In our studies on the primary immune response, we have used germfree, colostrum-deprived swine taken three to five days prematurely by hysterectomy. These piglets lack gamma globulin until they are immunized. Upon antigenic stimulation, early macroglobulin antibody is produced within 48 hours; subsequently late euglobulin antibody is produced. Our results have led me to formulate a new instructive model for the onset of antibody formation
