Preparation method of complete puffed compound feed for trachinotus ovatus

Abstract

The invention relates to a preparation method of a complete puffed compound feed for trachinotus ovatus. Belongs to the technical field of expanded feed for marine fish. The pregelatinized starch is used for lowering the temperature of the puffing and tempering section, and the water vapor is used for adjusting the initial water content to 19-23%, so that the high-temperature inactivation is reduced; the passing time of the screw section is controlled, and mechanical shearing and heat accumulation are reduced; the instant high-temperature pressure of the puffing section is suddenly reduced to form a porous structure, and the dissolution rate control of crude protein and crude fat is promoted by matching with the proper proportion of the pre-gelatinized corn starch and the cassava starch and the tackifying effect of the poultry eggs; probiotics and metabolites thereof in the fermentation liquor are reserved to the maximum extent; the viable count of probiotics in the puffed granules is remarkably increased and is far higher than that of conventional high-temperature granulation; butyric acid, lactic acid, antibacterial peptide and the like generated by fermentation are blended into the feed, so that growth of pathogenic bacteria is inhibited, and intestinal health of the trachinotus ovatus is enhanced.

Description

TECHNICAL FIELD

[0001] The application relates to a preparation method of a full-value puffed compound feed, in particular to a preparation method of a full-value puffed compound feed for Trachinotus ovatus. BACKGROUND

[0002] Trachinotus ovatus belongs to Perciformes, has an oval body shape, and has a silver-white body with golden yellow stripes. The fish is delicious and tender, is a precious marine economic fish in the south of China, and is deeply loved by people all over the country. The fish grows rapidly, and can reach a marketable size of 500-600 g after 5-6 months of breeding from a fry. Therefore, the fish has a broad breeding prospect. Due to the rapid growth, the fish has high nutritional requirements for feed: in the juvenile stage, the crude protein is 42%-45%, the crude fat is 10%-12%, and the carbon is less than or equal to 15%; in the adult stage, the crude protein is 38%-40%, the crude fat is 8%-10%, and the carbon is less than or equal to 15%. Fish meal is preferred for protein, and the content of soybean meal is controlled to be less than 15%; fish oil is preferred for fat, and a small amount of vegetable oil can be supplemented.

[0003] The nutritional components of feed not only affect the normal growth of fish, but also affect the immune disease resistance of fish. Meanwhile, for breeders, the price of feed is also a sensitive factor. Fish meal and fish oil are the main cost sources, but the plant-derived protein and fat must be limited within a certain range. Therefore, the breeding cost of Trachinotus ovatus is always high.

[0004] Black soldier fly larvae contain a large amount of protein and fat, and can be applied to the production of animal feed, and are a resource insect with great application prospect. In the prior art, there are reports on feed containing black soldier fly larvae, for example, the invention patent with the authorization announcement number CN113317413B discloses a fermentation feed processing method for aquatic products based on black soldier fly and application, and the technical scheme is as follows:

[0005] (1) Bacillus subtilis, Saccharomyces cerevisiae and lactic acid bacteria are respectively inoculated into corresponding liquid culture media for activation culture, and bacillus subtilis fermentation seed liquid, saccharomyces cerevisiae fermentation seed liquid and lactic acid bacteria fermentation seed liquid are respectively obtained; the lactic acid bacteria are composed of lactobacillus plantarum, fermentative lactobacillus, parafarnsceviciae, bacillus coagulans and lactobacillus rhamnosus;

[0006] (2) An anaerobic fermentation culture medium is prepared, and the weight percentage of each component is as follows: 50% of black soldier fly homogenate, 17.5% of bran, 16.5% of rice chaff, 15% of secondary powder and 1% of acid protease;

[0007] (3) The activated seed liquids are inoculated into the anaerobic fermentation culture medium, and are uniformly mixed to obtain an anaerobic fermentation mixture with a water content of 54%;

[0008] (4) anaerobic fermentation under sealed condition, fermentation temperature is 30 DEG C, after 7 days of fermentation, the finished product is obtained.

[0009] The fermentation feed prepared by the scheme needs to be added to ordinary aquatic feed when used. Furthermore, the feed is Chinese soft-shelled turtle feed.

[0010] Different aquatic animals have different feeding habits. Unlike Chinese soft-shelled turtles or benthic fish, goldfish belongs to warm water fish in the upper layer, and floating feed must be used during cultivation. Therefore, as the main feed of goldfish, it must have suitable bulk density and sufficient water stability, and suitable bulk density can make the feed float on the water surface, and sufficient water stability can make the feed not disperse for a long time, providing sufficient feeding time for goldfish. In the prior art, the bulk density of the feed can be reduced by puffing and granulation; at the same time, puffing can also improve the utilization rate of plant protein and have a certain sterilization effect. However, the conventional puffing and granulation can kill pathogenic bacteria, but also can kill probiotics in the fermentation liquor. Therefore, feed enterprises usually use a post-spraying scheme for addition. However, the fermentation liquor added by post-spraying will obviously increase the dissolution rate.

[0011] Therefore, there is an urgent need in the art for an economic cost moderate, containing live probiotics, and low dissolution rate of goldfish puffed feed. SUMMARY

[0012] The present application solves the above problems, and provides a preparation method of a full-value puffed compound feed for goldfish.

[0013] The technical scheme for solving the above problems is as follows:

[0014] S1, removing impurities and sterilizing 3-5 year-old black soldier fly larvae;

[0015] S2, beating the black soldier fly larvae into insect paste;

[0016] S3, adding soybean meal, chitooligosaccharide and water to the insect paste to prepare a substrate, and the water content of the substrate is controlled at 50-60%;

[0017] S4, adding a compound microbial agent to the substrate, adjusting the temperature to 30-38 DEG C, and performing aeration fermentation for 30-40 h; then stopping aeration, and after 5-7 days of closed fermentation, a fermentation liquor is prepared;

[0018] S5, preparing raw materials according to a basic formula, crushing and sieving, and uniformly mixing with the fermentation liquor or a powder prepared from the fermentation liquor; inputting the prepared raw materials into a puffing and granulating machine to prepare feed particles; finally, controlling the water content of the finished feed particles to be within 10%; during the puffing and granulating process,

[0019] In the conditioning section, the temperature is controlled at 70-80℃, the initial moisture content is controlled at 19-23% by inputting water vapor, and the pressure is 0.2-0.3 MPa;

[0020] In the screw section, the temperature is controlled at 90-110℃, the pressure is 2.0-5.0 MPa, and the passing time is controlled at 10-15 seconds;

[0021] In the expansion section, the temperature is controlled at 120-130℃, the pressure is suddenly reduced to 0.1-0.2 MPa, and the passing time is 0.1-0.5 seconds.

[0022] Preferably, in step S1, the sterilization is selected from one of the instant high-temperature sterilization and autoclave sterilization.

[0023] Preferably, in step S2, the mechanical used is a homogenizer.

