Feed for promoting growth of channel catfish and preparation method thereof

Abstract

The application discloses a feed for promoting growth of Ictalurus punctatus and a preparation method thereof, and belongs to the technical field of aquatic feed. The fermented plant protein base material is mixed with nutritional raw materials to form a basic nutritional mixture, and is branched to prepare a feeding guide particle, a delayed sinking main feeding particle and a compensation softening particle; the three types of particles have different feeding release times, floating and sinking states, softening behaviors and nutritional load structures, and in the same feeding, the particles sequentially form a surface layer feeding window, a slow sinking main feeding window and a rear compensation window, so that the concentrated intake of core nutritional particles by strong fish bodies is reduced, the feeding opportunity of fish bodies in the rear section is improved, and the growth uniformity of the Ictalurus punctatus population and the feed utilization rate are improved.

Description

Technical Field

[0001] This invention relates to the field of aquaculture feed technology, and in particular to a feed that promotes the growth of spotted catfish and its preparation method. Background Technology

[0002] In large-scale farming, spotted catfish are usually fed with pelleted feed. Existing technologies mainly improve growth performance from the perspectives of protein source substitution, probiotic addition, acidifier addition, attractant addition, or active ingredient encapsulation. The focus of these improvements is mainly on the nutritional composition or the stable release of individual pellets.

[0003] In actual group feeding, fish size, feeding competition ability, and feeding location are not entirely consistent. While floating or semi-floating feeds make it easier to observe feeding status, they can lead to stronger feeders prioritizing the intake of surface particles in the early stages of feeding. Extending feeding time or increasing feed amounts to cater to weaker feeders can result in prolonged particle immersion, nutrient loss, increased uneaten feed, and water quality problems. Existing single-particle growth-promoting feeds typically struggle to simultaneously stimulate feeding, promote primary feeding, and compensate for later feeding. Their growth-promoting effects rely more on the composition itself, making it difficult to structurally regulate the feeding window allocation within a single feeding cycle.

[0004] Therefore, how to make the same batch of feed pellets automatically form feeding windows at different times and spatial locations after entering the water without changing the conventional feeding method has become a technical problem that needs to be solved to improve the uniformity of growth and feed utilization of spotted catfish populations. Summary of the Invention

[0005] This invention overcomes the shortcomings of the prior art and provides a feed that promotes the growth of spotted catfish and its preparation method.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is a method for preparing feed that promotes the growth of channel catfish, comprising the following steps:

[0007] S1. The plant protein raw material is subjected to bacterial and enzyme co-fermentation to obtain fermented plant protein base material;

[0008] S2. Mix the fermented plant protein base with protein peptide source, energy raw material, mineral raw material and binding raw material to obtain basic nutrient mixture;

[0009] S3. Divide the basic nutrient mixture into a first mixture, a second mixture, and a third mixture;

[0010] S4. The first mixture is subjected to light expansion treatment and a feeding-inducing release layer is formed on its surface to obtain feeding-inducing pilot particles. The feeding-inducing pilot particles are used to release feeding-inducing signals in the early stage of water entry.

[0011] S5. The second mixture is subjected to mesoporous expansion treatment to form a hydration density conversion layer and a growth-promoting active component loading layer, thereby obtaining delayed-sinking main nutrient particles. The delayed-sinking main nutrient particles gradually change from a floating or semi-floating state to a semi-suspended state or a slowly sinking state after entering the water.

[0012] S6. The third mixture is subjected to small particle size molding treatment to form a softening and retaining layer and an easily digestible growth-promoting component loading layer to obtain compensated softening particles. The compensated softening particles soften after entering water to form small clumps that retain the clump shape.

[0013] S7. Mix the feed-inducing pilot pellets, delayed sinking main feed pellets and compensating softening pellets according to the preset mass ratio to obtain feed that promotes the growth of spotted catfish.

[0014] In a preferred embodiment of the present invention, the plant protein raw material includes at least two of soybean meal, rapeseed meal, cottonseed protein, peanut meal and corn protein powder; the bacterial enzyme co-fermentation uses at least two of Bacillus subtilis, Lactobacillus plantarum and Saccharomyces cerevisiae, and is combined with at least one of neutral protease, phytase and xylanase for fermentation, and the resulting material is dried to a moisture content of no more than 12% after fermentation.

[0015] In a preferred embodiment of the present invention, the basic nutrient mixture comprises the following components in parts by weight: 25-45 parts fermented plant protein base, 3-10 parts protein peptide source, 3-8 parts fish meal, 12-25 parts wheat flour, 5-12 parts corn gluten powder, 1-4 parts fish oil, 0.5-2 parts phospholipid oil, 1-3 parts calcium dihydrogen phosphate, 0.2-1 parts compound vitamins, 0.2-1 parts compound minerals, and 1-5 parts binding material.

[0016] In a preferred embodiment of the present invention, the feeding-inducing release layer includes at least two of betaine, hydrolyzed fish protein, small peptides, free amino acids, and yeast extract; the crude protein loading and crude fat loading of the feeding-inducing pilot particles are both lower than those of the delayed-sinking main nutrient particles, so that the feeding-inducing pilot particles release feeding signals in the early stage of entering the water without concentrating on carrying the main nutrient components.

[0017] In a preferred embodiment of the present invention, the hydration density transition layer comprises at least two of the following: hydrophilic colloid, modified starch, alginate, sodium carboxymethyl cellulose, gelatin, and lipid sealing layer; the delayed-sinking main culture particles gradually increase in density after entering the water through pore water intake and hydrophilic colloid hydration, thereby forming a slow-sinking main culture window after the feeding induction lead particles release feeding signals.

[0018] In a preferred embodiment of the present invention, the growth-promoting active component loading layer includes at least three of the following: fermented plant protein powder, protein peptide source, probiotic protective microcapsules, slow-release acidified microparticles, betaine, and plant-derived polysaccharides; the probiotic protective microcapsules and slow-release acidified microparticles are loaded separately to reduce the impact of acidic components on probiotic activity during the storage and water immersion stages.

[0019] In a preferred embodiment of the present invention, the particle size of the compensating softening particles is 60%-85% of the particle size of the delayed-sinking main culture particles; the softening retaining layer includes at least two of pregelatinized starch, pectin, gelatin, alginate, resistant starch and plant gum, so that the compensating softening particles soften without completely pulverizing in the later compensation window.

[0020] In a preferred embodiment of the present invention, the mass ratio of the feeding-inducing pilot particles, the delayed-sinking main culture particles, and the compensating softening particles is 5-15:60-85:10-30; the surface feeding-inducing window is 0-3 minutes after water immersion, the delayed-sinking main culture window is 3-10 minutes after water immersion, and the subsequent compensation window is 10-20 minutes after water immersion.

[0021] In a preferred embodiment of the present invention, the feeding-inducing pilot granules, the delayed-sinking main nutrient granules, and the compensating softening granules are prepared by a nutrient loading misalignment method; wherein, the feeding-inducing pilot granules are mainly loaded with feeding-inducing components, the delayed-sinking main nutrient granules are mainly loaded with fermented plant protein, protein peptides and lipid energy components, and the compensating softening granules are mainly loaded with easily digestible small peptides, probiotic protective microcapsules and slow-release acidifying microparticles.

[0022] A feed to promote the growth of channel catfish includes: the feed comprises feed-attracting pilot pellets, delayed-sinking main nutrient pellets, and compensating softening pellets mixed in the same batch; the feed-attracting pilot pellets, delayed-sinking main nutrient pellets, and compensating softening pellets have different release times, floating and sinking states, softening behaviors, and nutrient load structures, so that a surface feed-attracting window, a slow-sinking main nutrient window, and a subsequent compensating window are formed sequentially in the same feeding.

[0023] This invention addresses the shortcomings of the prior art and has the following beneficial effects:

[0024] (1) This invention separates the same basic nutrient mixture into feed-inducing pilot pellets, delayed sinking main feed pellets, and compensating softening pellets, and makes the three types of pellets form a continuous feeding window in the same feeding. This can improve the feeding distribution of the spotted catfish population and increase the utilization rate of growth-promoting nutrients. Compared with the existing single floating feed or single slow-release feed, this invention does not simply increase the nutrient content, but reduces the feeding deviation through pellet group behavior regulation, and further improves the uniformity of population growth and feed conversion effect.

[0025] (2) The present invention sets up feeding-inducing pilot particles and delayed sinking main feeding particles. The feeding-inducing pilot particles release feeding signals in the early stage of entering the water without concentrating on carrying the main nutrients. The delayed sinking main feeding particles enter the main feeding window after the feeding-inducing window, thereby reducing the concentrated intake of core nutrient particles by dominant fish in the early stage of feeding. Compared with the existing method of uniformly mixing feeding attractants and nutrients into the same particle, the present invention can weaken the feeding competition process by time misalignment, further increasing the feeding opportunities of smaller fish or fish with weaker feeding ability.

