INFLUENCE OF PARASITICIDE TREATMENT ON KINETICS OF ANTIGEN-SPECIFIC ANTIBODY-RESPONSE IN CATTLE INFESTED WITH HYPODERMA-LINEATUM (DIPTERA, OESTRIDAE)

The effect of parasiticide treatment on dynamics of antigen specific a ntibody responses to Hypoderma lineatum (De Villers) was investigated in naturally infested calves. Parasiticides were applied to cattle 1 m onth prior to, 1 week prior to, and coincident with the appearance of warbles in untreated calves from the same source herd. When cattle wer e treated approximately 1 month before warbles appeared in untreated c ontrol animals, antigen specific antibody levels increased for 25-34 d ays then declined to undetectable levels by approximately 75 days. Ant igen specific antibody levels sharply declined in cattle treated 1 wee k prior to appearance of warbles in untreated controls. Treatment appl ied coincident with arrival of grubs on the back did not alter the ant igen specific antibody profile, but reduced the relative magnitude of antigen specific antibodies present. Persistence of the antigen specif ic antibody following treatment will permit conduct of serological sur veillance programmes.