Low-fish-meal compound feed for improving muscle fiber density and muscle texture performance of pelteobagrus fulvidraco and application of low-fish-meal compound feed

Abstract

The invention discloses a low-fish-meal compound feed for improving the muscle fiber density and muscle texture performance of pelteobagrus fulvidraco and application of the low-fish-meal compound feed, and belongs to the field of feeds. After the mixed plant protein source (corn protein powder, rapeseed meal and soybean meal) is used for replacing 50% of fish meal, the growth performance, muscle fiber density and texture performance (hardness, elasticity and rupture strength) of the pelteobagrus fulvidraco have significant negative changes; by adding 0.6% of lysine, the adverse effects of the low-fish-meal feed on the muscle fiber density and the muscle texture performance of the pelteobagrus fulvidraco can be remarkably improved, namely, high muscle tenderness, elasticity and rupture strength can be kept, and the low dorsal muscle fiber density caused by low fish meal can be recovered; however, when the addition amount of the lysine exceeds 0.6%, the lysine has a significant negative effect on the growth of the pelteobagrus fulvidraco, and the influence of the lysine on the muscle growth and texture performance of the pelteobagrus fulvidraco is related to the regulation of ERK1 / 2 signal activity.

Description

Technical Field

[0001] The present invention belongs to the field of feeds, and more specifically, relates to a low-fishmeal compound feed for improving the muscle fiber density and muscle texture properties of Pelteobagrus fulvidraco and its application. Background Art

[0002] The muscle tissue of aquatic animals is an important source of animal protein for humans. Ensuring the high-quality growth of the muscles of farmed fish is one of the core goals of aquaculture. At present, the fishmeal resources on which aquaculture highly depends are increasingly scarce, while non-fishmeal protein sources with a wide range of sources often lack essential amino acids such as lysine, which easily cause problems such as slow muscle growth and decreased quality of farmed fish (Qian Y, Limbu S, Qiao F, et al. Seeking the best alternatives: A systematic review and meta-analysis on replacing fishmeal with plant protein sources in carnivorous fish species. Reviews in Aquaculture. 2024, DOI: 10.1111 / raq.12888.), which has become one of the key issues restricting the sustainable development of aquaculture in China.With the development and application of low-fishmeal diets, the excessive replacement of fishmeal with non-fishmeal protein sources has had varying degrees of negative impacts on the growth and health of various aquatic animals such as yellow catfish ([1] Cao XL, Li ZL, Hu Y. Effects of taurine supplementation in low-fishmeal diets on the growth, digestibility, and intestinal enzyme activities of ricefield eels. South China Fisheries Science. 2021, 17: 64-70. [2] Wang S, Li X, Zhang M, Jiang H, Li M. Dietary supplementation of crystalline amino acid improves growth performance and health of yellow catfish that reduced by plant proteins replacement of fishmeal. Aquaculture Nutrition. 2022, 2022: 1-14. [3] Li X, Wang S, Zhang M, et al. Comprehensive analysis of metabolomics on flesh quality of yellow catfish (Pelteobagrus fulvidraco) fed plant-based protein diet. Frontiers in Nutrition. [4] Xiao YB, Cao SP, Ao Q, et al. Effects of Hermetia illucens larvae meal replacement of fishmeal in low-fishmeal diets on the growth performance, digestive ability, plasma biochemical indices, and related gene expression of hybrid Gibel carp. Acta Hydrobiologica Sinica. 2023, 47: 1363-1373.); further research has demonstrated that restricted muscle growth is an important reason for the poor growth performance of farmed fish fed low-fishmeal diets.Among them, lysine is not only the first limiting amino acid in the vast majority of aquatic feeds but also the key effective amino acid for improving the muscle growth and development of farmed fish ([1] Azizi S, Nematollahi M, Amiri B, Vélez E, Lutfi E, Navarro I, Capilla E, Gutiérrez J. Lysine and leucine deficiencies affect myocytes development and IGF signaling in gilthead sea bream (Sparus aurata). PloS One. 2016, 11: e0147618. [2] Hu Y, Feng L, Jiang W, et al. Lysine deficiency impaired growth performance and immune response and aggravated inflammatory response of the skin, spleen and head kidney in grown-up grass carp (Ctenopharyngodon idella). Animal Nutrition. 2021, 7: 556 - 568.). Exploring the regulatory effect of lysine on muscle growth helps us deeply understand the nutritional regulation mode of fish growth and provides theoretical and practical bases for improving the utilization ability of farmed fish for low-fishmeal and low-protein feeds.

