Rice Bran for Weight Gain??

Hi yall! This is my first year raising a market steer, and it's going... Ok... When I first got him, I knew it would be hard to put weight on him. His loins are really sunk in, and is still ribby. He has been on feed for about 3 months now (he's about ~7 months). He gets 6 1/2 of Purina Show Chow for breakfast & dinner, along with at least 8 hours of turn out a day, but isn't gaining much, if any. He's UTD on vaccines & worming. I was doing some research last night & rice bran seemed like a good "go-to" supplement. Opinions? Feed form vs oil? My show is the first weekend of February, but I'd like to start putting weight on him now to get him caught back up with the other steers in the barn.