I guess one should be shocked that farmed fish are being fed byproducts rendered from cows - and what byproducts could that be? Any byproduct that could be of any value would already be diverted to another, profitable use and therefore, one would have to conclude that only the worthless byproducts are being fed to these fish. This very much raises the specter of suspected diseased tissue being used as food instead of being discarded/incinerated for safety purposes. This terrible disease was first believed to have originated in sheep, in which the related prion disease 'scrapie' is common. Bovine spongiform encephalopathy (BSE) infected cattle had been fed with meat and bone meal, a high-protein substance obtained from the remnants of butchered animals, including cows and sheep. And again, any byproduct of value would not end up as feed for other animals - plus, what sane person would think it made sense to feed the parts of one herbivore to another?! Would any sheep or cow voluntarily eat the remains of another? I think we all know the answer to that! Farmed animals, including fish, are totally dependent on their human owners for their food. It is either eat what is provided or starve. And again, why be surprised at such a practice. A known carcinogenic industrial waste, fluoride, has been in our water for decades, pathologically promoted as beneficial to dental health! After all, if a practice produces profit and eliminates the need/cost of disposing an unusable product in the process, what's not to like especially if you're a psychopath without conscience or empathy.