Effect of osmotic pressure on spermatozoa characteristics of cryopreserved buffalo bull (Bubalus bubalis) semen

Abstract

This study was designed to determine the effect of different osmotic pressures on spermatozoa characteristics of cryopreserved buffalo bull semen using tris egg yolk extender (TEYE). Semen of Nili-Ravi buffalo bulls (n = 4) housed at a semen production unit was collected at weekly intervals for 10 weeks. Three solutions of tris-citric acid-fructose with osmotic pressures of 255, 275 and 295 mOsm/kg were used in extender preparation. Semen straws containing 20 × 106 spermatozoa were processed and stored at −196°C in liquid nitrogen. Post-thaw analyses of spermatozoa included motility, viability, acrosomal integrity, plasma membrane integrity, DNA integrity and lipid per-oxidation. Significantly higher (P < .05) sperm motility, acrosomal and DNA integrity were recorded at osmotic pressures of 275 and 295 mOsm/kg compared to 255 mOsm/kg. However, differences in spermatozoa viability, plasma membrane integrity and lipid per-oxidation were non-significant among three osmotic pressures. It is concluded that osmotic pressure of the solution used in extender preparation plays an important role in post-thaw quality of cryopreserved buffalo bull semen.

Keywords

• Buffalo bull
• semen quality
• osmotic pressure
• cryopreservation