EFFECT OF YEAST-SUPPLEMENTED FEED ON SALMONELLA AND CAMPYLOBACTER POPULATIONS IN BROILERS

The effect of the yeast, Saccharomyces boulardii, on experimental ceca l colonization of broilers with Salmonella typhimurium and Campylobact er jejuni was investigated. Duplicate pens of broiler chicks were give n acl libitum access to a standard feed supplemented with no yeast (co ntrol), or 1 g (Ix), or 100 g (100x) dried S, boulardii/kg feed. All c hicks except negative controls were challenged on Day 4 with 3.2 x 10( 8) cfu S. typhimurium and 6.5 x 10(8) cfu C. jejuni by oral gavage. Af ter 3 wk, the broilers were euthanatized and ceca were aseptically rem oved and analyzed for Salmonella and Campylobacter. Frequency of Salmo nella colonization was significantly (P < 0.05) reduced due to yeast t reatment. Of the positive control birds, 70% were colonized with Salmo nella; whereas only 20 and 5% of the Ix and 100x yeast-treated birds w ere colonized. Mean number of Salmonella per gram of ceca and contents were log 1.64, 0.35, and 0.15, respectively, for the control, Ix, and 100x yeast-treated birds. Campylobacter colonization was not signific antly affected by yeast treatment. Similar results were obtained from a second trial conducted in larger isolation floor pens.