Effect of cecal cultures encapsulated in alginate beads or lyophilized in skim milk and dietary lactose on Salmonella colonization in broiler chicks.
Cultures of cecal bacteria that were grown under anaerobic conditions were prepared as lyophilized powder or encapsulated and lyophilized in alginate beads and compared with broth cultures for control of Salmonella typhimurium enteric colonization and for ease of delivery in four experiments. Day-old broiler chicks were provided a standard corn-soybean diet with: 1) no culture, no lactose (control); 2) dietary lactose; 3) broth culture by crop gavage; 4) culture in lyophilized powder; or 5) culture encapsulated and lyophilized in alginate beads. Two percent lactose (wt/wt) was included in the diet of chicks in Groups 2 to 5. The lyophilized powder was provided by mixing with the feed. Alginate beads were force-fed or top-dressed on the feed. All groups were challenged on Day 3 with 10(4) cfu of S. typhimurium per chick. Culture by gavage and culture in alginate beads and dietary lactose significantly (P < .05) reduced mean Salmonella colony-forming units in cecal contents by 3.4 to 5.3 log10 units at 10 d of age. Likewise, the number of cecal-culture-positive chicks in the groups provided culture by gavage or in beads was significantly less than controls. Eighty to 90% of the beads provided were consumed by the chicks within 2 h. The results indicated that cultures of cecal bacteria encapsulated and lyophilized in alginate beads were as effective as culture by crop gavage for the reduction of Salmonella colonization in broiler chicks and provide an effective and practical method of delivery.