My white/brindle male is 53 lbs, hes almost 6 months in a week, I use whey protein from GNC for my self, but about every other day I coat the top of his food and a lil in his water then we go on a walk for at least an hour a day usually in the canyon so I don't have to use a leash. We play tug with a rope too and ive noticed him getting strong quick. I'm going to need a dam harness soon.
Mine is 40 lbs and still has a lot of growing to do. But it depends on how big the puppies parents are