Effect of cooling on sperm motility before and after frozen-thawed stallion semen

Abstract

The aim of this study was to assess the effect of cooling on sperm motility before and after frozenthawed stallion semen. Fifteen ejaculates of three stallions were collected with artificial vagina. The progressive motility was determined under microscope immediately after collection, cooling (5°C for 0, 2, 7 or 24 h) before frozen-thawed and cooling (5°C for 0, 2, 7 or 24 h) after the semen was frozenthawed. Sperm progressive motility (83.1, 78.7, 74.8 or 70.3%, respectively) was significantly different (P<0.05) at different hours of cooling before freezing. Similar pattern was found when semen was subjected to cooling, frozen-thawed and cooling time resulted in a progressive reduction in motility from 39.4 to 26.9%. The motility of semen subjected only to cooling for 24 h before freezing was optimal (70.0%) for artificial insemination. Moreover, semen subjected to cooling for 7 or 24 h before and after frozen-thawed could be used still with some considerations for artificial insemination.