OMAHA (DTN) -- Sheep infected with scrapie and cows infected with BSE have elevated levels of manganese in their blood before clinical symptoms appear, according to new research by the University of Bath and reported in a university press relaese.The findings, published in the Journal of Animal Science, also show that scrapie-resistant sheep produce elevated levels of the metal when “challenged” with the disease.This suggests that elevated manganese levels in the blood and central nervous system are caused by the animal’s initial response to the disease.