I may be wrong, but I would really really doubt that there is. If you're going to spray herbicides and pesticides on your crop, and chemically fertilize it, then the GMO crops are going to do much better with fewer chemical inputs then non GMO crops.
I understand not wanting GMO, but why do you want non-organic? I'm assuming for a savings on cost?
I'm lucky that I have a source for non GMO, organic, soy free feed near me. Does it cost more? Yes. Do I think it's worth it to not be putting chemicals into our environment and rogue genes into our crops? Yes. Would I rather support a local family farmer who is farming the "right" way rather than a giant corporate farm with strong ties to the chemical/biotech firms? Yes.
I admire you for doing your research, and questioning our food system. The deeper you dig, the more depressing it can get. Look locally. So much of the cost of the chemically produced GMO feed is the transportation. You may find a local organic feed mill that has something at a reasonable price. Good luck!