Effects of bovine herpesvirus 1 on thawed bull sperm and evaluation of methods for its removal from experimentally infected semen

The first experiment assessed the effect of bovine herpesvirus 1 (BoHV-1) on thawed bull semen. Semen samples testing negative for BoHV-1 via Nested-PCR were incubated at 37 °C with viral concentrations of 0 (control), 10⁴, 10⁵, and 10⁶ TCID₅₀/mL. Sperm quality parameters were evaluated over an 8-hour period. The second experiment assessed the efficacy of two protocols for reducing the viral load (viral titration) in experimentally infected semen (10⁴ TCID₅₀/mL): Percoll gradient (PG) and magnetic nanoparticles coupled with anti-BoHV-1 antibodies (MNPs). Sperm kinematics were influenced by both bull and time, with bull × time interaction (P < 0.001). Membrane integrity and morphology were influenced only by time (P < 0.01), with no effect of viral infection (P > 0.05). In viral titration, all PG-treated samples tested negative. Samples treated with MNPs also yielded negative results after a 60 min-incubation. It is concluded that BoHV-1 had no direct effect on thawed bull sperm quality and that PG appears to be effective removing the viral load. Furthermore, MNP is a viable alternative for virus control in semen, with no apparent deleterious effects to sperm motility.