The Management of beef breeding programs

Abstract

In addition to characteristic "thrombo," Haemophilus somnus infection may result in acute respiratory disease or chronic stiffness of feedlot cattle. Unless the bovine practitioner performs very complete post mortem examinations, he may entirely miss the lesions of this disease, or mistake them for those of shipping fever or clostridial infection. Clinical signs and lesions characteristic of field cases may be experimentally reproduced in susceptible calves by either intravenous or intra tracheal innoculation with pure Haemophilus somnus cultures. Complement fixation tests confirm the widespread incidence of this infection. Development of immunizing agents for use in feedlot cattle may be warranted.