4. During the year before collection of the embryo, the donor cow must not have been present in a herd (or herds) which have shown any clinical sign of infectious bovine rhinotracheitis or infectious pustular vulvovaginitis.
4. During the year before collection of the embryo, the donor cow must not have been present in a herd (or herds) which have shown any clinical sign of infectious bovine rhinotracheitis or infectious pustular vulvovaginitis.