Cryopreservation of Ram Cauda Epididymal Spermatozoa Using Different Buffers and Sugar Combinations

The aim of this experiment was to study the effect of different sugars and buffers combinations in the extenders viz. Tris citric acid fructose (TCF), Tris citric acid glucose (TCG), Sodium citrate fructose (SCF) and Sodium citrate glucose (SCG) on the quality of Cauda epididymal spermatozoa of ram during cryopreservation and post thaw. Spermatozoa were recovered from Cauda epididymidis by incision method. Samples showing ≥70% progressive sperm motility were pooled. Each pooled cauda epididymal sperm sample was divided into four aliquots and spermatozoa in each aliquot were washed using isotonic buffer by double centrifugation. Washed spermatozoa in each aliquot were extended separately in the four different extenders using 20% egg yolk and 8% glycerol as cryoprotectant. The quality of spermatozoa was evaluated immediately after extension in the particular extenders (pre-freeze) and at post thaw. The percent sperm motility was significantly (p<0.05) higher for TCF (45.00±4.47) than TCG (27.50±6.55) and SCG (20.83±5.39) extenders at post thaw. The percentage of HOST reacted spermatozoa was significantly higher (P<0.05) for TCF (61.05±2.60) than SCF (45.81±4.90) and SCG (46.41±4.16) at post thaw. The percent intact acrosome was also significantly higher (P<0.05) in TCF (79.39±2.16), SCF (80.74±1.38) and SCG (78.34±2.94) than TCG (71.32±2.47) at post thaw. In conclusion, the use of fructose as energy source in the Tris extender (TCF) was found the best combination of buffer and sugar for maintaining higher sperm quality during cryopreservation of ram caudaepididymal spermatozoa.