Jordanh,
I'm just north, outside Columbia, so I know how bad the deer can be in this area. The tall rats even ate walnut seedlings I put out my first year here. Are you starting a commercial sized orchard, or are we talking a personal orchard? I've been planting fruit and nut trees for a few years, and I've fenced each tree with a five foot circle of welded wire fencing. When the trees get tall enough so that the deer can't turn them into shrubs by nipping the terminal buds, I move the fence to a new tree. I only have twenty or so trees fenced right now, and it's doable at that scale, but for a commercial orchard it obviously wouldn't make sense. The only commercial orchard I'm familiar with around here is in Franklin, and it isn't fenced. I don't know if they protect the young trees somehow, but the mature trees can stand some browsing. On the other hand, it would be nice to be able to keep the deer completely out so you could use fallen fruit, at least for your own uses. The commercial orchards can't sell fallen fruit at any discount because of health regulations. In fact, they tell you not to pick it up even if it is as good or better than what's still on the trees. Last time we picked there the ground was covered with fine looking fruit, and since I'm into cider making it really hurt to see it going to waste.
Chuck