OPTIXcell improves the postthaw quality and fertility of buffalo bull sperm.

The present study was conducted to compare the liposome-containing, animal protein-free, commercially available OPTIXcell extender with the Tris-citric-egg yolk extender for postthaw quality and fertility of buffalo semen. Semen was collected from five adult Nili-Ravi buffalo (Bubalus bubalis) bulls of similar age group with an artificial vagina (at 42 °C) for 3 weeks (replicates). Semen ejaculates from each buffalo bull were divided into two aliquots and diluted (at 37 °C having 50 × 10(6) spermatozoa/mL) in the OPTIXcell or Tris-citric-egg yolk (control) extender. Diluted semen was cooled to 4 °C in 2 hours, equilibrated for 4 hours, and filled in 0.5-mL straws. The semen straws were kept over liquid nitrogen vapors (5 cm) for 10 minutes. The straws were then plunged and stored in liquid nitrogen (-196 °C). After 24 hours of storage, the semen straws were thawed at 37 °C for 30 seconds to assess postthaw quality. Percentages of sperm motility, plasma membrane integrity, viability, and acrosomal integrity were improved (P < 0.05) in the OPTIXcell extender compared to the Tris-citric-egg yolk extender. Values for DNA integrity (%) did not differ in the OPTIXcell and Tris-citric-egg yolk extenders. The overall conception rate in buffaloes was improved (P < 0.05) with semen cryopreserved in the OPTIXcell extender (59.5%) compared to semen cryopreserved in the Tris-citric-egg yolk extender (41.5%). It is concluded that the liposome-containing commercially available OPTIXcell extender is more efficient to conserve postthaw quality and resulted in higher fertility rate of buffalo in the field.