what food is best for my 5 mnth puppy

Question
I have a 5 mnth young puppy and she is a mix between a black lab and a golden retriever.From the time we got her she has shown signs of healthy growth, Prior to us getting her she was being fed the Wal-Mart brand of food, however we eventually phased her into the Diamond brand food for puppies. I have been reading and realised that she is going to be a large breed dog, Blitz (is her name) currently weight a good 50lbs and she is ideal in her wieght. I am now considering to switch to the Purina brand of puppy chow, however they have three different varieties of puppy chow. They have the complete & balanced, the large breed formula and the healthy morsels. I would love to get the large breed formula, but unfortunately on Hyvee has this type of puppy chow and they only stock the small quantity bags, I was wondering if feeding either of the other two available puppy chow's would work for Blitz. I just want to make sure that she gets all that is required to be a strong and healthy dog when she goes to be full size. I currently have a 34lbs bag of the Purina Healthy Morsels but I haven't yet started the switch over. Please help me to make a decision. Thanks

Answer
I would go to an adult chow now.  Switching to an adult chow for the larger breeds early, slows growth and helps develop sturdier joints.

Your dog definitely should be narrower at the waist than the hips and chest. You should be able to easily feel the ribs, but not see them. Each dog is different. Standard recommendations are a good place to start, but each dog must have its food and exercise adjusted to its individual needs. Here is a link to a good illustrated guide, http://www.longliveyourdog.com/twoplus/RateYourDog.aspx

I have seen excellent results with a wide verity of common chows in large, professionally managed programs.  I doubt it will make much difference to your dog which one you select.  If you choose one of the meat based formulas, your dog will have smaller, firmer stools that are easier to clean up.  Other than that, you may as well select one that is readily available in larger packages.  Just be careful to keep the food closed up away from the air.  Putting the bag in an air tight tub is a good idea.  

You may be able to exchange the Healthy Morsels for an adult chow.

There is much more evidence that the common brands are good for dogs than that the premium ones are better.