First question I want to ask you is Why? Second question is What do you want to get out of a cross or from your bull? There should always be a "plan" in breeding to try to achieve some specific goal. For example: Conformation? Horn? Color? Beef and marbling? Lean Beef? Good milker (milch cow or mama cow)? Size? Temperament? Body condition? The list goes on and on. Just to breed something to something else to get a calf can sometimes have unpredictable results. Finally, what do you want to get by crossing a Milch Cow(Bull) with a Beef Cow(Bull)?