Evaluation of comparative efficacy of egg yolk and soya based extenders for refrigeration preservation (5°C) of buffalo semen

The aim of this study was to compare commercially available soybean based extenders, viz. Bioxcell (R) and Optixcell (R) (IMV, France) with standard Tris-citrate-fructose-egg yolk-glycerol (TFYG) extender for refrigeration preservation of buffalo semen. Forty eight good quality ejaculates (8/bull) having initial motility >70% obtained at weekly interval in AV from 6 mature Surti buffalo bulls were split-diluted (at 34 degrees C keeping 100x 106 sperm ml-1) in TFYG, Bioxcell and Optixcell extenders and stored in refrigerator at 5 degrees C for 72 hrs. The mean percentages of progressively motile spermatozoa observed on dilution (0-hr), and after 24, 48, 72 hrs of refrigeration preservation of semen at 5 degrees C were 78.54 +/- 0.30, 68.30 +/- 0.30, 59.38 +/- 0.35 and 51.63 +/- 0.47; live sperm 90.48 +/- 0.19, 76.89 +/- 0.51, 69.51 +/- 0.35 and 61.86 +/- 0.45; morphologically normal sperm 93.85 +/- 0.08, 90.70 +/- 0.11, 89.08 +/- 0.10 and 87.66 +/- 0.10; intact acrosome 94.40 +/- 0.12, 88.22 +/- 0.13, 84.60 +/- 0.14 and 81.70 +/- 0.17, and HOS reactive sperm 79.35 +/- 0.24, 65.99 +/- 0.31, 57.69 +/- 0.36 and 50.70 +/- 0.43, respectively, all of which decreased gradually and highly significantly (P<0.01) with increase in storage time. The results were significantly (P<0.05) superior with Optixcell followed by TFYG extender than with the Bioxcell. The overall mean percentages of sperms with abnormal head, mid-piece and tail and those with different forms of acrosomal defects like swollen, ruffled, detached and denuded acrosome also followed the pattern of morphologically normal sperm and intact acrosomes. The values of all these traits increased significantly (P<0.05) with increase in storage duration at 5 degrees C. The sperm protective ability of Optixcell extender was superior followed by TFYG and the least of Bioxcell. The Optixcell, a recently launched improved soybean milk based extender, excelled the Bioxcell extender and was statistically similar to TFYG in respect of all the sperm quality parameters to satisfactorily preserve the quality of buffalo semen at refrigeration temperature up to 3 days.