In vitro and in vivo comparison of egg yolk-based and soybean lecithin-based extenders for cryopreservation of bovine semen.
Semen diluents containing egg yolk as a cryoprotectant may pose hygienic risks and are difficult to standardize. Although a new generation of semen diluents free of animal ingredients is available, egg yolk-containing extenders are still widely used for cryopreserving semen. We compared the effects of using different extenders on bovine sperm function in vitro and on fertility in vivo. A soy lecithin extender (SL; AndroMed) and an egg yolk-containing (TRIS-EY) extender were tested. No differences (P>0.05) were detected between the two extenders for sperm-zona pellucida binding capacity (HZI=115+/-13). Assessment of the inducibility of the acrosome reaction with progesterone showed no differences (P>0.05) between extenders for live acrosome-reacted sperm (15+/-2.36 and 14.42+/-2.02%, respectively, for SL and TRIS-EY). However, post-thaw sperm motility was significantly lower (P<0.05) when semen was extended in the TRIS-EY diluent. Field trials revealed that nonreturn rates of SL-extended semen showed significantly higher insemination success (P<0.0001) compared with the nonreturn rates for the TRIS-EY extender (70.45 and 67.85%, respectively). We suggest that consistent with quality standards that should be required for cryoprotectant media and because of the superior quality of the egg yolk-free extender, a defined soybean lecithin-containing diluter might be the better choice as a semen extender in the future.
Center of Dermatology and Andrology, Justus-Liebig-University, Gaffkystrasse 14, Giessen 35385, Germany.
Viviana A
VA
Aires
Klaus Dieter
KD
Hinsch
Frank
F
Mueller-Schloesser
Katja
K
Bogner
Susanne
S
Mueller-Schloesser
Elvira
E
Hinsch
D000177:Acrosome / Q000502:physiology; D000818:Animals; D002417:Cattle; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D004530:Egg Yolk; D008297:Male; D010713:Phosphatidylcholines; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D013025:Glycine max / Q000737:chemistry*; D013075:Sperm Capacitation; D013081:Sperm Motility
D010713:Phosphatidylcholines