Potential Application of Dandelion (Taraxacum Mongolicum Hand.-Mazz.) on Broiler Chickens: Growth Performance, Expression of Tight Junction Protein and Mucin Genes, and Microbiota Composition in Ileum

Abstract

Background Chinese herbs is becoming an exploitable alternative to the use of widely prohibited antibiotics in the poultry industry. We investigated the effects of dandelion on the growth performance and intestinal barrier function of broiler chickens. One-hundred and sixty 1-day-old Arbor Acres (AA) male broilers were randomly divided into four groups, with five replicates of eight birds each. The birds were fed a basal diet supplemented without (control group, [CON]) or with 500 (low dose [LD]) or 1000 (high dose [HD]) mg/kg dandelion or with 50 mg/kg chlortetracycline (CTC) for 42 days, including the starter phase (d 1 to 21) and the grower phase (d 22 to 42). Results During the starter phase, the average daily feed intake (ADFI) and feed/gain ratio (F/G) of LD was lower than CON, HD and CTC (P < 0.05). In the overall phase, the F/G of LD and HD both decreased (P < 0.05). At 21 days old, the gene expression of claudin, occludin-1, and mucin-1 of the LD and HD birds were significantly higher than that of CON and CTC birds (P < 0.05); the gene expression of claudin and occludin-1 was significantly higher in HD birds than in LD birds; and the gene expression of zonula occludens-1 (ZO-1) in HD birds was higher than that of CON and LD birds, but lower than that of CTC birds (all P < 0.05). At 42 days old, the gene expression of claudin, occludin-1, and mucin-1 of the LD birds was significantly higher than that of the other groups, whereas the gene expression of zo-1 was higher in the HD birds than in CON and LD birds (all P < 0.05). In the analysis of intestinal microbiota, decreased α-diversity was observed in 21-days-old HD birds, while LD and HD birds showed a significantly decreased relative abundance of Bacteroidata and Bacteroides at the level of phyla and genera (P < 0.05). Conclusion Overall, dietary dandelion supplementation can enhance growth performance by improving the intestinal barrier function of broilers. Therefore, dandelion represents a promising feed additive for broilers, although the optimal supplementation dose requires further study.