The efficacy of the bacteriocinogenic Enterococcus faecalis 14 in the control of induced necrotic enteritis in broilers.

Abstract

PURPOSE: To demonstrate the efficacy of the bacteriocinogenic Enterococcus faecalis 14 (E. faecalis 14) in the control of induced necrotic enteritis (NE) in broilers. METHODS: Six groups of 504 broilers consisting of an infected untreated control (IUC) group, an infected and amoxicillin treated control (ITC) group, and groups receiving prophylactically (2 groups) or therapeutically (2 groups) E. faecalis 14 or its Δbac mutant were used. All groups were challenged with Clostridium perfringens 56 to induce NE. To predispose the boilers to develop subclinical NE, a high protein grower diet containing 15 % fishmeal and a coccidial inoculum were administered. RESULTS: NE lesions were observed on D26 in all groups except ITC and those receiving prophylactically and therapeutically E. faecalis 14. On D27, only ITC and the group prophylactically treated with E. faecalis 14 (T03) were without lesions. Average body weight and daily weight gain remained lower in the treated groups compared to the ITC group, but there was a clear improvement in the period between D21 to D27, especially in the group prophylactically treated with E. faecalis 14. Specifically, the daily weight gain (DWG) in this period for group T03, was second highest after the group ITC. Metataxonomic analyses showed a positive effect of E. faecalis 14 in maintaining the diversity and richness of the intestinal microbiota, in contrast to ITC group and other conditions. CONCLUSIONS: The results of this in vivo study demonstrated the efficacy of the prophylactic administration of the bacteriocinogenic E. faecalis 14 in preventing of the NE lesions caused by C. perfringens.