I have always been alittle to worried about A.I ing heifers to a Sim bull. I have always used either red or black angus calving ease bulls when i have A.I'ed my commercial heifers. The group of heifers i have this year have alot of angus or red angusblood, (most are 3/4 or better angus). My question i guess is.. If I use a calving ease and low birth weight proven Sim bull,(thinking maybe Shear Force at Genex, or Olie at ABS) do you think i will get along ok, or am i going to be cussing what i thought was a good idea,next spring. I run a commercial herd where i shoot for no less than 50% angus genetics, red or black, and no more than 50% Sim genetics. If I used Sim. genetics on my heifers a few of the resulting calves might go over that 50% barrier just a touch but if i use Angus genetics, alot of the resulting calves will be 7/8 or higher angus blood. I use F1 bulls on most of my cowherd, and that would be an option, but there are no real F1 bulls available that ilike, or are proven enough to make me feel confortable. Any suggestions, or warnings?