Genetically-engineered cattle can withstand mad cow disease, says new study

... The genes of cattle can be altered to omit a protein that causes the mad cow disease without any adverse effect on the cattle. Scientists at Hematech Inc., a unit of Japanese company Kirin Brewery Co., and the U.S. department of agriculture found that cows bred without the prion protein were healthy at age 20 months and their tissue showed signs of resistance to the brain-destroying disease called bovine spongiform encephalopathy. ...