11^th International Veterinary Congress

Biography

Biography: S D Ingole

Abstract

The production of Reactive Oxygen Species (ROS) during cryopreservation of semen alters the sperm motion and mobility characteristics, which results in poor or failure of conception rate after artificial insemination. Melatonin (MLT) being an antioxidant molecule is able to modulate the effect of ROS and prevents spermatozoa by reducing the oxidative stress during freezing process. Total of eight ejaculates were collected from eight healthy Holstein Friesian bulls and diluted with Tris egg yolk glycerol extender. Each ejaculates were divided into five equal aliquots as control - pre-freeze, control – post-thaw without addition of melatonin and other three aliquots with 0.1 mM, 0.2 mM and 0.25 mM melatonin. After 48 hours of cryopreservation, the post-thaw samples were analyzed for motility parameters by Computer-Assisted Sperm Analysis (CASA) and ultrastructure changes by means of transmission electron microscopy. The CASA results showed no significant difference between the control – post-thaw samples and melatonin treated samples, however, the velocity of spermatozoa with regard to the Straight Line Velocity (VSL), Average Path Velocity (VAP) showed highest increase in the 0.25 mM MLT treated semen followed by 0.1 mM MLT treated semen except for VCL where velocity increased with increase in the concentration of melatonin. The vigour of spermatozoa regard to Beat Cross Frequency (BCF), Straightness (STR), Linearity (LIN), recorded highest increase in the 0.25 mM MLT treated semen followed by 0.1 mM MLT treated semen except for the Lateral Head Displacement (ALH) where vigour increased with increase in the concentration of melatonin. The electron micrography images illustrated that the addition of 0.1 mM melatonin protected the plasma membrane and acrosome region and maintained the ultrastructure integrity of the cryopreserved spermatozoa when compared to control group, whereas the electron micrography of spermatozoa treated with 0.2 and 0.25 mM melatonin illustrated highest damage to the plasma and acrosome membrane. Thus concluding that inclusion of melatonin to sperm extender can improve the post-thaw quality of cryopreserved bull spermatozoa.