I think you'll find that the digestive systems of cows and humans are somewhat different, especially in their ability to digest cellulose.
I'm not pro grain. The only way I've ever been able to control my weight is on some variant of the Atkins diet. One of the unfortunate side effects of the Atkins diet for me is sleeplessness eventually involving paranoia and general nastiness. I'd rather be a little plump and jolly, weight lift, and walk a bunch than be flat out nuts.
Everyone needs to choose his/her own path. Godspeed!