501. BACTERIOSPERMIA AND ITS CONTROL IN BUBALINE SEMEN

Abstract

The present study was designed to investigate the bacterial species incriminated in bubaline semen and to find out the effectiveness of antibiotics (GTLS; gentamycin, tylosin and linco-spectin or SP; streptomycin and penicillin) in cryodiluent on bacterial control and quality of buffalo bull spermatozoa. For this purpose four experiments were conducted. In experiment 1, a total of 11 bacterial species were identified from buffalo ejaculates. The predominant bacteria were Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa in the ejaculates. In experiment 2, total aerobic bacterial counts in post-thaw samples were lower (P<0.05) in GTLS than in SP or NC (negative control). Fewer bacterial genera were identified in semen samples having GTLS than SP. Majority of the bacterial isolates from ejaculates showed more sensitivity towards GTLS than SP. In experiment 3, motilities (visual and computer-assisted), velocities (straight-line, average path and curvilinear), amplitude of lateral head displacement and plasma membrane integrity in post-thaw semen samples did not differ (P>0.05) due to antibiotics. Spermatozoal abnormalities (acrosome, head, mid-piece and tail) were lower (P<0.05) in GTLS and SP than in NC. In experiment 4, the fertility rates for SP-based vs. GTLS-containing frozen semen of buffalo bull were 42.8 and 55.2%, respectively. The results for GTLS were significantly higher than SP. The fertility rates also differed significantly in the first and second batch of inseminations performed with SP or GTLS-based cryopreserved semen of buffalo bull. In conclusion, a number of bacterial species are isolated from bubaline semen. Bacterial and seminal quality measured by standard laboratory tests and field fertility trials indicate that GTLS is more suitable in extender for cryopreservation of buffalo bull spermatozoa.