Soybean lecithin-based extender as an alternative for goat sperm cryopreservation

Abstract

The aim of this study was to evaluate the effect of different concentrations of soybean lecithin (SL) in extenders for sperm goat cryopreservation. Sexually mature male Saanen goats (n=4) were used, and the ejaculates were obtained using an artificial vagina method. The semen samples were pooled and diluted in a skim milk-based extender (control group; CG) or Tris extender supplemented with SL at different concentrations (G1=0.04%, SL G2=0.08% SL and G3=0.16%) for a final concentration of 240×106spermatozoa/mL. The semen samples were packed in straws (0.25mL), frozen using an automated system and stored in liquid nitrogen (−196°C). After thawing (37°C/30s), the samples were evaluated for sperm quality parameters, including sperm motility, membrane integrity, acrosome integrity and mitochondrial activity. No significant difference was observed among the experimental and control groups for all of the parameters (P>0.05). However, even though the control group presented a significantly lower mitochondrial membrane potential compared to fresh semen (P<0.05), the same did not occur for the extender supplemented with soybean lecithin, that is, it did not differ from fresh sperm (P>0.05). The extender containing soybean lecithin at different concentrations preserved the sperm quality parameters in a manner similar to the conventional skim milk-based extender. Thus, it is concluded that an extender containing soybean lecithin as the lipoprotein source can be used for freezing goat semen.