Development of a novel artificial insemination system with bovine sex-sorted semen using uterine immune reaction control technology

Research Project

Project/Area Number	16K18810
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Multi-year Fund
Research Field	Veterinary medical science
Research Institution	Fukuoka Agricultural and Forestry Research Center
Principal Investigator	YAMAGUCHI shoichiro 福岡県農林業総合試験場, 畜産部, 研究員 (30502520)
Project Period (FY)	2016-04-01 – 2019-03-31
Project Status	Completed (Fiscal Year 2018)
Budget Amount *help	¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000) Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000) Fiscal Year 2017: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000) Fiscal Year 2016: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Keywords	性選別精液 / 人工授精 / 牛 / カフェイン / 深部注入器 / 子宮内免疫反応制御 / 白血球 / 精子 / 牛性選別精液 / 子宮 / 多形核白血球 / 受胎率 / 押出し液 / 泌乳牛 / 子宮内白血球
Outline of Final Research Achievements	A lower number of encapsulated spermatozoa is obtained from bovine sex-sorted semen compared with normal semen; thus, it has a low conception rate in dairy cows. In this study, we examined whether the conception rate of bovine sex-sorted semen could be improved by increasing the number of uterine sperm and controlling the migration of polymorphonuclear leukocytes into the uterine lumen. The conception rate in a deep intrauterine artificial insemination system was suggested to be improved by coinjection of bovine sex-sorted semen and caffeine-supplemented diluent (usually air-infused), thereby inhibiting the migration of polymorphonuclear leukocytes into the uterine lumen and improving sperm viability.
Academic Significance and Societal Importance of the Research Achievements	本研究により、カフェイン添加押出し液を用いることによって牛性選別精液人工授精に起因する子宮内での白血球の増加が抑制され、精子生存性が高まることで受胎率が向上する可能性が示唆された。現在、性選別精液は経産牛で受胎率が低いため未経産牛での使用が推奨されている。しかし、酪農家からは能力が判明している経産牛での利用拡大が求められている。今後さらなる技術改良を行うことによって性選別精液利用拡大による酪農生産基盤拡大が期待される。