Instant extender for buck semen (Inexb): Impact on semen quality and fertility

Abstract

The preservation of buck semen plays a crucial role in enhancing reproductive biotechnology in small ruminants. This study evaluated the effectiveness of the Instant Extender for Buck Semen (Inexb) supplemented with different concentrations of organic α-tocopherol on semen quality and in vivo fertility. A completely randomized design with ten replications was applied, consisting of four treatments: Tris egg yolk without α-tocopherol (TFF0) and Tris egg yolk supplemented with 5% (TFF5), 7% (TFF7), and 9% (TFF9) α-tocopherol (v/v). Fresh semen was diluted to a final concentration of 150 × 10⁶ spermatozoa/mL and stored at 5°C for 120 hours. Semen quality parameters, including total motility, progressive motility, plasma membrane integrity, and viability, were evaluated at 24-hour intervals. Data were analyzed using ANOVA followed by Duncan’s multiple range test. Results demonstrated that TFF5 and TFF7 maintained significantly higher total motility (44.0 ± 2.2% and 47.2 ± 2.0%) compared with TFF0 and TFF9 after 120 hours (P < 0.05). Similar trends were observed in progressive motility, plasma membrane integrity, and viability, indicating that α-tocopherol at moderate concentrations effectively reduced oxidative damage during liquid storage. In vivo fertility trials revealed that semen extended with TFF7 achieved the highest pregnancy rate (33%) after 120 hours of storage at 5°C. These findings indicate that the inclusion of 5–7% α-tocopherol in Inexb provides optimal antioxidant protection, preserves sperm functionality, and sustains fertility during extended storage. Further optimization of extender formulation is recommended to enhance reproductive efficiency and facilitate wider application in goat artificial insemination programs.