I cook my oatmeal just to make sure the anti-nutritional factor assoc with (uncooked) it will not be a problem (altho if you feed just a bit along with a commercial feed I wouldn't worry too much about it as the commercial feed as added enymes and such to deal with anti-nutritional factors).
A cornell Univ. paper (don't have link to post for you at the moment) mentioned that (cooked) oatmeal is good for the digestion and uptake of calcium ... I add just enough to their normal daily portion of feed to make it all clump together (helps prevent wastage this way too!)