[0024] Preferably, in step S3, the mass parts of the insect pulp, soybean meal and chitosan are as follows: insect pulp 35-45 parts, soybean meal 5-10 parts, and chitosan 1-3 parts.

[0025] Preferably, in step S3, 0.5-1 mass parts of anthocyanins are further included in the substrate.

[0026] Preferably, in step S5, the starch component in the basic formula adopts pregelatinized starch.

[0027] Preferably, in step S5, the specific parameters of each stage are further controlled as follows: in the screw section, the screw speed is 250-300 rpm; in the forming section, template cooling is adopted, the temperature is controlled at 60-90℃, and the template hole diameter is controlled at 2-5 mm; in the rotary cutting section, the normal temperature and pressure are adopted, and the blade speed is controlled at 200-500 rpm.

[0028] Preferably, the basic formula includes the following mass parts of components:

[0029] Fish meal 35-45

[0030] Shrimp meal 3-5

[0031] Plant protein powder 15-20

[0032] Fish oil 2-5

[0033] Vegetable oil 1-3

[0034] Poultry eggs 3-8

[0035] Pregelatinized corn starch 6-10

[0036] Pregelatinized cassava starch 3-5

[0037] Feed-grade zeolite powder 0.5-2

[0038] Calcium phosphate 0.3~0.6

[0039] Antifungal agent 0.1~0.3.

[0040] As preferred, the base formula separates the fat-soluble components, the poultry eggs and other components when batching, mixes the other components in dry state first, emulsifies the fat-soluble components with the poultry eggs, and then mixes and stirs the fat-soluble components with the other components.

[0041] In the above technical solution of the present application, the plant protein powder is selected from one or more of soybean meal powder, peanut meal powder, corn gluten powder, wheat gluten powder, and rapeseed meal powder.

[0042] As preferred, the mass ratio of the total mass of the base formula to the mass of the dry matter of the fermentation liquor is 100 / (3~10).

[0043] As preferred, a protective agent is added to the fermentation liquor, the protective agent accounts for 8~12% of the wet weight of the fermentation liquor; the protective agent includes trehalose and an auxiliary protective agent, the auxiliary protective agent is selected from at least one of sucrose, skimmed milk powder, and glycerol.

[0044] As preferred, the trehalose accounts for 50~80% of the mass of the protective agent.

[0045] As preferred, in step S5, the powder prepared from the base formula raw materials and the fermentation liquor is stirred uniformly, the powder prepared from the fermentation liquor is prepared by first dispersing the protective agent into the fermentation liquor and then through low-temperature spray drying, and the low-temperature spray drying controls the temperature at 50~70℃.

[0046] As preferred, the complex microbial agent includes Saccharomyces boulardii, Bacillus licheniformis, Lactobacillus, and Clostridium butyricum; in mass parts, Saccharomyces boulardii 30~40 parts, Bacillus licheniformis 25~35 parts, Clostridium butyricum 15~25 parts, and Lactobacillus 10~20.

[0047] As preferred, in step S4, the initial pH is controlled at 6.0~6.5, in 0~24h, the temperature is controlled at 35~37℃, and the aeration amount is 0.8~1.2vvm; in 24~36h, the temperature is controlled to drop by 1~2℃, and the aeration amount is 0.5~0.8vvm; in 36~40h, the temperature is controlled to drop by 1~2℃, and the aeration is stopped; after 40h until the end of fermentation, the temperature is controlled at 30~32℃.

[0048] As preferred, the complex microbial agent further includes Saccharomyces cerevisiae, and in mass parts, Saccharomyces cerevisiae 5~10.

[0049] As preferred, the addition amount of the complex microbial agent is 0.3~1.0% of the mass of the substrate.

[0050] In summary, the present application has the following advantages:

[0051] 1、The present application uses multiple probiotics to ferment the substrate mainly composed of black soldier fly larvae paste, adds the fermentation liquor / fermentation liquor dry powder into the raw materials of the basic formula, uses pregelatinized starch to reduce the operating temperature of the conditioning section of the expansion equipment, controls the passing time of the screw section, reduces the killing effect on probiotics, and maximizes the retention of probiotic living bodies in the expanded pellet feed;

[0052] 2、The present application uses pregelatinized starch to reduce the temperature of the expansion conditioning section, which is lower than the traditional 90~100℃, adjusts the initial moisture content to 19~23% by water vapor, reduces the high-temperature inactivation, controls the passing time of the screw section, reduces mechanical shearing and heat accumulation, and the sudden drop of the instantaneous high temperature and pressure in the expansion section forms a porous structure, which, combined with the appropriate proportion of pregelatinized corn starch and cassava starch and the viscosity-increasing effect of eggs, promotes the control of the dissolution rate of crude protein and crude fat; in the preferred scheme, a protective agent is also used to combine with low-temperature spray drying to embed the bacterial bodies, further reduce the high-temperature inactivation in the conditioning stage, and maximize the retention of living bacteria (Buller yeast, Bacillus licheniformis, etc.) and their metabolites (antibacterial peptides, etc.) in the fermentation liquor; the number of living probiotics in the expanded pellets is significantly increased (such as Buller yeast, which can reach 1.0×10 8 CFU / g above, plate counting method), which is much higher than the conventional high-temperature granulation (living bacteria number <1.0×10 6 CFU / g, plate counting method); the butyric acid, lactic acid, antibacterial peptides, etc. produced by fermentation are integrated into the feed to inhibit the growth of pathogenic bacteria (such as Haemophilus) and enhance the intestinal health of golden pompano;

[0053] 3、In the fermentation of black soldier fly larvae paste, a multi-stage temperature control aeration process is used to drive the synergistic proliferation of the composite bacterial agent: in the initial stage, Bacillus licheniformis and Saccharomyces cerevisiae are used as the main bacteria, the former secretes protease and amylase to decompose macromolecules, and the latter synthesizes B vitamins and generates mannose oligosaccharide to inhibit pathogenic bacteria; in the middle stage, the temperature is reduced to 34~36℃ and the aeration is reduced, Buller yeast and Lactobacillus become dominant bacteria, the former directly antagonizes pathogenic bacteria by secreting antibacterial peptides, protease and phospholipase, and also produces a small amount of organic acid to assist in inhibiting bacteria, and the latter produces lactic acid to reduce the local pH to strengthen the antibacterial effect; in the later stage, the aeration is stopped and the temperature is reduced to 30~32℃, and Clostridium butyricum proliferates in the anaerobic environment, and the synthesized butyric acid can participate in the mucosal repair of the intestinal tract of golden pompano; in addition, the flavor substances produced by Buller yeast and the flavor substances produced by Saccharomyces cerevisiae synergistically enhance the feeding attractiveness of the feed to golden pompano, forming a whole-chain functional system of "nutrient decomposition - pathogen inhibition - feeding enhancement - mucosal repair";

[0054] 4. Black soldier fly larvae slurry is rich in chitinase, protease, and antimicrobial peptides. After synergistic fermentation with a compound microbial agent, it can promote the digestion of plant-derived substances such as soybean meal in feed, thereby improving feed utilization. Antimicrobial peptides enhance fish immunity and reduce the use of antibiotics. Plant protein powder is added to the basic formula to complement the small peptides in the fermentation broth and balance the amino acid composition. Anthocyanins act as antioxidants to protect fat-soluble vitamins.

