Aquaculture Reports (Dec 2024)
The positive effects of dietary inositol on juvenile hybrid grouper (♀Epinephelus fuscoguttatus × ♂ Epinephelus lanceolatu) fed high-lipid diets: Growth performance, intestinal digestive enzymes, tissue morphology, and intestinal microbiota
Abstract
The aim of study was to explore the beneficial effects of adding inositol to high-lipid diets on intestinal digestive enzymes, tissue morphology, and intestinal microbiota in juvenile hybrid grouper (♀ Epinephelus fuscoguttatus × ♂ Epinephelus lanceolatu). Six isonitrogenous (CP 51 %) and isolipidic (CL 16 %) diets were formulated, each containing different levels of inositol: 0 % (J1, as the control group), 0.04 % (J2), 0.08 % (J3), 0.16 % (J4), 0.32 % (J5) and 0.64 % (J6) inositol. Grouper (initial body weight of 6.76 ± 0.34 g) were fed experimental diets continuously for 8 weeks. Results showed that inositol significantly increased the specific growth rate of J3, J4, J5, J6 groups compared to the control group (P > 0.05). Amylase, lipase, and trypsin activities generally increased with higher inositol levels. Amylase activities were significantly higher in J4, J5, and J6 groups compared to the control group (P 0.05), but increased plica width, muscularis thickness, and goblet cell number (P 0.05). The Simpson index was significantly higher in the J3 group compared to J1 group (P 0.05). The dominant intestinal phylum mainly consists of Proteobacteria and Cyanobacteria, while the dominant family mainly consists of Vibrionaceae and Burkholderiaceae. In summary, supplementing high-lipid diets with appropriate inositol can enhance digestive ability, improve the morphology of hybrid grouper intestines, increase the abundance of beneficial bacterial microbiota, maintain intestinal health, and promote growth.