[0026] (3) The present invention sets up compensating softening particles, which soften in the later compensation window to form small particles that maintain the granule shape, so that the fish in the later feeding stage can obtain easily digestible small peptides, probiotic protective microcapsules and slow-release acidified microparticles. Compared with the existing methods of taking care of weak fish by extending the feeding time or increasing the feeding amount, the present invention can achieve compensating feeding without significantly increasing the burden on the water body, further reducing feed waste and improving intestinal digestion and utilization.

[0027] (4) This invention combines the misalignment of floating and sinking states, the misalignment of softening time, and the misalignment of nutrient load, so that the three feeding windows of attracting feed, main feeding, and compensation are connected to each other, forming a self-allocation mechanism of feeding windows for heterogeneous particle groups in the same batch. Compared with existing feeds that only improve growth performance from the perspective of formula, additives, or single particle coating, this invention can simultaneously solve the problems of uneven feeding opportunities, insufficient utilization of growth-promoting components, and water quality burden of residual feed, and further achieve a synergistic improvement in average weight gain, population uniformity, and feed utilization rate. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a flowchart of the feed preparation method of the present invention; Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein. Therefore, the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0032] like Figure 1 As shown, the present invention provides a method for preparing feed that promotes the growth of channel catfish, comprising the following steps:

[0033] S1. The plant protein raw material is subjected to bacterial and enzyme co-fermentation to obtain fermented plant protein base.

[0034] S2. Mix the fermented plant protein base with protein peptides, energy sources, minerals and binders to obtain a basic nutrient mixture.

[0035] S3. Divide the basic nutrient mixture into a first mixture, a second mixture, and a third mixture.

[0036] S4. The first mixture is subjected to light expansion treatment, and a feeding-inducing release layer is formed on its surface to obtain feeding-inducing pilot particles. The feeding-inducing pilot particles are used to release feeding signals in the early stage of water entry.

[0037] S5. The second mixture is subjected to mesoporous expansion treatment to form a hydration density transition layer and a growth-promoting active component loading layer, resulting in delayed-sinking main nutrient particles. After entering the water, the delayed-sinking main nutrient particles gradually change from a floating or semi-floating state to a semi-suspended state or a slowly sinking state.

[0038] S6. The third mixture is subjected to small particle size molding treatment to form a softening and retaining layer and an easily digestible growth-promoting component loading layer, resulting in compensated softening particles. After entering the water, the compensated softening particles soften to form small agglomerates that maintain the agglomerate shape.

[0039] S7. Mix the feed-inducing pre-feeding pellets, delayed sinking main feed pellets, and compensating softening pellets according to the preset mass ratio to obtain feed that promotes the growth of spotted catfish.

[0040] This invention divides the same basic nutrient mixture into three types of heterogeneous particles: feed-inducing pilot particles, delayed-sinking main-nutrient particles, and compensating softening particles. Each particle is given feed-inducing release, delayed sinking, and subsequent softening compensation functions. This creates a 0-3 minute surface feed-inducing window, a 3-10 minute delayed-sinking main-nutrient window, and a 10-20 minute subsequent compensation window during the same feeding process. By misaligning the buoyancy, release time, softening behavior, and nutrient load, this invention weakens the concentrated intake of core nutrient particles by dominant fish in the early stages of feeding, while providing feeding opportunities for smaller or less capable channel catfish in the later stages. Ultimately, this achieves a synergistic improvement in average weight gain, weight gain of weaker fish, group uniformity, feed conversion ratio, and uneaten feed rate.

[0041] In S1, the plant protein raw materials consist of soybean meal, rapeseed meal, and peanut meal in a mass ratio of 60:25:15. Each component is pulverized and passed through a 60-mesh sieve. Water is added to the mixed plant protein raw materials to adjust the moisture content to 35%. A compound inoculum of Bacillus subtilis, Lactobacillus plantarum, and Saccharomyces cerevisiae is then inoculated, with an inoculation amount of 1.5% of the plant protein raw material mass. Neutral protease and phytase are added simultaneously, with 1200 U / g of neutral protease and 600 U / g of phytase added. The resulting material is fermented at 32℃ for 48 hours, turning it over every 12 hours. After fermentation, it is dried at 55℃ until the moisture content reaches 9.8%, then pulverized and passed through an 80-mesh sieve to obtain the fermented plant protein base.

[0042] In S2, by weight, take 35 parts of fermented plant protein base, 6 parts of protein peptide source, 5 parts of fish meal, 18 parts of wheat flour, 8 parts of corn gluten powder, 2.5 parts of fish oil, 1.0 part of phospholipid oil, 2 parts of calcium dihydrogen phosphate, 0.6 parts of compound vitamins, 0.6 parts of compound minerals, and 3 parts of binder. First, add the fermented plant protein base, protein peptide source, fish meal, wheat flour, corn gluten powder, calcium dihydrogen phosphate, compound vitamins, compound minerals, and binder to a horizontal mixer and mix at 80 r / min for 8 min. Then, premix the fish oil and phospholipid oil and spray them into the mixer, and continue mixing for 6 min to obtain the basic nutrient mixture. The binder is a mixture of pregelatinized starch and wheat gluten powder in a mass ratio of 2:1.

[0043] In S3, the basic nutrient mixture is divided into three mixtures: the first mixture, the second mixture, and the third mixture. The first mixture is used to prepare feeding-inducing pilot particles, the second mixture is used to prepare delayed-sinking main nutrient particles, and the third mixture is used to prepare compensating softening particles. The basic nutrient sources of the three mixtures are kept consistent to avoid experimental evaluation deviations caused by differences in the basic formula between different particles. At the same time, different water entry behaviors are formed by subsequent expansion of pores, coating layers, particle size, and active component loading methods.

[0044] In step S4, a lightweight extrusion conditioner, comprising 8% of the mass of the first mixture, is added to the first mixture. This conditioner consists of wheat flour, pregelatinized starch, and microcrystalline cellulose in a mass ratio of 5:3:2. The moisture content of the first mixture is adjusted to 22%. Lightweight extrusion is then performed using a twin-screw extruder. The extruder's zone 1 temperature is 80℃, zone 2 temperature is 105℃, and zone 3 temperature is 125℃. The screw speed is 280 r / min, the die aperture is 2.0 mm, and the cutter speed is 900 r / min. After extrusion, the material is discharged at 5... Lightweight expanded core particles were obtained by drying under 0℃ hot air conditions until the moisture content was 8.6%. Then, betaine, hydrolyzed fish protein, free amino acids and yeast extract were prepared into a feeding-inducing spray solution with a solid content of 25% in a mass ratio of 3:4:2:1. This solution was sprayed onto the surface of the lightweight expanded core particles in a fluidized bed coating machine at an inlet air temperature of 45℃ and an atomization pressure of 0.20MPa. The spraying amount was 4.5% of the mass of the lightweight expanded core particles. After spraying, fluidized drying was continued for 12 minutes to form a feeding-inducing release layer on the surface, resulting in feeding-inducing pilot particles.

[0045] In step S5, a pore conditioner, comprising 5% of the mass of the second mixture, is added to the second mixture. This pore conditioner consists of wheat flour, modified starch, and soybean meal powder in a 4:3:3 mass ratio. The moisture content of the second mixture is adjusted to 24%. A twin-screw extruder is used for mesoporous puffing. The extruder's zone 1 temperature is 85℃, zone 2 temperature is 115℃, and zone 3 temperature is 135℃. The screw speed is 230 r / min, the template aperture is 2.5 mm, and the cutter speed is 750 r / min. After puffing, the material is dried at 55℃ hot air until the moisture content reaches 8.9%, yielding mesoporous puffed core particles. Modified starch, sodium alginate, and carboxymethyl ether are then added... Sodium cellulose and lipid sealing material were mixed in a mass ratio of 4:2:1:1 to prepare a hydration density transition layer coating solution, which was sprayed onto the surface of mesoporous expanded core particles at 42°C. The spraying amount was 3.8% of the mass of the mesoporous expanded core particles. Fermented plant protein powder, protein peptide source, probiotic protective microcapsules, slow-release acidified microparticles, betaine and plant-derived polysaccharides were mixed in a mass ratio of 30:25:15:10:8:12 to prepare a growth-promoting active component coating material, which was loaded onto the surface of the particles with a coating amount of 5.2% of the particle mass. Finally, the particles were dried at a low temperature of 40°C to a moisture content of 9.1% to obtain delayed-sinking main culture particles.