[0003] The yellow catfish (Pelteobagrus fulvidraco) is one of the famous and high-quality aquatic animals for large-scale farming in China, with an annual output of over 620,000 tons. The yellow catfish has a requirement for dietary protein level of over 40% and has a relatively high dependence on fishmeal. The development and utilization of new feed protein sources have alleviated the tight supply situation of fishmeal to a certain extent, but new protein sources lack essential amino acids such as lysine, which easily cause problems such as slow muscle growth and reduced quality of the yellow catfish (Li X, Wang S, Zhang M, et al. Comprehensive analysis of metabolomics on flesh quality of yellow catfish (Pelteobagrus fulvidraco) fed plant-based protein diet. Frontiers in Nutrition. 2023, 10: 1166393.). Summary of the Invention

[0004] In view of the above industrial problems, the main object of the present invention is to reduce the fish meal content in the Pelteobagrus fulvidraco feed by using a mixed plant protein source mainly composed of corn gluten meal to replace fish meal; at the same time, adding a specific proportion of lysine to improve the muscle fiber density and muscle texture properties of farmed Pelteobagrus fulvidraco without affecting its growth performance. In addition, the present invention has screened the key molecular marker protein ERK1 / 2 that regulates the muscle growth of Pelteobagrus fulvidraco under low-fish-meal diet. Previous studies have shown that lysine is the first limiting amino acid for the growth of aquatic animals, but the optimal addition amount of lysine in the low-fish-meal feed of Pelteobagrus fulvidraco has not been clarified, nor has the regulatory effect of lysine on the muscle fiber density and muscle texture properties of Pelteobagrus fulvidraco been explained. The present invention will provide a more precise nutritional regulation strategy for improving the muscle growth and quality of farmed fish in China, and further provide a theoretical and practical basis for improving the utilization ability of farmed fish for low-fish-meal feed.

[0005] The specific technical solution of the present invention is as follows:

[0006] The present invention provides a low-fish-meal compound feed for improving the muscle fiber density and muscle texture properties of Pelteobagrus fulvidraco, which is composed of a basic low-fish-meal feed and lysine; calculated by the weight of the low-fish-meal compound feed, the addition amount of lysine is 0.3%-1.2%;

[0007] The basic low-fish-meal feed replaces 50% of the fish meal by weight with a mixed plant protein source, and the mixed plant protein source includes corn gluten meal, rapeseed meal and soybean meal; after replacement, the fish meal content in the basic low-fish-meal feed is reduced from 30% to 15%.

[0008] Preferably, the addition amount of lysine is 0.6%. In the experimental results of adding lysine to improve the growth and muscle texture properties of Pelteobagrus fulvidraco in the low-fish-meal feed of the present invention, adding 0.6% lysine to the low-fish-meal feed (15% fish meal) can effectively improve the growth performance of Pelteobagrus fulvidraco and has a significant improvement effect on its muscle texture properties.

[0009] Specifically, the basic low-fish-meal feed is composed of the following raw materials in weight percentages:

[0010] Fish meal 15%, corn gluten meal 25%, soybean meal 16%, rapeseed meal 16%, fish oil 5.5%, corn starch 11%, casein 0.8%-1.7%, microcrystalline cellulose 4.69%, calcium dihydrogen phosphate 1.5%, vitamin / mineral premix 1.2%, choline chloride 0.11%, calcium dihydrogen phosphate 1.5%, sodium carboxymethyl cellulose 2%.

