I've heard many people feed their dog with some raw chicken,fish and other veggies etc in addition to the dog food in their diet. How many of You actually do this (other then feeding fish etc for coat shine etc) on a regular basis?
I give the boys some Salmon with their meals once a week or so. One suggestion if your pup is less than a year old I wouldn't do too much of that though, you do not want to throw off the nutritional balance that is very important with young and developing dogs.
I rarely add things as the kibble I feed (Nutro, and ProPlan for one) is all in one. No need to supplement if the dog is doing well on the kibble. That said they do get leftovers from whatever we are eating if appropriate and the odd raw egg/bone but I don't consider this supplementing.