I will personally stick with Ration Balancers from now on! Right now I feed Enrich 32 as it's the only one available to me. I LOVE the results I get with it! I have a 5yr old barrel prospect on it and two coming yearlings on it as well.
For extra calories I give oats as I don't have a lot of options here. The babies get MAYBE 1lb a day simply as a treat. My mare just got upped and will be getting about 2lbs a day.