[0011] The present invention also provides the application of the above low-fish-meal compound feed in the cultivation of Pelteobagrus fulvidraco.

[0012] Specifically, the low-fishmeal compound feed is used to improve the muscle growth, muscle fiber density and muscle texture properties of Pelteobagrus fulvidraco, and the specific manifestations are as follows:

[0013] Reduce the viscerosomatic index of Pelteobagrus fulvidraco;

[0014] Increase the elasticity, breaking strength and tenderness of the muscle of Pelteobagrus fulvidraco;

[0015] Restore the decrease in muscle fiber density and / or specific growth rate caused by the low fishmeal content in the basal low-fishmeal feed.

[0016] Preferably, during application, lysine in the low-fishmeal compound feed restores the decrease in muscle fiber density caused by the low fishmeal content in the basal low-fishmeal feed by activating the ERK1 / 2 pathway. Adding lysine to the low-fishmeal feed can effectively improve the muscle fiber growth of fish, and lysine regulates the transcription of myogenic regulatory factor myf5 and the proliferation of satellite cells in Pelteobagrus fulvidraco through the ERK1 / 2 pathway. Therefore, ERK1 / 2 is a new key molecular marker identified in the present invention for regulating the muscle growth of Pelteobagrus fulvidraco.

[0017] The present invention also provides a method for culturing Pelteobagrus fulvidraco, using the low-fishmeal compound feed to raise Pelteobagrus fulvidraco.

[0018] Preferably, during feeding, control the dissolved oxygen content in the culture water body > 7.5 mg / L, the ammonia nitrogen content < 0.05 mg / L, the pH is 6.5 - 7.0, the water temperature is 29 ± 2 °C, and the light cycle is 12 hours of light / 12 hours of darkness.

[0019] Advantages of the present invention:

[0020] After the present invention replaces 50% of fishmeal with a mixed plant protein source (corn gluten meal, rapeseed meal, soybean meal), significant negative changes occur in the growth performance, muscle fiber density and texture properties (hardness, elasticity, breaking strength) of Pelteobagrus fulvidraco. However, adding 0.6% lysine can significantly improve the adverse effects of the low-fishmeal feed on the muscle fiber density and muscle texture properties of Pelteobagrus fulvidraco, manifested as maintaining higher muscle tenderness, elasticity and breaking strength, and restoring the low dorsal muscle fiber density and low specific growth rate caused by low fishmeal; but when the lysine addition amount exceeds 0.6%, it will have a significant negative effect on the growth performance of Pelteobagrus fulvidraco. And the effect of lysine on the muscle growth and texture properties of Pelteobagrus fulvidraco is related to the regulation of ERK1 / 2 signal activity. Description of the Drawings

[0021] Figure 1Adding lysine to low-fishmeal diets to improve the growth of Pelteobagrus fulvidraco; among them, A is the flow chart for making experimental diets; B and C are the final body weight (FBW) and specific growth rate (SGR) of Pelteobagrus fulvidraco growth performance respectively; D and E are the viscerosomatic index (VSI) and hepatosomatic index (HSI) of Pelteobagrus fulvidraco body shape indexes respectively.

[0022] Figure 2 Adding lysine to low-fishmeal diets to improve the muscle texture properties of Pelteobagrus fulvidraco; among them, A-D are the texture parameters (hardness, tenderness, elasticity and breaking strength) of the dorsal muscle of Pelteobagrus fulvidraco.

