produce slaughter animals with only one inactive
copy of the gene. To do that and plan matings for herd replacements, breeders
could use a genetic test to determine which forms of the genes animals have.
Last fall, ARS and Celera AgGen, a PE
Corporation business, entered a two-year Cooperative Research and Development
Agreement to develop a genetic test aimed for commercial use. MARC research shows that cattle with the inactive myostatin produce beef
with less marbling, or intramuscular fat, as well as less fat outside of
muscle. But in this case, less marbling doesn't always mean less tender. The
scientists expect to pinpoint numerous genes that together control tenderness. ARS is the chief research agency of the U.S.
Department of Agriculture. An article about the beef leanness gene appears
in the June issue of Agricultural
Research magazine. The article is also online at: http://www.ars.usda.gov/is/AR/archive/jun99/beef0699.htm Scientific contact: Timothy P. Smith, ARS Roman L. Hruska U.S. Meat
Animal Research Center, Clay Center, Neb., phone (402) 762-4366, fax (402)
762-4390, [email protected];
Paul Gilman, Celera Genomics, Rockville, Md., phone (240) 453-3302, fax (240)
453-3650, [email protected]. U.S. Department of Agriculture | |