Reproduction Abstracts

Introduction: Postpartum dairy cows are susceptible to uterine infections that leading to poor fertility. During this period the uterine defence mechanisms were compromised by poor energy status and the preceding viral infections, e.g. bovine herpesvirus 4 (BoHV-4) resulting in uterine pathology initiated by microorganisms. BoHV-4 has been isolated from healthy cows and cows experienced with mastitis, metritis and endometritis worldwide.

Methods: Samples of bulk tank milk, blood and endometrium were collected from four commercial dairy herds located in the centre of Thailand. After viral DNA extraction, PCR was performed to detect BoHV-4 glycoprotein B (gB) DNA, and nested-PCR was performed for the detection of BoHV-4 thymidine kinase (TK) DNA. The retrieved amplicons were sequenced, aligned and compared with other available BoHV-4 DNA sequence data from GenBank.

Results and discussion: Amplicons of the gB and TK DNA were evidenced in bovine endometrial samples and blood, but not in bulk tank milk. To our knowledge, this is the first report of BoHV-4 isolated from dairy cows in Thailand. Phylogenetic analyses showed that the BoHV-4 TK DNA recovered from bovine endometrium in Thailand shared similarity with the Argentinean strains obtained from vaginal discharge of aborted cows and Brazilian strain obtained from central nervous system, while the BoHV-4 gB DNA recovered from blood located in a distinct branch compared with other sequences from Germany, Ireland, Belgium, Brazil and Turkey. An assessment of genomic survey of BoHV-4 and its correlation with uterine pathology may improve the strategies of reproductive management in the dairy industry.