A Novel Recombinant Eel Pout (Macrozoarces americans) Type III Antifreeze Protein Improves Cryosurvival of Buffalo Sperm.

BACKGROUND The quality of cryopreserved buffalo semen is low due to high susceptibility of sperm membranes to cold shock. OBJECTIVE The present study was designed to investigate the effect of recombinant type-III antifreeze protein from the eel pout Macrozoarces americanus (rAFPIII) on freezability of buffalo semen. MATERIALS AND METHODS Semen was collected from three buffalo bulls for three weeks (replicates). Qualified ejaculates (N=18) were split into four aliquots and diluted in Tris-citric acid extender containing 0.0, 0.1, 1 and 10 µg mL-1 of rAFPIII. Semen was cooled to 4 C, evaluated for sperm motility and PMI, cryopreserved and assessed for post-thaw quality. RESULTS Supplementation of the extender with rAFPIII didn't affect motility and PMI of chilled semen. Post-thaw sperm motility and PMI were higher in extender supplemented with rAFPIII (10µg mL-1) compared to control. Sperm viability and acrosome integrity remained the same. CONCLUSION Addition of rAFPIII in extender improved motility and PMI of cryopreserved buffalo semen.