Evaluation of the effect of mannan-oligosaccharides on the competitive exclusion of Salmonella Enteritidis colonization in broiler chicks

This study evaluated the protection against colonization by Salmonella enterica serovar Enteritidis in the chick's caecum when dosed with caecal contents from hens fed dietary carbohydrates based on mannose. Protection was investigated by comparing the effects of four suspensions of hen caecal contents (HCC) fed diets supplemented with 2.5% D-mannose (MAN-HCC), 2.5% mannose-oligosaccharide (MOS-HCC), 2.5% palm kernel meal (PKM-HCC) or unsupplemented mash (Mash-HCC). Four trials to quantify and compare their effectiveness, showed that chicks were better protected when given MOS-HCC or PKM-HCC combined with diets supplemented with the same oligosaccharide given to the hens. Protection remained with the caecal contents diluted up to 10(6)-fold but was reduced or lost at higher dilutions, with better protection produced by the addition of carbohydrates to the diet. In conclusion, this study showed that HCC from hens fed diets supplemented with MOS or PKM were more effective against S. Enteritidis colonization in chicks than the HCC from hens fed unsupplemented mash.