Presence of Mycoplasma agalactiae in semen of naturally infected asymptomatic rams

The purpose of the present study was to assess the presence of Mycoplasma agalactiae (Ma), the main causative agent of ovine contagious agalactia (CA), in semen of naturally infected rams. Therefore, semen samples from 167 rams residing in three different artificial insemination (AI) centers of a CA–endemic area were studied by microbiological and molecular techniques. In addition, serial ejaculates from the same rams were evaluated to determine the excretion dynamics of Ma. Of the 384 samples studied, Ma was detected in 56 (14.58%) which belonged to 44 different rams (26.35%). These findings confirm the ability of Ma to be excreted in semen of asymptomatic rams. Furthermore, these results also evidence the presence of these asymptomatic carriers of Ma in ovine AI centers, representing a serious health risk regarding the spread and maintenance of CA, especially in endemic areas. Moreover, the excretion of Ma in semen also points to the risk of venereal transmission of this disease. The current results highlight the need to implement control measures to prevent the admission of infected rams in AI centers and the necessity to continuously monitor semen samples to effectively detect infected individuals.