[0023] Figure 3 Adding 0.6% lysine to low-fishmeal diets to improve the muscle fiber density of Pelteobagrus fulvidraco and activate the ERK1 / 2 signal; among them, A is the transverse section of the dorsal muscle of Pelteobagrus fulvidraco stained with H&E; B is the statistical analysis of the muscle fiber density of the dorsal muscle of Pelteobagrus fulvidraco; C is the gene expression of the myogenic regulatory factors (myf5, myod1, ccnd1, myogenin) in the raw meat of the dorsal muscle of Pelteobagrus fulvidraco; D and E are the protein expression and quantitative analysis of ERK1 / 2 and pERK1 / 2 in the dorsal muscle of Pelteobagrus fulvidraco respectively;

[0024] Figure 4 Experiment on incubating myoblasts with different amino acids; among them, A is the schematic diagram of incubating myoblasts with different amino acids; B is the expression level of the myogenic regulatory factor myf5; C and D are the protein expression and quantitative analysis of ERK1 / 2 and pERK1 / 2 respectively;

[0025] Figure 5 Experiment on feeding Pelteobagrus fulvidraco with the ERK1 / 2 inhibitor U0126; A is the schematic diagram of feeding Pelteobagrus fulvidraco with the ERK1 / 2 inhibitor U0126; B-D are the protein expression, quantitative analysis of ERK1 / 2 and pERK1 / 2 in the dorsal muscle of Pelteobagrus fulvidraco and the expression of muscle growth-related genes (myf5, myod1, paxbp1, ccnd1) after feeding Pelteobagrus fulvidraco with U0126. Detailed implementation mode

[0026] Example 1

[0027] 1. Feed formula

[0028] In this experiment, fish meal, corn gluten meal, rapeseed meal and soybean meal were used as protein sources, and fish oil was used as the fat source. A total of six diets were formulated, namely a low-fish meal control diet (LFM, 15% fish meal) without added lysine (abbreviated as Lys), lysine diets supplemented with 0.3% (LFM + 0.3% Lys), 0.6% (LFM + 0.6% Lys), 0.9% (LFM + 0.9% Lys), 1.2% (LFM + 1.2% Lys), and a high-fish meal diet (HFM, 30% fish meal) without added lysine. The diet formulations and the nutritional components of the four diets are shown in Table 1. The protein content was 37.12% - 37.66%, the fat content was 8.72% - 9.30%, the ash content was 5.99% - 6.91%, and the moisture content was 7.16% - 8.18%. The feed raw materials were passed through a 40-mesh sieve, thoroughly mixed, and then made into 2-mm pellets by a feed machine (SLR-45, Fisheries Machinery Research Institute, Chinese Academy of Fishery Sciences), dried at 60 °C, and stored sealed in a 4 °C cold storage for later use.

[0029] 2. Rearing of experimental fish and experimental treatment

[0030] Yellow catfish were purchased from Dengjiazhou Aquaculture Farm (Wuhan, Hubei, China), and then temporarily raised in a 1500-L round tank for 2 weeks of acclimation, with feeding twice a day at 8:30 and 16:30. The aquaculture experiment was carried out in an indoor recirculation system. One day before the experiment, the experimental fish were starved for 24 h. Individuals with strong physiques and uniform specifications (30 tails, average weight 3.3 ± 0.05 g) were selected, weighed, and then placed into 18 aquaculture square tanks (150 L, 3 tanks / treatment, 30 tails / tank). During the experiment, an air stone was used to continuously aerate and increase oxygen during non-feeding periods. The water temperature ranged from 29 ± 2 °C, the light cycle was 12L / 12D, the light time was from 8:00 to 20:00, and LED lights were used as the light source. The dissolved oxygen and ammonia nitrogen in the water were monitored weekly, with the dissolved oxygen > 7.5 mg / L, ammonia nitrogen < 0.05 mg / L, and pH 6.5 - 7.0. The aquaculture experiment period was 8 weeks, with feeding twice a day (8:30, 16:30).

[0031] Table 1 Formulations and basic components of experimental diets

[0032]

[0033]

[0034] Vitamin premix (mg / kg or IU / kg feed): retinyl acetate, 10000 IU; cholecalciferol, 1000 IU; all-rac-α-tocopheryl acetate, 30 IU; menadione nicotinamide bisulfite, 7 mg; thiamine hydrochloride, 6 mg; riboflavin, 3 mg; pyridoxine hydrochloride, 12 mg; calcium D-pantothenate, 30 mg; niacin, 50 mg; biotin, 1 mg; folic acid, 6 mg; cyanocobalamin, 0.03 mg.

