Molecular detection and evaluation of bovine gammaherpesvirus 6 (BoGHV6) in semen and genital tract of bulls from Mato Grosso State, Brazil.

Bovine gammaherpesvirus 6 (BoGHV6), formerly described as bovine lymphotropic virus, is a member of the genus Macavirus, subfamily Gammaherpesvirinae, within the family Orthoherpesviridae. Viruses of this genus infect domestic and wild ruminants and swine, typically causing latent, asymptomatic infections. This study aimed to detect BoGHV6 genomic DNA in the semen and genital tract tissues of bulls from the state of Mato Grosso, Brazil. Semen samples were collected from 38 breeding bulls, whereas testicular and epididymal tissue fragments were retrieved from 47 animals at local abattoirs. Semen samples were initially evaluated for volume, swirling, motility, vigor, concentration, and sperm morphology. Testicular and epididymal tissue samples were subjected to histopathological analysis. The semen and pooled tissue samples were subsequently subjected to nested PCR targeting panherpesvirus DNA. Positive samples were further analyzed via BoGHV6-specific PCR to amplify a partial region of the DNA polymerase gene. All semen samples, except one, presented sperm parameters within the normal range for the species. Histopathological examination revealed epithelial lesions in the seminiferous tubules in 11 tissue samples. BoGHV6 DNA was detected in 26 out of the 85 animals tested, including 16 semen samples and 10 tissue samples. Only one of the BoGHV6-positive semen samples exhibited abnormal sperm morphology. Histopathological changes were observed in three of the ten corresponding tissue samples. In conclusion, BoGHV6 is present in cattle herds in the state of Mato Grosso. Moreover, its ability to be detected in semen, testicular, and epididymal tissues suggests its potential for venereal transmission.