[Vaccination against IBR: a recommendation for dairy herds]

In view of the results of previous serological studies on the presence of SN antibodies to IBR virus in a minimum of ten per cent of the herd, the following procedure is suggested: (1) Vaccination of serologically negative herds in areas menaced by IBR virus. (2) Vaccination of IBR-negative groups of animals in herds in which serologically IBR-positive animals are present. When sampling shows that IBR-negative animals are present in every age group, vaccination of the entire herd should be contemplated. (3) Vaccination of all animals which are added to dairy herds including animals showing antibodies to IBR virus.