Funny you mention Jock.Jock. Have used Montego Monty & Me for our Pitbull mix for a few months. We mix in some high quality imported brand foods from time to time but don't stress about it.
Been using Jock junior for my pitbull pup. Good price, great food, and came highly recommended by a breeder that I trust.
I've used it for years and suddenly my dogs would not eat it, just left it for days.
So I assumed a dud bag, and I bough another bag, same issue.
So now I'm on Wuma