Most show feeds are pretty well balanced. As a first heifer, I would suggest that the focus be more on learning the fundamentals of exhibiting cattle, and focus on the competitive aspect later. Splitting hairs with feed supplements is not as crucial as people put on... If I could give any advice, I would tell you to get a system and stick with it. Feed at regular times, keep the calf on a monthly worming schedule, and keep fresh clean water in front of her all the time. Put emphasis on making it a fun experience at first, then you can focus on the blue ribbons.