Have to agree. When I first started reading these boards, all the talk about sweet feed, tubs, loose feed, etc, etc got me wondering what I was doing wrong. One look at the cows convinced me that grass was doing the job just fine. I've been known to supplement a light group of heifers or light pairs, but I supplement with alfalfa that the hay crew has somehow managed to screw up, and that doesn't happen very often. In this area anyway if a cow has enough grass she can get to, she will do just fine.
Wife wanted to try feeding some cob to a steer couple of winters ago to fatten it up a bit before we butchered. The cost of that stuff could break anyone in no time, and she was just feeding a coffe can a day for a couple months. I thought the beef was no good anyway, dang fat was white, not yellow like a good grass finished steer. How anyone could afford to even feed a little to a commercial cow is beyond me.
I guess I will have to take some pictures of some desert cows and what they eat, all spring and summer. Might take 50-60 acres or more to feed a pair, but they do it just fine with no extra feeds. Mostly rocks, a little dirt and sagebrush. Cows do good as long as they don't have to walk to far to water.