Efficacy of egg yolk based and egg yolk free soya bean milk based extenders for cryopreservation of Zebu cattle and buffalo semen

This study was undertaken on three mature bulls each of Gir cattle and Surti buffalo breeds to evaluate the comparative efficacy of egg yolk based standard TFYG (Tris-citrate-fructose-yolk-glycerol) extender and egg yolk free soybean based commercial extenders Optixcell (R) (IMV, France) and Andromed (R) (Minitube, Germany) under split-sample technique. The ejaculates (9/bull) were extended @ 100 x10(6) sperm ml(-1) with three extenders and frozen using biofreezer following 4 hr of equilibration. The pooled means of progressively motile sperm observed (irrespective of extenders) at initial, pre-freeze and post-thaw stage in Gir bulls semen were 76.53 +/- 0.53, 71.11 +/- 0.53 and 39.86 +/- 0.90% and in Surti buffalo 80.76 +/- 0.39, 74.65 +/- 0.45 and 40.35 +/- 1.07%, respectively. The corresponding values for live sperm were 75.64 +/- 0.76, 69.01 +/- 0.97 and 47. 99 +/- 1. 11 % for Gir and 80.90 +/- 0.45, 75.76 +/- 0.48 and 52.33 +/- 0.86 % for Surti buffalo; and those of intact acrosome 94.29 +/- 0.25, 90.29 +/- 0.27 and 79.29 +/- 0.33 % for Gir bulls, and 93.94 +/- 0.21, 89.94 +/- 0.23 and 78.95 +/- 0.26 % for Surti buffalo semen, respectively. The HOS reactive sperm at initial, pre-freeze and post-thaw stage were 76.18 +/- 0.74, 71.04 +/- 0.76 and 27.90 +/- 0.70 % for Gir, and 81.83 +/- 0.35, 76.47 +/- 0.39 and 27.83 +/- 0.68 % for Surti bulls, respectively. The overall mean postthaw incubation (37 degrees C) survival of spermatozoa observed at 60, 120 and 180 min were 28.40 +/- 0.91, 17.78 +/- 0.86 and 9.44 +/- 0.72% for Gir bulls semen, and 28.01 +/- 0.99, 18.40 +/- 1.01 and 10.51 +/- 0.93% for Surti buffalo semen, respectively. Optixcell was proved superior, and at par with TFYQ than the Andromed in maintaining greater motility, viability, morphology, acrosomal/plasma membrane integrity including post-thaw sperm longevity of cattle and buffalo spermatozoa with significant differences only in sperm motility and post-thaw longevity. The motile, live and HOST reactive sperm were significantly higher in buffalo semen than cattle at initial and pre-freeze stage, but not at post-thaw stage. The results showed that egg yolk free commercial Optixcell extender and egg yolk based TFYG extender were at par in terms of most of the sperm quality traits, hence any one of them can be preferred over Andromed for successful routine cryopreservation of cattle and buffalo semen.