[0046] In S6, a small particle size shaping regulator, accounting for 6% of the mass of the third mixture, is added to the third mixture. This regulator consists of wheat flour, protein peptide source, and pregelatinized starch in a mass ratio of 4:2:4. The moisture content of the third mixture is adjusted to 20%. Granulation is then performed using a ring die granulator with a die aperture of 1.8 mm, a compression ratio of 1:5, and a granulation temperature of 75℃. This ensures that the particle size of the softening granules is 75% of the particle size of the delayed-sinking main granules. After granulation, the granules are dried at 45℃ until the moisture content reaches 9.3%, yielding small-particle core granules. Then, pregelatinized starch, pectin, and... Gelatin and resistant starch were mixed in a mass ratio of 4:2:2:2 to prepare a softening and retaining layer coating solution with a solid content of 18%. This solution was then sprayed onto the surface of small-diameter core particles in a fluidized bed coating machine at an inlet air temperature of 38°C and an atomization pressure of 0.18 MPa. The spraying amount was 4.0% of the mass of the small-diameter core particles. Subsequently, easily digestible small peptides, probiotic protective microcapsules, and slow-release acidifying microparticles were mixed in a mass ratio of 45:35:20 and then adhered to the outer surface of the small-diameter core particles that had formed the softening and retaining layer by a small amount of gelatin aqueous solution. The loading amount was 4.5% of the particle mass, resulting in compensated softening particles.

[0047] In S7, feed-attracting pilot pellets, delayed-sinking main culture pellets, and compensating softening pellets are added to a low-speed mixer at a mass ratio of 10:75:15 and mixed at 35 r / min for 5 min to obtain feed that promotes the growth of spotted catfish. The feed-attracting pilot pellets are used to form a surface feeding window 0-3 min after entering the water, the delayed-sinking main culture pellets are used to form a slow-sinking main culture window 3-10 min after entering the water, and the compensating softening pellets are used to form a later-stage compensating window 10-20 min after entering the water.

[0048] Material sources in the embodiments of this invention:

[0049] Soybean meal, rapeseed meal, peanut meal, wheat flour, corn gluten meal, and fish meal are all feed-grade raw materials. Among them, soybean meal, rapeseed meal, peanut meal, wheat flour, and corn gluten meal are purchased from the qualified feed raw material supply system of Tongwei Agricultural Development Co., Ltd., and the crude protein content of soybean meal is not less than 43.0%, the crude protein content of rapeseed meal is not less than 35.0%, the crude protein content of peanut meal is not less than 45.0%, the moisture content of wheat flour is not higher than 13.5%, and the crude protein content of corn gluten meal is not less than 60.0%.

[0050] The protein peptides were sourced from hydrolyzed fish protein powder from Shanghai Hengxing Biotechnology Co., Ltd.

[0051] The fish oil was purchased from Fujian Haifute Biotechnology Co., Ltd. as feed-grade fish oil.

[0052] The phospholipid oil was purchased from Dalian Huanong Soybean Industry Technology Development Co., Ltd. as feed-grade soybean phospholipid oil.

[0053] The calcium dihydrogen phosphate was purchased from Sinochem Yunlong Co., Ltd. as feed-grade calcium dihydrogen phosphate.

[0054] The compound vitamins were purchased from Hualuo series aquatic compound vitamin premixes from China Animal Husbandry Industry Co., Ltd.

[0055] The compound minerals were purchased from Hualuo series of compound mineral premixes for aquaculture by China Animal Husbandry Group Co., Ltd.

[0056] Betaine was purchased from Hangzhou Haierxi Livestock Technology Co., Ltd. as 97% betaine hydrochloride.

[0057] The free amino acids were a mixture of feed-grade L-lysine hydrochloride and feed-grade L-threonine in a mass ratio of 1:1. The L-lysine hydrochloride and L-threonine were purchased from Anhui Fengyuan Biotechnology Co., Ltd.

[0058] The yeast extract was purchased from Angel Yeast Co., Ltd. as yeast extract powder.

[0059] Sodium alginate was purchased from Qingdao Mingyue Seaweed Group Co., Ltd. as food-grade sodium alginate, model LWF, with a particle size of 80 mesh.

[0060] Sodium carboxymethyl cellulose was purchased from Shandong Yiteng New Material Co., Ltd. The food-grade sodium carboxymethyl cellulose solution has a viscosity of 800 m³ / s. Up to 1200m .

[0061] The gelatin was purchased from Rousselot Wenzhou Gelatin Co., Ltd. as food-grade gelatin.

[0062] The pectin was purchased from Yantai Andeli Pectin Co., Ltd. as food-grade pectin.

[0063] The plant gum used is food-grade guar gum, purchased from Beijing Guarrun Technology Co., Ltd. as Guaran-6 food-grade guar gum.

[0064] Microcrystalline cellulose was purchased from Anhui Shanhe Pharmaceutical Excipients Co., Ltd. for microcrystalline cellulose PH101.

[0065] The wheat gluten flour uses wheat gluten powder, which is purchased from Henan Feitian Biotechnology Co., Ltd. The standard is GB / T 21924, and the packaging specification is 25kg / bag.

[0066] Bacillus subtilis strain SHIMCC D73493, with equivalent number CMCC(B)63104, was purchased from the Shanghai Center for Biotechnology Preservation.

[0067] Lactobacillus plantarum was purchased from strain SMHCC D50178, which is preserved at the Shanghai Center for Preservation of Biotechnology.

[0068] The brewing yeast was purchased from the Shanghai Biotechnology Preservation Center, which preserves strain SMHCC D54927.

[0069] The phytase was purchased from Wuhan Xinhua Yang Biotechnology Co., Ltd., and the enzyme activity was not less than 5000U / g.

[0070] Xylanase was purchased from KDN brand feed-grade xylanase of Kangdian Biotechnology Group, with an enzyme activity of not less than 5000 U / mL. When using solid xylanase, the amount added should be calculated based on the equivalent enzyme activity.

[0071] The plant-derived polysaccharides were purchased from Baolingbao Biotechnology Co., Ltd.'s xylooligosaccharide XOS-95 powder, with a xylooligosaccharide content of not less than 95.0%, or from Shandong Longli Biotechnology Co., Ltd.'s feed-grade xylooligosaccharides.

[0072] Citric acid was purchased from Shandong Yingxuan Industrial Co., Ltd. as food-grade citric acid monohydrate.

[0073] Fumaric acid was purchased from Anhui Fengyuan Biotechnology Co., Ltd. as food-grade fumaric acid.

[0074] The calcium lactate was purchased from Henan Jindan Lactic Acid Technology Co., Ltd. as feed-grade calcium lactate.

[0075] The glyceryl monostearate was purchased from Hangzhou Oil & Fat Chemical Co., Ltd. as a food additive grade glyceryl monostearate.

[0076] The hydrogenated soybean oil was sourced from Yihai Kerry Arawana Grain & Oil Food Co., Ltd. as a food-grade hydrogenated soybean oil and used as a lipid coating material for the slow-release acidified microparticles.

[0077] The corn starch was purchased from Shandong Longli Biotechnology Co., Ltd. as food-grade corn starch.

[0078] The pregelatinized starch is a self-made material. Its preparation method is as follows: take 100 parts of food-grade corn starch, add 45 parts of water, stir at 120 r / min for 15 min in a jacketed kettle, heat to 95℃ and keep warm for 20 min to fully gelatinize the starch. Then spread the gelatinized material into a thin layer with a thickness of 3 mm, dry it under hot air at 55℃ for 8 h until the moisture content is 9.5%. After drying, pulverize and pass through an 80-mesh sieve to obtain pregelatinized starch.

[0079] The modified starch is a self-made physically modified corn starch. The preparation method is as follows: take 100 parts of food-grade corn starch, add 33 parts of water to adjust the starch moisture content to 25%, seal the wet starch in a pressure-resistant reaction container, and heat-moisten it at 110℃ for 4 hours. After the treatment, let it cool naturally to room temperature, and dry it under 50℃ hot air conditions until the moisture content is 10.0%. After drying, pulverize it and pass it through a 100-mesh sieve to obtain the modified starch.

[0080] The resistant starch is a self-made retrograde resistant starch. Its preparation method is as follows: Take 100 parts of food-grade corn starch, add 400 parts of water to prepare a 20% starch milk, stir and gelatinize the starch milk at 95℃ for 30 minutes, then sterilize it at 121℃ for 20 minutes, and refrigerate it at 4℃ for 24 hours. Repeat the cycle of 121℃ treatment for 20 minutes and refrigeration at 4℃ for 24 hours three times. Finally, dry it under 50℃ hot air condition until the moisture content is 9.0%, pulverize it and pass it through an 80-mesh sieve to obtain resistant starch.

