The Ministry of Agriculture, Forestry and Fisheries in Japan revealed on Friday that meat and bone meal (MBM) was given to 7,973 cows in 18 prefectures across the country.

The Associated Press also reported that MBM, which is widely believed to be at the root of the spread of mad cow disease, has also been used on another 22 farms in the Hokkaido, Yamagata and Saga prefectures.

The exact number of cows fed with livestock based feed on these farms is as yet unknown however.