Open AccessEffects of dietary protein levels on growth performance, serum indexes, PI3K/AKT/mTOR/S6K signalling and intestinal microbiota of abalone Haliotis discus hannai
Author(s) -
Ma Shuoli,
Li Xinxin,
Sun Li,
Fan Wenhao,
Chen Hao,
Yu Haixia,
Zhou Wanyou,
Zhang Wenbing,
Mai Kangsen
Publication year - 2021
Publication title -
aquaculture nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.941
H-Index - 79
eISSN - 1365-2095
pISSN - 1353-5773
DOI - 10.1111/anu.13230
Subject(s) - haliotis discus , abalone , p70 s6 kinase 1 , biology , ribosomal protein s6 , zoology , pi3k/akt/mtor pathway , weight gain , protein kinase b , food science , endocrinology , biochemistry , body weight , fishery , phosphorylation , signal transduction
A 120‐day feeding trial was conducted to assess the effect of dietary protein levels on growth performance, serum indexes, PI3 K/AKT/mTOR/S6 K signalling pathway and intestinal microbiota of abalone Haliotis discus hannai . Abalones (initial body weight: 15.88–16.54 g; initial shell length 41.70–42.40 mm) were fed nine isoenergetic (~16.08 kJ/g) and isolipidic (~42.0 g/kg) experimental diets with 93.5, 116.9, 151.1, 191.8, 230.3, 275.9, 320.3, 360.5 and 405.9 g/kg protein contents, respectively. Results showed that the optimal dietary protein level for H . discus hannai was determined as 259.4 g/kg through second‐order polynomial regression analysis for weight gain rate (WGR). Serum TP and urea nitrogen levels were significantly increased when dietary protein levels were higher than 320.3 g/kg ( p < .05). The highest gene expressions of phosphatidylinositol 3 kinase (PI3 K), target of rapamycin (mTOR) and ribosomal protein S6 kinase (S6 K) in muscle were found in the treatment with 275.9 g/kg of dietary protein. The excessive dietary protein level (405.9 g/kg) significantly decreased the gene expression of S6 K. Meanwhile, abalone fed with 275.9 g/kg of dietary protein exhibited the highest microbial diversity in intestine as measured by Chao richness and Shannon diversity index. In conclusion, dietary protein level reduced from 259.4 g/kg to 154.0 g/kg or increased from 259.4 to 323.0 g/kg, the WGR of abalone might be depressed with 5% likelihood. Over high (>360.5 g/kg) or low (<151.1 g/kg) dietary protein levels had negative effects on growth performance, serum indexes, PI3 K/AKT/mTOR/S6 K signalling and microbial diversity in intestine of abalone.