IMMUNOLOGICAL AND PHYSIOLOGIC RESPONSES OF CALVES INOCULATED WITH POTASSIUM THIOCYANATE EXTRACT OF PASTEURELLA-MULTOCIDA TYPE-A

Abstract

Inoculation of calves with KSCN extract of P. multocida type A in saline-tris buffer or in Freund''s incomplete adjuvant or modified Freund''s incomplete adjuvant resulted in the elicitation of agglutinating, hemagglutinating, bactericidal and homocytotropic antibodies. The antibody response was significantly (P = 0.05) higher in calves inoculated with the KSCN extract in either adjuvant than in those inoculated with the extract in saline-tris buffer. Hemagglutination also was observed if the KSCN extract of P. haemolytica was used for sensitizing the tanned sheep red blood cells. Calf anti-P. multocida extract antisera also was bactericidal to P. haemolytica. The KSCN extract of P. multocida was nontoxic to calves at 2 doses tested, as judged by an evaluation of total and differential leukocyte counts, body temperature and pulse rates at various intervals after inoculation.