Sperm concentration influences the post-thaw livability of frozen goat semen

Abstract

In this study, goat semen was cryopreserved in a reduced concentration of 75×10 6 , 50×10 6 and 25×10 6 sperm/ml and evaluated based on post-thaw motility and livability. The ejaculated semen samples were collected using an artificial vagina, extended with an egg yolk Tris extender, cryopreserved in straws using glycerol (7%) and egg yolk (5%) as permeating and non-permeating cryoprotectants in LN2. Post-thaw semen evaluation showed motility scores of 36.6±2.13%, 35.4±2.04%, 27.0±3.0% and 19.2±2.78% for the control, T-A (75×10 6 ), T-B (50×106) and T-C ( 25×10 6 ), respectively. The mean post-thaw percentage livability obtained in the control (60.6±4.39) was higher than T-A (42.86±1.83), T-B (39.36±2.86) and T-C (19.2±5.27). The percentage abnormal sperm in all treatment groups were less than 10%, indicating that the method used for freezing of goat semen in reduced concentration could be useful in artificial insemination and in vitro fertilization studies. The reduced sperm motility and livability after thawing merits further studies on the factors influencing the survivability of sperm during cryopreservation in creating a standardized and better freezing protocol for goat semen.