Vincent, deer are my biggest problem. I almost quit growing fruit trees because of them. It takes a lot of expense in fencing. My current best effort is 6-foot-tall wire fencing around each tree, between 6 foot steel fence-posts, and I add finer mesh plastic fencing in places so the deer cant push against the fence and pull branches through. It’s more work maintaining the fence and area around the trees. I mulch either with tree chips, free from local arborists, or leaves I collect from neighbors.
My current thought is that they don’t usually browse branches above 6 feet high, so I prune off lower branches to limit attractions for deer, and let the higher branches grow. They don’t seem to eat above 6 feet on peaches, cherries, or plums, (or lindens, or mulberries) but might on apples. Especially if weight of fruit pulls the branches down. If I fall off a ladder and kill myself picking fruit, at least I got a few.