Dairy producers probably underestimate the number of cows that leave the herd for reproductive reasons, says Jerry Olson, technical services veterinarian for Pharmacia & Upjohn. On average, dairy herds have a pregnancy rate of about 14 percent. At that rate, it takes five estrous cycles beyond the voluntary waiting period to get 50 percent of the herd bred.

So, what can you do to improve your pregnancy rate? Basically, you have two options: improve heat detection (service rate) or improve conception rate.

On the heat detection side, several programs exist — targeted breeding, modified targeted breeding and presynch. All of these programs were designed to synchronize cows for breeding. Talk to your veterinarian to determine which one is right for you.

Regarding conception rate, make sure your inseminators use good technique and that they thaw no more than two straws at a time. Check your records, because conception rate can vary by inseminator. The chart below shows how making a change in these areas can improve pregnancy rate:










Heat detection Conception rate Pregnancy rate
Average pregnancy rate 40% 35% 14 %
Timed AI program 100% 35% 35 %
Improve conception rate 40% 50% 20%
Timed AI/improved conception rate 100% 50% 50%



If your pregnancy rate is less than you’d like, talk to your veterinarian or AI representative about ways to improve it.