Aubrey: Farmers kill cows when they see symptoms of mad cow disease, grind it up and put it in the food. Aubrey: This is like really 101 stuff. The one non botched government response was to assign researchers to find out how this started. A couple different factors that appear to have led to this are increasing use of this bone meal protein stuff; there was also a change in the way that they create bone meal. So I don't know if this is a trigger warning, but if you're eating right now, stop eating.