Matt,
Last year I purchased 5 units of I80 semen. I had 5 first service conceptions and 5 live very vigorous calves. They were all out of cows and the birth weights ranged from 65 to 91#, with a 79.6# average. The cow that had the 91# calf had 116 and 124# calves the two previous years, so he took a lot of birth weight out of the cows. They keep getting better every day. We plan on breeding a lot more cows and a few heifers to him this year.
Thanks,
Scott Swanek, Ph.D
Swanek Nutrition Consulting
Dexter, MN
507-269-8350