Developing a predictive tool for reactive oxygen species damage during bovine sperm storage at ambient temperature

Preservation of sperm at ambient storage temperature (25°C) provides a simplified alternative for short-term storage applications. The goals of the study were (i) to improve the storage ability of bovine sperm in liquid suspension by scavenging the reactive oxygen species (ROS) with the help of antioxidants and chelators, (ii) to develop a predictive tool to determine sperm motility as a function of storage temperature. Two types of antioxidants (catalase and superoxide dismutase, SOD) and 2 chelators (Desferal and ethylenediaminetetraacetic acid, EDTA) were used. Different concentrations of the supplements were added in egg yolk Tris (EYT) extender and stored at 4°C, room temperature (25°C), and 37°C, respectively. Motility and membrane integrity (MI) were assessed on days 1, 4, 7, 10, and 14 for samples stored at 4°C and 25°C. Results did not suggest the beneficial effect of SOD and EDTA. Catalase caused a slight improvement in motility at 4°C storage and its effectiveness was found to increase at higher storage temperature. The presence of Desferal resulted in a much higher increase in motility and membrane integrity at both 4°C and 25°C. Similarly, the fitting of Arrhenius damage model to the motility data provided a useful tool to predict motility degradation time as a function of storage temperature.