Dietary Supplementation with Multi-strain Probiotic Formulation (Bifidobacterium B8101, Lactobacillus L8603, Saccharomyces bayanus S9308, and Enterococcus SF9301), Betaine or their Combination Promotes Growth Performance Via Improving Intestinal Development in Broilers.

This study aimed to investigate the effect of a multi-strain probiotic (Bifidobacterium B8101, Lactobacillus L8603, Saccharomyces bayanus S9308, Enterococcus SF9301), betaine, and their combination on intestinal epithelial development and growth performance in broilers. A total of 2800 one-day-old Ross 308 chickens were randomly divided into four groups: control (Ctrl) fed with a basal diet, multi-strain probiotic (Pb) group fed with basal diet + 100 mg/day/bird probiotic (1-14 d), betaine (Bet) fed with basal diet + 0.1% betaine (1-35 d), and a combination (Pb&Bet) fed with both probiotics and betaine. Each group was set with 10 replicates, with 70 chickens in each replicate. Result showed that betaine significantly increased the body weight (BW) of broilers at 14 d of age and decreased the feed conversion ratio (FCR) from 1 to 14 d of age. Multi-strain probiotic significantly increased BW at 21 and 35 d of age, and decreased FCR from 15 to 21 d of age. Pb&Bet group exhibited a higher BW but lower FCR than Ctrl throughout entire experiment (p < 0.05). Consistently, Pb&Bet group had a higher pectoralis muscle weight, fiber diameter and cross-sectional area compared to Ctrl group (p < 0.05). Pb&Bet group also increased villus height and the ratio of villus height to crypt depth (V/C) in duodenum at both 21 d and 35 d of age. Moreover, at 35 d of age, the mucin 2 (MUC2) expression in duodenum and jejunum was significantly increased in Pb&Bet group, and the interaction of betaine and probiotics was observed on claudin 1 (CLDN1), zonula occludens 1 (ZO1), and junctional adhesion molecule 2 (JAM2) expression in the ileum (p < 0.05). In conclusion, the combination of probiotics and betaine shows better potential for improving growth performance and promoting small intestinal development.