Effects of Enteromorpha polysaccharide dietary addition on the diversity and relative abundance of ileum flora in laying hens

Abstract

This experiment explored the effects of different levels of Enteromorpha polysaccharide dietary addition on the intestinal flora structure in laying hens. A total of 300 Hy-line brown laying hens aged 280 days old were selected according to the principle of equal weight and egg production rate. Group 1 was the blank control group fed with basic diet, Group 2 was the antibiotic control group supplemented with bacitracin zinc (0.005%) and basic diet, and Groups 3-5 were the experimental groups that received 0.1%, 0.2%, and 0.4% Enteromorpha polysaccharides in their diets, respectively. Four replicates per group and 15 repeats per replicate were prepared. The pretrial period was 10 days, and the normal trial period was 42 days. The ileum contents of laying hens were collected aseptically toward the end of the test to detect the diversity and relative abundance of the flora. Results were as follows. (1) Bacterial abundance (ACE and Chao1) and diversity (Simpson and Shannon) indexes were not significantly different between the control and test groups (P > 0.05). (2) Compared with that in group 1, the relative abundance of Firmicutes in groups 4 and 5 significantly increased by 14.13% (P < 0.05) and 13.70% (P < 0.05), respectively. The relative abundance of Bacilli in group 4 was significantly increased by 11.94% (P < 0.05) and 12.86% (P < 0.05) compared with those in groups 1 and 3, respectively. The relative abundance of Lactobacillales in group 4 was significantly increased by 27.02% (P < 0.05) compared with that in group 1. The relative abundance of Lactobacillaceae in group 4 was significantly increased by 22.92% (P < 0.05) and 11.4% (P < 0.05) compared with those in groups 1 and 3, respectively. The relative abundance of Lactobacillus in groups 4 and 5 was increased by 19.75% (P < 0.05) and 18.54% (P < 0.05), respectively. CONCLUSION: The dietary addition of 0.2% Enteromorpha polysaccharides can remarkably increase the relative abundance of Firmicutes phylum, Bacilli class, Lactobacillales order, Lactobacillaceae family, and Lactobacillus genus in the ileum of laying hens. This effect was equivalent to the action of bacitracin zinc and had no substantial influence on the diversity of ileum flora.

Keywords: Enteromorpha polysaccharides; Flora; Intestinal; Laying hen.