Well, personally, I'd have to agree with your breeder. (sorry Dr.) Your breeder knows more about her specific breed than does your vet, naturally. Your vet knows about dogs in general.
Eukanuba is way too rich for a newf puppy. Your breeder's choice is made of human quality food with lower protein. You want to grow your newfie puppy slowly to protect hips and joints. Eukanuba, while an excellent food for many dogs could make your newfie grow in leaps and bounds giving him all the bad medical problems we all try to avoid.
As for the chicken necks, I for one definately agree. Also some veggies is a good idea. It's my understanding that dogs are not affected by salminella (sp).
Did your breeder suggest gluclosamine and chondroitin? This is good for the pups joints and hips. Vitamin C is good, so is a little vitamin E.
Now I'll tell you what I feed my dogs. I was ready to start them on Eagle or Canadae, or the California you're using - all human grade ingredients, and lower in protein. I was going to add the chicken parts, veggies, etc. But, after doing some research, I have now decided to feed my dogs strictly raw meats and raw veggies. No kibble whatsoever.
My dogs are: 2 seven year old golden retrievers
1 6 month old newfie girl
1 3 year old foster newf girl
1 8 week old newf will be joining us soon.
Everyone of these dogs including the 8 week old will be fed this way.
I really do believe your breeder has the best advice for you. It sounds right on track to me.
Good luck. Linda