A Study of the Passively Acquired Antibody to Tr. Foetus in the Blood of Young Calves and its Behaviour in Agglutination Tests and Intradermal Reactions

Abstract

Summary The foregoing paper deals with experiments in new-born calves showing the absorption of the antibody against Tr. foetus from the maternal colostrum into the blood of the calf by way of the alimentary canal in the first hours of life; the fixation of the passive antibody in the skin; the distinction between normal and specific agglutinins; and the theoretical similarity between the action of antibody in high titre serum and in colostral whey. The antibodies against Tr. foetus present in the whey of the colostrum can be absorbed by the new-born calf at the first feed after birth, and to some extent at 12 hours after birth, the calf having received boiled milk as its first feed at four hours old. If the calt has been fed on boiled milk for 24 hours the antibody present in the colostrum is not absorbed. The antibody passively acquired by calves reacts in agglutination tests with the living Trichomonas. It also becomes fixed in the skin and reacts with Trichomonas extract producing a positive skin reaction. The normal non-specific agglutinin for Tr. foetus is present in the serum of all adult bovines; it combines with living Trichomonas but it is not produced by Trichomonas antigen. It is not found in the blood of the new-born calf, but arises during the first six months of life. The non-specific agglutinin does not become fixed in the skin and does not react with the antigen of Trichomonas extract in intradermal injection.