Study on the Effects of Dietary Enzymes and Probiotics on Intestinal Escherichia Coli of Broilers

Abstract

The purpose of this study was to explore the effects of enzymes, probiotics and their combinations on intestinal histopathological indexes of broilers. One hundred and fifty broilers were randomly assigned to five diet groups for 42 days. We measured the performance indicators of five treatment groups. On the 42nd day, 2 chickens per replicate were collected for microbe count, and about 5cm of the distal ileum was resected for histopathological examination. The results showed that the total heterotrophic count of the basal diet and the probiotics diet was similar to that of the other diets, but significantly (P <0.05) higher than that of the other diets. The lactic acid bacteria count was the highest in the probiotics + enzyme feed, and the lowest in the probiotics (2.58×105 CFU/mL) and enzyme supplemented feed (1.45×105 CFU/mL). The total coliform number of antibiotic diet (14.12×105 CFU/mL) was significantly lower than that of other diets (P <0.05). The total number of Escherichia coli was the highest in the antibiotic diet and the lowest in the probiotics + enzyme mixture diet. Micrograph of ileum under basal diet showed mucosal shedding and villi degeneration. In this experiment, the supplementation of probiotics, enzymes or their combinations had no significant effects on the growth response of broilers. However, the birds' gut integrity was improved. In poultry nutrition, a mixture of 0.4% probiotics plus 0.1% enzymes is recommended as an alternative to antibiotic growth promoters.