Infectious bovine rhinotracheitis of the breeding bulls in the artificial insemination centre
The latent form of IBR is the dominating form in bulls-donors of semen in artificial insemination centre. Infectious animals secrete BHV-1 episodically, not constantly. The serologic profile of infectious bulls has a wave shaped creature. There is no correlation between antibody levels and presence of BHV-1 in their ejaculates. According with it the exploitation especially valuable infectious bulls is possible in case keeping physically apart from other animals, subjecting their every ejaculate to a virus isolation or PCR and wiping contaminated pulls. Vaccination do not prevent production of contaminating semen. More of this vaccinated infectious bulls oftener secret BHV-1 in comparison with unvaccina- ted ones. The spontaneous elimination BHV-1 is possible but taken a rather long time.