Mad Cow Breakthrough? Genetically Modified Cattle Are Prion Free
The U.S. Department of Agriculture’s Agricultural Research Service (ARS) have announced initial results of a research project involving prion-free cattle. ARS scientists evaluated cattle that have been genetically modified so they do not produce prions, and determined that there were no observable adverse effects on the animals’ health.
Prions are proteins that are naturally produced in animals. An abnormal form of prion is believed to cause devastating illnesses called transmissible spongiform encephalopathies (TSEs), the best known of which is BSE.
ARS studied eight Holstein males that were developed by Hematech Inc., a pharmaceutical research company based in Sioux Falls, S.D. The evaluation of the prion-free cattle was led by veterinary medical officer Juergen Richt of ARS’ National Animal Disease Center (NADC) in Ames, Iowa. The evaluation revealed no apparent developmental abnormalities in the prion-free cattle.
Richt said, "The cattle were monitored for growth and general health status from birth up to 19 months of age. Mean birth and daily gain were both within the normal range for Holsteins. General physical examinations, done at monthly intervals by licensed veterinarians, revealed no unusual health problems."
ARS, with assistance from researchers at Hematech and the University of Texas, evaluated the cattle using careful observation, post-mortem examination of two of the animals, and a technology that amplifies abnormal proteins to make them easier to detect. Further testing will take at least three years to complete.
The evaluation was reported today in the online version of the scientific journal Nature Biotechnology. ARS is USDA’s chief intramural scientific research agency.
Source: USDA/Agricultural Research Service. December 2006