Corn versus Sunglo Sumo for steers

My daughters steer is 45 days out from terminal fair and we're working on his final cover.  I was going to go the usual route of adding some corn to his diet but started thinking about Sumo.  This time of year we have to buy a huge bag to support the cover on our hogs and I'm wondering if we could use it for a fat additive for our steer as well?  He'd be getting 5-6lbs of corn per day so I'm trying to figure out the Sumo equivalent for top dressing.