Evaluation of uterine body and bilateral uterine horn insemination techniques.

Uterine body and bilateral horn insemination techniques were compared in 364 Jersey cows and 138 heifers by two inseminators. For horn inseminations, approximately one-half of the semen was placed in left uterine horn just prior to the point of resistance. The remainder of semen was then placed in the right uterine horn just prior to the point of resistance. Animals were inseminated in the uterine body on even days of the month throughout the study. On odd days of the month, animals were inseminated in both uterine horns. A total of 62.9% of 286 animals inseminated in the uterine body were pregnant versus 54.2% of 216 animals inseminated in both uterine horns. Differences were greater for cows than for heifers and at first and second services than at third or greater services. These results favor current recommended techniques to deposit semen into the uterine body correctly.