What is the main idea of this excerpt? Mad cow disease ended because of government bans on feeding cows certain foods, but people were angry that governments did not act sooner. Mad cow disease was originally caused when governments allowed for cows' food sources to be contaminated, so people were angry at their leaders. Both farmers and customers had been aware of mad cow disease, but they did not think their governments should have done anything to stop it. Both farmers and customers protested to prevent their governments from interfering with the farming and selling of cows and meat.