On Monday, it’s reported that mad cow disease has been found in Japan. Now Japan is testing about 30 plants that produce compound feed for cattle to see if they are using meat and bone meal. This disease is caused when cattle eat the infected meal.
It will cause cattle to die. Experts said the disease enters a country through imports of bone dust and meal from infected cattle. Since January 1, China has stopped the import of feed made with the animals from the European Union, where the first case of mad cow disease was reported. Mad cow disease spread to a number of countries in Europe and caused cattle industries huge losses.

How did mad cow disease spread and cause cattle to die().