The silver lining of the moldy grain is that now I'm thinking of finding a more suitable menu for Scout. He had been on a very small amount of sweet feed - our feed store calls it 1/3, 1/3, 1/3 Rolled Corn, no brand name, just the feed-store sweet feed. He literally gets one small handful 2x a day when the other horse in the barn eats, purely to prevent mutiny. The amount doesn't even register on my grain scale.
I'm thinking of switching to a pelleted feed. My Dad thinks that a dry pellet will resist mold and last longer than the "gooey" sweet feed, as Scout eats so little of it and a 50 lb. Bag is the smallest I can buy. I'd prefer not to cut out grain altogether, since he doesn't get any other kind of vitamin/mineral supplement (He does have free access to a salt block), and he "expects" breakfast and dinner when the other horse gets his.
Some info on Scout - Ballpark 8 years old, ridden 4-7 days per week as weather allows, medium work/light trail riding, and daily turnout as weather allows (no real shelter from rain or sun in the paddock, unfortunately). He isn't a hot horse by nature, but I don't really need him to have grain-fueled energy at this point. He has free choice hay of good quality when stalled, free access to grass during turnout. Currently in very good weight, a condition score of 4 to 5.
I'm somewhat constrained by what Tractor Supply carries regularly as far as what is readily available in my area. I was looking at Blue Seal's Strider formula (11% min. Crude protein, 3.5% min. Crude fat, 7.0% max. Crude fiber) as a potential candidate.
Opinions or advice on what to switch to? As I said, the grain is essentially his supplement, and I'm looking to get away from the sweet feed and not have him hopped-up on high octane horse feed.
Sorry that got so long... e-cookies for reading; trying to cram in unnecessary info, as always.