4.—(1) During quarantine, the centre veterinarian must ensure that the bovine animals are tested for BVD/MD as follows–
(a)a virus isolation test or a test for virus antigen at least 21 days after being admitted to quarantine, with negative results; and
(b)a serological test to determine the presence or absence of antibodies, at least 21 days after being admitted to quarantine.
(2) The centre veterinarian may allow bovine animals to be moved to an EC collection centre or a domestic collection centre only if the serological test finds no seroconversion in any bovine animal which gave a negative result to the serological test under paragraph 2(1)(e)(ii) for BVD/MD antibodies.
(3) If seroconversion occurs in any bovine animal in the quarantine centre, the centre veterinarian must ensure that bovine animals that are seronegative–
(a)remain in quarantine; and
(b)are not sent to a semen collection centre until at least three weeks have elapsed during which there has been no further seroconversion.
(4) The centre veterinarian may allow serologically positive bovine animals to be sent to a semen collection centre after–
(a)completion of 28 days' quarantine; and
(b)they have been tested in accordance with sub paragraph (1).