Pangawkar, G. R.Kumar, Naresh2018-11-282018-11-281996http://krishikosh.egranth.ac.in/handle/1/5810084603The effect of incorporating chloroquine diphosphate(10-5M) and nystatin levels as 5, 20, 30 and 40 ug/ml separately and together to Tris-yolk glycerol extender was studied in relation to presence of fungi during cryopresevation of buffalo bull semen. Twelve ejaculates, from each of the five bulls were processed and preserved in Tris-yolk glycerol and modified extenders. Sperm motility, live sperm per cent, sperm morphology and isolation, identification, quantitation and toxigenic screening of fungi were studied in neat, post -equilibrated and post -freeze thaw semen. Microbial assay of nystatin was done in preserved semen so as to assess the optimal level of drug to be added to semen for effective quality control without altering sperm morphology. Sperm motility and live sperm count were higher in extenders having nystatin 30 ug/ml. Sperm head abnormalities were significantly lower in post -equilibrated and post freeze thaw semen having 30 ug/ml of nystatin,while sperm tail and acrosomal abnormalities were significantly low at this level of nystatin in post -freeze thaw semen. ALT and LDH enzymes release were significantly higher in post -freeze thaw semen. No fungal growth was observed in the extended semen containing 30 and 40 ug/ml of nystatin. Few toxigenic strains of Aspergillus and Penicillium were isolated from preserved semen. The presence of fungus was observed to be significantly negatively correlated with sperm motility and live sperm count in fresh and preserved semen while it was significantly positively correlated with AST and ALT enzymes and acrosomal abnormalities at post -freeze thaw stage. Chloroquine diphosphate was observed to exert its membrane stabilizing effect on spermatozoa better when extenders used were having 30 ug/ml of nystatin.EnglishThesis