DEVELOPMENT OF PHOTOBIOMODULATION SYSTEM FOR ASSESSING BULL SPERM QUALITY
Loading...
Date
2022
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ICAR-NDRI, KARNAL
Abstract
The goal of the current study was to determine the impact of various light spectra with different timings of exposure over the critical characters of sperm. An in-housing light chamber was constructed from the modifications of a spectrophotometer. This apparatus uses a halogen LED to produce non-chromatic light, which is then transformed into a monochromatic light by the filter. Light from the 400-700nm wavelength range was used in the pilot study with a time range of 1-4 min. 28 combinations of wavelength and time were used to evaluate the sperm motility immediately and two hours after the exposure. Six ejaculates were used in the PBS diluent in the pilot trial and kept at 37 °C. Among the 28 combinations, we selected the top 5 combinations based on motility for the objective-I, which were 600 nm for 2 min (T1), 600 nm for 3 min (T2), 650 nm for 2 min (T3), 650 nm for 3 min (T4), and 700 nm for 3 min (T5). In objective 1, extended ejaculates were split into 6 aliquots and exposed to all different treatments, with one split kept as a control. Motility, viability, HOST and acrosome integrity were basic semen parameters that were measured with time gaps ranging from 30 minutes and analysed up to 2 hours. It was found that motility was significantly higher (p<0.05) in all treatment groups after light exposure. The T1 and T4 groups had significantly higher (p<0.05) than control 60 min after light exposure, although no significant difference was found in the motility of all groups after 60 min. Viability was found to be non-significant between groups, although the T4 group exhibited greater values. There were no appreciable variations in the acrosome and membrane integrity between the control group and the other groups. Based on the values observed, T1 and T4 were selected for further experiments in Objective II. In objective-II, T1 (600 nm for 2 min) and T2 (650 nm for 3 min) were used for exposing semen. Under this objective, semen was evaluated at different cryopreservation stages: post-dilution, pre-freeze, and post-thaw. Progressive motility was significantly higher (p<0.05) in both treatment groups at all stages. CFDA-PI analysis revealed that the post-thaw viability of sperm in the T1 and T2 groups were significantly higher (p<0.05) than that of the control group. At the post-thaw stage, membrane intact spermatozoa were discovered to be significantly higher (p<0.05) in T1 and T2. The average percentage of intact acrosome sperm at the pre-freeze and post-thaw stages was higher in both treatment groups. The proportion of spermatozoa with higher MMP was significantly elevated (p<0.05) in T1 and T2 compared to control. In contrast, cryocapacitation and lipid peroxidation of spermatozoa were substantially reduced (p<0.05) in T1, compared to control group. In summary, polarised light selected wavelength and time exposure can improve seminal characteristics by reducing lipid peroxidation and enhancing the mitochondrial respiratory chain activity.