This makes me think of Valley Proteins here in Va, I was talking with an ex DWR employee (dept of wildlife) , and he said they found that Valley Proteins weren’t incinerating carcasses at a high enough temperature, and since that protein was being put into deer supplement blocks and That is supposedly why deer were developing Chronic Wasting Disease (CWD)

I do not know this to be a fact, but maybe a point for some research.