If you plan to win, your Show Heifers have to be too fat. I've never bought in to the fat in the udder = won't milk issue. Maybe every heifer we raised and exhibited was an exception, but we never had a milking problem with any of them. Sure, some first calf heifers didn't give as much milk as they did with the second or third calf, but as far as I know that's the rule, not an exception. Any calf we were going to show, or sell for show was started on feed no later than 4 months old, and would be eating 20lbs/day within 3-4 weeks. Our heifer mix was a low protein, high fat and fiber mis not intended to be a growth ration, but designed to fill those fat cells and got they muscle growth kicked into high gear. We learned that if you can get them fat when they'er young, it's a whole lot easier to keep them fat as they mature. Our ration also contains a high amount of Cottonseed Hulls, which many will argue causes fertility problems. We never had a calf that didn't breed within the first 2-3 AI attempts. So, to answer your question; how to feed a show heifer? Keep them parasite free, push them of feed, and always keep out a high quality mineral.