It would really depend on the heifer's breeding and her size, etc. The first one was a out of a JPJ X Yahtzee heifer. She is a big girl 1300-1400#; the calf was about 90 pounds, easy pull, 4 days late. The other was out of a Milkman heifer (moderate framed heifer about 1200#) Her bull calf was maybe 70-75# born unassisted, 5 days late. I will tell you that we will be breeding him to some heifers again.