[0055] 5. Black soldier fly larvae slurry replaces part of the fish meal (approximately 3% to 10% of the fermentation broth dry matter content); flexible combination of multiple plant protein powders reduces dependence on expensive fish meal; feed costs are reduced by approximately 10% (calculated based on a 5% addition); and the diversified raw material sources meet sustainable production requirements.

[0056] 6. In the basic formula, fat-soluble components such as fish oil and vegetable oil are emulsified by poultry eggs, achieving uniform dispersion with components such as fish meal, shrimp meal, and starch, significantly improving the uniformity and stability of the raw materials. At the same time, poultry eggs can also serve as a nutritional supplement and improve the water stability of feed pellets by increasing adhesion.

[0057] 7. In the forming section, the template cooling temperature is 60-90°C and the aperture is 2-5mm to control the particle fineness. By combining the proportion of each substance in the basic formula with the coordination of other process parameters (such as initial humidity, temperature, pressure, and passage time of the conditioning and screw sections), the particle density, hardness, and fineness are controlled, significantly improving the water stability of the feed particles and achieving a solubility loss rate of <8%;

[0058] 8. In summary, the present invention ferments black soldier fly larvae slurry with multiple probiotics and applies it to the preparation of puffed pellet feed. It combines formula optimization, process parameter optimization, and protective agent design to balance the puffing processing intensity and the survival requirements of probiotics, maximize the retention of probiotic live bodies and metabolites, ensure pellet quality and production efficiency, enhance the immune regulation and digestion-promoting functions of feed, and reduce raw material costs. Compared with the existing technology, the number of viable probiotics is ≥1.0×10 8 CFU / g (traditional expanded granules <1.0×10 6 CFU / g), and the economic cost is reduced by 10%; it is especially suitable for high-density aquaculture scenarios (such as golden pomfret cage farming), and can significantly improve the health level of fish and aquaculture efficiency. DETAILED DESCRIPTION

[0059] This specific implementation is merely an explanation of the present invention and is not intended to limit the present invention. Any changes made by those skilled in the art after reading the specification of the present invention will be protected by patent law as long as they are within the scope of the claims.

[0060] Example 1

[0061] 1. Pretreatment of Black Soldier Fly Larvae

[0062] The black soldier fly larvae in the culture tray (containing feed residues, molting, etc.) are poured into a multi-layer vibrating screen (upper layer screen hole 10 mm, middle layer 3-5 mm, lower layer 1 mm), and the larvae are separated from larger impurities (such as uneaten feed particles) by mechanical vibration; the screened larvae are washed by water flow through a cleaning tank, and 0.02% food-grade Tween-80 is added to the washing water to better remove the mucus on their surface; the cleaned larvae are immediately sent to a steam jet tunnel (length 3 m, temperature 105°C, residence time 30 seconds) by a screw conveyor; after sterilization, the larvae are removed from the surface water by a vibrating filter screen and temporarily stored in a 4°C refrigerator (storage time ≤4 hours); and the homogenizer is pulped (according to production requirements, i.e. ready-to-use).

[0063] Substrate preparation: according to mass parts, 40 parts of worm pulp, 8 parts of soybean meal, 2 parts of chitosan, and 0.8 parts of anthocyanin are mixed, and water is added to adjust the moisture content to 55%.

[0064] Compound inoculation and fermentation: add 0.5% of the compound microbial agent (35 parts of Brettanomyces, 30 parts of Bacillus licheniformis, 20 parts of Clostridium butyricum, and 15 parts of Lactobacillus) to the substrate, adjust the initial pH to 6.5, and aerate at 37°C for 24 hours (aeration rate 1.0 vvm); continue to ferment at 35°C for 12 hours with an aeration rate of 0.6 vvm; after stopping aeration, seal and ferment at 30°C for 6 days to obtain the fermentation broth.

[0065] Viable bacteria detection: plate count method is used to determine the viable bacteria count of the fermentation broth as 2.0×10^9 CFU / g, of which the proportion of Brettanomyces is about 60%.

[0066] II. Drying of fermentation broth and embedding of protective agent

[0067] Protective agent preparation: mix trehalose (70%), skimmed milk powder (20%), and glycerol (10%) to account for 10% of the wet weight of the fermentation broth.

[0068] Low-temperature spray drying: disperse the protective agent into the fermentation broth, and dry at 60°C by low-temperature spray drying to obtain the fermentation broth powder.

[0069] III. Preparation of puffed feed

[0070] Basic formula: according to mass parts, 40 parts of fish meal, 4 parts of shrimp meal, 10 parts of plant protein powder (soybean meal powder: corn gluten meal = 1:1), 3 parts of fish oil, 2 parts of vegetable oil, 5 parts of poultry eggs, 8 parts of pre-gelatinized corn starch, 4 parts of pre-gelatinized tapioca starch, 1 part of feed-grade zeolite powder, 0.5 part of calcium dihydrogen phosphate, and 0.2 part of mold inhibitor.

[0071] Raw material preparation: dry components such as fish meal, shrimp meal, etc. were mixed uniformly by a three-dimensional mixer; fish oil and vegetable oil were mixed and emulsified with poultry eggs; dry components and emulsified oil components were stirred uniformly.

[0072] Fermentation broth powder addition: the total mass of the base formula to the mass of the fermentation broth powder was 100:5, and the mixture was stirred uniformly.

[0073] Puffing and granulation:

[0074] Conditioning section: 75°C, water vapor adjusted moisture content 23%;

[0075] Screw section: 95°C, pressure 4.0 MPa, rotation speed 250 rpm, passing time 15 seconds;

[0076] Puffing section: 130°C, pressure suddenly dropped to 0.20 MPa, passing time about 0.5 seconds;

[0077] Molding section: mold cooling temperature 75°C, pore size 3 mm; rotary cutting section blade rotation speed 300 rpm.

[0078] Drying: the moisture content of the finished feed particles was dried to 10% by a fluidized bed dryer.

[0079] Example Two

[0080] The difference from Example 1 is that the fermentation broth is not dried, but directly added to the base formula. The specific process is as follows:

[0081] Base formula: by mass, fish meal 40 parts, shrimp meal 4 parts, vegetable protein powder 10 parts (soybean meal powder: corn gluten meal = 1:1), fish oil 3 parts, vegetable oil 2 parts, poultry eggs 5 parts, pre-gelatinized corn starch 8 parts, tapioca starch 4 parts, feed grade zeolite powder 1 part, calcium dihydrogen phosphate 0.5 parts, and mildew inhibitor 0.2 parts.

[0082] Raw material preparation: dry components such as fish meal, shrimp meal, etc. were mixed uniformly by a three-dimensional mixer; fish oil and vegetable oil were mixed and emulsified with poultry eggs; dry components and emulsified oil components were stirred uniformly. The total mass of the base formula to the mass of the dry matter of the fermentation broth was 100:5.

