Preservation of Black Bengal buck semen in soybean lecithin based chemically defined extender

This experiment was conducted with the aim to study the effect of replacing egg yolk with soybean lecithin (SL) for cryopreservation of Black Bengal buck semen. Sexually matured Black Bengal buck (n = 5) were used and the ejaculates were obtained using an artificial vagina method. The semen samples were pooled and diluted in Tris extender with 5% Glycerol containing either 15% egg yolk (control group) or SL at different concentrations (1% SL, 1.5% SL and 2% SL). The semen samples were filled in straws and cooled gradually to 5 degrees C. Semen straws were equilibrated for 3 hours at 5 degrees C and were frozen in static liquid nitrogen vapor and stored in liquid nitrogen. Semen samples were evaluated after initial dilution, after completion of equilibration and after freeze thawing for in vitro sperm characters such as sperm motility, functional membrane integrity and malondioldehyde (MDA) concentration. Semen samples preserved in extender containing 1% SL was able to maintain in vitro sperm characters similar to the extender containing egg yolk. However, significant (P<0.05) reduction in all semen parameters was observed as the concentration of soybean lecithin increased above 1% level. It is concluded that an extender containing soybean lecithin @ 1% with 5% Glycerol can be used for replacing egg yolk for cryopreservation of Black Bengal buck semen.