Effect of equex STM paste on the quality and motility characteristics of post thawed cryopreserved goat semen

Abstract

The aim of this study was to evaluate the effect of Equex STM Paste on goat semen quality after cryopreservation. Semen samples were consecutively collected once a week, from six mature bucks. The semen samples with adequate motility (>60%) and sperm concentration (>1,500×106 sperm/ml) were frozen in an egg yolk-Tris semen extender supplemented either with (E+) or without (E-) Equex STM Paste. The semen quality including motility, viability, morphology, acrosome integrity and membrane functional integrity were evaluated before processing and after cryopreservation. Computer-assisted-semen analysis (CASA) was used to characterize the sperm motion patterns during the thermal resistance test at 0, 1, 2 and 3 hours post-thawing. After thawing, the sperm motility was higher in E+ group at 0 (p=0.0009), 1 (p>0.05) and 2 hours (p>0.05) compared to E- group. The positive effect of Equex was also observed in terms of viability (p=0.0002), normal tail (p<0.0001) and the percentage of acrosome-intact spermatozoa (p>0.05). While semen in E- group exhibited better plasma membrane integrity, higher number of normal sperm head, some of the motility characteristics seem better than that of E+ group but not significantly. In conclusion, the improvement of the quality of post thawed buck semen in extender supplemented with Equex STM Paste was noticeable only in the first two hour after thawing.