Effect of pawpaw juice extract on the microscopic parameters of buck epididymal semen

Abstract

Antioxidants are key to sperm viability due to their protective effects against formation the formation of free oxygen radicals and cell damage of spermatozoa during preservation. In order to improve the life span of refrigerated buck semen, this study was carried out to determine the effect of pawpaw juice extract on spermatozoa viability of semen since it is rich in antioxidants. Pooled semen from three indigenous (Mubende) bucks, abuck per week diluted with Tris-egg yolk-based extender and supplemented with pawpaw fruit juice extract at different concentrations of 0, 2, 5 and 7/100ml respectively. Following dilution, the semen samples were assessed subjectively after invitro storage at 5°C for 0, 24, 48 and 72 hours as regard sperm motility, abnormality and integrity using a phase-contrast microscope. The results showed highest level of sperm abnormalities in extended semen supplemented with pawpaw juice extract 7/100ml in all time intervals and lowest levels of sperm abnormalities in extended semen supplemented with pawpaw juice extract at 5/100ml at 0hours but higher than the control. This indicated a protective measure in pawpaw juice extract at 5/100ml. The results also showed highest levels of sperm motility in control compared to other samples with time. However better progressive motility was recorded in extended semen supplemented with pawpaw juice extract at 2/100ml compared to all pawpaw juice extract extenders. It is also important to note a sharp decrease in progressive motility in extended semen supplemented with 5/100ml with time when compared with the rest of the samples. The results showed almost a similar level of acrosome integrity in all categories of the semen extenders with time. Highest levels of acrosome integrity were observed in the control sample at 0 hours and the least levels of acrosome integrity was observed in extended semen supplemented with pawpaw juice extract at 7/100ml. The findings revealed that the antioxidants in pawpaw fruit have less protective ability to maintain sperm viability during storage of sperms at low temperatures.