[0083] Puffing and granulation:

[0084] Conditioning section: 75°C, water vapor adjusted moisture content 23%, passing time 30 seconds;

[0085] Screw section: 95°C, pressure 4.0 MPa, rotation speed 250 rpm, passing time 15 seconds;

[0086] Puffing section: 130°C, pressure suddenly dropped to 0.10 MPa, passing time about 0.5 seconds;

[0087] Molding section: mold cooling temperature 75℃, pore size 3 mm; rotary cutting section blade rotation speed 300 rpm.

[0088] Drying: use a fluidized bed dryer to control the moisture content of the finished feed particles to 10%.

[0089] Example Three

[0090] The difference from Example 1 is that no protective agent is added when the fermentation broth is dried. The details are as follows:

[0091] The prepared fermentation broth is spray dried at 60℃ to obtain fermentation broth powder. The fermentation broth powder is added in the same way as in Example 1.

[0092] Example Four

[0093] The difference from Example 1 is that:

[0094] 1. Fermentation broth powder addition: the mass ratio of the total mass of the basic formula to the mass of the fermentation broth powder is 100:2;

[0095] 2. After the expansion and granulation is completed, the pellet feed is sprayed with a vacuum sprayer with the fermentation broth of Example 1; the mass ratio of the total mass of the basic formula to the dry mass of the fermentation broth is 100:3; after the spraying is completed, the moisture content of the finished feed particles is controlled to 10% using a fluidized bed dryer.

[0096] Example Five

[0097] The difference from Example 1 is that the proportion of the complex microbial agent is optimized.

[0098] Microbial agent ratio: Saccharomyces boulardii 30 parts, Bacillus licheniformis 25 parts, Clostridium butyricum 15 parts, Lactobacillus 10 parts, Saccharomyces cerevisiae 8 parts.

[0099] Fermentation parameters: initial pH 6.0, 0~24h 36℃ / 1.0 vvm, 24~36h 35℃ / 0.7 vvm, 36~40h 34℃ / stop aeration, 30℃ after 40h to the end of fermentation.

[0100] Comparative Example One

[0101] Traditional expansion process

[0102] Basic formula: by mass, fish meal 40 parts, shrimp meal 4 parts, plant protein powder 10 parts (soybean meal powder: corn gluten meal = 1:1), fish oil 3 parts, vegetable oil 2 parts, corn starch 8 parts, cassava starch 4 parts, feed-grade zeolite powder 1 part, calcium dihydrogen phosphate 0.5 parts, antifungal agent 0.2 parts.

[0103] Raw material preparation: use a three-dimensional mixer to mix the dry components such as fish meal and shrimp meal; mix the dry components and the oily components evenly.

[0104] Expansion parameters:

[0105] Conditioning section: 95°C, water vapor to adjust moisture content to 16%;

[0106] Screw section: 120°C, pressure 4.0 MPa;

[0107] Expansion section: 130°C, pressure suddenly dropped to 0.20 MPa;

[0108] Forming section: mold cooling temperature 90°C, aperture 3 mm; rotary cutting section blade rotation speed 300 rpm.

[0109] Drying: use fluidized bed dryer to control the moisture content of finished feed particles to 10%.

[0110] Comparative Example Two

[0111] Basic formula: by mass, fish meal 40 parts, shrimp meal 4 parts, plant protein powder 10 parts (soybean meal powder: corn gluten meal = 1:1), fish oil 3 parts, vegetable oil 2 parts, corn starch 8 parts, cassava starch 4 parts, feed grade zeolite powder 1 part, calcium dihydrogen phosphate 0.5 parts, antifungal agent 0.2 parts.

[0112] Raw material preparation: use a three-dimensional mixer to mix the dry components such as fish meal and shrimp meal; mix the dry components, the fermentation broth of Example 1, and the oily components evenly. The total mass of the basic formula and the dry mass of the fermentation broth are in a ratio of 100:5.

[0113] Expansion parameters:

[0114] Conditioning section: 95°C, water vapor to adjust moisture content to 16%;

[0115] Screw section: 120°C, pressure 4.0 MPa;

[0116] Expansion section: 130°C, pressure suddenly dropped to 0.20 MPa;

[0117] Forming section: mold cooling temperature 90°C, aperture 3 mm; rotary cutting section blade rotation speed 300 rpm.

[0118] Drying: use fluidized bed dryer to control the moisture content of finished feed particles to 10%.

[0119] Comparative Example Three

[0120] Basic formula: by mass, fish meal 40 parts, shrimp meal 4 parts, plant protein powder 10 parts (soybean meal powder: corn gluten meal = 1:1), fish oil 3 parts, vegetable oil 2 parts, corn starch 8 parts, cassava starch 4 parts, feed grade zeolite powder 1 part, calcium dihydrogen phosphate 0.5 parts, antifungal agent 0.2 parts.

[0121] Raw material preparation: mix the dry components such as fish meal and shrimp meal in a three-dimensional mixer; mix the dry components and the oily components evenly.

[0122] Puffing parameters:

[0123] Conditioning section: 95℃, water vapor to adjust the moisture content to 16%;

[0124] Screw section: 120℃, pressure 4.0 MPa, rotation speed 200 rpm, passing time 20s;

[0125] Puffing section: 130℃, pressure suddenly drops to 0.20 MPa;

[0126] Molding section: mold cooling temperature 90℃, pore size 3 mm; rotary cutting section blade rotation speed 300 rpm.

[0127] After the puffing granulation is completed, the pellet feed is sprayed with the fermentation broth of Example 1 by a vacuum spraying machine; the total mass of the base formula and the dry mass of the fermentation broth are in a mass ratio of 100:5; after the spraying is completed, the finished feed pellets are dried in a fluidized bed dryer to control the moisture content to 10%.

[0128] Comparative Example Four

[0129] Commercially available goldfish compound feed (Jinma brand goldfish compound feed, full-fledged floating material 45% protein), 2.2~2.6mm specification, selling price 258 yuan / 20kg. The protein composition is mainly imported fish meal, the shrimp meal content is about 3%, and the plant protein content is about 15%.

[0130] I. Determination of feed water body stability and loss rate

[0131] 1. Test equipment and materials

[0132] Constant temperature water bath (water temperature 25~28℃, simulating aquaculture environment);

[0133] 1L glass beaker (transparent, easy to observe);

[0134] Electronic balance (accuracy 0.001g);

[0135] Mesh screen (pore size 2mm, separate un-dispersed particles);

[0136] Timer;

[0137] Test feed sample (puffed pellets, initial moisture content ≤12%).

[0138] 2. Test steps

[0139] 2.1 Sample preparation

[0140] Take 10 g of the feed to be tested (accurate to 0.001 g), evenly spread on a dry petri dish, and placed in a 105°C oven to dry to constant weight. After cooling, weigh and record the dry weight m1 (used to correct moisture interference).

