Okazaki Tetsuji, Ikoma Erena, Tinen Tukasa, Akiyoshi Teiichi, Mori Manabu, Teshima Hisanori
Smaller Livestock and Environment Section, Livestock Research Institute, Oita Prefectural Agriculture, Forestry and Fisheries Research Center, Bungo-ono, Oita, Japan.
Anim Sci J. 2014 Jan;85(1):8-14. doi: 10.1111/asj.12089. Epub 2013 Jul 5.
Oxytocin (OXT) contained in boar semen is known to produce uterine contraction; therefore, we hypothesized that the co-injection of OXT with sperm would improve artificial insemination (AI) using liquid or frozen-thawed boar sperm. We initially examined whether OXT added to semen extender improved sperm transport to the oviduct. Although the addition of OXT did not affect the fresh or frozen-thawed sperm motility or acrosomal integrity, it significantly increased the number of sperm in the oviduct at 6 h after AI injection with OXT, as compared with the control (P < 0.05). Moreover, some sperm were observed in the sperm reservoir of the isthmus in the OXT treatment group, whereas few sperm were observed in the control. When OXT was added to the semen extender immediately prior to AI, the conception rates were significantly higher in both fresh semen and frozen-thawed semen than in the control group (P < 0.05: liquid, 87.5% vs. 70.5%; frozen-thawed, 89.8% vs. 75.0%). From these results, we concluded that the addition of OXT to the semen extender assisted in sperm transportation from the uterus to the oviduct, which resulted in improved reproductive performance.
