Farming the white-tailed deer native to the Americas has become somewhat common in the old world and reindeer have also been domesticated as beasts of burden across northern Eurasia. AAIU, the body structure of white-tailed deer isn't very suitable for labor, they can jump very high, and are not particularly gregarious or easy to keep in herds. The North American caribou (reindeer) population only inhabits the far north and is seasonally nomadic, migrating over very long distances. Other, larger, native species like moose are usually considered too big and too aggressive to tame.

I think plenty of animals eat acorns. It's just that humans can't really do much with them.

I think you can eat a few in an emergency, but there's some chemicals in there that ain't so good for humans in larger quantities.