I hope you're kidding.
Mad cow disease is caused by bacteria that eats away at the brain stem, brains, and spinal cord of cattle. The way that the cattle can get this bacteria is by eating the affect areas of the infected cattle. Sometimes parts from the slaughtered cattle wind up in thier feed by accident or sometimes the farmers are so broke they have no choice but to feed the animal parts to thier livestock. The
only way that humans can actually be affected by this is by eating the brains, brian stem, and spinal cord.