First thing there must always be hay for them weather a round bale or flakes but they need this. Second what I do is right now when I'm getting them they go on a finisher. Ill put them on full feed till about the first of the year then ill start adding in depth charge continue on that till the first of may or when I breed them. Then u have to determine that calf's condition. Needs more condition ill continue with finisher but ill add beet pulp and winning fill with the depth charge. If she getting to fat. Ill go to a grower but ration will be higher with the fibers. I think the main key to belly is getting one bred early ad staying on those filler like hay depth charge winning fill and beet pulp