Successful pregnancy in estrus-synchronized Himalayan tahrs (<i>Hemitragus jemlahicus</i>) by transcervical insemination.

Abstract

<h4>Importance</h4>Assisted reproductive technologies have not been widely applied to Himalayan tahrs (<i>Hemitragus jemlahicus</i>), a Near Threatened species, despite increasing concerns over population management and conservation. Developing effective estrus synchronization and artificial insemination protocols is critical for their reproductive management.<h4>Objective</h4>To evaluate the effectiveness of transcervical insemination using extended-fresh (EF) and extended-chilled (EC) semen following estrus synchronization using controlled internal drug release (CIDR) and hormonal treatments in female Himalayan tahrs.<h4>Methods</h4>This study involved eight female Himalayan tahrs, which were divided into two treatment groups of 13-day and 15-day according to duration of CIDR insertion. Hormonal treatments including pregnant mare serum gonadotropin, human chorionic gonadotropin, and prostaglandin F2 alpha (PGF_2α) were administered. Semen was collected from two males by electroejaculation, extended, and used either fresh, frozen-thawed, or chilled. Transcervical insemination was performed at fixed times after CIDR removal, and pregnancy was diagnosed 64 days post-insemination using Doppler ultrasonography.<h4>Results</h4>Three of four females in the 13-day group and one of four in the 15-day group were confirmed pregnant. Vaginal and cervical changes were more favorable for insemination in the 13-day group. Hormonal data supported that a sharp drop in progesterone after CIDR removal was associated with successful conception.<h4>Conclusions and relevance</h4>Thirteen-day CIDR insertion combined with gonadotropins and PGF_2α is effective for estrus synchronization in Himalayan tahrs. Transcervical insemination using EF and EC semen resulted in successful pregnancy, offering a practical and reproducible protocol for <i>ex situ</i> conservation breeding in this species.