[0035] Mineral salt premix (mg / kg feed): calcium dihydrogen phosphate monohydrate, 1000 mg; ferrous sulfate heptahydrate, 40 mg; zinc sulfate heptahydrate, 40 mg; manganese sulfate monohydrate, 40 mg; copper sulfate pentahydrate, 2 mg; calcium iodate hexahydrate, 3 mg; sodium selenite, 0.05 mg; cobalt sulfate, 0.05 mg.

[0036] 3. Samples and data analysis

[0037] At the beginning of the experiment, three groups (9 fish per group) of fish were randomly selected, blotted dry, weighed, and placed in a -20 °C refrigerator for initial body composition analysis. After 8 weeks of feeding, the feeding experiment was terminated. The experimental fish were starved for 24 h, weighed, and sampled. Ten fish were randomly selected from each tank, anesthetized with MS-222 (80 mg / L), and then 2 fish were blotted dry, weighed, and stored in a -20 °C refrigerator for final body composition analysis; 4 fish were weighed respectively, body length was measured, and then the internal organs were removed and weighed to calculate the viscerosomatic index and hepatosomatic index of the experimental fish; the last 4 fish were used to collect muscle samples. The experimental fish were dissected on an ice plate, and muscle tissue samples of 2 fish were wrapped with tin foil and stored in an -80 °C refrigerator; 2 fish were stored in 4% paraformaldehyde for fixation for HE staining.

[0038] The moisture, protein, fat, and ash of the feed and whole fish samples were analyzed according to the methods described by AOAC (2003). Moisture was measured by drying at 105 °C to a constant weight; crude protein was determined using a Kjeldahl nitrogen analyzer (2300 Kjeltec Analyzer Unit, FOSS TECATOR, Sweden); crude fat was determined by Soxhlet extraction (Soxtoc system HT6, Tecator, Haganas, Sweden) using ether as the solvent; ash was measured by complete combustion in a muffle furnace (Jianli Electric Furnace Factory, Yingshan County, Hubei, China) at 550 °C.

[0039] HE staining: After the muscle tissue was fixed in 4% paraformaldehyde, the tissue was dehydrated in a series of ethanol with increasing concentrations, embedded in paraffin, and cut into 4-μm-thick sections, with 12 consecutive sections for each sample. After HE staining of the tissue sections, morphological differences were observed and photographed.

[0040] Determination of muscle texture parameters: Remove the lateral skin of the fish to expose the fresh muscle. Use a TMS-TOUCH texture analyzer (Food Technology Corporation, West Sussex, VA, USA) to perform texture profile analysis (TPA) through double compression, including hardness, resilience, tenderness, rupture strength, etc.

[0041] Western blot: Extract proteins from Pelteobagrus fulvidraco and measure the protein concentration using the bicinchoninic acid (BCA) protein assay (Biosharp, Beijing, China). Separate 30 μL of protein using a 10% SDS-PAGE gel and then transfer it to a polyvinylidene difluoride (PVDF) membrane. Immunoblotting was performed using rabbit anti-ERK (1:2000, T40071), pERK1 / 2 (1:2000, T40072), and GAPDH (1:10000, 10494-1-AP) to detect phosphorylated pERK1 / 2 and GAPDH.

[0042] Specific growth rate (SGR, % / d) = (ln average body weight after the experiment - ln average body weight before the experiment) × 100 / number of feeding days; hepatosomatic index (HSI, %) = liver weight (g) / body weight (g) × 100; viscerosomatic index (VSI, %) = visceral weight (g) / body weight (g) × 100; the results are expressed as mean ± standard error of the mean (S.E.M). Statistical analysis was performed using the statistical software SPSS 19.0. The experimental results were first subjected to a homogeneity of variance test; after homogeneity of variance, one-way analysis of variance (Oneway ANOVA) was performed; if the differences between the experimental groups were significant, Duncan's multiple comparison was performed. P < 0.05 indicates a significant difference.

