Study on the mechanism for diminishing fetal ovarian reserve mediated by maternal testosterone

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K18787
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Animal production science
• Research Institution: Hokkaido Research Organization
• Principal Investigator: Koyama Keisuke 地方独立行政法人北海道立総合研究機構, 農業研究本部酪農試験場, 研究主任 (50611026)
• Research Collaborator: Yanagawa Yojiro ; Hirayama Hiroki
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 血液生化学性状 / 飼養管理 / 乳牛 / 妊娠 / 繁殖性 / AFC / AMH

Outline of Final Research Achievements

It is desirable that dairy cows have high fertility. However, the cows with low ovarian reserve have low fertility. In the present study, we aimed to clarify the risk of declining fetal ovarian reserve via maternal testosterone under a general feeding system in domestic dairy cows.
In the present study, we demonstrated that the risk of declining fetal ovarian reserve under a general feeding system in domestic dairy cows is that the dam is a heifer and the maternal blood testosterone concentration is high at 4 and 5 months of gestation. Moreover, we also clarified that maternal testosterone concentration changes due to some changes in feeding management. However, the changes in feeding management did not affect the fetal ovarian reserve.

Free Research Field

獣医繁殖学

Academic Significance and Societal Importance of the Research Achievements

本研究により、国内における通常の乳牛飼養管理には、産子の卵巣予備能低下リスク、すなわち産子の繁殖性低下リスクが存在することが明らかとなった。これらのリスクに対応した方策を実施することで、繁殖性が低い乳牛が産まれるリスクを下げることが可能になると考えられる。また、テストステロン投与により、卵巣内卵胞動態に変化が及ぶことを示せており、同ホルモンの活用による新たな卵胞動員の技術開発への発展も期待できる。