The transfer from ewe to lamb of clostridial antibodies

Abstract Extract Many farmers in New Zealand find it necessary to vaccinate their sheep flocks against certain of the clostridial diseases. Effective vaccines are available to protect sheep against the major scourges of blackleg, enterotoxaemia (pulpy kidney), malignant oedema, tetanus and black disease, but, to secure the full protective potential of each vaccine, it must be applied in the optimum fashion. This means using a potent vaccine, correctly administered to responsive sheep at such time before exposure that protection will have reached its peak when the challenge is encountered. It is generally accepted that such an ideal set of circumstances is only rarely achieved in the field.