Boy oh boy did we ever learn a lesson on trying to store extra chicken layer pellets, the 40 pound bags started heating up from enzyme action, just like composting, then thousands of little weavels hatched out and some we crawling up the wall behind the sacks, they also got into sacks of rice, it got pretty crazy until we got rid of all of the infestation and yes, the mold. Probably the only way one could long term store some feeds would be to have the bags in a freezer, that would kill the bug eggs, and stop rancidness that comes from the natural oils in grain germ. As it is, for long term storage of brown rice, we store it in a freezer. When I was working custodial/maintenance for the local school district I had to stack government commodities in a storeroom of the elementary, some of those things were regular wheat flour, whole wheat flour and corn meal, this room never got all that warm due to the large walk-in freezer that was in the same room, but many times when I walked into that storage room, I could smell rancidness, especially from the whole wheat flour and the corn meal. I told the kitchen boss that they needed to put those in the freezer and that's what we ended up doing. Anyway, there's my 2 cents worth of experience, hope it's of some help.