I might be wrong but I think heifers need to be feed large amounts of roughage during their development stage to become efficient cows later. We never fed out a heifer for show but the few heifers I have retained have done well as far as growing and adding condition on basic free choice quality hay (kept feeder full) and 1.5 to 2 percent of their weight of show feed, with a pound of Stabilized Rice Bran a day. I will add that all but one came from one cow family and were very easy keepers, the one heifer I fed out to eat was fed the same way and turned out just right as far as cover and marbling (commercial Hereford purchased to feed out)
This was the feed 12.5 protein 3.0 fat:
Cracked Corn, Cane Molasses, Cottonseed Hulls (Not More Than 9.5%), Soybean Meal, Rolled Barley, Whole Oats, Plain Dried Beet Pulp, Ground Corn, Ground Wheat, Wheat Millrun, Suncured Alfalfa Pellets, Distillers dried grains, Calcium Carbonate, Corn Germ Meal, Corn Gluten Meal, Sodium Bicarbonate, Sodium Chloride, Vegetable Oil & Animal Fat Blend, Potassium Chloride, Sodium Bentonite, Cobalt Glucoheptonate, Zinc Amino Acid Complex, Manganese Amino Acid Complex, Copper Amino Acid Complex, Potassium Sulfate, Tallow, Magnesium Sulfate, Condensed Lignin Sulfonate, Ferrous Sulfate, Dried Yeast, Sodium Selenite, Magnesium Oxide, Copper Chloride, Copper Sulfate, Ethoxyquin (Preservative), Natural and Artificial Flavor Thiamine Mononitrate, Vitamin E Supplement, Ethylenediamine Dihydroiodide, Cobalt Carbonate, Selenium yeast, Brewers dried yeast, Niacin Supplement, Propionic Acid, Ammonium Hydroxide, Sorbic Acid, Benzoic Acid, Phosphoric Acid, Propylparaben, Methylparaben, Butylated Hydroxyanisole, (Preservatives)
Heifer at 13 months fed as mentioned above.