Evaluation of different levels of soybean lecithin as an alternative to egg yolk for cryopreservation of goat and ram spermatozoa [electronic resource].

Includes references.

The purpose of the present study was to investigate the effect of different concentrations of soybean lecithin (SL) in goat and ram semen extenders as a substitute for egg yolk. In this study, thirty-six ejaculates were collected from each breed (3 adult goat bucks and 3 adult rams) aged >2.5 years old. Ejaculates were collected during the breeding season by means of an artificial vagina. The semen ejaculates were divided into six equal aliquots and diluted (1semen:4 diluent) to form six different cryoprotectant media (M). The control medium (MO) contained 2.5% and 15% egg yolk for goat bucks and ram semen extenders, respectively. Treatment extender media were M1 contained 1.5% SL, M2 included 2.5% SL, M3 supplemented with 3.5% SL, M4 contained 4.5% SL and M5 contained 5.5% SL. The semen samples were packed in straws (0.50 mL) and equilibrated in refrigeration at 5°C for 3 hours. After the equilibration period straws were warmed and sperm characteristics such as progressive motility, viability and abnormal tails were assayed. For freezing technique, the straws were suspended on a racK 5 cm above the liquid nitrogen vapor for 15 min at -120 °C. Then, straws immersed and stored in liquid nitrogen (-196°C). After thawing at 37°C/60 seconds, post- thawing motility, intact plasma membrane, sperm head damage and abnormal tails were evaluated. Results indicated that soybean lecithin at a level of 3.5 % attained higher (P < 0.05) sperm parameters than other concentrations of soybean lecithin and egg yolk in goat and ram semen extenders after the equilibration period.

Summary in Arabic.

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