It had nothing added to it. I always boil the roast to tenderize. The broth is a milky white and I have never seen this happen before. Is it safe to eat?
It sounds like you have emulsified the fat from the meat into the broth. This will happen if you don't skim the fat and then cook at a rolling boil. The oil droplets will become very fine and disperse light, which is what causes the broth to appear white. If that is in fact the cause of the whiteness, it isn't a safety risk.