I have a degree in wildlife management and I think the most overrated factor in antler growth is genetics. Sure genetics count, but who knows the true (i.e. scientific) genetic makeup of their local herd, even the biologists usually don't really know how the genetics in their local herd compares to neighboring herds. Consequently, genetics becomes basically a b.s. dump, whenever we run out of other explanations, we can tout genetics and sound smart.

By far the most important factor in antler growth is buck survival. They've got to make it through 3-5 hunting seasons to get big. To me the second most important factor is food. I don't know the exact relative merits of individual crops, but I have some ideas based on what I've seen in MT. The worst food type, producing the smallest antlers is big woods habitat and mixed woods interspersed with pasture land. Step up a level, to alfalfa and wheat and bucks add 5-10 B&C inches by 3 1/2 years old. The next level would be represented by corn and soybeans. We don't have this kind of farmland in MT, but I'll bet that's worth another 5-10 inches. Yet another level may be reached by planting deer-specific food plots.

Here in MT, in a big woods enivironment, a 3 1/2 y.o. buck will net score 100-125 BC. In the midwest, I believe that range would be more like 120-150. The difference can be explained almost entirely by the jump in feed quality from big woods browse to corn and beans. I would bet that if you took a western MT 3 1/2 y.o. buck scoring 120 and put him in IL, he'd score 150+ at 4 1/2. Now take a 3 1/2 y.o. IL buck scoring 140 and stick him in western MT, and I'll bet his 4 1/2 y.o. rack shrinks below 140.

Anyhow, to put my two cents directly on the question you asked, I think probably corn and beans beat wheat, maybe also alfalafa. Also, think minerals. We have a general selemium deficiency here in western MT and that may play a role, too. (Forgive my wordiness I ain't trying to argue, just my opinion!)