[0141] 2.2 Soaking experiment

[0142] Transfer all the dried feed particles to a 2mm mesh sieve, suspend the mesh sieve in a 1L beaker (avoid direct contact with the bottom of the beaker), and add 500mL of 25-28°C warm water (simulate the water body in aquaculture) to the beaker.

[0143] Start timing, and at 5min, 15min, 30min, and 60min, remove the mesh sieve, tilt and shake 5 times (simulate water flow scouring), and remove the loose surface attachments.

[0144] 2.3 Separation and weighing

[0145] After soaking, transfer the non-disintegrated particles in the mesh sieve to a petri dish that has been dried to constant weight, and placed in a 105°C oven to dry to constant weight. After cooling, weigh and record the remaining dry weight m2.

[0146] At the same time, the dried non-disintegrated particles and the particles that have not been soaked are used as different samples (residuals & original), and their crude protein and crude fat contents are measured (Kjeldahl nitrogen determination method for protein GB / T 6432, Soxhlet extraction method for fat GB / T6433).

[0147] 2.4 Key indicator calculation

[0148] (1) Water body stability (macroscopic integrity)

[0149] Non-disintegration rate = (m2 / m1) x 100%;

[0150] Acceptance criteria: The non-disintegration rate of gold pompano feed is ≥85% (soaked for 60 minutes).

[0151] (2) Loss rate (microscopic integrity)

[0152] Crude protein loss rate = 1 - (residual crude protein mass / original crude protein mass) x 100%;

[0153] Crude fat loss rate = 1 - (residual crude fat mass / original crude fat mass) x 100%.

[0154] 2.4 Test result analysis

[0155] The test results are shown in Table 1.

[0156] Table 1 Test results of each example and comparative example Soaking time Un-decayed rate Crude protein loss rate Crude fat loss rate Example 1 60 min 93% 6.9% 2.5% Example 2 60 min 96% 6.3% 2.2% Example 3 60 min 95% 7.1% 2.9% Example 4 60 min 94% 9.9% 2.6% Example 5 60 min 92% 7.3% 2.2% Comparative Example 1 60 min 81% 12.1% 5.5% Comparative Example 2 60 min 85% 11.9% 6.8% Comparative Example 3 60 min 82% 14.5% 6.1% Comparative Example 4 60 min 92% 6.6% 3.1%

[0157] As can be seen from Table 1, the present application significantly improves the stability of feed pellets by using pregelatinized starch and poultry eggs as key raw materials. Specifically, the present application has the following advantages:

[0158] Pellet stability: The unsink rate of the present application is significantly higher than that of the comparative examples, indicating that the synergistic effect of pregelatinized starch and poultry eggs effectively enhances the structural strength of the feed pellets, making them less likely to sink in water.

[0159] Nutrient loss control: The crude protein loss rate and crude fat loss rate of the examples are generally lower than those of the comparative examples, indicating that the present application has better nutrient retention ability in water and better quality stability.

[0160] It is worth noting that:

[0161] Abnormal data of Example 4: Its crude protein loss rate is relatively high, which may be related to the spraying process of the fermentation liquor. Although this process has limited impact on the overall water stability of the feed, the protein substances in the fermentation liquor are easily dissolved in water, resulting in local nutrient loss of the feed after spraying, which may have a certain negative impact on the feed coefficient.

[0162] Loss rate problem of comparative examples: The loss rate of the comparative examples is significantly higher than that of the present application, mainly due to the lower unsink rate. Although the comparative examples use a higher conditioning temperature and longer screw segment passing time, the use of raw starch (the gelatinization degree may be insufficient) and the absence of poultry eggs as an auxiliary binder result in insufficient pellet structure strength, and the water stability is significantly poor.

[0163] II. Determination of probiotic bacteria count

[0164] Using plate counting method, the number of probiotic bacteria in the feed pellets of Examples 1-5 and Comparative Examples 2-3 (Comparative Example 1 does not add probiotic ingredients and is not involved in the test; the probiotic ingredients in Comparative Example 4 are unknown) is determined.

[0165] 1. Detection principle

[0166] By diluting the sample and inoculating it into a specific selective medium, the growth characteristics of the three types of probiotic bacteria are used to form specific colonies, and the number of colonies (CFU) is used to quantify the viable bacteria content.

[0167] 2. Applicable scope

[0168] Detection object: The number of viable bacteria of Saccharomyces boulardii, Bacillus licheniformis, and Clostridium butyricum in pellet feed.

[0169] Detection limit: 10^2 ~ 10^9 CFU / g.

[0170] 3. Instruments and reagents

[0171] 3.1 Main instruments

[0172] Bio-safety cabinet, constant temperature incubator (precision ±1℃), anaerobic incubator (for Clostridium butyricum), electronic balance (precision 0.0001g), vortex shaker, sterile pipette (1mL, 10mL), sterile culture dish (diameter 90mm), pH meter, autoclave.

[0173] 3.2 Culture medium and reagents

[0174] Bull's yeast: YPD agar (yeast extract powder 1%, peptone 2%, glucose 2%), 28~30℃, 48~72h (aerobic), 0.1mg / mL chloramphenicol (to inhibit bacterial contamination);

[0175] Bacillus licheniformis: nutrient agar (NA), 36±1℃, 48h;

[0176] Clostridium butyricum: TSC agar (tryptone peptone 5%, soybean peptone 3%, glucose 1%, sodium thioglycolate 0.5%), 36±1℃, anaerobic, 48h.

[0177] 4. Operation steps

[0178] 4.1 Sample pretreatment

[0179] Crushing and homogenization:

[0180] Take 10g of representative pellet feed sample and grind it into powder (pass through a 40-mesh sieve) with a sterile mortar, then transfer it to a sterile homogenization bag.

[0181] Gradient dilution:

[0182] Add sterile normal saline to 100mL and vortex for 2min to make a 10⁻¹ dilution;

[0183] Dilute sequentially by 10 times to 10^-5~10^-9 (adjust according to the number of viable bacteria).

[0184] 4.2 Inoculation and culture

[0185] Bull's yeast: spread method (1mL of diluent / plate), YPD agar, 28~30℃, aerobic for 48~72h; colony characteristics: milky white, round, smooth surface;

[0186] Bacillus licheniformis: spread method (1mL of diluent / plate), NA agar, 36±1℃, 48h; colony characteristics: off-white, irregular edge, dry surface;

[0187] Clostridium butyricum: pour plate method (1 mL of diluent / plate), TSC agar, 36±1℃, anaerobic for 48h; colony characteristics: black, raised in the center, with a transparent ring around.

[0188] Key operations:

[0189] Clostridium butyricum: anaerobic culture requires pre-reduction medium (boil to drive oxygen, then cool, add resazurin indicator to colorless) 24h in advance;

[0190] Bacillus licheniformis: if spores in the sample are not fully recovered, the diluent can be activated by 80℃ water bath for 15min (activate spores), then inoculate after cooling.

