All cattle are different, but not seeing the heifer and knowing she is an April, I would definately say the grower ration at this point. A growing ration should have a higher Protein % and lower fat %, this combination supports muscular and skeletol development, which is what is most important on a calf at this age. The finishing feeds typically use the same ingredients, they just change the ratio a little so that it lowers the protein % a little and rasies the fat % a little. Most people look at it and think its close enough to not make a difference, but that little change in ratio completely changes the outcome. While a finisher still supports some muscular and skeletal development, a finishers main job is to lay fat cover down and "finish" the calf, thus we see a lot of calves slow down frame wise when put on a finisher and is why we put larger framed calves on a finisher earlier to try and slow that frame down a little.
Everyone has their own opinion on feeding heifers, and you probably will get a lot of different answers here, what you have to do is the research and decide which philosophy you agree with most and stick with it. I personally never feed a breeding heifer a finisher, just my opinion. We here a lot of breeders, especially the commercial type, talk about how we burn show heifers out on show feed and ruin them as cows. Personally as a judge I dont think any show heifer should ever be gotten fat to the point that it affects her breeding, if one gets that fat I am going to penalize her in the show ring as are a lot of judges. However my concern is that if I want a heifer to go on and be a cow that lasts in the herd for a long time, I have to ensure that her skeletal system has had time to mature at a natural rate and that I havent affected it, this is what grower and developer rations are intended for. My concern is that if I try to alter the bodies development by switching to a finisher I may prematurely shut down her skeletal development shortening her lifespan in the herd.
But again this is just my opinion, you will no doubt get a lot of them here! My advice is to find someone knowledgeable in your area. If you are feeding Purina talk to the local Purina Rep, have someone knowledgeable look at your heifer and together come up with a feeding plan that works both for you and the heifer!!!
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