Everyone has a differing opinion about corn.
Some will say ditch it all together.
For me, I do give scratch/corn in Moderation! but I feed a 20% protein feed free choice.
If nothing else, don't throw away your corn that's a waste, just cut way back on how much you give at one time, then think about whether you want to buy more or give something else as a treat - some veggies/fruit, etc. I like to switch things up as far as treats go. When it's gardening season, my birds get more fruits/veggies/weeds, winter they get more scratch.