
I feed Prize Choice... never fed it with mixer (dont mix raw and cooked foods in the same meals just upsets tummies), and have raised several pups on it now, from as young as 6 weeks, small breeds and BIIIIIIG ones.
The way i understand it, meat is the more natural food source - theres only a finite amount of food a pup can eat in one day, if you add to the quality food (meat) something with less useful content (complete) are you not taking up space in a pups tummy that could be better filled wit more meat?