Effect of -Coated Diets on the Growth, Digestive Enzyme Activity, and Intestinal Microbial Diversity of Songpu Mirror Carp Songpu.

The present study was conducted to evaluate the effect of a -coated diet on growth performance, digestive enzymes, and intestinal microbial diversity in Songpu mirror carp ( Songpu). The fish were manually fed two diets (a control diet and a -coated diet) three times daily until apparent satiation for 56 days. Compared with the control group, supplementation with the -coated diet enhanced the fish growth and significantly reduced the feed conversion ratio ( < 0.05). The activities of foregut amylase and lipase in the treatment group were significantly higher than those in the control group ( < 0.05). The activities of foregut, midgut, and hindgut proteases in the treatment group were all higher than those in the control group ( > 0.05). The results of sequencing the 16S rDNA genes of the microbiota through high-throughput sequencing showed that the diversity and abundance of the intestinal microflora increased along with Songpu mirror carp growth. The Songpu mirror carp fed a diet coated with displayed increased proportions of intestinal and at the genus level, and both were significantly higher than those of the control group ( < 0.05). These results therefore suggest that dietary application can improve the growth and digestive enzyme activity of Songpu mirror carp and enrich the beneficial genus composition of its main intestinal microflora.