Homemade dog kibble base?

Firstly the GSD part of your dog may make him prone to a sensitive stomach, have you wormed him recently? This may account for the dull coat. My personal opinion is feed whatever suits your dog, i feed my two on James Wellbeloved and they look great. If you decide on a kibble make sure to read the label before buying. The first ingredient should always be meat, NOT meat derivative or by product but MEAT, don't buy a cheap cereal based kibble. Keep away from all kibble that has any artificial colorants, preservatives etc these can contribute towards skin problems and like children can sometimes lead towards hyperactivity which you don't want in GSD x Lab! :-) If i had the time i would home cook for my two monsters that way you know exactly whats going into the food. We have a saying in UK "fit as a butchers dog" which is absolutely true. 30-40yrs ago maybe even less we didn't have these mass produced commercial kibbles, and the dogs were very fit and healthy living on table scraps. Good luck I'm sure your dog will do fine.

Research raw meat diets for dogs. They are far better than any kibble. And that's a lot of starch.

Edit: Like I said, research raw meat diets. They are far better than any cooked kibble. http://healthydogforlife.com/

You don't need to MAKE foods for your dogs. You buy them from butcher shops, grocery stores, etc. and feed them raw. Much more nutritious and a lot less farting around than making kibble.

Personally I feel that has way too many grains in it. I know you said base so will be adding your proteins but I can't tell the percentages based on this without knowing your protein base.

You can also check out the Dr. Richard Pitcairn books for his recipes too.

How about a raw diet? This dog food has too much wheat.