[0043] 4. Experimental results

[0044] (1) Adding lysine to low-fishmeal diets improves the growth and muscle texture properties of Pelteobagrus fulvidraco

[0045] Using a mixed plant protein source (corn gluten meal, rapeseed meal, soybean meal) as a fishmeal replacement protein source, high-fishmeal (HFM, 30% fishmeal), low-fishmeal (LFM, 15% fishmeal), and low-fishmeal diets with different lysine addition levels (0.3%, 0.6%, 0.9%, 1.2%) were designed and prepared ( Figure 1 A). After an 8-week feeding experiment, it was found that the low-fishmeal diet significantly inhibited the growth performance of Pelteobagrus fulvidraco, while adding 0.3% and 0.6% lysine could significantly improve its growth (FBW, SGR) ( Figure 1B and C), and adding more than 0.6% has a negative effect on its growth; in addition, adding 0.6%, 0.9% and 1.2% lysine can significantly reduce the viscerosomatic index (VSI) and hepatosomatic index (HSI) of yellow catfish ( Figure 1 D and E). Further analysis of the muscle texture index found that LFM significantly increased the hardness, resilience and rupture strength of yellow catfish muscle, while reducing its tenderness; adding 0.6%, 0.9% and 1.2% lysine restored the tenderness of yellow catfish muscle to a certain extent and reduced its hardness, while adding 0.6% lysine could still maintain relatively high elasticity and rupture strength ( Figure 2 A-D). There were no significant differences in the dry matter, crude fat and ash content of yellow catfish among different treatment groups. The low-fishmeal diet did not significantly affect the crude protein content, while the crude protein content decreased after adding 0.3% lysine, and the crude protein content gradually increased with the increase of lysine addition (Table 2).

[0046] Based on the above results, adding 0.6% lysine to the low-fishmeal diet (15% fishmeal) can effectively improve the growth performance of yellow catfish and significantly improve its muscle texture properties.

[0047] Table 2 Effects of adding lysine in the diet on the proximate composition of yellow catfish (mean ± SEM)

[0048]

[0049] Data in the same column with different lowercase letters in the superscript indicate significant differences (P < 0.05), and data with the same lowercase letters or no letters indicate no significant differences (P > 0.05).

[0050] (2) Adding 0.6% lysine to the low-fishmeal diet improves the muscle fiber density of yellow catfish and activates the ERK1 / 2 signal

[0051] Based on the above experimental results, we selected three treatment groups of HFM, LFM and LFM + 0.6% lysine for further experimental analysis. Through HE section of the dorsal muscle, it was found that the low-fishmeal diet significantly reduced the muscle fiber density of the dorsal muscle, while adding 0.6% lysine could significantly improve the muscle fiber density of the dorsal muscle ( Figure 3 A and B). In addition, the low-fishmeal diet significantly reduced the ERK1 / 2 signal and the expression of myogenic regulatory factors in the dorsal muscle of yellow catfish, while adding 0.6% lysine significantly activated the ERK1 / 2 signal in the dorsal muscle of yellow catfish and increased the expression of myogenic regulatory factors ( Figure 3 C-E).

[0052] After incubating mouse myoblasts (C2C12) with lysine, methionine, and histidine added to the basal medium (DMEM) for 24 hours ( Figure 4 A), it was found that lysine is the key effector amino acid that activates the ERK1 / 2 pathway in muscle cells and induces the transcription of the myogenic regulatory factor myf5 ( Figure 4 B-D); while feeding the yellow catfish with the ERK1 / 2 inhibitor U0126 ( Figure 5 A), it was found that the phosphorylation level of muscle ERK1 / 2 was inhibited, and the transcription level of muscle myf5 was significantly decreased ( Figure 5 B-D). These results indicate that adding lysine to low-fishmeal diets can effectively improve fish myofiber growth, and lysine regulates the transcription of myogenic regulatory factors such as myf5 in yellow catfish through the ERK1 / 2 pathway. Therefore, ERK1 / 2 is a newly identified key molecular marker for regulating yellow catfish muscle growth in this invention.

