Effects of fishmeal replacement with cottonseed protein concentrate on growth, digestive proteinase, intestinal morphology and microflora in pearl gentian grouper (♀ Epinephelus fuscoguttatus  × ♂ Epinephelus lanceolatu )

Abstract

A 56-day feeding trial was conducted to study the effects of cottonseed protein concentrate (CPC) as fishmeal (FM) replacement on growth, digestive proteinase, intestinal morphology and microflora in pearl gentian grouper (♀Epinephelus fuscoguttatus × ♂Epinephelus lanceolatu). FM of 0% (FM), 12.00% (R12), 24.00% (R24), 36.00% (R36), 48.00% (R48) and 60.00% (R60) was replaced with CPC, to prepare six diets and feed groupers. Weight gain (WG) and specific growth rate (SGR) were highest in the R24 group, and the lowest feed coefficient rate (FCR) was observed in this group compared with the other groups (p < .05). Pepsin activity of the R12 group and chymotrypsin activity of the R36 group reached significant maximum (p < .05). With increasing CPC replacement, the plica height and width and the lamina propria thickness of intestine decreased significantly (p < .05). 16S rDNA amplicon sequencing suggested dominant intestinal microflora of grouper subjected to different treatments was similar. At the phylum level, the abundance of Proteobacteria, Firmicutes, Verrucomicrobia, Bacteroidetes and Actinobacteria was high, while Photobacterium, Pseudoxanthomonas, Romboutsia, Akkermansia, Vibrio and Bifidobacterium were the dominant taxa at the genus level. The abundance of probiotics (Bifidobacterium) decreased, whereas the abundance of opportunistic pathogen (Proteobacteria, Actinobacteria and Vibrio) increased. These results suggested that CPC replacement affected growth, digestive proteinase activity, intestinal morphology and microflora structure in grouper. Under the conditions of this experiment, the fishmeal replacement with CPC (24% level) yielded the most satisfactory results, providing reference for sustainable aquaculture. K E Y W O R D S cottonseed protein concentrate, digestive proteinase, fishmeal replacement, growth, intestinal microflora, intestinal morphology

Advances in practical feed formulation and adoption for hybrid grouper (Epinephelus fuscoguttatus♀ × E. lanceolatus♂) aquaculture

“…Several studies have recently addressed the suitability of different raw materials for TGGG hybrid grouper, including soybean protein concentrate (SPC) 35,89,90 cottonseed protein concentrate, 89,91 haemoglobin meal 92 mixed rendered animal proteins 93 and poultry meal. 94 Those that have addressed raw materials have looked at the TA B L E 5 Summary of vitamin requirement studies for grouper species capacity of specific raw materials to replace fish meal protein, and the results are therefore a combination of our knowledge on the value of fish meal and the value of the alternative proteins being tested.…”

Supplementing Chitosan Oligosaccharide Positively Affects Hybrid Grouper (Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂) Fed Dietary Fish Meal Replacement With Cottonseed Protein Concentrate: Effects on Growth, Gut Microbiota, Antioxidant Function and Immune Response

“…According to the methods of Chen et al (2020), microbiome sequencing technology was used to detect the hybrid grouper intestinal microbiota, with the assistance of Biomarker Technologies Co., Ltd. (Beijing, China). The microbiome analyses of the samples of each treatment were performed in triplicate.…”

“…As a new type of plant protein, cottonseed protein concentrate (CPC) has recently received much attention from researchers (Wan et al, 2018;Ye et al, 2020). Accordingly, the experimental replacement of fish meal with CPC has been conducted for certain aquaculture species, such as hybrid grouper (Chen et al, 2020), juvenile golden pompano (Trachinotus ovatus) (Shen et al, 2020), and pacific white shrimp (Litopenaeus vannamei) (Wan et al, 2018). However, researchers have found that replacing fish meal with high levels of CPC can decrease growth performance and cause intestinal inflammation issues in hybrid groupers (Yin et al, 2018).…”

Addition of enzyme‐digested hydrolysed porcine mucosa to low‐fishmeal feed improves growth, intestinal microbiota, and intestinal peptide and amino acid transporter expressions in hybrid groupers ( Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂)

“…With 60 g/kg EH addition, the Shannon index was significantly and diversity of intestinal bacterial communities were significantly increased compared with other groups. The dominant bacterial phyla in vertebrates include Proteobacteria, Firmicutes and Bacteroidetes (Chen et al., 2020; Qin et al., 2010; Ye et al., 2020), which accounted for 86.30%, 87.93%, 64.02%, 84.88% and 86.32% of the relative abundances of the entire flora in groups EH0, EH3, EH6, EH9 and EH12, respectively. The top 10 dominant phyla and genera had no significant difference in category.…”

“…Since vegetable protein sources are rich in protein and relatively cheap, many researchers have studied their use as potential FM substitutes for feeding to hybrid groupers. These include cottonseed protein concentrate (Chen et al., 2020; Yin et al., 2018), soy protein concentrate (Faudzi et al., 2018) and low‐gossypol cottonseed protein (Ye et al., 2020). Such research has reduced the FM content and cost of fish feed (Ye et al., 2019; Zhang, Pu, et al., 2018).…”