Anybody ever make there own dog food with a farm hamermill??

We used to have a huge bull test feedlot and raised corn and milo as well. We bought a New Holland hammermill to mix up our own feed rations for the bulls and I ran across a company in Full Cry Magazine that sold a suplement that one bought from them, they had a high fat/ high protein ration that used used cooking oil to increase the fat level in the dogfood you could make with there suplement. All one had to do is add cooked meat scraps (now i not sure if they still sell this due to mad cow diease) oats, corn, milo, barely etc in various percentages dump in the 25 pounds of vitimain/ suplement that Vitagroom?? sold with there ration. I tried this stuff but at first it was making all of my dogs scour and some ate to much and some went off feed. It was in bulk and not pelleted by the way. I complained to the Vitagroom company and they told me to send in a sample of what i was actually putting in the self feeders. They sent back a professional report by a feed specialist they had look at it and they told me that i had the wrong screen in the hammermill and it was leaving the corn too large to be digested by a dogs system. Anyway, went to the New Holland dealer and looked up smaller holed hammermill screens, got one really small and tried it again with the fine screen vs the large one that came with the mixer/grinder. Went back to feeding the dogs the bulk feed again with the supplement and adding in the used cooking oil from a pards chicken to go place. The change worked, stools, stiffened up, dogs got fat as heck and of course the price was really cheap less than 1/2 the wayyyyTooooHigghhhh store price for dog food. I quit mixing my own dogfeed when the ranch got split up when dad died and the ranch was divided up. I was just wondering if anybody here had ever got dog food custom ground in bulk lately and where did you get the vitimains ans supplement mix from nowdays?? Any dairy or feedlot dog hunters on here ever thought about this?? I wish somebody could get it going again for members here and save us some money and have our own custom feed too. I had a pack of straight javilaina dogs, big hog dogs, wolf dogs and some coon dogs prob at least 40 back them so if was worth all of the hassle to do it yourself since we had the mixer and our own corn, milo etc.