Soybean lecithin–based extender improves Damascus goat sperm cryopreservation and fertilizing potential following artificial insemination

Abstract

Objective: To study the effect of adding different concentrations of soybean lecithin in Tris based extender and to compare the results of Tris soybean lecithin extender with two commercial diluents (egg yolk-based: BullXcell and plant-based: OptiXcell) for Damascus goat sperm cryopreservation. Methods: The ejaculates from 4 mature male Damascus goats were obtained by using an artificial vagina. Semen samples were pooled and diluted in Tris extender supplemented with soybean lecithin at different concentrations of 1.5%, 3.0%, 6.0% and 10.0% to get better concentration to be used for further experiments, with a final concentration of 240x106 spermatozoa/mL. Semen samples were packed in straws (0.25 mL), frozen by using an automated system and stored in liquid nitrogen at -196 °C for 48 h. After thawing (37 °C/30 s), the samples were evaluated for sperm quality parameters, including sperm motility, membrane integrity and acrosome integrity. Malondialdehyde concentration was estimated as a marker for lipid peroxidation. Based on the previous investigations, only Tris extender supplemented with 3.0% soybean lecithin (based on its positive results) was used versus BullXcell and OptiXcell for sperm ultrastructure evaluation and artificial insemination by using electron microscope and artificial insemination of the synchronized does. Results: There was no significant difference between Tris-soybean lecithin at 3.0% and BullXcell/OptiXcell diluents in post-thaw sperm parameters and fertility following artificial insemination; meanwhile, the other concentrations of soybean lecithin (1.5%, 6.0% and 10%) showed lower sperm parameters following cryopreservation. Conclusions: Using of Tris-soybean lecithin based extender at the level of 3.0% can be an appropriate alternative to either BullXcell or OptiXcell for Damascus goat sperm cryopreservation.