Autogenous bacterins were prepared from pasteurella multocida (PM) type 2:D previously isolated from ducks in the New-Valley,
as well as bivalent A and 2:D, which produced dense growth in tryptose agar. The bacterins were injected S/C into duckl ings at 3 and 5 weeks of age, such ducklings experienced significant less mortality than unimmunized controls follow ing challenge with live culture of the homologous strain at monthly intervals. Immunity lasted for (6) months with 100% protection.