First dose optimization study on freezing Anatolian buffalo semen

Abstract

The main objective of sperm production centers is to produce as many straws as possible from the obtained ejaculates using the optimal dilution rate. To this end, this study is the first to evaluate the effect of different semen extender rates on Anatolian buffalo semen quality. Ejaculates were collected by artificial vagina from three Anatolian buffalo bulls (n=105). These ejaculates were divided into three aliquots and filled into 0.25 ml straws with soy-based extenders at the concentrations of 35, 25, and 15 million spermatozoa/straw. The straw samples of different spermatozoa concentrations were frozen. The quality of spermatozoa was evaluated after thawing (37 °C, 30 sec) and following the thermoresistance test (37 °C, 3 h). The post-thaw total motility and progressive motility values were similar between the groups. However, following the thermoresistance test, there was a significant decrease in total motility in the 35 million spermatozoa/straw group, and the progressive motility was significantly higher in the 25 million spermatozoa/straw group. There was no statistically significant difference between the groups in terms of sperm kinetic parameters, except VSL after thawing except the VAP and LIN values following the thermoresistance test. In conclusion, it is recommended to dilute the Anatolian buffalo semen at a concentration of 25 or 100 million spermatozoa/ml per straw when freezing it with a soy-based semen extender. In addition, it is considered that soy-based extenders compensate for cryo-damage to sperm motility for a short time, and the thermoresistance test should be applied for objective evaluation in dose optimization studies.