It’s sire summary time again. Before you make your selections, Bill Graves, extension dairy scientist at the University of Georgia, recommends that you keep the following rules in mind:

  • Select top-ranked bulls with a high Net Merit Dollars value (NM$).
  • Use bulls with a reliability of 80 percent or more.
  • Select sires that are in the top 30 percent of the current sire list.
  • Select bulls of high fertility to use on repeat breeders. Use estimated relative conception rate data from Dairy Records Management Systems to help make your decision. You can find it online at
  • Always use bulls with a low score for percent difficult births with heifers. The current average score for all bulls is 8.65 percent difficult births with heifers.
  • Keep only a six-month supply of semen in your tank.
  • Use a software program, such as PC-DART, to maintain a semen inventory list.

While sire selection is critical, Graves warns you can’t forget the cow. To have a successful AI program, your cows must have a healthy reproductive tract and be cycling every 21 days. Depending on your success with heat detection, you may want to consider using estrus and ovulation synchronization programs to help get animals bred sooner.