| Popis: |
As the number of wild Asian elephants (In total, 153 ejaculates were collected by manual rectal stimulation from 25 bulls. The volume, pH, sperm concentration, progressive motility, viability, morphology, and membrane integrity were investigated in each ejaculate. Assessment of accessory sex glands was conducted using transrectal ultrasonography to compare the relative seminal vesicle size and semen characteristics, and the bulls were divided into two groups according to the size of the ampulla (7 or ≥7 cmFrom 153 ejaculates, the mean±standard error values of progressive motility, semen volume, sperm concentration, pH, and viability were 40.18%±2.28%, 40.94±3.86 mL, 1,205.58±62.26×10The semen characteristics of Asian elephants can be used as the baseline reference for further applications. The ampullae size indicates semen quantity but not quality. Our success in producing an elephant calf from AI using frozen and chilled semen demonstrated that AI can be used as an alternative approach for the breeding management of Asian elephants. However, the semen of Asian elephants is of poor quality, especially in terms of membrane integrity; thus, the improvement in semen quality through intensive and careful management of elephant health and fertility remains a challenge for the future. Furthermore, a sperm bank should be established to develop sperm cryopreservation, which will be invaluable for improving the genetic diversity of the Asian elephant. |
