Two feet of the ground at a minimum. Where my place is it would be better 2 1/2 feet off the ground. I have plenty hogs and some bears, plenty pests in general.
I have always heard bucks adapt to troughs easier and more quickly than any other type of feeder, but I don’t know how you minimize the waste to other animals. Good luck.
Your first looks well built and will last. I especially like your base; as it looks like it would be tough for a boar or a bear to flip the feeder over.
From an older guy who has made more than his share of mistakes- your roof design has two glaring problems:
1) it's going to act as a sail. It will catch wind and be prone to flipping.
2) the way you have the roof attached to the upright IS NOT STURDY. A decent breeze, and the leverage created by the long roof will peel the roof right off. You need to brace the roof. Better yet, a peaked roof with bracing will be even better.
I also would recommend you using some type of roofing material over the plywood. Even if it's marine grade it's going to suffer deterioration bc of rain, dew, and sun.