You're wrong. Cows will eat meat, horses will eat meat, pigs will eat meat, chickens will eat meat, deer will eat meat. If they can get it in their mouth, they will eat it.

The point of eating meat is that it's easy to digest. This isn't a case where two things are difficult in different ways and you want to do the thing you're specialized in. Meat is easy to digest, and plants are hard to digest, no matter what.

I don't know but I once watched a deer eat a bird so they clearly have some incentive

It's plants you need a fancy setup for. Also, the microbiome thing, surprisingly, isn't universal, a lot of animals have no stomach microbiome to speak of.

https://www.theatlantic.com/science/archive/2020/04/animals-...

> For herbivores, meat is objectively bad food .

We feed cattle the leftovers from processing meat. It's how we got mad cow disease.

Most herbivores I’m aware of will at least occasionally eat meat or insects. Even grazers.

I would be kind of surprised if there’s any “true and pure” herbivorous vertebrate.

Meat is rich in nutrients that even herbivores need and is difficult to get entirely from plants.

Vegans are the anomaly.

I would guess that a digestive system that can extract adequate nutrition from grass will extract something of value from meat. On the other hand, if the meat content became a significant part of the diet, I can imagine it could become harmful, for example by messing with the digestive process or by delivering toxic levels of certain products.

>What is the point of eating something that is hard to process and digest and has no nutritional value for you

Wouldn't that make it dietary fiber then? What's functionally dietary fiber varies from species to species, but like with humans we eat things exactly like that for GI health. Birds of prey for instance eat casting (fur and feathers) which is functionally like dietary fiber for them where it would be unhealthy if you just gave them a steak without having them also eat the indigestible bits as they wouldn't be able to properly form and regurgitate pellets. Certain animals might not need something that functions like dietary fiber but for at least certain animals - like humans - eating certain indigestible things is important for good health.

"Better" is kind of a vague term. A more precise and limited statement is that meat has the highest protein quality index. There could be some other disadvantages, depending on your species.

The cows would be happy, but that would be significantly more expensive than feeding them plants.

Note that mad cow disease came from feeding cows to cows. Giving them meat isn't exactly an innovation.