Medical and sanitary prevention of a growing number of major infectious diseases of bovines has led IFFA-Mérieux to investigate the association of vaccines and to define methods of utilization. Care has been taken to limit the number of interventions and at the same time to retain in the combined valences the efficacy they had when in a state of single constituent. The work which has been carried out for the last ten years, including the study of adjuvants as well as of incompatibility of associations, has permitted the improvement of formulas, reduced in volume (5 ml for a plurivalent dose), in aqueous excipient (aluminum hydroxide and saponin) or oily excipient (oil in water type). These formulas combine 3 foot-and-mouth disease valences with a rabies valence (fixed strain grown on cell culture) or with a brucellosis valence (strain B. abortus MacEwen 45/20 and B. melitensis H 38). The innocuity of these associations allows them to be used in sanitary compaigns; their efficacy is equal to that of monovalent vaccines. A logical vaccination calendar is proposed.