Optimalization of the Swim-Up Method for Bali Bull Sperm: Effect of Incubation Time and Medium on Sperm Kinetics

Bali bulls (Bos javanicus) are an essential part of Indonesia’s indigenous livestock, prized for their ability to thrive in challenging environments, their natural disease resistance, and their strong reproductive capabilities. The aim of this study was to refine the swim-up technique for preparing Bali cattle sperm. We evaluated the effects of two commonly used media Tyrode's Albumin Lactate Pyruvate (TALP) and Brackett-Oliphant (BO) and various incubation times (30, 45, and 60 minutes) on sperm motility, progressive motility, and movement characteristics. Semen samples from Bali cattle were processed using the swim-up technique and then analyzed using a Computer-Assisted Sperm Analysis (CASA) system. The results were quite interesting: After 45 minutes of incubation, in both TALP and BO media, there was a significant increase in sperm motility and progressive motility. Unfortunately, after 60 minutes, these values actually decreased, likely due to oxidative stress and energy exhaustion of the sperm. Key movement parameters, such as Curvilinear Velocity (VCL) and average path velocity (VAP), also reached their peak values at 45 minutes. Equally important, both media TALP and BO, were shown to support sperm capacitation and viability. There were no significant differences between the two. Our findings highlight the importance of managing incubation time in the swim-up procedure. Forty-five minutes is the optimal duration for obtaining the highest quality sperm. This knowledge is invaluable, especially for assisted reproductive technologies such as ICSI. By following this optimized swim-up protocol, the chances of obtaining sperm with agile movement and superior kinematics are greater ultimately increasing the likelihood of successful fertilization. On a broader scale, this research not only supports the conservation of Bali cattle, but also contributes to maintaining their genetic diversity and supporting sustainable livestock farming practices in the tropics.