The U.S. Department of Agriculture’s Agricultural Research Service (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. These genetically engineered cattle would not get mad cow disease.
Bovine spongiform encephalopathy (BSE) is a chronic, degenerative disorder affecting the central nervous system of cattle.
“These cattle can help in the exploration and improved understanding of how prions function and cause disease, especially with relation to bovine spongiform encephalopathy, or BSE,” said Edward B. Knipling, administrator of ARS. “In particular, cattle lacking the gene that produces prions can help scientists test the resistance to prion propagation, not only in the laboratory, but in live animals as well.”
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.