The chance that cottenseed in any style our amount is enough for me to not use it at all.
That said I used to stress out and get frustrated each and every year with my feed mix. What should the mix all contain? How much of what minerals? Is there some "secret mix" that some guys are using? What do I feed the bucks and what doe I feed the does? Pellet or loose mix? And then all the problems with the feed mills around here. They would make my feed and then later say, "oops we forgot to put you soybeans in" or some other ingredient. I finally said enough all ready and picked one mix and have it made in small (1,000LB) batches in a loose mix. I pick it up, look at the feed closely. Smell it, and feed it. I do plan to get my own mixer and mix my own feed to insure everything gets into the feed that is supposed to be in there though. I just haven't committed the money to that yet. But I have stopped chasing that "secret mix" and boy it feels good to not stress about something in my life
Could I have bigger bucks if I did something different? Maybe. But you know what? If I can raise good deer with what I am feeding now then I know my deer are big because of the quality of the genetics and not the feed. And I think that is what people want to buy.
P.S. I don't mean that others shouldn't try and feed their deer a good mix, or strive to produce the biggest bucks they can. I didn't mean that at all. I just mean it feels good to me to have been able to get past worrying about it ALL the time.