They are supposed to eat grass.
Discussion
and when they eat grass, the people, the animals, and the environment are all healthier.
to be fair, goats eat all the things that are made out of carbon, but sheep, horse and cow all yes grass primarily
they all will nip at other things if the grass is thin, but goats are browsers and get bored with eating one thing, they will eat a little of every thing near them that seems like food
also, it should be pointed out that all these "animal based diet" animals eat plants, and if this vegan stupid person did any research he would know that every step further from the animal that eats animals you increase the density of potentially toxic materials
eg, lead, carcinogenic whatever, drugs from said vegan's psychiatric medicines, and so on
there is also another type of problematic meat too, that which is scavengers and carrion eaters
crows, rooks, and so on, probably not good eating
blackbirds, canaries, rural pigeons and doves, all mainly eat seeds and worms, good eating, worms are also ok, as are insects, mostly, that mostly feed off rotting plants or living plants
pigeons feeding off the grabage in a city, probably not good, because that includes GMO bullshit
lions? tigers? bears? also not good options, since their main foods are other animals, and those animals can indeed also be eaters of other animals
shark, definitely out... and several popular fishing targets, like ... what are they, big toothy fish, fish that eat other fish, not good fish to eat
i may have confused, i didn't say eating bugs was good
definitely didn't mean that
i'd avoid eating birdfood at all, generally
birds eat worms, insects and seeds
ergo
worms, insects and seeds are not human food