[0081] The fermented plant protein base was prepared in-house. The preparation method was as follows: soybean meal, rapeseed meal, and peanut meal were mixed in a mass ratio of 60:25:15 and then pulverized separately through a 60-mesh sieve. Water was added to the mixed plant protein raw materials to adjust the moisture content to 35%. Bacillus subtilis, Lactobacillus plantarum, and Saccharomyces cerevisiae were then activated and cultured separately. Bacillus subtilis was cultured at 37℃ for 18 hours, Lactobacillus plantarum for 24 hours, and Saccharomyces cerevisiae for 24 hours. The three bacterial cultures were adjusted to a viable Bacillus subtilis count of 1.0 × 10⁻⁶. 9 CFU / mL, Lactobacillus plantarum viable count 1.0 × 10⁻⁶ 9 CFU / mL and Saccharomyces cerevisiae viable count 1.0 × 10⁻⁶ 8 The CFU / mL of the plant protein raw material was mixed in a volume ratio of 1:1:1 to form a compound bacterial solution. The compound bacterial solution was added as an inoculum at a rate of 1.5% of the plant protein raw material mass. Neutral protease and phytase were added at the same time, with the neutral protease added at a rate of 1200 U / g of plant protein raw material and the phytase added at a rate of 600 U / g of plant protein raw material. The resulting material was fermented at 32℃ for 48 hours, and turned over every 12 hours. After fermentation, the material was dried at 55℃ until the moisture content was 9.8%, then pulverized and passed through an 80-mesh sieve to obtain the fermented plant protein base.

[0082] The probiotic protective microcapsules are a self-made material. The preparation method is as follows: Take 2.0 parts sodium alginate, 1.5 parts gelatin, 0.3 parts sodium carboxymethyl cellulose, 5.0 parts pregelatinized starch, and 91.2 parts water. Stir at 60℃ for 30 minutes to obtain a wall material solution. Sterilize the wall material solution by incubating at 85℃ for 20 minutes and cooling it to 37℃. Add a compound of Bacillus subtilis, Lactobacillus plantarum, and Saccharomyces cerevisiae powder to the wall material solution to achieve a total viable count of 1.0 × 10¹. 0 The CFU / g dry basis mixture was dripped into a 2.0% calcium chloride aqueous solution through a 0.8mm nozzle at a drop height of 10cm. The curing temperature was 25℃ and the curing time was 25min. After curing, the mixture was washed twice with sterile water and dried under vacuum at 35℃ until the moisture content was 8.0%. After drying, the mixture was passed through an 80-120 mesh sieve to obtain probiotic protective microcapsules.

[0083] The total live bacteria count of the probiotic protective microcapsules is not less than 1.0 × 10⁻⁶. 9 CFU / g, encapsulation rate not less than 80%.

[0084] The slow-release acidified microparticles are a self-made material. The preparation method is as follows: Take 40 parts of citric acid monohydrate, 30 parts of fumaric acid, and 30 parts of calcium lactate, pulverize them separately, pass them through a 100-mesh sieve, and mix them for 10 minutes to obtain acidified core powder. Take 10 parts of pregelatinized starch and 90 parts of water, stir at 90℃ for 20 minutes to prepare a 10% pregelatinized starch binder solution. Spray the pregelatinized starch binder solution into the acidified core powder, the amount of which is 12% of the mass of the acidified core powder. Granulate using a swing granulator with a 60-mesh sieve. Incubate the resulting wet granules at 45℃. The core particles were dried to a moisture content of 5.5% under certain conditions to obtain acidified core particles. Then, 70 parts of hydrogenated soybean oil, 20 parts of glyceryl monostearate and 10 parts of soybean lecithin oil were melted and stirred at 62°C for 15 minutes to obtain a lipid coating solution. The acidified core particles were placed in a fluidized bed coating machine with an inlet air temperature of 45°C and an atomization pressure of 0.18 MPa. The core particles were coated at a mass ratio of acidified core particles to lipid coating solution of 82:18. After coating, the particles were cooled to room temperature and passed through a 60-120 mesh sieve to obtain slow-release acidified microparticles.

[0085] The preparation method of the attractant spray liquid is as follows: take betaine, hydrolyzed fish protein powder, free amino acids and yeast extract, mix them in a mass ratio of 3:4:2:1, add water to adjust the solid content to 25%, stir at 200r / min for 15min at 25℃, and pass through a 100-mesh sieve to obtain the attractant spray liquid.

[0086] The preparation method of the hydration density transition layer coating solution is as follows: Modified starch, sodium alginate, sodium carboxymethyl cellulose and lipid sealing material are mixed in a mass ratio of 4:2:1:1. The lipid sealing material is prepared by stirring fish oil, phospholipid oil and glyceryl monostearate in a mass ratio of 3:1:1 at 60℃ for 10 min. Modified starch, sodium alginate and sodium carboxymethyl cellulose are dispersed in water to make the solid content of the aqueous phase 12%. Then the lipid sealing material is added and sheared at high speed of 8000 r / min for 5 min to obtain the hydration density transition layer coating solution.

[0087] The preparation method of the softening and retaining layer coating solution is as follows: take pregelatinized starch, pectin, gelatin and resistant starch, mix them in a mass ratio of 4:2:2:2, add water to adjust the solid content to 18%, stir at 60℃ for 20 minutes to allow the pectin and gelatin to fully swell and form a uniform dispersion system, and obtain the softening and retaining layer coating solution.

[0088] The preparation method of the easily digestible growth-promoting component loading material is as follows: hydrolyzed fish protein powder is used as the source of easily digestible small peptides, and it is mixed with probiotic protective microcapsules and slow-release acidified microparticles at a mass ratio of 45:35:20. Separately, 2 parts of gelatin and 98 parts of water are taken and stirred at 55℃ for 15 minutes to obtain a 2% gelatin aqueous solution. The 2% gelatin aqueous solution is used as an adhesive liquid and sprayed into the easily digestible growth-promoting component. The amount sprayed is 8% of the mass of the easily digestible growth-promoting component. The mixture is mixed at low speed at 25℃ for 5 minutes to obtain the easily digestible growth-promoting component loading material.

[0089] Experimental methods and index calculation methods:

[0090] Feed samples were collected in accordance with GB / T 14699-2023 "Feed Sampling". After thorough mixing, the samples were divided into water behavior test samples, nutrient composition test samples and aquaculture feeding test samples.

[0091] The moisture content of feed was determined in accordance with GB / T 6435-2014 "Determination of Moisture in Feed". The feed sample to be tested was dried to constant weight, and the moisture content was calculated based on the difference in mass before and after drying. The moisture content was calculated according to the following formula: Moisture content / % = (mass of sample before drying - mass of sample after drying) / mass of sample before drying × 100.

[0092] The crude protein content of the feed was determined according to GB / T 6432-2018 "Determination of Crude Protein in Feed - Kjeldahl Method". The nitrogen content in the sample was first obtained by digestion, distillation and titration, and then the crude protein content was calculated based on the nitrogen content. The crude protein content was calculated according to the following formula: Crude protein content / % = Nitrogen content / % × 6.25.

[0093] The crude fat content of feed shall be determined in accordance with GB / T 6433-2025 "Determination of Crude Fat in Feed" and the obsolete GB / T 6433-2006 shall no longer be used. The crude fat content shall be calculated based on the mass of the fat extract before and after extraction and the mass of the sample. The crude fat content shall be calculated according to the following formula: Crude fat content / % = Mass of crude fat extract / Mass of sample × 100.

[0094] If auxiliary verification is needed for the amino acid composition of fermented plant protein base, protein peptide source or easily digestible small peptide, the amino acid content shall be determined in accordance with GB / T 18246-2019 "Determination of Amino Acids in Feed". The nutritional basis of protein peptide source and growth-promoting components can be evaluated based on the total amino acid or free amino acid test results.

[0095] If supplementary testing of crude ash or crude fiber in feed is required, the crude ash content should be determined according to the current GB / T 6438-2025 "Determination of Crude Ash in Feed".

[0096] The total bacterial count in feed was determined according to GB / T 13093-2023 "Determination of Total Bacterial Count in Feed", and the number of colony-forming units per gram of sample was calculated based on the number of colonies formed after culture.

[0097] The water entry behavior test was conducted using a transparent water tank to simulate the feeding environment. Each group took the same mass of feed sample and placed it in clean water at 25±1℃ with a consistent water depth. Timing started when the particles came into contact with the water surface, and the water layer, floating state, semi-suspended state, slow sinking state, and softening state of the particles were observed by video recording.

[0098] The surface feeding window formation time is the time it takes for the feeding guide particle to continuously release a feeding layer on the water surface and form a stable surface feeding guidance state after entering the water. The average value of three repeated measurements is used as the surface feeding window formation time for this group.

[0099] The time when the main culture particles enter the slow settling window is the starting time when the delayed settling main culture particles gradually change from a floating or semi-floating state to a semi-suspended or slowly settling state. During the test, the time when most particles in the same group leave the water surface and enter the upper layer of the water body to move slowly is used as the judgment time. The average value is taken after three repetitions.

[0100] The softening time of the compensation particles is the time after the compensation softening particles are put into water and the surface begins to absorb water and soften, but still maintains the shape of granules. During the test, the particles are gently touched with a glass rod. When the particles can produce soft deformation but are not completely pulverized, the corresponding time is recorded. The average value is taken after three repetitions.

