Identification of bovine viral diarrhoea virus type 2 in cattle bull semen from southern India and its genetic characterization

Abstract

Although bovine viral diarrhoea virus (BVDV) is prevalent in Indian cattle causing economic losses in cattle farming, its detection in bull semen has not yet been reported. Following passage of raw bull semen (n = 4) on MDBK cells, testing for BVDV was done by antigen ELISA and real-time RT-PCR. BVDV type-2 (BVDV-2) was identified in three samples from southern India by real-time RT-PCR. Genetic typing of the 5'-UTR sequences classified all the three BVDV strains as BVDV-2a subtype. These were found genetically closely related to the strains from USA, but divergent from the BVDV-2a strains from northern India. Phylogenetic analysis of Npro sequences confirmed the findings. The results provide evidence of circulation of BVDV-2a strains in southern India. The detection of BVDV in bull semen from India highlights the importance of mandatory testing of breeding bulls and bull semen for BVDV to minimize the risk of BVDV transmission.