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Objective: To compare the effects of different diluents with levels of 13 and 7% glycerol on motility of buffalo spermatozoa (pre¬and post- freezing and thawing).
Samples: Comparative experimental study.
Animals: Twelve ejaculates of2 buffalo bulls (4.5 and 6 years old). Procedure: Semen samples with initially very good and excellent quality (motility 4 and 5) were selected and immediately evaluated for motility. Then, aliquots of each semen sample were subjected to dilution, cooling, equilibration, freezing and thawing as follow: Experiment 1. Phosphate and citrate extenders with 13 and 7% glycerol were used. Experiment 2. Glucose and cysteine were added in the same extenders and were compared to the effects of tris extender on motility of buffalo spermatozoa.
Statistical analysis: Descriptive statistics.
Results: The motility of spermatozoa maintained up to a limited time of storage in phosphate and citrate extenders with low level of glycerol and beyond of this storage time (after equilibration and thawing) the motile life of spermatozoa deteriorates quickly. Tris diluent proved to be superior in maintaining the motility of spermatozoa. Also, the sperm motility and recovery rate were higher in the semen extended in tris diluent with 13% glycerol as compared to those extended with 7% glycerol (70 and 87.5% versus 52 and 65%). Clinical implications: Based of our findings, we suggest the use of tris diluent with 13% glycerol for the cryopreservation of buffalo bull
spermatozoa. J. Fac. Vet. Med. Univ. Tehran. 58, 4:355-358, 2003