RESULTS AND DISCUSSION
Synchronization and Pregnancy Outcomes
Of the 141 cows enrolled in the Double Ovsynch
protocol for first TAI, 3% (4/141) failed to synchronize because of lack of complete luteal regression or lack of ovulation after the last GnRH injection, and these 4 cows were removed from all analyses. Overall, 42% (57/137) of synchronized cows were diagnosed pregnant 32 d after TAI. Two cows were diagnosed with twins based on ultrasonography 32 d after TAI, and these 2 cows were removed from all subsequent analyses. Overall, 87% (48/55) of pregnant cows maintained a singleton pregnancy from 32 to 102 d after TAI. Thus, the incidence of pregnancy loss from 32 to 102 d after TAI for cows diagnosed with singleton pregnancies was 13% (7/55).