Inhibitory effects of competitive exclusion and fructooligosaccharide, singly and in combination, on Salmonella colonization of chicks.

摘要

The inhibitory effects of competitive exclusion (CE; a bacterial preparation, Broilact) and 0.1% concentration of fructooligosaccharide (FOS), singly and in combination, on the colonization of chicks by Salmonella were investigated. The major caecalflora (Bifidobacterium, Bacteroides, Lactobacillus, and Escherichia coli) was quantified. Day-old birds were divided into four groups: (i) control, (ii) CE, (iii) FOS, and (iv) CE plus FOS. Chicks received Salmonella Enteritidis at 7 days (experiment 1)or 21 days (experiment 2). Birds in each group were killed at 1 day, 7 days, and 14 days after inoculation of Salmonella Enteritidis for salmonella in caecal contents to be counted. In experiment 1, the mean number of Salmonella Enteritidis in the chicks inoculated with CE was significantly decreased compared with the other three groups at 1 day after inoculation. In experiment 2, the mean numbers of Salmonella Enteritidis in the chicks of the FOS group and the FOS plus CE group were significantly decreased compared with the control group at 1 day and 7 days after inoculation. In 7- and 21-day-old chicks, few changes on number of total bacteria, Bifidobacterium, Bacteroides, Lactobacillus, and E. coli were observed in the caecal contents of treated groups compared with the control group. Low-dose feeding of FOS in the diet of chicks with a CE treatment may result in reduced susceptibility to Salmonella colonization but may not lead to a shift in the intestinal gut microflora of 7- and 21-day-old chicks.