ShivarajNITHYANANDA, V. C.2024-01-032024-01-032022https://krishikosh.egranth.ac.in/handle/1/5810205464The semen samples were collected from three semen collection centres located in and around Bangalore. Eight HF bulls and five bubaline bulls from Farm-A, twelve HF bulls from Farm-B, eight HF bulls and eleven bubaline bulls from Farm-C, were selected for the study. Three ejaculates from each bull at fortnightly intervals were collected and subjected for the estimation of total bacterial load in the neat, extender and frozen semen to evaluate the level of contamination occurring during handling, processing and storage of semen. The bacterial load of the semen was found to be within the prescribed guidelines of BIS suggestive of the hygienic measures followed during semen collection, processing and preservation. The isolates were subjected to the genus level typing using cultural, staining characteristics and molecular methods. The isolates isolated in the present study were Staphylococcus spp., Bacillus spp., Klebsiella spp., Corynebacterium spp., Serratia spp. and Proteus spp., etc. The antibiogram of Staphylococcus isolates were highly sensitive to Imipenem, followed by Piperacillin Tazobactam and Ofloxacin. Bacillus, Klebsiella, Corynebacterium and Proteus isolates were highly sensitive to Imipenem, Piperacillin Tazobactam. Serratia isolates were highly sensitive to Piperacillin Tazobactam. The study revealed that the conventional antibiotics used in the semen stations were sufficient to reduce the bacterial load in the semen along with strict hygienic measures during the collection and processing of semen. But it was found that the conventionally used antibiotics like Penicillin G and Streptomycin were resistant to many bacterial isolates obtained in the present study.EnglishThesis