Your calves look nice. One thing I see right off the bat, however, is that they all look a bit straight fronted. I think it can be hard to see this problem in babies around the time of selection. From what I can tell, it comes from the notion that a perfectly straight topline is ideal. I select my breeding cattle with a strong, but loose top. This usually means there is a slight (very slight) "break" behind the withers. Cattle made in this way can hold up better structurally in a show barn setting. None of these animals look like they will be too steep shouldered to be useful, but remember to be mindful of it.
As an aside, and I think this goes for 90% of show families: There is nothing wrong with giving breeding heifers a break from full show feeds in the off season. We really don't feed our heifers from about March 1 to April 10th or so. A 45-75 day break (depending on their condition) can do absolute wonders come Jr Nationals or State Fair time.