DETECTION OF BOVINE HERPESVIRUS-1 IN THE SEMEN OF EXPERIMENTALLY INFECTED BULLS BY DOT-BLOT HYBRIDIZATION, POLYMERASE CHAIN-REACTION AND VIRUS ISOLATION

Two 18-month-old bovine herpesvirus 1 (BHV1)-seronegative bulls were i noculated experimentally with BHV1 via their prepuces. Semen collected at intervals was examined by optimised virus isolation, dot-blot hybr idisation and the polymerase chain reaction (PCR) for detection of BHV 1, and the infection was monitored serologically by using a virus neut ralisation test. Antibodies were first detected 10 days after inoculat ion and were still present 40 days after inoculation. Semen collected from four to 40 days after inoculation was positive by PCR with Southe rn blot hybridisation whereas only the semen collected on day 4 was po sitive by dot-blot hybridisation, virus isolation and PCR with ethidiu m bromide staining. These results indicate that the bulls started to s hed the virus in semen before they developed any detectable antibody. PCR with Southern blot hybridisation was the most sensitive of the thr ee methods and detected virus for the longest period.