Correlation between sperm motility and hypoosmotic swelling test on cryopreserved goat semen

Abstract: The hypoosmotic swelling test (HOST) has been proved to be a good tool for evaluating the membrane integrity of spermatozoa of various domestic animals including goats, cattle, horses, and swine. The aim of this study was to evaluate the correlation between HOST and sperm motility on cryopreserved goat semen. Two adult Parda Alpina breed males were used, totalizing 8 semen collections for each one. Semen was diluted and packaged into 0.25 mL straws. Semen was cooled to 5 °C for 1 hour and pre-freezing was performed in liquid nitrogen vapor for 15 minutes. After this period, the straws were immersed in liquid nitrogen. Samples were thawed in water bath at 37 °C for 30 seconds; then, sperm motility assessment, hypoosmotic swelling test (HOST) and thermoresistance test were performed. Sperm motility and HOST showed high correlation ( r = 0.62; P < 0.0001) fitted to a mathematical formula (Sperm Motility = 6.43995 + 1.11884 HOST) by a regression analysis. In conclusion, HOST proved to be a good complementary test to support the analysis of goat sperm motility; however, it should not be used as a unique test for sperm quality assessment. Keywords: Caprine, Cryopreservation, Statistical assessment