Animal Health |
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Genetic research may yield better beef cattleBy Bonnie Coblentz MISSISSIPPI STATE -- Grill masters everywhere have their own tricks for bringing the juiciest, most tender steak to the table, but much of its final success is determined long before that steak hits the hot coals. Terry Kiser, head of Animal and Dairy Science at Mississippi State University, said genetics play a major role in the tenderness and juiciness of beef. "The genetic component is highly heritable," Kiser said. "If we can ever get a handle around the genetics, we can effect some permanent change in tenderness in the beef population." One problem standing in the way of this research is the fact that tenderness cannot be measured in a live animal. Only after it is processed can a researcher or diner know that a particular cow had good genetics. Certain procedures such as chilling rates and aging in the processing stages can enhance the meat's tenderness. Chefs can further age the beef at home in the refrigerator, and they can cut against the grain and marinate the beef to make it as tender as possible before cooking it. Kiser said 26 percent of the beef cattle population contributes tough meat. Mississippi Agricultural and Forestry Experiment Station researcher Erdogan Memili is applying science to the problem of tough steaks. His applied research focuses on bovine genetics. "Marbling is a characteristic where small specks of fat in the muscle make the meat more juicy. Even though marbling and tenderness are associated with each other, they are influenced by different genes," Memili said. "So the question is, how do we get meat with high marbling?" Memili said a gene has been identified that, when present in a cow, displays more marbling. A test has been developed to determine if this gene is present in a calf. "The test is effective, but the gene is not 100 percent predictive of marbling," Memili said. "We need a more powerful, genomic approach. We must find more markers related to marbling." Memili said researchers elsewhere are sequencing the bovine genome, which will provide a genetic blueprint for cows. Once this blueprint is complete, researchers such as Memili can focus their research on areas of the genetic code where desirable characteristics are found. "Breeding programs try to develop breeds that produce tender meat, and researchers screen animals to try to determine whether a calf will give good marbling and tenderness," Memili said. "The other approach involves genomics and would make cows with the desired characteristics. This is quite straightforward once we know the genetic sequence of a cow." Research at MSU will look for the genetic markers for marbling, tenderness and other desirable, selectable traits that can be chosen and carried to the next generation. These traits include heat tolerance, disease resistance, feed efficiency, marbling and others. "Because of the information lacking in the genetic blueprint for cows, we don't know as much as we want to know right now," Memili said. "But the technology is right and the timing is right to undertake this study." Work should begin next year in a newly established lab in the Department of Animal and Dairy Sciences and at MSU's Life Sciences and Biotechnology Institute. -30- Released:
Sept. 23, 2004 |
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