WASHINGTON - Federal agriculture officials said yesterday that they had traced a Holstein infected with mad cow disease in southeastern Washington state to a herd of 74 dairy cows brought to the United States more than two years ago from Alberta, Canada.
"That's most likely where she became infected," said Dr. Ronald DeHaven, chief veterinarian for the Department of Agriculture, who added that officials were working with cattlemen to locate the other 73 cows.
But a disagreement flared between the Americans and Canadians regarding the age of the Holstein - and in which of the two countries the animal most likely acquired mad cow disease. Canadian authorities said their records showed that the Holstein was about 6 1/2 years old, while the U.S. officials, citing documentation maintained by owners of the cow, placed the age at closer to 4 years.
The cow's age is important because in 1997 both...