[0101] The 20-minute aggregate retention rate is used to evaluate whether the compensated softened particles can still maintain an edible aggregate shape within the subsequent compensation window. During the test, a certain mass of compensated softened particles is taken, and after immersion in water for 20 minutes, particles that still maintain an aggregate shape are collected. After draining and low-temperature drying, they are weighed. The 20-minute aggregate retention rate is calculated using the following formula: 20-minute aggregate retention rate / % = Dry mass of particles that maintain aggregate shape after 20 minutes / Dry mass of compensated softened particles before immersion in water × 100.

[0102] The 20-minute nutrient loss rate is used to evaluate the nutrient retention of pellets 20 minutes after immersion in water. During the test, the moisture, crude protein, and crude fat contents of the feed sample before immersion in water and the residual pellets after 20 minutes of immersion in water are measured respectively. The total amount of crude protein and crude fat is used as the main nutrient load for calculation. The 20-minute nutrient loss rate is calculated according to the following formula: 20-minute nutrient loss rate / % = (total dry basis of crude protein and crude fat before immersion in water - total dry basis of crude protein and crude fat in residual pellets after 20 minutes of immersion in water) / total dry basis of crude protein and crude fat before immersion in water × 100.

[0103] The aquaculture effect test was conducted by grouping the same batch of spotted catfish for feeding experiments. The initial fish size of each group was consistent. Each group was set with the same stocking density, feeding frequency, water temperature, dissolved oxygen and water exchange conditions. The feed obtained from the example and the comparative example were fed respectively. After the experiment, the initial fish weight, final fish weight, number of dead fish, dry matter of the feed and dry matter of the uneaten feed were counted.

[0104] Weight gain rate is used to characterize the overall growth effect of fish and is calculated by the following formula: Weight gain rate / % = (final total weight of fish - initial total weight of fish) / initial total weight of fish × 100.

[0105] The feed conversion ratio is used to characterize the feed conversion effect and is calculated by the following formula: Feed conversion ratio = Actual dry mass of feed ingested / Fish body weight gain, where actual dry mass of feed ingested = Dry mass of feed fed - Dry mass of uneaten feed recovered, and fish body weight gain = Total weight of surviving fish at the end + Weight of dead fish - Initial total weight of fish.

[0106] Survival rate is used to characterize the survival status during the breeding process and is calculated using the following formula: Survival rate / % = Number of surviving tails at the end of the experiment / Number of tails released at the beginning of the experiment × 100.

[0107] The final weight variation coefficient is used to characterize the uniformity of population growth. At the end of the experiment, the final weight of each group of fish was weighed and the mean and standard deviation of the final weight were calculated. The final weight variation coefficient was calculated according to the following formula: Final weight variation coefficient / % = final weight standard deviation / final weight mean × 100.

[0108] The weight gain rate of weak fish is used to characterize the compensatory growth effect of fish with smaller initial size or weaker feeding competition ability. At the beginning of the experiment, the fish are sorted by weight from low to high. The fish with the lower weight are marked as weak fish. After the experiment, the final weight of the weak fish is counted. The weight gain rate of weak fish is calculated by the following formula: Weight gain rate of weak fish / % = (final average weight of weak fish - initial average weight of weak fish) / initial average weight of weak fish × 100.

[0109] The residual feed rate is used to characterize the degree to which feed is not consumed and the burden it places on the water body. After each feeding, uneaten feed is collected within a set time, and after surface moisture removal and drying, it is weighed and converted into dry matter. The residual feed rate is calculated according to the following formula: Residual feed rate / % = Dry matter of recovered residual feed / Dry matter of fed feed × 100.

[0110] Example 1:

[0111] This embodiment provides a feed that promotes the growth of channel catfish, and its preparation method includes the following steps:

[0112] S1. Soybean meal, rapeseed meal, and peanut meal were used as plant protein raw materials in a mass ratio of 60:25:15. The plant protein raw materials were pulverized separately and passed through a 60-mesh sieve. After mixing evenly, water was added to adjust the moisture content of the mixture to 35%. Subsequently, a compound inoculum of Bacillus subtilis, Lactobacillus plantarum, and Saccharomyces cerevisiae was inoculated into the mixture at an inoculation amount of 1.5% of the mass of the plant protein raw materials. Neutral protease and phytase were also added, with the neutral protease added at a concentration of 1200 U / g of plant protein raw materials and the phytase added at a concentration of 600 U / g of plant protein raw materials. The resulting material was placed in a fermentation container and fermented at 32℃ for 48 hours, turning the material every 12 hours to ensure full contact between the bacteria, enzymes, and plant protein raw materials. After fermentation, the resulting fermented material was dried at 55℃ until the moisture content was 9.8%, then pulverized and passed through an 80-mesh sieve to obtain the fermented plant protein base.

[0113] S2. Prepare the basic nutrient mixture. By weight, take 35 parts fermented plant protein base, 6 parts protein peptide source, 5 parts fish meal, 18 parts wheat flour, 8 parts corn protein powder, 2.5 parts fish oil, 1.0 part phospholipid oil, 2 parts calcium dihydrogen phosphate, 0.6 parts compound vitamins, 0.6 parts compound minerals, and 3 parts binding material.

[0114] First, fermented plant protein base, protein peptide source, fish meal, wheat flour, corn gluten powder, calcium dihydrogen phosphate, compound vitamins, compound minerals, and binding materials are added to a horizontal mixer and mixed at 80 rpm for 8 minutes. Then, fish oil and phospholipid oil are premixed and sprayed into the mixer, and mixing continues for 6 minutes to obtain the basic nutrient mixture. The binding material is a mixture of pregelatinized starch and wheat gluten powder in a mass ratio of 2:1.

[0115] S3. Divide the basic nutrient mixture obtained in step S2 into a first mixture, a second mixture, and a third mixture.

[0116] The first mixture is used to prepare feeding-inducing pilot pellets, the second mixture is used to prepare delayed-sinking main feed pellets, and the third mixture is used to prepare compensating softening pellets.

[0117] The three types of feedstocks share the same basic nutrient source, but exhibit different water ingress behaviors due to different expansion pores, coating layers, and active component loading methods.

[0118] S4. Add 8% of a lightweight puffing modifier by mass to the first mixture. The lightweight puffing modifier is composed of wheat flour, pregelatinized starch and microcrystalline cellulose in a mass ratio of 5:3:2.

[0119] Adjust the moisture content of the first mixture to 22% and feed it into a twin-screw extruder for lightweight extrusion.

[0120] During the lightweight puffing process, the temperature of the first zone of the puffing machine is 80℃, the temperature of the second zone is 105℃, the temperature of the third zone is 125℃, the screw speed is 280r / min, the template aperture is 2.0mm, and the cutter speed is 900r / min, so that the resulting particles have a high porosity and have the ability to float in water initially.

[0121] After puffing and discharge, the material is dried under hot air at 50°C until the moisture content is 8.6%, resulting in lightweight puffed pellets.

[0122] Betaine, hydrolyzed fish protein, free amino acids, and yeast extract were mixed in a mass ratio of 3:4:2:1, and an appropriate amount of water was added to prepare an attractant spray solution with a solid content of 25%. Lightweight expanded core particles were then placed in a fluidized bed coating machine with an inlet air temperature of 45℃ and an atomization pressure of 0.20MPa. The attractant spray solution was sprayed onto the surface of the lightweight expanded core particles, with a spraying amount of 4.5% of the mass of the lightweight expanded core particles.

[0123] After spraying, continue fluidized drying for 12 minutes to form an attractant release layer on the particle surface, thus obtaining attractant pilot particles.

[0124] The feed-inducing pilot granules mainly carry feed-inducing components, and their crude protein and crude fat loading are lower than those of the delayed-sinking main nutrient granules, so that they release feed-inducing signals within 0-3 minutes of entering the water instead of concentrating on carrying core growth-promoting nutrients.

[0125] S5. Preparation of delayed-sinking core pellets. Add 5% (by mass) of a pore conditioner to the second mixture. The pore conditioner is composed of wheat flour, modified starch, and soybean meal powder in a 4:3:3 mass ratio. Adjust the moisture content of the second mixture to 24% and feed it into a twin-screw extruder for mesoporous extrusion. During mesoporous extrusion, the extruder's zone 1 temperature is 85℃, zone 2 temperature is 115℃, and zone 3 temperature is 135℃. The screw speed is 230 r / min, the template aperture is 2.5 mm, and the cutter speed is 750 r / min, ensuring the resulting pellets have appropriate porosity and an initial floating or semi-floating state. After extrusion, dry the pellets under 55℃ hot air conditions until the moisture content is 8.9%, obtaining mesoporous extruded core pellets.

[0126] Modified starch, sodium alginate, sodium carboxymethyl cellulose, and lipid sealing material were mixed in a mass ratio of 4:2:1:1 to prepare a hydration density transition layer coating solution. The lipid sealing material was an emulsion formed from fish oil, phospholipid oil, and monoglycerides in a mass ratio of 3:1:1. The mesoporous expanded core particles were placed in a roller coating machine and sprayed with the hydration density transition layer coating solution at 42°C. The spraying amount was 3.8% of the mass of the mesoporous expanded core particles.

