I must admit I hadn't looked at this thread before because I'm happy to feed my dog a good commercial biscuit combined with sardines a couple of times/wk and a weekly beef bone.
But I did just want to comment on a couple of things that I've experienced. People can take it or leave it, totally up to them. It's just things I've experienced.
Firstly I never feed a dog pork.
For those showing and breeding be very careful how much calcium you feed to a bitch you plan to put into pup and this applied right thru until puppies are weaned.
When my father was breeding Kelpies we had access to free chicken necks for a while. During that period when the dogs were on regular chicken necks the bitches did not cycle regularly. He stopped feeding the chicken necks and they returned to normal. Things may have changed since then but I am still careful and only give my bitches a chicken neck or two every couple of weeks.