Preliminary study of the microbial spectrum of the digestive tract in broilers fed diets with and without antibiotic supplementation

Abstract

The predominant bacteria in the small intestine of broilers were Lactobacillus spp., Escherichia coli and Streptococcus spp. Compared with the antibiotic-supplemented group, experimental groups receiving mannan oligosaccharide, lactic acid bacteria, and organic acids contained more Enterococcus spp., Escherichia coli, Streptococcus spp. in the intestinal content. The predominant bacteria in the caecum were Escherichia coli, Lactobacillus spp. and Enterococcus spp. Unlike the other groups, no Clostridium spp. bacteria were found in the caecum of birds receiving antibiotic supplements. There was no effect of the type of acid (fumaric vs formic) in feed on the composition of intestinal microflora of chickens.