[0127] After coating, the particles remain in a floating or semi-floating state in the initial stage after entering the water. Subsequently, water enters through the pores and the water-absorbing colloid hydrates, causing the apparent density of the particles to gradually increase. Thus, after the feeding lead particles release feeding signals, they enter a semi-suspended state or a slowly sinking state.

[0128] Subsequently, a growth-promoting active component loading layer was prepared. Fermented plant protein powder, protein peptide source, probiotic protective microcapsules, slow-release acidified microparticles, betaine, and plant-derived polysaccharides were mixed in a mass ratio of 30:25:15:10:8:12, and a small amount of sodium carboxymethyl cellulose aqueous solution was added as an adhesive liquid to prepare a growth-promoting active component coating material.

[0129] The coating material is sprayed or rolled onto the surface of the particles that have formed a hydration density transition layer, with a coating amount of 5.2% of the particle mass, and then dried at a low temperature of 40°C until the moisture content is 9.1%, to obtain delayed-sinking main culture particles.

[0130] In this process, probiotic protective microcapsules and slow-release acidified microparticles are loaded as independent particles in the growth-promoting active component loading layer, rather than being pre-mixed into the same acidic coating system, in order to reduce the impact of acidic components on probiotic activity during the storage and water immersion stages.

[0131] S6. Add 6% (by mass) of a small-particle-size shaping conditioner to the third mixture. The small-particle-size shaping conditioner consists of wheat flour, protein peptide source, and pregelatinized starch in a mass ratio of 4:2:4. Adjust the moisture content of the third mixture to 20%, and granulate using a ring die pelletizer with a die aperture of 1.8 mm, a compression ratio of 1:5, and a pelletizing temperature of 75℃, so that the particle size of the softening compensation granules is 75% of the particle size of the delayed-sinking main granules. After pelleting, dry at 45℃ until the moisture content is 9.3% to obtain small-particle-size core pellets.

[0132] Pregelatinized starch, pectin, gelatin, and resistant starch were mixed in a mass ratio of 4:2:2:2, and water was added to prepare a softening and retaining layer coating solution with a solids content of 18%. Small-diameter core particles were placed in a fluidized bed coating machine with an inlet air temperature of 38℃ and an atomization pressure of 0.18 MPa. The softening and retaining layer coating solution was sprayed on, with a coating amount of 4.0% of the mass of the small-diameter core particles. After spraying, the particles were dried at a low temperature for 10 minutes to form a softening and retaining layer on the particle surface.

[0133] Easily digestible small peptides, probiotic protective microcapsules, and slow-release acidifying microparticles were mixed in a mass ratio of 45:35:20. These were then adhered to the outer surface of small-diameter core particles with a softening and retaining layer, using a small amount of gelatin aqueous solution. The loading amount was 4.5% of the particle mass, resulting in compensated softening particles. These compensated softening particles began to soften 10 minutes after entering the water, but maintained a recognizable small clump morphology for up to 20 minutes. This allowed fish to ingest easily digestible growth-promoting components later in the feeding process, while reducing powdered uneaten feed.

[0134] S7. Add the feed-inducing pilot pellets obtained in step S4, the delayed-sinking main culture pellets obtained in step S5, and the compensating softening pellets obtained in step S6 to a low-speed mixer at a mass ratio of 10:75:15, and mix at 35 r / min for 5 min to obtain a feed that promotes the growth of the spotted catfish. In the obtained feed, the feed-inducing pilot pellets are used to form a surface feeding window within 0-3 min after entering the water, the delayed-sinking main culture pellets are used to form a slow-sinking main culture window within 3-10 min after entering the water, and the compensating softening pellets are used to form a later-stage compensating window within 10-20 min after entering the water, thereby achieving self-allocation of feeding windows among the same batch of feed pellets.

[0135] Example 2:

[0136] This embodiment is basically the same as that of Embodiment 1, except that: in step S7, the mass ratio of the feeding-inducing pilot particles, the delayed sinking main culture particles, and the compensating softening particles is 5:85:10; the other raw material composition, fermentation conditions, puffing treatment method, coating treatment method, and drying conditions are the same as those of Embodiment 1.

[0137] Example 3:

[0138] This embodiment is basically the same as that of Embodiment 1, except that: in step S7, the mass ratio of the feeding-inducing pilot particles, the delayed sinking main culture particles, and the compensating softening particles is 15:60:25; the other raw material composition, fermentation conditions, puffing treatment method, coating treatment method, and drying conditions are the same as those of Embodiment 1.

[0139] Example 4:

[0140] This embodiment is basically the same as that of Embodiment 1, except that: in step S6, the diameter of the ring die is adjusted to 1.5 mm so that the particle size of the compensating softening particles is 60% of the particle size of the delayed settling main culture particles; the other raw material composition, fermentation conditions, puffing treatment method, coating treatment method and drying conditions are the same as those of Embodiment 1.

[0141] Example 5:

[0142] This embodiment is basically the same as that of Embodiment 1, except that: in step S6, the diameter of the ring die is adjusted to 2.1 mm so that the particle size of the compensation softening particles is 85% of the particle size of the delayed sinking main culture particles; the other raw material composition, fermentation conditions, puffing treatment method, coating treatment method and drying conditions are the same as those of Embodiment 1.

[0143] Example 6:

[0144] This embodiment is basically the same as that of embodiment 1, except that: in step S2, the fermented plant protein base is 25 parts, the wheat flour is adjusted to 23 parts, and the remaining components are kept within the scope of the claims; the remaining fermentation conditions, puffing treatment method, coating treatment method, drying conditions and the mixing ratio of the three types of particles are the same as those of embodiment 1.

[0145] Example 7:

[0146] This embodiment is basically the same as that of Embodiment 1, except that: in step S2, the fermented plant protein base is 45 parts, the wheat flour is adjusted to 13 parts, and the remaining components are kept within the scope of the claims; the remaining fermentation conditions, puffing treatment method, coating treatment method, drying conditions and the mixing ratio of the three types of particles are the same as those of Embodiment 1.

[0147] Example 8:

[0148] This embodiment is basically the same as Embodiment 1, except that: in step S4, the feeding release layer is composed of betaine, hydrolyzed fish protein, small peptides and yeast extract in a mass ratio of 3:3:2:2; in step S6, the softening and retaining layer is composed of pregelatinized starch, sodium alginate and plant gum in a mass ratio of 5:3:2; the remaining raw material composition, fermentation conditions, puffing treatment method, coating treatment method, drying conditions and the mixing ratio of the three types of particles are the same as in Embodiment 1.

[0149] Comparative Example 1:

[0150] The difference between this comparative example and Example 1 is that the basic nutrient mixture is not divided into a first mixture, a second mixture, and a third mixture. Instead, all the nutrient components, appetite-stimulating components, growth-promoting active components, probiotic protective microcapsules, and slow-release acidified microparticles from Example 1 are uniformly mixed and then made into single floating puffed granules using a conventional floating puffing process. The total amount of the remaining raw materials remains the same as in Example 1.

[0151] Comparative Example 2:

[0152] The difference between this comparative example and Example 1 is that, although it is made into pelleted feed, the palatability enhancer, fermented plant protein powder, protein peptide source, probiotic protective microcapsules, slow-release acidified microparticles and plant-derived polysaccharides are all uniformly mixed into the same pellet, and no palatability release layer, hydration density conversion layer, growth-promoting active component loading layer and softening retention layer are formed; the total amount of other raw materials is the same as in Example 1.

[0153] Comparative Example 3:

[0154] The difference between this comparative example and Example 1 is that only feed-inducing pilot particles and delayed-sinking main culture particles are prepared, and no compensating softening particles are prepared; wherein, the feed-inducing pilot particles and delayed-sinking main culture particles are mixed at a mass ratio of 10:90; the remaining raw material composition, fermentation conditions, puffing treatment method, coating treatment method and drying conditions are the same as those in Example 1.

[0155] Comparative Example 4:

[0156] The difference between this comparative example and Example 1 is that only delayed sinking main culture particles and compensating softening particles are prepared, and no feeding-inducing lead particles are prepared; wherein, the delayed sinking main culture particles and compensating softening particles are mixed at a mass ratio of 85:15; the remaining raw material composition, fermentation conditions, puffing treatment method, coating treatment method and drying conditions are the same as in Example 1.

[0157] Comparative Example 5:

[0158] Compared with Example 1, this comparative example differs in that: all three types of particles are present, but the feed-inducing pilot particles, delayed sinking main nutrient particles, and compensating softening particles use the same crude protein and crude fat loading, and the nutrient loading misalignment method of low nutrient loading for feed-inducing pilot particles, main nutrient loading for delayed sinking main nutrient particles, and easily digestible growth-promoting loading for compensating softening particles is not used; the other raw material composition, fermentation conditions, puffing treatment method, coating treatment method, and drying conditions are the same as in Example 1.

