I haven't seen tons of mini cows, but the Jerseys I've seen are larger than the Dexters or mini shorthorns. A Dexter cow usually tops out around 36 inches, that's pretty short. I'm not sure what the carcass weight is, but I'd rather eat beef than goat any day of the week. Then again, I have a big soft spot for pigs, just didn't mention them as they didn't seem to fit your criteria. Keep in mind you can easily barter beef or pork. there might be a trade market for lamb if you have more than you can eat, but I'm not sure there's much for goat.