About 15 years ago, we planted 4 acres of forage sorghum in 30" rows against the woods on the advice of a friend who said deer wouldn't eat it. They didn't. On the other hand, they loved to run down the rows to wipe the flies off them, and did so most of the summer. We harvested it for silage in late September and did get a nice yield. IMHO, I think all we did was make the deer walk farther for alfalfa and corn, and provided a fly-free environment on the way. I guess it was a win-win for the deer population.