Member States shall ensure that:
all female animals and all bulls from type B1 herds destined for type B2 herds:
if more than 12 months old, have passed an officially approved serological test carried out within the 30 days prior to movement and are accompanied by a certificate to this effect from the official veterinarian,
are isolated immediately upon arrival for at least 60 days and if more than 12 months old, have passed a further officially approved serological test before admission to the type B2 herd;
all female animals and all bulls from a type B2 herd destined for another type B2 herd:
if more than 12 months old, have passed an officially approved serological test carried out within the 30 days prior to movement and are accompanied by a certificate to this effect from the official veterinarian,
do not come into contact, during transfer, with animals from herds of a lower health status;
transfers of animals between B3 and B4 herds are carried out subject to the observance of the requirements of Directive 64/432/EEC.