Effect of Cecal Cultures Lyophilized in Skim Milk or Reagent 20 on Salmonella Colonization in Broiler Chicks

Abstract

Mixed cultures of cecal bacteria that were grown under continuous flow anaerobic conditions were prepared as lyophilized powder in skim milk or Reagent 20 (R-20; a mixture containing sucrose and bovine serum albumin fraction V) and compared with broth cultures for reduction of Salmonella typhimurium enteric colonization. Day old broiler chicks were provided a standard corn-soybean diet with: 1) no culture, (control); 2) broth culture administered by crop gavage; 3) broth culture added to the drinking water; 4) culture lyophilized in skim milk and added to drinking water; 5) culture lyophilized in skim milk in gelatin capsules and force-fed; 6) culture lyophilized in R-20 and added to drinking water; and 7) culture lyophilized in R-20 in gelatin capsules and force-fed. All groups were challenged on Day 3 with 104 cfu of S. typhimurium per chick. Culture by crop gavage, culture in the drinking water, skim milk powder in capsules, and R-20 powder in the water and in capsules significantly (P < .05) reduced mean Salmonella colony-forming units in cecal contents by 3.21 to 5.26 log10 units at 10 d of age. Likewise, the number of cecal-culture-positive chicks in the same groups was significantly less than controls with reductions of 27 to 67%. The numbers of Salmonella per gram of cecal contents and the percentage of cecal-culture-positive chicks in the skim milk powder in the drinking water group were not different from control chicks in one of two experiments. The results suggest that the culture of cecal bacteria lyophilized in R-20 was as effective as the same culture in broth form for the reduction of Salmonella colonization in broiler chicks and demonstrate a practical delivery method that could be easily incorporated into current industry practices.