[Unexpected change in BVD state of high-tech farm]

animal health bovin laitier bovine diarrhoea pestivirus certification control de enfermedades dairy cattle dairy farming dairy farms disease control disease transmission enfermedades infecciosas ferme pilote fincas experimentales ganado de leche granjas lecheras infectious diseases maladie infectieuse pestivirus de la diarrea bovina pestivirus maladie des muqueuses pilot farms sanidad animal transmission des maladies