The agriculture department of the Hokkaido Prefectural Government confirmed Tuesday that the sixth cow infected with mad cow disease was fed a milk substitute similar to the one given to all five cows previously found suffering from the disease.
A dairy farmer in Shibecha, Hokkaido, raised the Holstein on nine types of feed, including Miru Food A Super, the department said, confirming an announcement by the town's agricultural cooperative Jan. 20.
The milk substitute was produced at a factory in Takasaki, Gunma Prefecture, that manufactured the feed given to the first five cows found with the brain-wasting disease also known as bovine spongiform encephalopathy.
The sixth cow was sold to a Wakayama farmer on Feb. 17, 1999, according to the report by the prefectural agriculture department. The health ministry confirmed on Jan. 19 that the animal was infected with mad cow disease.
Four days later, the ministry confirmed that a seventh cow, also raised in Hokkaido, has been infected with mad cow disease. Hokkaido public health department officials suspect the cow consumed the same type of feed.
The first five cows had been fed either Miru Food A or a similar brand, called Pure Milk, that has nearly identical ingredients. Pure Milk is also made by the Gunma factory.
The feed was found to have included animal fat made in the Netherlands, which has also experienced an outbreak of mad cow disease. The causal relationship between the feed and the infections has not been determined.
The sixth cow produced a female calf in January 1999 that was killed in February 2002 after suffering an injury, according to the report.