Effect of Temperature on the Survival of Bovine Spermatozoa Stored in Carbonated Diluents

Abstract

Summary Effects of different above-freezing storage temperatures, substrate-temperature interactions, and extreme temperature fluctuations on survival of bovine spermatozoa in carbonated diluents have been studied. In all cases, except when egg yolk was absent from the diluent, storage at 5 C was best for sperm survival and a progressive decrease in survival occurred as the temperature was increased to 15.5, 26.5, or 37 C. Little difference was noted between 5 and 15.5 C for the first ten days of storage; however, sperm lived better at 5 C during the next ten days. Interactions between egg yolk level, glucose concentration, and storage temperature were apparent. At 5 C the best survival was with 10 or 20% egg yolk in the diluent, with the higher percentage giving slightly better results. An egg yolk level of 40% gave better results than 0 or 5%, but poorer sperm survival than the 10 or 20% level. At 26.5 C the 40% level supported poorer survival than the others. Generally, as the glucose concentration was increased from zero to 0.067 and 0.133 m , better livability resulted, particularly at higher storage temperatures (26.5 and 37 C). Sperm survival at 37 C was best when egg yolk was absent from the diluent and the glucose was increased to 0.133 m . The carbonated Illini variable temperature diluent supported considerably better sperm survival than either an egg yolk-citrate diluent or a yolk-citrate milk diluent during temperature fluctuations between 0 and 26.5 C every 12 hr. Also, at 26.5 C, the IVT diluent supported considerably better livability than the EYC or YCM diluents.