[0191] 4.3 Colony count and calculation

[0192] Select plates with 30~300 CFU of colonies for counting, and the calculation formula is:

[0193] Probiotic content (CFU / g) = (average number of colonies on the plate / volume of coating corresponding to the mass of feed) x dilution factor

[0194] Example:

[0195] The average number of colonies on the plate of Saccharomyces boulardii at a dilution of 10^-5 is 20 CFU, and the coating volume is 1mL;

[0196] Therefore, the content (CFU / g) = 20 / 1x10^5 CFU / 10g = 2.0x10^6 CFU / 10g = 2.0x10^7 CFU / g.

[0197] 5 Results and analysis

[0198] The determination results are shown in Table 2.

[0199] Table 2 Content determination results of each probiotic in Examples 1~5 and Comparative Examples 2~3 B. brafer CFU / g B. licheniformis CFU / g C. butyricum CFU / g Example 1 2.0×10^8 1.5×10^8 7.5×10^7 Example 2 1.8×10^7 1.3×10^8 3.0×10^7 Example 3 1.5×10^7 1.2×10^8 2.0×10^7 Example 4 5.0×10^7 2.0×10^8 5.0×10^7 Example 5 1.6×10^8 1.7×10^8 8.0×10^7 Comparative Example 2 1.0×10^5 2.0×10^6 1.0×10^5 Comparative Example 3 5.3×10^7 1.8×10^7 4.6×10^7

[0200] As can be seen from Table 2, by using the composite microbial agent fermentation combined with the protection agent embedding and the puffing process optimization, the pre-gelatinized starch is used to reduce the puffing temperature and the short screw segment passing time to further reduce the heat damage, which significantly improves the survival rate of probiotics in feed and ensures the stability of high-activity probiotics in the puffed particles.

[0201] Specifically, the specific performance is:

[0202] Survival rate of probiotics: The viable cell count of B. braj, B. licheniformis and C. butyricum in Examples 1-5 reached 10^7 CFU / g, which was significantly higher than that of the comparative examples. Among them, Examples 1-5 reduced the temperature of the puffing conditioning section (70-80°C) by using pre-gelatinized starch, controlled the screw section passing time (10-15 seconds), and especially Examples 1 and 5 also carried out protective agent embedding (trehalose + skimmed milk powder + glycerol), which maximized the retention of viable cells and metabolites (organic acids, antibacterial peptides, etc.) in the fermentation broth.

[0203] Synergistic effect of protective agent and process: Examples 1-5 added trehalose (70%), skimmed milk powder (20%) and glycerol (10%) as protective agents, and used low-temperature spray drying (60°C), which significantly improved the stress resistance of the bacteria and increased the survival rate of viable cells by 1-2 orders of magnitude compared with Comparative Example 2; compared with Examples 2-4, there was also a significant increase.

[0204] It is worth noting that:

[0205] Although Comparative Example 3 supplemented part of the viable cells by vacuum spraying, the data in this test were comparable to Examples, but its water stability was poor and the dissolution rate was high, which would result in a significant decrease in the viable cell count of B. braj, B. licheniformis and C. butyricum compared with Examples in actual use.

[0206] Comparative Example 2 caused the inactivation of probiotics due to high-temperature puffing, which verified the lethal effect of high temperature on probiotics.

[0207] III. Determination of feed coefficient

[0208] Net cage specifications: A small net cage with a size of 3m x 3m x 2.5m and a mesh size of 2-3cm was used.

[0209] Stocking density: 5-8 tails / m² to avoid insufficient dissolved oxygen due to high density.

[0210] Stocking environment: wind-avoiding sea area, water temperature 25-30°C, salinity 15‰-30‰, dissolved oxygen ≥5mg / L.

[0211] Feed type: divided into experimental group and control group. The experimental group feed was the puffing granular feed prepared according to Examples 1-5; the control group feed was the puffing granular feed prepared according to Comparative Examples 1-4.

[0212] Feeding method: twice a day (7:00, 18:00), taking advantage of the dawn and dusk feeding peaks; the initial fry were all 10g; feeding at 5% of body weight (0.5g / tail for 10g fish per day), the total feeding amount per day = average body weight x number of tails x 5%; a circular feeding platform was set in the center of the net cage, and the feed was scattered in three times (with an interval of 3 minutes), the feeding situation of the fish school was observed, and the residual feed rate was controlled within 5%.

[0213] Water quality monitoring: Daily test of dissolved oxygen (≥5mg / L), ammonia nitrogen (<0.5mg / L), and water temperature (25~30℃), and turn on the aerator for 2~3 hours in the afternoon to prevent hypoxia.

[0214] Growth monitoring: Samples were taken and weighed every 10 days, and the feeding amount was adjusted (after the weight gain reached 20g, the feeding rate was reduced to 4%); on day 15, the fish weight reached 20-30g; after feeding at 18:00 on the 30th day, the weight gain rate was calculated the next day.

[0215] Expected effect: Weight gain to 40~50g in 30 days (weight gain rate 300%~400%), survival rate ≥95%.

[0216] 100 fish were randomly caught using a net bag and their weight gain rates were calculated. The results are shown in Table 3.

[0217] Table 3: Breeding conditions of various embodiments and comparative examples 1~20 tail average weight g 21~40 tail average weight g 41~60 tail average weight g 61~80 tail average weight g 80~100 tail average weight g Total weight of fry g Feed consumption g Example 1 47.8 48.5 47.6 50.2 49.3 4868 3900 Example 2 49.2 48.7 41.2 40.5 43.6 4464 3900 Example 3 43.6 44.7 47.2 40.8 46.4 4454 3900 Example 4 46.6 43.7 49.2 45.7 42.9 4562 3900 Example 5 49.6 48.7 45.3 44.8 53.5 4838 3900 Comparative Example 1 40.7 38.9 37.4 38.3 41.8 3942 3900 Comparative Example 2 37.6 38.5 39.8 40.2 42.7 3976 3900 Comparative Example 3 43.2 43.7 44.1 42.8 46.1 4398 3900 Comparative Example 4 42.6 43.3 47.8 45.6 46.2 4510 3900

[0218] Example 1 Feed coefficient = 3900 / (4868-1000) = 1.01;

[0219] Example 2 feed coefficient = 3900 / (4464-1000) = 1.12;

[0220] Example 3 Feed coefficient = 3900 / (4454-1000) = 1.13;

[0221] Example 4 Feed coefficient = 3900 / (4562-1000) = 1.09;

[0222] Example 5 Feed coefficient = 3900 / (4838-1000) = 1.01;

[0223] Comparative Example 1 feed coefficient = 3900 / (3942-1000) = 1.32;

[0224] Comparative Example 2 Feed Coefficient = 3900 / (3976-1000) = 1.31;

[0225] Comparative Example 3: Feed coefficient = 3900 / (4398-1000) = 1.15;

[0226] Comparative Example 4 feed coefficient = 3900 / (4510-1000) = 1.11.

[0227] As can be seen from Table 3, the present invention significantly improves the breeding effect of golden pomfret through composite bacterial fermentation and process optimization.

