engleski

The effect of parapox ovis virus – induced immunomodulation on sperm quality in breeding bulls

Breeding bulls are high-health status animals that are kept in artificial insemination (AI) centres with very low disease problems. Those animals are often under chronic stress that leads to immunosuppression through lymphocyte reduction. Immunosuppressesion and process of sperm taking facilitate genitourinary infection. Our objective was to investigate effect of immunomodulation on reproduction performance of breeding bulls. It was shown that animals pre-treated with prophylactic application of inactivated Parapox ovis virus had reduced susceptibility or milder symptoms and more rapid recovery from infectious diseases From the herd of 49 fertile Simmental bulls (3– 8-year-old) serving at an artificial insemination (AI) centre seven bulls were randomly allocated in the experimental and seven in the control group. The experimental group was treated with Baypamun® flüssig, an immunomodulator constructed from the D1701 strain of sheep parapoxvirus and control bulls received placebo. Sperm production parameters, volume (SV), density (SD) and motility of fresh (SMF) and thawed (SMT) spermatozoa and concentration of white blood cells (WBC) in semen were monitored for two months before and after treatment. Semen samples were collected from all bulls using an artificial vagina at 4 day intervals. All semen samples obtained throughout the experiment were bacteriologically examined. Differences in studied sperm parameters before and after treatment in the experimental and control group were examined using analysis of variance (ANOVA) methods. Our results strongly suggest that immunostimulation has significantly positive effect on SMF, SMT and SD in bulls. Also, our results indicated that immunostimulation has no effect on mean SV, SD and presence of WBC in semen. It is likely that immunostimulation will reduce the infection potential of microorganisms and decrease effect of chronic stress in breeding bulls at the similar way as for other infections in domestic animals. Therefore, immunomodulation may play important role in increasing the sperm viability in breeding bulls.

bull; immunomodulation; sperm; stress; artificial insemination

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