The incubation period in cattle is four to five years , said Stephen Sundlof of the U.S. Food and Drug Administration .
The incubation period in cattle is four to five years , said Dr. Stephen Sundlof of the Food and Drug Administration ( news - web sites ) .
Mr Martin reported that the company is remaining to stay "cautiously optimistic" due to the huge improvement in sales and operating performance trends in the second half of 2003.