Investigators are trying tofind the source of feed that may have infected the Holstein cowthat was infected with the first US case of mad cow disease,a US Food and Drug administration official said today.
During a news conference, US officials said the cowapparently was 6-1/2 years old when she was slaughtered,meaning she was born before the United States and Canada bannedthe use of cattle remains in cattle feed.
"We're going back to the establishment that we presume thecow came from in Canada, going back through all the recordstrying to determine where feed may have come from," saidMr Stephen Sundlof, director of the center for veterinary medicineat the Food and Drug Administration.