CRYOPRESERVATION OF SEMEN OF MITHUN AND SIRI BULLS

The objective of the study was to assess the semen characteristics of Jersey, Mithun and Siri breeds of bulls and to compare the suitability of Tris Eggyolk Citrate and commercial soya lecithin based BIOXcell extenders for cryopreservation of semen from the these breeds of bulls. The mean semen volume was 4.55 ± 1.57, 4.86±1.33 and 4.83±1.72 ml in Jersey, Mithun and Siri bulls, respectively. Mean mass activity of 3, mean initial motility of 78.0±4.22, 80±4.47 and 78.33±4.08%, mean sperm concentration of 1416±484.19, 1530.91±517.41, 1122.83±293.68 x10 6 and mean livability of 69.20±6.81, 70.45±8.42, 76.67±8.17 % was found in Jersey, Mithun and Siri bulls, respectively. There is no significant difference in all above mentioned variables among the breeds. The post-thaw motility of semen cryopreserved in Tris Eggyolk Citrate extender was found to be 45.50 ± 4.38, 46.82 ± 6.81 and 47.50 ± 8.22 % in Jersey, Mithun and Siri bulls, respectively. Whereas in BIOXcell extender, it was 45.50 ± 5.99, 46.36 ± 5.05 and 49.17 ± 5.85 % in Jersey, Mithun and Siri bulls, respectively. Similarly, the plasma membrane integrity of thawed spermatozoa in Tris eggyolk extender was 17.50±2.32, 21.00±3.12 and 21.58±3.83 % in Jersey, Mithun and Siri bulls, respectively. Whereas in BIOXcell extender, it was found to be 20.45±2.86, 20.86±2.281 and 22.33±3.24 % in Jersey, Mithun and Siri bulls, respectively. No significant difference (p>0.05) was observed in post-tha