Show Steer won't eat! ! !

[pepperswamp]

I show steers annually for my local county fair. I purchased my 5th steer, an angus X calf that is now 15 months old. He has never really had a ravenous appetite, however he is not gaining weight like he should and is not excited come feed time. I feed a mix that is created locally, and have never had a problem with this feed prior to this year. By this time, my steer will usually clean up 8+ scoops when this one will not even finish 3. I have tried ProBios granules and gel with little results and tried to switch to a different feed but with no success. I attempted to add molasses to increase both his appetite and the makeup of the feed. He got mad at the molasses and dumped out all of the feed that I mixed it with in his trough. He drinks fine and is crazy about hay, however I have cut him back on roughage to hopefully encourage his desire for his grain. I just can't seem to get him to eat and fair time is approaching! I have never encountered this problem before and would like to both solve it and learn for future reference. What do I do? Thanks!