Final answer:
The main idea of this excerpt is that mad cow disease was caused by contaminated food sources for cows, and government bans were implemented to end the disease, although people were angry that governments did not act sooner.
Step-by-step explanation:
The main idea of this excerpt is that mad cow disease was originally caused when governments allowed for cows' food sources to be contaminated, sparking bans on feeding cows certain foods by governments in order to end the disease. However, people were angry that governments did not act sooner to prevent the disease. Additionally, 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. However, both farmers and customers protested to prevent their governments from interfering with the farming and selling of cows and meat.