What is the main problem stated in this excerpt? Cows can't hold their heads up and fall down. Brain tissue gets spongy. BSE causes death in humans and cows. Cows die from the disease.

The word BSE is short but it stands for a disease with a long name, bovine spongiform encephalopathy. "Bovine" means that the disease affects cows, "spongiform" refers to the way the brain from a sick cow looks spongy under a microscope, and "encephalopathy" indicates that it is a disease of the brain. BSE is commonly called "mad cow disease."