Genetics. If you buy a calf that is a little cut up in the flank, when he's a fat steer he's still going to be a little cut up in the flank. Beet pulp is a good filler, and it has about the same amount of protein as cotton seed hulls. Winning fill is just for shows. Feed it the night before and the morning of. One of my favorite products is Full Tank. I've always fed heifers, and I fed a balanced ration that contained cotton seed hulls, and I would add beet pulp, and they were always on full tank.