Investigation of Chlamydiaceae in semen and cauda epididymidis and seroprevalence of Chlamydophila abortus in breeding bulls

BACKGROUND Reproductive disorders associated with chlamydial infection have been reported worldwide in cattle and there are indications of potential venereal transmission. METHODS Semen samples from 21 dairy bulls and cauda epididymidis tissue samples from 43 beef bulls were analysed for chlamydial agent by real-time polymerase chain reaction (PCR) including an internal amplification control (mimic). Additionally, presence of antibodies against Chlamydophila (Cp.) abortus among the bulls was investigated with the commercial Pourquier ELISA Cp. abortus serum verification kit. RESULTS No chlamydial agent was detected by PCR in either the semen samples or in the tissue samples. Additionally, no antibodies against Cp. abortus were detected. CONCLUSIONS The results suggest that Cp. abortus is very rare, or absent in Swedish bulls and thus the risk for venereal transmission of chlamydial infection through their semen is low. However, because Chlamydophila spp. infection rates seem to differ throughout the world, it is essential to clarify the relative importance of transmission of the infection through semen on cattle fertility.