Administering mucosal competitive exclusion flora for control of salmonellae

We compared three methods to administer various dilutions of mucosal compet itive exclusion (MCE) culture to reduce Salmonella colonization in the inte stinal tract of broiler chicks: 1) spraying onto the chicks using a "Newcas tle" automatic spray cabinet; 2) directly gavaging into the crop of the chi cks; and 3) a combination of spraying and gavaging the chicks. Day-of-hatch broiler chicks were provided selected treatments, or served as controls. A combination of strains of S. typhimurium, S. montevideo, and S. california were used 4 hr after treatment to challenge the treated and control chicks . The chicks were sacrificed 5 days post challenge, and cecal contents were analyzed for the presence and numbers of the Salmonella isolates. The opti mum level of MCE to reduce Salmonella colonization depended on the efficacy of the original MCE culture. A 10(-6) dilution of freshly prepared MCE pro vided protection similar to the undiluted MCE that had been stored for more than 2 months. A combination of spraying and gavaging MCE was more effecti ve than either of the two single treatment methods tested.