Dutt, Raviyadav, Usha2023-06-302023-06-302024-05https://krishikosh.egranth.ac.in/handle/1/5810197863The aim of the present study was to evaluate the bacterial load and semen quality of buffalo bull semen in fresh and cryopreserved semen samples by using extenders supplemented with antibiotics, without antibiotics and substitutes of antibiotics. For this study, ejaculates were collected from sixteen Murrah bulls and two experiments were performed. The second experiment was further divided into two independent experiments (1) and (2) respectively. For the estimation of microbial load 80 ejaculates were collected through AV method for experiment 1 and semen quality was assessed in 16 samples, whereas 5 and 16 ejaculates respectively for experiment (1) and (2) for estimation of microbial load and semen quality. For experiment 1, each ejaculate was divided into two aliquots: 1) control (NAB), 2) extender supplemented with antibiotics (AB). For experiment (1) of second experiment, semen samples were diluted in extenders supplemented with KA (0.02, 0.04, 0.06, 0.08 and 0.1g/L), AB and control (NAB), for experiment (2), extenders supplemented with epsilon polylysine (0.64 and 1.28g/L), AB and control (NAB) and cryopreserved. After post-thaw, the following parameters were studied; thermal resistance of sperm by incubation test, sperm motility and kinetics by (CASA), acrosome integrity, mitochondrial membrane potential (MMP) and mitochondrial superoxide levels through flow cytometry. The results of the present study showing a non-significant difference in bacterial load (CFU/mL) and a non-significant effect on sperm motility and kinetic parameters, plasma membrane integrity, HMMP and increased superoxide levels in AB and NAB groups. There was no significant difference in endotoxin levels estimated by kit in both the groups. The results of different treatment groups of Kojic Acid in comparision to AB and NAB showed non significant difference in bacterial load and sperm quality parameters. The results of different treatment groups of epsilon-polylysin showed non-significant decrease in bacterial load whereas quality parameters were improved significantly. In conclusion, the microbial load was controlled in semen extenders without the addition of antibiotics and sperm quality parameters parameters were equivalent in group AB and NAB. Addition of Kojic acid in semen extender did not show any antibacterial effect whereas epsilon-polylysin showed antibacterial effect and improved semen quality.EnglishThesis