91色情片

CHRONIC wasting disease (CWD), a prion disease similar to BSE that affects
elk and mule deer in North America, can jump the species barrier. Elk and deer
carcasses were fed to cattle in the US until 1997. Now researchers at the
National Animal Disease Center in Ames, Iowa, have discovered that brain tissue
from deer with CWD gives cattle the disease when injected into their brains.
Feeding experiments are still in progress (Journal of Veterinary Diagnostic
Investigation, vol 13, p 91).