Feeding Show Cattle

Is it safe to just feed show cattle corn and Mooreman's supplement?  A friend of mine who works for a feedlot recommended this feeding program.  I am a little concerned about this.  Thanks!

This deal has been around for a while, the mineral? Is supposed to let the guts use whole corn.  For what you are wanting to do it ain't worth the time or money.  Corn prices are the main force, cooking whole corn is a better deal price wise and results wise also.

As far as safe goes, I can't see any reason it wouldn't be. That doesn't mean it's a good idea though.  Remember that a feedlot ration has one purpose - to get them fat as quickly as possible.  It's not going to help your chances in the show ring because show rations provide more fill, bloom, hair quality, etc...