[0053] This study found that after replacing 50% of the fishmeal with a mixed plant protein source (corn gluten meal, rapeseed meal, soybean meal), significant negative changes occurred in the growth performance, myofiber density, and texture properties (hardness, elasticity, breaking strength) of yellow catfish. However, adding 0.6% lysine could significantly improve the adverse effects of low-fishmeal diets on the myofiber density and muscle texture properties of yellow catfish, manifested as maintaining higher muscle tenderness, elasticity, and breaking strength, and restoring the low dorsal muscle myofiber density caused by low fishmeal; but when the lysine addition amount exceeded 0.6%, it had a significant negative effect on the growth performance of yellow catfish. The effect of lysine on yellow catfish muscle growth and texture properties is related to the regulation of ERK1 / 2 signal activity. In summary, adding 0.6% lysine to the low-fishmeal diet replacing 50% of the fishmeal with a mixed plant protein source (corn gluten meal, rapeseed meal, soybean meal) has the best effect on improving the growth performance, myofiber density, and muscle texture properties of yellow catfish, and ERK1 / 2 is the newly identified key molecular marker for regulating yellow catfish muscle growth in this invention.

Claims

1. A low-fishmeal compound feed for improving muscle fiber density and muscle texture performance of yellow catfish, characterized in that: It is composed of basic low fish meal feed and lysine; the amount of lysine added is 0.3%-1.2% based on the weight of the low fish meal compound feed; The basic low-fishmeal feed replaces 50% of fishmeal by weight with a mixed plant protein source, wherein the mixed plant protein source comprises corn protein meal, rapeseed meal and soybean meal; after the replacement, the fishmeal content in the basic low-fishmeal feed is 15%.

2. The low fish meal compound feed according to claim 1, characterized in that: The added amount of lysine is 0.6%.

3. The low fish meal compound feed according to claim 2, characterized in that: The basic low fish meal feed is composed of the following raw materials in percentage by weight: Fish meal 15%, corn gluten meal 25%, soybean meal 16%, rapeseed meal 16%, fish oil 5.5%, corn starch 11%, casein 0.8%-1.7%, microcrystalline cellulose 4.69%, monocalcium phosphate 1.5%, vitamin / mineral premix 1.2%, choline chloride 0.11%, monocalcium phosphate 1.5%, sodium carboxymethyl cellulose 2%.

4. Use of the low fish meal compound feed according to any one of claims 1 to 3 in yellow catfish farming.

5. The use according to claim 4, characterized in that: The low fish meal compound feed is used to improve the muscle growth, muscle fiber density and muscle texture performance of yellow catfish, which is specifically manifested as follows: Reduce the body index of yellow catfish; Increase the elasticity, bursting strength and tenderness of yellow catfish muscle; To restore decreased muscle fiber density and / or specific growth rate caused by low fishmeal content in basal low fishmeal diets.

6. The use according to claim 5, characterized in that: When used, the lysine in the low fish meal compound feed restores the decreased muscle fiber density caused by the low fish meal content in the basic low fish meal feed by activating the ERK1 / 2 pathway.

7. A method for cultivating yellow catfish, characterized in that: The low-fishmeal compound feed according to any one of claims 1 to 3 is used to feed yellow catfish.

8. The method for cultivating yellow catfish according to claim 7, characterized in that: During breeding, the dissolved oxygen content of the breeding water is controlled to be greater than 7.5 mg / L, the ammonia nitrogen content is less than 0.05 mg / L, the pH is 6.5-7.0, the water temperature is 29±2°C, and the light cycle is 12 hours light / 12 hours dark.

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