In vitro Assessment of Tris Egg Yolk and Soybean Lecithin Based Extenders for Cryopreservation of Crossbred Ram Semen.

BACKGROUND: The replacement of egg yolk with alternative plant-derived soybean lecithin is gaining interest in both animal and human sperm cryopreservation owing to biosecurity issues with egg yolk based extenders. OBJECTIVE: To evaluate the comparative effect of egg yolk and soyabean lecithin based extenders on the quality of cryopreserved crossbred ram semen. METHODS: Pooled ejaculates (total ejaculates = 36) were divided into two aliquots and extended with Tris egg yolk extender (Tris extender) and soybean lecithin based commercial extender (Ovixcell) RESULTS: Among the two extenders, Ovixcell showed better sperm quality both at the pre-freeze (Sperm motility) and post-thaw stages. Lower malondialdehyde (MDA) level (nmol/mL) was observed in Ovixcell as compared to Tris extender. Both sperm quality and MDA level decreased significantly (P < 0.05) from pre-freeze to post-thaw in both the extenders. CONCLUSION: The findings of the present study indicate that Ovixcell is a comparable alternative to Tris extender for the cryopreservation of crossbred ram semen.

In vitro assessment of egg yolk-, soya bean lecithin- and liposome-based extenders for cryopreservation of dairy bull semen.

The study was conducted to compare the effect of four commercially available extenders (Triladyl®- egg yolk-based; Andromed® and Bioxcell®-plant based and Optixcell®-liposome-based) on post-thaw sperm quality and functionality variables evaluated using computer-assisted sperm analysis and flow cytometry. A total of 30 ejaculates from five bulls were analysed. With use of Triladyl®, sperm had a greater post-thaw total motility than with use of Bioxell® and Optixcell® but there was no difference as compared with use of Andromed® with the greatest (P < 0.05) percentage of progressively motile cells. With use of Optixcell®, there was a greater (P < 0.05) percentage of sperm with an intact membrane than with use of Triladyl® and Bioxcell®, but values were similar with use of Andromed®. Acrosome damage in semen preserved with use of Optixcell® was less than with use of Bioxcell® and Andromed®. With use of Optixcell®, there was a greater percentage of viable spermatozoa with a lesser lipid disruption (P < 0.05) when compared with the other extenders. Production of peroxides was greater for sperm cryopreserved with use of Triladyl® and Optixcell® while less superoxide was produced in the samples cryopreserved with the egg yolk-based extender. Optixcell® appears to be a promising alternative to replace traditional egg yolk extenders. With use of Optixcell®, however, there were greater peroxide concentrations after thawing. With use of Andromed®, there were similar results as with use of Optixcell®, therefore, it could be an effective substitute for egg-yolk based media due to the greater proportion of highly and progressively motile spermatozoa at thawing.

In vitro assessment of soybean lecithin and egg yolk based diluents for cryopreservation of goat semen.

Soybean lecithin is a suitable plant-based cryoprotectant for freezing ruminant sperm. Optimum level of lecithin was not clear for goat semen cryopreservation. The objective of this study was to investigate the effects of different levels of soybean lecithin in semen extender on post-thaw sperm quality including CASA-motion parameters, viability, plasma membrane integrity and lipid peroxidation. Semen samples were collected from 4 Mahabadi bucks using an artificial vagina. Different concentrations of soy lecithin (SL, 0.5%, 1%, 1.5%, 2% and 2.5% w/v) were compared to 15% (v/v) egg yolk-based extender (TR-EY). No significant difference was observed for sperm progressive motility, viability or plasma membrane integrity in 1.5% SL media (33.8%, 66%, and 62.7%, respectively) and TR-EY medium (35.4%, 67.2%, and 64.9%, respectively). Sperm motion characteristics (VAP, VSL, VCL, ALH and LIN) and rapid spermatozoa were improved with extender containing 1% and 1.5% SL, compared to TR-EY extender. Furthermore, egg yolk produced significantly higher malondialdehyde (4.02±0.21) than other groups. Results suggest that the optimal lecithin concentration in the semen extender was 1.5% and also soy lecithin can substitute for egg yolk during cryopreservation for caprine sperm.