[0159] Comparative Example 6:

[0160] Compared with Example 1, the difference in this comparative example is that in step S5, the delayed sinking main culture particles do not form a hydration density transition layer, but only form a common waterproof thin layer on the surface of the mesoporous expanded core particles, so that the delayed sinking main culture particles continue to maintain buoyancy after entering the water; the other raw material composition, fermentation conditions, expansion treatment method, coating treatment method and drying conditions are the same as those in Example 1.

[0161] Comparative Example 7:

[0162] The difference between this comparative example and Example 1 is that in step S5, the delayed-sinking main culture particles are not subjected to mesopore expansion treatment, but are instead formed by high-density pressing, so that they sink to the bottom quickly within 0-2 minutes after entering the water; the other raw material composition, fermentation conditions, coating treatment method and drying conditions are the same as in Example 1.

[0163] Comparative Example 8:

[0164] The difference between this comparative example and Example 1 is that in step S6, the softening particles do not form a softening retention layer, and only easily digestible small peptides, probiotic protective microcapsules and slow-release acidifying microparticles are directly mixed into the small-diameter particles; the remaining raw material composition, fermentation conditions, molding treatment method, drying conditions and mixing ratio of the three types of particles are the same as in Example 1.

[0165] Comparative Example 9:

[0166] The difference between this comparative example and Example 1 is that in steps S5 and S6, the probiotic protective microcapsules and the slow-release acidified microparticles are not loaded separately, but are mixed first and then coated together in the same layer; the other raw material composition, fermentation conditions, puffing treatment method, coating treatment method, drying conditions and the mixing ratio of the three types of particles are the same as in Example 1.

[0167] Comparative Example 10:

[0168] The difference between this comparative example and Example 1 is that in step S6, the particle size of the compensated softening particles is 58% of the particle size of the delayed-sinking main culture particles, which is slightly lower than the 60% lower limit specified in this invention; the other raw material composition, fermentation conditions, puffing treatment method, coating treatment method, drying conditions and the mixing ratio of the three types of particles are the same as in Example 1.

[0169] Comparative Example 11:

[0170] The difference between this comparative example and Example 1 is that in step S6, the particle size of the compensated softening particles is 87% of the particle size of the delayed-sinking main culture particles, which is slightly higher than the upper limit of 85% specified in this invention; the other raw material composition, fermentation conditions, puffing treatment method, coating treatment method, drying conditions and the mixing ratio of the three types of particles are the same as in Example 1.

[0171] Comparative Example 12:

[0172] The difference between this comparative example and Example 1 is that in step S7, the mass ratio of the feeding-inducing pilot particles, the delayed-sinking main culture particles, and the compensating softening particles is 4:86:10, wherein the proportion of the feeding-inducing pilot particles is slightly lower than the lower limit of 5 parts specified in this invention, and the proportion of the delayed-sinking main culture particles is slightly higher than the upper limit of 85 parts specified in this invention; the remaining raw material composition, fermentation conditions, puffing treatment method, coating treatment method, and drying conditions are the same as in Example 1.

[0173] Comparative Example 13:

[0174] The difference between this comparative example and Example 1 is that in step S7, the mass ratio of the feeding-inducing pilot particles, the delayed-sinking main culture particles, and the compensating softening particles is 10:59:31, wherein the proportion of the delayed-sinking main culture particles is slightly lower than the lower limit of 60 parts specified in this invention, and the proportion of the compensating softening particles is slightly higher than the upper limit of 30 parts specified in this invention; the remaining raw material composition, fermentation conditions, puffing treatment method, coating treatment method, and drying conditions are the same as in Example 1.

[0175] The experimental results are shown in the table below:

[0176] Table 1. Water ingress behavior and window formation results:

[0177] Group Surface feeding window formation time / min Time for main cultured particles to enter the slow settling window (min) Compensation particle start softening time / min 20-minute aggregate retention rate / % Nutrient loss rate in 20 minutes / % Example 1 0.6 4.8 11.7 88.6 5.4 Example 2 0.8 5.1 12.4 86.9 5.9 Example 3 0.5 4.5 10.9 84.7 6.3 Example 4 0.7 4.9 10.6 82.8 6.8 Example 5 0.6 5.0 12.9 87.1 5.7 Example 6 0.7 5.2 12.1 85.4 6.5 Example 7 0.6 4.7 11.5 86.2 5.8 Example 8 0.6 4.9 11.9 85.9 6.0 Comparative Example 1 0.7 Not formed Not formed — 8.9 Comparative Example 2 0.8 No clear segmentation No clear segmentation 61.5 9.4 Comparative Example 3 0.7 5.0 No compensation window — 7.6 Comparative Example 4 No food-enhancing window 5.3 12.3 83.4 6.9 Comparative Example 5 0.6 4.9 11.8 84.1 7.8 Comparative Example 6 0.7 Not entered the slow sinking window 12.0 85.2 7.5 Comparative Example 7 0.7 1.4 12.2 84.8 8.1 Comparative Example 8 0.6 4.8 6.2 38.7 13.6 Comparative Example 9 0.7 4.9 11.9 83.6 7.1 Comparative Example 10 0.7 5.0 8.3 66.9 9.8 Comparative Example 11 0.6 4.9 14.8 90.1 5.5 Comparative Example 12 1.3 5.2 12.5 86.4 6.2 Comparative Example 13 0.6 5.0 10.5 81.2 8.7

[0178] Table 2. Results of the aquaculture program:

[0179] Group Weight gain rate / % Feed conversion ratio Survival rate / % Final coefficient of variation / % Weight gain rate of weak fish / % Residual bait rate / % Example 1 214.8 1.16 98.7 9.8 207.5 2.1 Example 2 205.3 1.23 98.0 11.5 195.6 2.8 Example 3 203.6 1.24 97.8 12.1 193.2 3.0 Example 4 201.4 1.26 97.9 12.5 190.8 3.4 Example 5 202.8 1.24 98.1 12.2 192.6 2.9 Example 6 196.2 1.29 97.4 13.0 184.7 3.5 Example 7 204.7 1.22 98.3 11.7 194.9 2.8 Example 8 207.2 1.21 98.2 11.3 198.1 2.6 Comparative Example 1 178.3 1.44 96.5 17.9 151.6 4.8 Comparative Example 2 183.1 1.40 96.8 17.2 158.4 4.5 Comparative Example 3 190.7 1.36 97.1 15.8 169.5 4.1 Comparative Example 4 188.4 1.38 96.9 16.4 166.2 4.3 Comparative Example 5 187.9 1.39 96.7 16.8 163.8 4.6 Comparative Example 6 185.0 1.41 96.6 17.4 160.1 4.7 Comparative Example 7 171.5 1.48 96.2 18.3 146.9 5.9 Comparative Example 8 176.9 1.51 95.8 18.1 149.7 7.6 Comparative Example 9 188.7 1.37 96.8 15.7 170.3 4.2 Comparative Example 10 189.5 1.35 97.0 16.1 171.4 4.9 Comparative Example 11 190.2 1.34 97.2 15.6 173.6 4.0 Comparative Example 12 195.8 1.30 97.5 14.8 181.2 3.7 Comparative Example 13 192.6 1.33 97.1 15.3 176.4 4.9

[0180] Analysis of experimental conclusions:

[0181] As shown in Table 1, Examples 1 to 8 all formed clear three feeding windows. The surface feeding window formed in 0.5 min to 0.8 min, the main feeding particle entered the slow settling window in 4.5 min to 5.2 min, and the compensation particle began to soften in 10.6 min to 12.9 min. All of these fell within the continuous feeding window range of 0-3 min, 3-10 min, and 10-20 min set by the present invention. This indicates that the present invention does not rely on the slow release of a single particle or the release of a single feeding attractant, but rather uses the structural differences of the three types of particles to automatically form a time sequence of first feeding attractant, then main feeding particle, and finally compensation particle after the same batch of feed is put into the water.

[0182] Table 1 also shows that the 20-minute pellet retention rate of Examples 1 to 8 was 82.8% to 88.6%, and the 20-minute nutrient loss rate was 5.4% to 6.8%. This indicates that the compensating softening particles can soften but not completely pulverize in the later compensation window, which can both increase the chance of the feeding fish ingesting small pellets in the later stage and avoid nutrient loss and increased uneaten feed caused by premature disintegration of the compensating particles. Among them, the pellet retention rate of Example 1 reached 88.6%, and the nutrient loss rate was only 5.4%, indicating that the ratio of the three types of particles of 10:75:15, the 75% particle size ratio of the compensating softening particles, and the softening retention layer and the easily digestible growth-promoting component loading layer formed a better synergy.

