Effect of glutamine addition to freezing extender on crypreserved semen parameters and subsequent fertility of Egyptian buffalo bull

Abstract

Objective: The aim of this study was to evaluate the effect of glutamine addition to the tris-extender on the quality of cryopreserved buffalo spermatozoa and subsequent fertility. Methodology: Semen ejaculates from six clinically normal and sexual mature Egyptian buffalo bulls were collected once weekly and pooled. Qualifying ejaculates were split into 6 aliquots for dilution (80×106 spermatozoa) with tris egg yolk extender containing 0, 20, 40, 60, 80 and 100 mM glutamine. The extended semen was packed into 0.25 mL French straws using a semen filling machine. Semen samples were cooled and equilibrated before cryopreservation. Results: The results showed that sperm progressive motility and viability of Egyptian buffalo bulls were significantly higher (p<0.05) in extenders containing 20, 40 and 60 mM glutamine than control and other glutamine extenders. The further increase in glutamine to 100 mM caused a significant reduction (p<0.05) in sperm progressive motility and viability. The addition of glutamine led to improve sperm abnormalities diluted in the all extenders tested. Addition of 20 or 40 mM glutamine significantly increased post-thawed acrosome and plasma membrane integrity. The highest fertility rate was recorded for spermatozoa diluted in extenders containing 20 mM glutamine (72.7%) followed by 40 mM (64.3%) and 60 mM glutamine (60%). Conclusion: It’s concluded that the addition of 20-60 mM glutamine to tris-based extender improved the post-thaw quality of buffalo bull spermatozoa and subsequent fertility.