Chickens eat worms. Feeding them crab or fish meal is fine.

Cows are herbivores. Feeding them meat is abhorrent.

> Feeding them meat is abhorrent.

"Meat" is a relative term though.

If I dry carcasses with some muscle and tissue still on them, grind it up into a powder, and add that powder to grain, is that meat?

"For dust thou art, and unto dust shalt thou return," etc.

If you look at it that way, anything can be anything. We feed soybeans to pigs, ergo I can serve you edamame beans and call them ribs.

What you described - desiccated waste meat and grain - is a dog biscuit.

> dog biscuit

Now with 50% less horse!

Processing foods is what makes many things like olives palatable to humans

I helped my dad castrate some of cattle one time, and we just tossed the ... parts ... off into the grass. Later I saw one of them come over and eat one. So I'm not so surethey would not eat meat on their own, but since they are too slow to catch any, and they couldn't tear it off the carcass, anyway. I expect that chopped up meat is in short supply in the grasslands.

> Later I saw one of them come over and eat one

One weirdo from the herd showed a preference for it one time. Whereas if you threw it among your dogs they'd likely fight over it. That's the difference.

Do the cows know they are herbivores? Why would the fact that they don’t predate on other animals in the wild make it “abhorrent” to feed them animal products in captivity?

> Do the cows know they are herbivores?

How can we really know what cows know? What we know is they follow a herbivorous diet when possible. Their teeth and digestive system are optimized for consuming plants.

> Why would the fact that they don’t predate on other animals in the wild make it “abhorrent” to feed them animal products in captivity?

The reason you said.

On the facts, cows are grazers with incredibly robust digestive systems. They're too lumbering to hunt, but they're biologically prepared to extract nutrients from pretty much anything that ends up in their mouth while they're eating: grasses, insects, carcasses, rodents, etc. Ultimately, feeding them animal byproducts wouldn't be viable or cost-efficient (ugh) if that were not meaningfully the case.

As others are noting, it's the wacky industrial modernity doing its grossly myopic hyper-optimization thing that's the problem (and not just in animal husbandry or agriculture...).