Long Term Effects of Immunization Against Inhibin on Fresh and Post-Thawed Semen Quality and Sperm Kinematics During Low and Peak Breeding Seasons in Beetal Bucks

The present study was aimed to determine the carry-over effects of immunization against inhibin alpha-subunit (AIINHA) on fresh and post-thawed sperm quality during peak breeding (PBS) and low breeding seasons (LBS). Six Beetal bucks (n = 6) were either immunized against inhibin (AIINHA; n = 3) or kept untreated (CON; n = 3). Initially, the AIINHA group was treated with primary dose of inhibin alpha-subunit (0.50 mg) at Day 0 and followed by a booster dose 28 days later. The semen collection and cryopreservation were started five weeks post-AIINHA treatment and continued for eight consecutive weeks during LBS (n = 16 replicates; 8 in CON and 8 in AII-NHA) and resumed in forthcoming eight weeks of PBS (n = 16 replicates; 8 in CON and 8 in AIINHA). Prior to cryopreservation, the fresh semen quality was assessed and afterwards, cryopreserved semen was evaluated for progressive motility, sperm kinetics, membrane, acrosomal and DNA integrities. The results indicated that AIINHA (P < 0.01) and season (P < 0.05) have significant effect on fresh semen quality parameters; moreover, there was a positive interaction (P < 0.01) between AIINHA and season for sperm concentration, plasma membrane, and acrosome integrities in fresh semen. Similarly, AIINHA significantly increased (P < 0.01) the post-thaw sperm parameters except acrosome and DNA integrity. A significant interaction of AIINHA and season was observed for total and progressive motility (P < 0.05), sperm kinetics (P < 0.05) and sperm morphology (P < 0.05) in post-thaw semen. Taken together, the current findings suggest that AIINHA enhances the fresh and post-thaw semen quality in Beetal goat bucks during LBS or PBS.