Freezing of equine semen is influenced by exposure time and concentration of the cryoprotectant glycerol.

Abstract

BACKGROUND Glycerol is a cryoprotectant widely used in the freezing of mammalian semen, but no study has demonstrated its optimum concentration and the appropriate exposure time for equine species. OBJECTIVE To demonstrate that the exposure time (15, 30, 45, 60, 75 and 90 min) versus concentration (2, 3, 4 and 5%) of the cryoprotectant glycerol influences the freezing success of equine semen. MATERIALS AND METHODS The ejaculate of 12 stallions were frozen in different glycerol concentrations following different exposure times. The thawed sperm was evaluated for kinetic parameters using a Computer Assisted Semen Analysis (CASA) system and cell feature parameters were assessed by flow cytometry. RESULTS Considering the total and progressive motility of the spermatozoa, we concluded that protocols using 5% glycerol for 15 and 30 min exposure, 4% glycerol for 45 min exposure and 3% glycerol for 90 min exposure generated the best results. CONCLUSION We suggest the use of any of these protocols for a better cryopreservation of equine semen. Doi: 10.54680/fr23410110412.