[0228] The total weight of the fry in Examples 1-5 was significantly higher than that in the comparative examples, and Examples 1 and 5 performed best, with the total weight of the fry reaching 4868 g and 4838 g, respectively, which were significantly higher than 3942 g in Comparative Example 1 and 4510 g in Comparative Example 4. This shows that the feed of the present application can significantly promote the growth and weight gain of the golden pompano.

[0229] The weight uniformity of the fry in Examples 1-5 was relatively balanced (e.g., the weight of 1-20 fry in Example 1 was 47.8 g to 80-100 fry was 49.3 g, with a fluctuation range of only 1.5 g), while the weight fluctuation of Comparative Examples 1-3 was larger (e.g., the weight of 1-20 fry in Comparative Example 1 was 40.7 g to 80-100 fry was 41.8 g, with a fluctuation range of 1.1 g but a lower overall average), indicating that the feed of the present application can maintain the consistency of the growth of the golden pompano.

[0230] The feed conversion rate of Examples 1 and 5 was the lowest (both 1.01), which was significantly better than that of the comparative examples. Among them, the feed conversion rate of Example 1 was reduced by 23.5% compared with Comparative Example 1 and by 9.0% compared with Comparative Example 4, indicating that the feed of the present application can significantly improve the feed utilization efficiency of the golden pompano.

[0231] Functional differences:

[0232] Advantages of Examples: In Examples 1-5, the viable counts of B. braunii, B. licheniformis and C. butyricum were high, the metabolic products (organic acids, antibacterial peptides) effectively inhibited pathogenic bacteria, improved intestinal health, promoted nutrient absorption, and showed fast weight gain and low feed conversion rate.

[0233] Limitations of Comparative Examples: Comparative Examples 1-2 had low survival rate of probiotics or did not contain probiotics, had poor bacteriostatic and growth-promoting effects, and had high feed conversion rate. Although Comparative Example 3 added fermentation broth, the spray process led to an increase in loss rate, and the feed conversion rate was still 1.15, which was significantly higher than that of the examples.

[0234] Data of Examples 2 and 3 were slightly lower: Although the fermentation broth was added, the total weight of the fry (4464 g and 4454 g) and the feed conversion rate (1.12 and 1.13) were slightly lower than those of Examples 1 and 5, which may be related to the lack of protective agents.

[0235] It is worth noting that:

[0236] The feed conversion rate determination in this case has great limitations, limited by actual conditions, with a small sample size and a short test period in the early stage of fry growth. Therefore, the feed conversion rate determination results in this case only have reference value and cannot be used as authoritative data.

[0237] Four, economic benefit measurement

[0238] 1. Black soldier fly worm paste fermentation broth dry powder

[0239] Raw material cost: Black soldier fly larvae slurry uses black soldier fly larvae as raw material, which mainly relies on organic waste (such as kitchen waste, livestock and poultry manure), and the cost of raw material is low (the cost of large-scale breeding is about 2000~3000 yuan / ton); fermentation process (adding compound microbial agent and aeration fermentation) further converts organic matter into high-protein insect slurry, and the processing cost (including microbial agent, energy consumption, etc.) is about 1000~1500 yuan / ton, and the total cost of raw material and fermentation is about 3000~4500 yuan / ton.

[0240] Dry powder preparation cost: Fermentation broth is prepared into dry powder by low-temperature spray drying (low energy consumption, temperature 50~70℃), and the processing cost is about 800~1200 yuan / ton (including protective agent, equipment depreciation, etc.), and the total cost is about 3800~5700 yuan / ton.

[0241] Market price: The market price of large-scale production of black soldier fly larvae slurry fermentation broth dry powder is about 4000~6000 yuan / ton (affected by the quality of insect source, fermentation process and dry powder yield).

[0242] 2, imported fish meal

[0243] Imported fish meal uses deep-sea fish in Peru, Chile and other sea areas as raw material, with high cost of fishing, processing and sea transportation (the production cost of Peru super steam fish meal is about 8000~10000 yuan / ton); international sea transportation, customs duty and exchange rate fluctuation further increase the cost.

[0244] Market price: The average price of imported fish meal in the domestic market in 2023 is about 12000~15000 yuan / ton (the price can reach more than 16000 yuan / ton in high price period).

[0245] At present, the average price of imported fish meal in the domestic market still maintains a high level of 12500~14500 yuan / ton; compared with imported fish meal, the price advantage of black soldier fly larvae slurry fermentation broth dry powder is obvious. With the maturation of black soldier fly breeding technology and the promotion of large-scale production, its economic nature of replacing imported fish meal will be further highlighted, becoming an important choice for reducing cost and increasing efficiency of aquatic feed.

[0246] 3, comparison of nutritional value between black soldier fly larvae slurry fermentation broth dry powder and imported fish meal

[0247] Imported fish meal: crude protein content is about 65%, protein digestibility is about 92%, essential amino acids are balanced, and macromolecular proteins are mainly used, with less functional ingredients;

[0248] Fermentation broth dry powder: crude protein content is about 50%, protein digestibility is about 89%, contains all essential amino acids, but lysine and methionine are slightly lower than fish meal; contains antibacterial peptide and enzymatic protein (high proportion of small peptides);

[0249] The crude protein content of the imported fish meal is about 15% higher than that of the dry powder of the black soldier fly fermentation liquor; in terms of protein digestibility, the difference between the two is small, and the proportion of small peptides in the dry powder of the black soldier fly fermentation liquor is higher, and the actual difference is smaller; in addition, the dry powder of the fermentation liquor contains special functional ingredients such as antibacterial peptides, which can improve the intestinal health of the golden pompano, and the actual gap is further reduced.

[0250] Comprehensive benefit comparison: under the control condition of the balanced feed coefficient, the example 1 and the comparative example 1 are simply calculated as follows:

[0251] In example 1, the amount of fish meal is converted to about 49%, the amount of poultry egg is converted to about 6%, and the amount of fermentation liquor dry powder is 4.8%;

[0252] In comparative example 1, the amount of fish meal is converted to about 55%, the amount of poultry egg is 0%, and the amount of fermentation liquor dry powder is 0%;

[0253] The price of fish meal is the median value of 13500 yuan / ton, and the average price of poultry egg is about 6000 yuan / ton; the dry powder of fermentation liquor is taken as the median value of 5000 yuan / ton;

[0254] Therefore, in example 1, the animal protein cost of 3.9 kg of feed = 3.9 x 0.49 x 13.5 + 3.9 x 0.06 x 6.0 + 3.9 x 0.048 x 5.0 = 28.14 (yuan);

[0255] In comparative example 1, the animal protein cost of 3.9 kg of feed = 3.9 x 0.55 x 13.5 = 28.95 (yuan);

[0256] In addition, pregelatinized starch is also used in example 1, and the purchase price of pregelatinized starch is about 60%~70% higher than that of raw powder, for example, the price of pregelatinized starch is 10000 yuan / ton, and the price of raw powder is 6000 yuan / ton; the amount of pregelatinized starch used in example 1 is about 14.7%, so the starch cost of 3.9 kg of feed in example 1 = 3.9 x 0.147 x 10 = 5.7 (yuan); the amount of starch used in comparative example 1 is about 16.5%, so the starch cost of 3.9 kg of feed in comparative example 1 = 3.9 x 0.165 x 6.0 = 3.6 (yuan). Therefore, the cost of example 1 is about 1.3 yuan / 3.9 kg more than that of comparative example 1.

