Effects of a blend of chestnut and quebracho tannins on gut health and performance of broiler chickens

Abstract

Consumer demands and increased regulations on the use of antimicrobials in farm animals accentuated the need to develop strategies to replace antimicrobial growth promoters (AGPs) in food-producing animals. The present study evaluates the productive and gut health outcomes during the implementation of AGPs free programs based on the inclusion of a tannin blend compared with AGPs based program under commercial conditions. In the first trial, 6 farms were randomly assigned to AGP or tannin-based programs. In a second trial, both programs were applied simultaneously in one farm and the results were studied over 1 year. Although productive results from both trials were similar among treatments, evaluations of gut health indicators show improvements in the tannins treated flocks. Frequency and severity of intestinal gross lesions were reduced in jejunum (42% vs 23%; p<0.05 - 1.37 vs. 0.73; p<0.01, respectively) and ileum (25% vs. 10%; p<0.0.5 - 1.05 vs. 0.58; p<0.01) in tannins treated birds. Results from 16S studies, show that cecal microbiota diversity was not differentially affected by AGPs or tannins, but changes in the relative abundance of certain taxa were described, including Lactobacillus and Bifidobacterium groups. Additional evaluations using an in vivo model for C. perfringens necrotic enteritis showed that tannins treated birds had reduced incidence of gross lesions in jejunum (43.75 vs. 74.19%; p<0.01) and ileum (18.75% vs. 45.16%; p<0.05) compared with control. These results suggest that AGPs can be replaced by tannins feed additives, and contribute in the implementation of antimicrobial-free programs in broilers without affecting health or performance.