부산대학교 도서관

Description of the subject. The growth of new antibiotic-resistant strains of pathogens represents a huge problem in poultry rearing. There is evidence that dietary yeast could be effective in the protection against a variety of pathogens that can affect poultry health and cause foodborne diseases in humans. Since still few or contradictory information are available for this topic. Objectives. The objective of this study was to investigate the effects of live yeast supplementation in broiler chickens on Salmonella enteritidis and Campylobacter jejuni content in feces, cecum, and skin. Method. Supplemented yeast consisted of Saccharomyces cerevisiae (Levucell® SB20, type boulardii I-1079, Lallemand, France) and was administered at a rate of 1 x 106 CFU·g-1 of feed. On day ten of life, birds were orally challenged with S. enteritidis (1 x 105 CFU/bird) and C. jejuni (3 x 105 CFU/bird). Growth performance, and coliforms, yeasts and lactobacilli enumeration were evaluated on day 0, 10, 20 and 38. Ten and eighteen days post infection (PI), 10 animals per replicate were slaughtered and pooled ceca content were analyzed for yeast enumeration and Salmonella and Campylobacter frequency and enumeration. The presence and the enumeration of Salmonella and Campylobacter in neck and breast skin were performed on one subject per replicate. Results. Dietary S. cerevisiae increased yeast and lactobacilli (p = 0.01) count, while Salmonella enumeration and frequency significantly decreased in neck (p = 0.03) and tended to decrease in cecum (p = 0.06), feces (p = 0.06), and breast (p = 0.08). On 10d PI Campylobacter presence was decreased in cecum (p = 0.01), feces (p < 0.01), breast skin (p = 0.04) and neck skin (p < 0.01), while the enumeration was found to be lower in feces (p < 0.01) and neck skin (p = 0.05). At the end of the trial the frequency of this pathogen was decreased in feces (p < 0.01), and breast skin (p = 0.02), while the enumeration was diminished in cecum (p < 0.05) and feces (p < 0.05). Conclusions. The present study shows that the inclusion of Levucell® SB20 can significantly control Campylobacter carriage in chickens with some positive effects also on Salmonella presence, thus reducing the contamination of carcasses at slaughtering and preventing human foodborne diseases.