Hydrolyzed beef protein isolate refers to collagen, connective tissues, ears, hooves etc...aka "cow parts". It is not powdered lean beef meat, that is a common misconception. It is like a powdered hot dog? Would you consider hot dogs to be a quality source of protein for a bodybuilder? Not only that, but things like collagen and connective tissues have poor bioavailability. It has also significantly less leucine content than way. It is better than nothing, but it is inferior to whey, egg, and milk protein