A comparison of transvaginal artificial insemination procedures for use in commercially farmed deer

Abstract

The site of semen deposition (vaginal, cervical or uterine) and the time required for transvaginal artificial insemination (AI) using the Gourley Scope method of AI vs. a standard speculum-guided AI gun was assessed in three species of farmed deer (fallow, red and white-tailed deer). Pregnancy rates using these two transvaginal AI methods were also compared in a commercial herd of fallow does. The estrous cycles of fallow ( n=53), red ( n=27) and white-tailed ( n=27) deer were synchronized using half of a Norgestomet ear implant inserted for 14 days. Following implant removal, does were artificially fix-time inseminated with frozen-thawed semen using either a 0.5 ml standard French-style speculum-guided AI gun or the Gourley Scope method of AI. The time-frame (i.e., duration in minutes) for the AI procedures performed on each animal and the location of semen deposition was recorded. To assess effectiveness of AI, transrectal ultrasonography was conducted in fallow deer 45 days post-AI for pregnancy diagnosis. In fallow does and red deer hinds, use of the Gourley Scope (96.3 and 100%, respectively) enabled a greater ( P<0.05) percentage of intrauterine inseminations compared to the speculum-guided AI gun (73.1 and 42.9%, respectively). In contrast for white-tailed does, both the speculum-guided AI gun and the Gourley Scope resulted in a similar proportion of intrauterine inseminations (92.3 and 100%, respectively). The duration for performing the two transvaginal AI techniques were also similar in red and white-tailed deer. However in fallow does, AI with the aid of the Gourley Scope took longer ( P<0.05) to conduct than the speculum-guided AI gun (6.6±0.72 and 4.3±0.34 min, respectively). The pregnancy rate using both methods of AI combined was overall 32.1% for fallow does. The total percentage of fallow does that conceived with the speculum-guided AI gun was 42.3% whereas the pregnancy rate using the Gourley method of AI was only 22.2% ( P<0.05). Although both AI methods may be acceptable for use in farmed deer, the standard speculum-guided AI gun is simpler and produced more pregnancies compared to the Gourley Scope method in fallow deer, despite a greater proportion of intrauterine inseminations using the Gourley Scope.