Effectiveness of strain in maintaining long-term genetic diversity of Tajima cattle

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K08045
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Animal production science
• Research Institution: Kobe University
• Principal Investigator: Oyama Kenji 神戸大学, 農学研究科, 教授 (70322203)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 黒毛和種 / 遺伝的多様性 / 系統分類

Outline of Final Research Achievements

Genetic diversity of Japanese Black cattle is rapidly decreasing in exchange for significant genetic improvement. In this study, we investigated the long-term effectiveness of the systematic strain classification actually adopted in Tajima cattle that does not allow gene introduction from the outside. Computer simulations of Tajima cattle up to 15 generations ahead (approximately 150 years ahead) showed that continued within-strain mating promoted gene homogenization and reduced genetic diversity attributed to within-strain, but it became clear that the genetic diversity among strains can be maintained greatly.

Free Research Field

家畜育種学

Academic Significance and Societal Importance of the Research Achievements

系統分類の継続による遺伝的多様性の推移、とくに実在の集団を材料としてコンピュータシミュレーションした報告は皆無である。また、短期的にはその有効性が確認されていたものの、本研究では但馬牛に採用されている系統分類手法の長期的な有効性が確認され、現実集団における本手法の適用の正当性を示すこととなる。ただし、設定した5つの系統のうち、15世代先までの維持が難しい系統も明らかとなり、系統の特徴を強めてゆく新たな方策が求められる。