[0257] The feed coefficient of example 1 is about 1.01, and the feed coefficient of comparative example 1 is about 1.32.

[0258] Let the cost of comparative example 1 = a (yuan / kg), then the cost of example 1 = a + 1 / 3 (yuan / kg);

[0259] In Example 1, according to the feed coefficient 1.01, 1010 kg of feed is needed for every 1000 kg of weight gain of the golden pomfret, about (a+1 / 3) x 1010=1010a+1010 / 3≈1010a+337 (yuan).

[0260] In Comparative Example 1, according to the feed coefficient 1.32, 1320 kg of feed is needed for every 1000 kg of weight gain of the golden pomfret, about 1320a (yuan).

[0261] Therefore, for every 1000 kg of weight gain of the golden pomfret, Example 1 saves (310a-337) yuan compared to Comparative Example 1.

[0262] At present, the market price of the golden pomfret feed is about 258 yuan / 20 kg, which is about 12.9 yuan / kg, i.e. a≈12.9. According to the weight gain of the golden pomfret, Example 1 saves 310a-337=3662 yuan / ton compared to Comparative Example 1.

[0263] Small to medium-sized farms usually use deep water net cages for breeding, with an annual output of about 1000-5000 tons (such as some breeding farms in Guangxi Fangchenggang). Assuming that the feed enterprises give all the benefits to the breeders, by implementing this project, the breeders can save tens of millions to hundreds of millions of yuan per year; even compared with Comparative Example 4 (feed coefficient 1.11, while assuming that Comparative Example 4 is comparable to Comparative Example 1 in price), it can save about 950 yuan / ton, which can save several million yuan per year for breeders (based on an annual output of about 1000 tons). Compared with the investment of tens of millions of yuan per year in total feed cost, about 10% is saved.

[0264] It is worth noting that:

[0265] The determination of the feed coefficient has great limitations, therefore, the breeding benefits calculated based on the feed coefficient only have reference value and cannot be used as authoritative data.

Claims

1. A method for preparing a complete puffed feed for golden pomfret, comprising the following steps: S1. Decontamination and sterilization of 3rd to 5th-instar black soldier fly larvae; S2, beating the black soldier fly larvae into a slurry; S3, adding soybean meal, chitosan oligosaccharide and water to the insect pulp to prepare a substrate, wherein the moisture content of the substrate is controlled at 50-60%; S4, adding a composite bacterial agent to the substrate, adjusting the temperature to 30-38° C. for aeration and fermentation for 30-40 hours; then stopping aeration and sealing and fermenting for 5-7 days to obtain a fermentation liquid; S5, prepare the raw materials according to the basic formula, crush and sieve them, and mix them with the fermentation liquid or the powder prepared from the fermentation liquid; input the mixture into the puffing granulator to prepare feed pellets; finally, control the moisture content of the finished feed pellets within 10%; during the puffing granulation process, In the tempering section, the temperature is controlled at 70-80°C, the initial moisture content is controlled at 19-23% by inputting water vapor, and the pressure is 0.2-0.3 MPa; In the screw section, the temperature is controlled at 90~110℃, the pressure is 2.0~5.0Mpa, and the transit time is controlled at 10~15 seconds; In the puffing section, the temperature is controlled at 120~130℃, the pressure drops suddenly to 0.1~0.2Mpa, and the passing time is 0.1~0.5 seconds.

2. The method for preparing a complete puffed feed for golden pomfret according to claim 1, wherein: In step S5, the specific parameters of each stage are further controlled as follows: in the screw section, the screw speed is 250-300 rpm; in the forming section, the template is cooled, the temperature is controlled at 60-90°C, and the template aperture is controlled at 2-5 mm; in the rotary cutting section, the blade speed is controlled at room temperature and pressure and is 200-500 rpm.

3. The method for preparing a complete puffed feed for golden pomfret according to claim 1, wherein: The basic formula includes the following components in parts by mass: Fishmeal 35~45 Shrimp powder 3~5 Plant protein powder 15~20 Fish oil 2~5 Vegetable oil 1~3 3~8 eggs Pregelatinized corn starch 6~10 Pregelatinized tapioca starch 3~5 Feed grade zeolite powder 0.5~2 Calcium dihydrogen phosphate 0.3~0.6 Antifungal agent 0.1~0.

3.

4. The method for preparing a complete expanded feed for golden pomfret according to claim 1, 2 or 3, wherein: The mass ratio of the total mass of the basic formula to the dry matter of the fermentation broth is 100 / (3~10).

5. The method for preparing a complete puffed feed for golden pomfret according to claim 4, wherein: A protective agent is added to the fermentation broth, and the protective agent accounts for 8-12% of the wet weight of the fermentation broth; the protective agent includes trehalose and an auxiliary protective agent, and the auxiliary protective agent is selected from at least one of sucrose, skim milk powder, and glycerol.

6. The method for preparing a complete puffed feed for golden pomfret according to claim 5, wherein: The trehalose accounts for 50-80% of the mass of the protective agent.

7. The method for preparing a complete expanded feed for golden pomfret according to claim 5 or 6, characterized in that: In step S5, the raw materials of the basic formula are mixed with the powder obtained from the fermentation broth. The powder obtained from the fermentation broth is prepared by first dispersing the protective agent into the fermentation broth and then by low-temperature spray drying. The low-temperature spray drying temperature is controlled at 50-70°C.

8. The method for preparing a complete puffed feed for golden pomfret according to claim 1, wherein: The composite bacterial agent comprises Saccharomyces boulardii, Bacillus licheniformis, Lactobacillus and Clostridium butyricum; in parts by mass, the composite bacterial agent comprises 30-40 parts of Saccharomyces boulardii, 25-35 parts of Bacillus licheniformis, 15-25 parts of Clostridium butyricum and 10-20 parts of Lactobacillus.

9. The method for preparing a complete expanded feed for golden pomfret according to claim 8, wherein: In step S4, the initial pH is controlled at 6.0-6.5, the temperature is controlled at 35-37°C, and the ventilation volume is 0.8-1.2 vvm at 0-24 h; the temperature is controlled to drop by 1-2°C at 24-36 h, and the ventilation volume is 0.5-0.8 vvm; the temperature is controlled to drop by 1-2°C at 36-40 h, and the ventilation is stopped; and the temperature is controlled at 30-32°C after 40 h until the end of fermentation.

10. The method for preparing a complete puffed feed for golden pomfret according to claim 9, characterized in that: The composite bacterial agent also includes 5 to 10 parts by weight of saccharomyces cerevisiae.