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KNOXVILLE, Tenn. (October 31, 2002) — Researchers with the University of Tennessee Agricultural Experiment Station have their hands full with the exponential success of the UT Cloning Project. They are caring for 10 clones of a single adult Jersey cow. Three additional clones were born alive, but they failed to thrive. The live births of thirteen clones of one large adult mammal are among the most ever announced by a public institution. The clones were born July 25 through August 15, and nine of the calves are thriving. However, the researchers, including a team of veterinarians from the UT College of Veterinary Medicine, are concerned about the health of one of the young females. She is being monitored for possible liver dysfunction, which underscores the sometimes delicate health of clones. All of the clones were derived from an ovary cell taken from a cow that was chronically infected with mastitis. Mastitis is a bacterial infection that results in inflammation of the udder. It causes billions of dollars annually in lost revenue to the dairy industry due to lost production, investments in animal care, poor reproductive performance, and milk that has to be discarded. This results in higher consumer costs for dairy products. “We are attempting to establish the genetic relationship of mastitis susceptibility,” said Dr. Lannett Edwards, the lead scientist for the UT Cloning Project. Edwards, along with her partner Dr. Neal Schrick, are responsible for producing the clones. “The overall goal of this research effort is to enhance the quantity, quality and safety of milk and meat produced by dairy cows while simultaneously increasing farmer profitability,” said Dr. Steve Oliver, co-director of the UT Food Safety Center of Excellence and an internationally renowned mastitis expert. Oliver and others plan to compare the clones’ performance and disease susceptibility to each other and to the adult cow from which they are derived. “These calves are genetically identical to each other and to a cow that is known to have been chronically infected with Streptococcus uberis, one of the bacterial agents responsible for environmental mastitis,” Edwards said. Oliver says mastitis differs from most other animal diseases in that several diverse bacteria are capable of infecting the udder. “Many pathogens can invade the udder, multiply there and produce harmful substances that result in inflammation, reduced milk production and altered milk quality,” he said. Current methods of mastitis prevention and control are not as effective against Streptococcus uberis and other environmental mastitis pathogens. Treatment of cows with chronic mastitis typically involves multiple administrations of various antibiotics during the infection period. There is a growing perception that the use of antibiotics in animal agriculture may be partly responsible for the emergence of drug-resistant bacteria, which may decrease effectiveness of similar antibiotics used in human medicine. "The clones may be invaluable for determining potential genes, immune components, and other factors associated with and responsible for mastitis resistance. Identifying these factors could lead to improved animal selection strategies and novel approaches for eradicating or reducing diseases of food-producing animals," Oliver said. The research may also result in reduced use of antibiotics for treatment of mastitis. Grants from the UT Food Safety Center of Excellence helped fund the use of cloning technology. ### Contact: Patricia
Clark McDaniels |
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