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. 2022 May 12:9:816341.
doi: 10.3389/fnut.2022.816341. eCollection 2022.

Assessment of Fish Protein Hydrolysates in Juvenile Largemouth Bass (Micropterus salmoides) Diets: Effect on Growth, Intestinal Antioxidant Status, Immunity, and Microflora

Ze Fan  1 , Di Wu  1 , Jinnan Li  1 , Yuanyuan Zhang  1 , Zhiying Cui  2 , Tianbi Li  2 , Xianhu Zheng  1 , Hongbai Liu  1 , Liansheng Wang  1 , Hongqin Li  3
Affiliations

Assessment of Fish Protein Hydrolysates in Juvenile Largemouth Bass (Micropterus salmoides) Diets: Effect on Growth, Intestinal Antioxidant Status, Immunity, and Microflora

Ze Fan et al. Front Nutr. .

Abstract

Varying dietary inclusion levels of fish protein hydrolysates (FPH) were applied in a feeding experiment with juvenile largemouth bass (Micropterus salmoides) to assess their effects on growth, intestinal antioxidant status, immunity, and microflora. FPH were added in 4 dietary levels: 0 g/kg (control group, FPH-0), 10 g/kg (FPH-10), 30 g/kg (FPH-30), and 50 g/kg (FPH-50) dry matter, respectively substituting 0, 5.3, 16.3, and 27.3% of fish meal with dietary fish meal. Quadruplicate groups of 25 juvenile largemouth bass with initial body weight 9.51 ± 0.03 g were fed during the 56-day feeding experiment. Experimental results showed that fish fed FPH-30 obtained a significantly higher weight gain rate (WGR), specific growth rate (SGR), protein efficiency ratio (PER), and significant feed conversion rate (FCR) compared to the other three groups (P < 0.05). FPH-30 group also promoted protein synthesis and deposition, as evidenced by the higher whole-body crude protein contents, the higher expressions of GH1, IGF-1, TOR, and S6K in the liver, and SLC7A5, SLC7A8, SLC38A2, and SLC15A2 in the intestine than the other three groups. FPH-30 group could also enhance intestinal health status by increasing the activities of SOD, POD, CAT, GSH-Px, and T-AOC activities by upregulating the expressions of SOD, GSH-Px, IL1β, and TNFβ, and by reducing the MDA contents and the expressions of IL15, Caspase 3, Caspase 9, and Caspase 10 than other groups. Compared to the control group, the Actinobacteriota abundance markedly decreased in FPH treatments, while the variation tendency of the phylum Proteobacteria was opposite. The peak value of Firmicutes:Bacteroidetes ratio and the lowest of Bacteroidetes abundance were seen in largemouth bass fed FPH-30 (P < 0.05). Fish in three FPH treatments had lower abundances of opportunistic pathogens Staphylococcus and Plesiomonas than fish in the control group. In conclusion, FPH is a nutritious feed ingredient for juvenile largemouth bass, and can be added to a dietary level of 30 g/kg dry matter replacing fish meal without any negative effect on growth and feed utilization. FPH supplements could also strengthen the intestinal immune mechanisms of largemouth bass to tackle the immunodeficiency produced by fish meal replacement.

Keywords: fish protein hydrolysates; intestinal health; intestinal immunity; intestinal microflora; largemouth bass; protein synthesis.

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Conflict of interest statement

ZC and TL are employed by Guangdong Xipu Biotechnology Co., Ltd. HLi is employed by New Hope Liuhe Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

Figure 1
Figure 1
Relative gene expressions of the GH/IGF-1 axis and TOR signal pathway in the hepatopancreas of largemouth bass (Micropterus salmoides) fed the diets containing different supplementation levels of fish protein hydrolysate (FPH). Lowercase letters (a, b, c or d) indicate a significant effect of relative gene expressions of the GH/IGF-1 axis and TOR signal pathway in hepatopancreas (P < 0.05), and the other figures are the same as in this figure.
Figure 2
Figure 2
Relative expression of immune response related gene in the intestine of largemouth bass (Micropterus salmoides) fed the diets containing different supplementation levels of fish protein hydrolysate (FPH).
Figure 3
Figure 3
Relative expression of relative peptide and AA transporters related genes in the intestine of largemouth bass (Micropterus salmoides) fed the diets containing different supplementation levels of fish protein hydrolysate (FPH).
Figure 4
Figure 4
The Venn diagram displays the overlapping and unique OTUs (operational taxonomic units) in largemouth bass (Micropterus salmoides) fed the diets containing different supplementation levels of fish protein hydrolysate (FPH).
Figure 5
Figure 5
Principal coordinate analysis (PCoA) analysis of the unweighted UniFrac scores of intestinal microflora of largemouth bass (Micropterus salmoides) fed the diets containing different supplementation levels of fish protein hydrolysate (FPH).
Figure 6
Figure 6
Histogram of relative abundance of intestinal microflora of largemouth bass (Micropterus salmoides) fed the diets containing different supplementation levels of fish protein hydrolysate (FPH) at the phylum level.
Figure 7
Figure 7
Histogram of relative abundance of intestinal microflora of largemouth bass (Micropterus salmoides) fed the diets containing different supplementation levels of fish protein hydrolysate (FPH) at the genus level.
See this image and copyright information in PMC

References

    1. Wang XJ, Hu JW, Wang Y, Zhou JH, Wu YB, Fang HY. Research progress of nutritional requirement for largemouth bass (Micropterus salmoides). Feed Res. (2019) 8:112–6. 10.13557/j.cnki.issn1002-2813.2019.08.031 - DOI
    1. Fishery Fishery Administration of the Ministry of Agriculture and Rural Affairs National Fisheries Technology Extension Station Chinese Fisheries Society . China fishery statistical yearbook-2020. Beijing: China Agriculture Press (2020).
    1. Chen NS, Xiao WW, Liang QL, Zhou HY, Ma XL, Zhao M. Effects of dietary lipid to protein ratios on growth performance, body composition and non-specific immunity of largemouth bass (Micropterus salmoides). J Fishof China. (2012) 36:1270–80. 10.3724/SP.J.1231.2012.27890 - DOI
    1. Cai ZN, Qian XQ, Xie SQ. Optimal dietary protein concentrations for largemouth bass (Micropterus salmoides) of different sizes (10 to 500 g). Aquac Int. (2020) 28:831–40. 10.1007/s10499-019-00498-9 - DOI
    1. Olsen RL, Hasan MR. A limited supply of fishmeal: impact on future increases in global aquaculture production. Trends Food Sci Technol. (2012) 27:120–8. 10.1016/j.tifs.2012.06.003 - DOI

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