Hahahaha F*ck me mate that's got to be the funniest question I've ever seen on the NET!
I personally think that you're worrying about it all too much, As good as the chicken is you'll need to give the dog more than just chicken carcasses, give it Lamb, Beef (Mince), Tripe and bones a few times a week. Don't worry about the fat in the Lamb, if it looks as though it's putting on too much weight then don't feed it as much Lamb.
BARF is the best way to feed a dog make no mistake of that, a dog isn't going to of evolved in the past few years to do better on a bag of dry food because of what