I grew up where hulls were cheap and plentiful, before the oil patch figured they could use them. It wasn't so much the filler part but the ability to make a ration lighter on the belly and still gain weight. We fed a lot of cattle where the 3 percent rule was pushing the capabilities of cattle but with some hulls, and some adjusting, that was pushed to 4 and in a few instances farther. Cattle bellies are meant to run best at ful capacity, they just do better. Now some have went to the pelleted feeds, and it works for them but those operations have a better genetic base than a lot of us do. The last carload I fed 20 head were averaging 4.4 gain and the intake was close to the same. Had very few digestive problems, cattle came to the bunk with some vigor and ate all I put out. This too was before the additive of the week, all we used out of the ordinary was golden flo and red cell. Hulls have gotten nearly as expensive as feed here, so doing the beet pulp deal, and some ground hay. Don't like it as well but its affordable at least.