MYCOPLASMA CONTAMINATION OF BULL SEMEN USED FOR ARTIFICIAL INSEMINATION

Technologies of artificial insemination of cattle are actively used in livestock farms in Russia. At the same time, quality control of semen production does not involve testing the bull semen for microorganisms of the genus Mycoplasma. The active use of molecular genetic methods allows for the rapid determination and species identification of pathogenic mycoplasmas; however, it does not indicate the viability of the identified pathogen. The paper aims to study mycoplasma contamination of semen products presented on the Russian market and determine the conformity of the results of the Polymerase Chain Reaction [PCR] method and the traditionally used microbiological method. The paper presents the results of the first Russian study of the occurrence and viability of pathogenic species Mycoplasma bovis, M. bovigenitalium, M. californicum, and Ureaplasma diversum in semen production. We investigated 447 samples of cryopreserved semen of bulls-producers of various breeds from Russian breeding centers and breeding farms of the USA, Great Britain, and the Netherlands, supplying these products to the Russian market. The analysis shows a high frequency of occurrence in the bull semen of DNA of microorganisms of the genus Mycoplasma (up to 70.9%). Besides, M. bovigenitalium appeared to be the most frequently detected type of mycoplasma from those tested. Cases of identifying several types of mycoplasmas in one sample were revealed: in 58.8% of the studied samples of semen products from Russian farms and 15% of semen samples from international breeding centers. The viability of mycoplasmas that were positive according to PCR analysis when testing 65 samples was demonstrated using the microbiological method for 94% of samples. The correspondence of the results of microbiological and molecular genetic detection of mycoplasmas and ureaplasmas was 88.3%. The results obtained indicate the prevalence of mycoplasmas in semen production and the need to improve the control system of breeding material in order to prevent the spread of mycoplasma infections of cattle using artificial insemination technologies.