You need to check and see if any of the local milling companies blend a deer feed. I just helped a guy get set up with Harrell Milling Company in Hartford, Al to supply feed for his new deer pen. Honestly for a wild herd you would be money ahead to plant plots and fertilize natural food sources for the deer. Most of the wild forage a deer uses is 16% or higher and that is all a deer can digest. I wouldn't doubt if over 50% of feed in a feeder is consumed by squirrels, coons, possums, birds and other critters as well as being wasted on the ground.