Comprehensive effects of fetal calf serum in soybean-lecithin based goat semen cryopreservation extenders and impacts on incubation resilience

Abstract

The aim of this study was to investigate the effects of various fetal calf serum (FCS) doses on %1 soybean lecithin-based semen extenders for goat semen cryopreservation and the impacts on spermatological parameters over post-thaw and post-incubation (6 h) time periods. Sperm samples collected via electro-ejaculation method were pooled to overcome the individual differences and were used in the study. The samples then were split into four equal aliquots to create study groups as; 0.25%, 0.50%, 0.75% FCS supplemented and a sample of FCS-free control group. Each sample group was diluted to approximately 150 x 106 spermatozoon/mL final concentration and two step dilution method was used for cryopreservation. Study groups were examined for sperm motility, plasma membrane functional integrity with hypoosmotic swelling test (HOST), acrosome integrity by FITC-Pisum sativum agglutinin (PSA-FITC) and DNA damage by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay (TUNEL). All samples were incubated for further 6 h in a humidified air chamber with 5% CO2 at 39 degrees C. The results indicated that FCS supplementation in soybean lecithin-based extenders for goat sperm cryopreservation had significant effects on post-thawing time point motility (P < 0.05), plasma membrane integrity (P < 0.05) and acrosomal integrity (P < 0.05) parameters. Subsequently to 6 h of incubation period, DNA integrity results yielded better scores comparing to control group in addition with other spermatological parameters (P < 0.05).