Effect of Eimeria tenella infection on resistance to Salmonella typhimurium colonization in broiler chicks inoculated with anaerobic cecal flora and fed dietary lactose.

This study evaluated the effect of Eimeria tenella infection on Salmonella typhimurium colonization of broiler chicks following oral inoculation with anaerobic cecal flora either alone or with a treatment of 10% dietary lactose. The number of chicks colonized by S. typhimurium was significantly lower (P < 0.05) in groups inoculated with cecal flora with or without the dietary lactose treatment than in control groups. In addition, significantly fewer S. typhimurium organisms were isolated from the cecal contents of chicks inoculated with anaerobic cecal flora and treated with 10% dietary lactose than in the control chicks. Infection with E. tenella had no effect on the resistance of treated groups to S. typhimurium colonization of the ceca but did cause higher S. typhimurium colonization in the untreated control chicks. The results indicated that: A) anaerobic cecal flora given orally on the day of hatch to chicks with or without dietary lactose enhanced the resistance of the birds to Salmonella cecal colonization; and B) coccidial infection had no detrimental effect on this resistance to Salmonella colonization.