Bovine alphaherpesvirus 1 and 5 in semen from bulls presenting genital lesions under field conditions in Brazil

Abstract

Bovine alphaherpesviruses 1 and 5 (BoHV-1/5) are main pathogens of respiratory, reproductive and neurological diseases in cattle. The aim of this study was to investigate the frequency of neutralizing antibodies against BoHV-1/5 in serum samples and to detect viral DNA in semen of bulls from beef cattle farms located in RS. A total of 372 serum and semen sample from bulls were collected in eighteen farms. Serum samples were submitted to virus neutralization (VN) assay, while semen samples were used to detect BoHV-1 and BoHV-5 DNA by PCR. VN results showed that BoHV-1/5 antibodies were detected in bulls of 66.7% (12/18) of the farms, 295 (79.5%) BoHV positive bulls, 287 for BoHV-1 and 234 for BoHV-; at 43 vaccinated bulls 72.1% (31/43) showing serology negative. BoHV-1/5 DNA was detected in the semen of three bulls; one of the them presenting BoHV-1, one out three presenting BoHV-5 and one BoHV-1/5.co-infection All BoHV DNA positive samples came from animals presenting posthitis and other genital lesions at sampling. Results showed a high seroprevalence of BoHV-1/5 antibodies in bulls as well as strong evidence that these viruses are actively circulating in the cattle farms. A remarkable finding is that in the presence of clinically evident lesions in the genital tract, both BoHV-1 and 5 may found in semen.

Detection of Bovine Herpesvirus 1 from Semen by Real-time PCR to Prevent the Spread of Infectious Bovine Rhinotracheitis Infection

“…The virus is secreted through nasal and eye secretions, placental fluid of aborted cattle, and semen (Rola et al, 2005). Regarding a study conducted on three bulls detected with BHV-1.5 in Brazil, it was found that BHV -1.5 was transmitted through nasal, ocular, genital contact (Henzel et al, 2019). The infectivity of BHV-1 remains stable during the storage of semen in liquid nitrogen.…”

“…This is related to good management in the farm so it was possible to impact BHV-1 shedding and enhance the immune system. The study of Henzel et al (2019) showed that two positive samples of BHV-1 PCR detection in bulls' semen in Brazil. Farms in Brazil have a history of nutritional and health management deficiencies, possibly favoring BHV-1 shedding in bull's semen.…”