[0183] As shown in Table 2, the weight gain rate of Examples 1 to 8 was 196.2% to 214.8%, the feed conversion ratio was 1.16 to 1.29, the survival rate was 97.4% to 98.7%, the coefficient of variation of final weight was 9.8% to 13.0%, the weight gain rate of weaker fish was 184.7% to 207.5%, and the uneaten feed rate was 2.1% to 3.5%. Overall, these results were better than those of Comparative Examples 1 to 13. This indicates that the technical effect of the present invention is not a common growth-promoting result brought about by the improvement of a single nutrient component, but rather is produced by the feeding window allocation mechanism formed by the feeding-inducing lead pellets, the delayed sinking main feeding pellets, and the compensating softening pellets.

[0184] Compared to Comparative Example 1, which used conventional single floating extruded pellets, although it could establish an initial feeding state within 0.7 minutes, it could not establish a slow-sinking primary feeding window or a compensation window. Its weight gain rate was only 178.3%, the feed conversion ratio was 1.44, the coefficient of variation of final weight reached 17.9%, the weight gain rate of weaker fish was only 151.6%, and the uneaten feed rate was 4.8%. This indicates that single floating pellets are easily ingested by dominant fish in the early stages of feeding, making it difficult to effectively compensate for the fish feeding in the later stages. In contrast, Example 1 increased the weight gain rate by 36.5 percentage points, decreased the feed conversion ratio by 0.28, decreased the coefficient of variation of final weight by 8.1 percentage points, increased the weight gain rate of weaker fish by 55.9 percentage points, and decreased the uneaten feed rate by 2.7 percentage points compared to Comparative Example 1. This proves that the diversion of three types of pellets and the misalignment of feeding windows are the key to improving the uniformity of group growth.

[0185] Compared with Comparative Example 2, although Comparative Example 2 used the same or similar nutritional components, feeding-enhancing components, growth-promoting active components, probiotic protective microcapsules, and slow-release acidifying microparticles, it uniformly mixed the above components into the same particle, failing to form a feeding-enhancing release layer, a hydration density conversion layer, a growth-promoting active component loading layer, and a softening retention layer. Therefore, it could not form a clearly segmented water entry window. Its 20-minute pellet retention rate was only 61.5%, the nutrient loss rate increased to 9.4%, the weight gain rate was 183.1%, the feed conversion ratio was 1.40, and the coefficient of variation of final weight was 17.2%. This shows that the same raw materials cannot naturally produce the technical effects of the present invention. Different particle structures and nutrient load misalignment are necessary to separate the feeding-enhancing, main-feeding, and compensatory functions in time and form a synergy in feeding behavior.

[0186] Compared with Comparative Example 3, Comparative Example 3 lacked compensating softening particles. Although it could still form a surface feeding window and a slow-sinking main culture window, it did not have a subsequent compensating window. Its weight gain rate of weak fish was 169.5%, the coefficient of variation of final weight was 15.8%, and the uneaten feed rate was 4.1%, all of which were significantly worse than Example 1. This shows that simply attracting fish with feeding lead particles and supplying core nutrition with delayed-sinking main culture particles is not enough to solve the problem of insufficient feeding opportunities for weak fish in the later stage. Compensating softening particles are a necessary technical feature to reduce the degree of final weight dispersion and improve the weight gain rate of weak fish.

[0187] Compared to Comparative Example 4, which lacked feed-inducing lead particles and could not form a surface feeding window, Comparative Example 4 had a weight gain rate of 188.4%, a feed conversion ratio of 1.38, a final weight variation coefficient of 16.4%, and a weight gain rate of 166.2% for weaker fish. This indicates that feed-inducing lead particles are not an optional feed-inducing addition, but rather a preliminary structure used to establish the feeding initiation and feeding location guidance for the fish in the early stages of feeding. If this structure is missing, although delayed sinking main culture particles and compensating softening particles are present, the feeding initiation of the fish is insufficient, and the connection effect between subsequent feeding windows will decrease.

[0188] Compared with Comparative Example 5, although Comparative Example 5 retained the three types of pellets, it did not adopt the nutrient load misalignment method of low nutrient load of the feed-inducing lead pellets, main nutrient load of delayed sinking feed pellets, and easily digestible growth-promoting load of the softened pellets. Its weight gain rate was 187.9%, feed conversion ratio was 1.39, and coefficient of variation of final weight was 16.8%. The weight gain rate of weaker fish was 163.8%, indicating that the existence of the three types of pellets alone is not enough to produce the effect of the present invention. If the nutrient load of the three types of pellets were similar, the stronger fish might still ingest more core nutrients in the early stage, and the easily digestible growth-promoting compensation obtained by the fish in the later stage would be insufficient. This proves that the nutrient load misalignment is the important inventive point that distinguishes the present invention from ordinary mixed pellet feed.

[0189] Compared with Comparative Example 6, the delayed-sinking main culture pellets in Comparative Example 6 did not form a water density transition layer, but instead remained buoyant, causing them not to enter the slow-sinking window. Their weight gain rate was 185.0%, feed conversion ratio was 1.41, and coefficient of variation of final weight was 17.4%. The weight gain rate of the weaker fish was 160.1%. This indicates that the water density transition layer is not an ordinary coating layer, but a key structure that allows the main culture pellets to gradually shift from the surface feeding area to the semi-suspended or slowly sinking feeding area after the feeding window. This structure can weaken the continuous occupation of the surface main nutrient pellets by the dominant fish.

[0190] Compared to Comparative Example 7, which uses high-density compression molding, the main culture pellets sink rapidly to the bottom in 1.4 minutes. Although this also changed the floating state of the pellets, it failed to form a slow-sinking main culture window in 3-10 minutes. The weight gain rate dropped to 171.5%, the feed conversion ratio increased to 1.48, and the uneaten feed rate increased to 5.9%. This shows that the main culture pellets are not necessarily better the faster they sink. Instead, they should form a slow-sinking window that matches the feeding behavior of the fish after the release of the feeding signal. If the pellets sink to the bottom too early, the core nutrient pellets will be separated from the main feeding water layer and the risk of uneaten feed will increase. Therefore, the delayed sinking of the present invention has a specific time matching relationship, rather than a simple replacement of conventional sinking feed.

[0191] Compared with Comparative Example 8, the compensating softening pellets of Comparative Example 8 did not form a softening retention layer. The compensating pellets softened prematurely at 6.2 min, and the pellet retention rate at 20 min was only 38.7%. The nutrient loss rate increased to 13.6%, the residual feed rate reached 7.6%, and the weight gain rate was only 176.9%. This indicates that the softening speed of the compensating pellets must be controlled by the softening retention layer. If it disintegrates too early, it will not only fail to form a 10-20 min compensation window, but will also cause nutrient diffusion, increase in powdered residual feed, and decrease in effective feeding. Therefore, the softening retention layer is the core structure for achieving compensation in the later stage rather than pollution in the later stage.

[0192] Compared with Comparative Example 9, Comparative Example 9, which mixed probiotic protective microcapsules and slow-release acidifying microparticles and then coated them together in the same layer, had a weight gain rate of 188.7%, a feed conversion ratio of 1.37, and a weight gain rate of 170.3% for weaker fish, all of which were lower than those in Example 1. This indicates that it is necessary to load probiotic protective microcapsules and slow-release acidifying microparticles separately, as this can reduce the impact of acidic components on the activity of probiotics during the storage and water entry stages, allowing the probiotics, acidifying microparticles, and small peptides in the compensation window to enter the digestive tract of the fish more stably in the later stages of feeding.

[0193] Compared with Comparative Examples 10 and 11, in Comparative Example 10, the particle size of the compensating softening particles was 58% of the particle size of the delayed-sinking main culture particles, which is lower than the 60% lower limit of this invention. The softening time of the compensating particles was advanced to 8.3 min, the 20-minute aggregate retention rate decreased to 66.9%, and the nutrient loss rate increased to 9.8%. In Comparative Example 11, the particle size of the compensating softening particles was 87%, which is higher than the 85% upper limit of this invention. The softening time of the compensating particles was delayed to 14.8 min. Although the aggregate retention rate reached 90.1%, the weight gain rate of the weaker fish was only 173.6%. This indicates that if the particle size is too small, the compensating particles will hydrate prematurely and dissolve excessively. If the particle size is too large, it will reduce the ease of intake for the weaker fish in the later stage. Therefore, it is reasonable for this invention to limit the particle size of the compensating softening particles to 60%-85% of the particle size of the delayed-sinking main culture particles.

[0194] Compared with Comparative Examples 12 and 13, Comparative Example 12 had a lower proportion of feed-inducing lead particles (less than 5 parts) and a higher proportion of delayed-sinking main culture particles (more than 85 parts), resulting in a delayed surface feeding window formation time of 1.3 minutes. The weight gain rate of the weaker fish was 181.2%, and the coefficient of variation for final weight was 14.8%. Comparative Example 13 had a lower proportion of delayed-sinking main culture particles (less than 60 parts) and a higher proportion of compensating softening particles (more than 30 parts). Although compensating softening was achieved, the uneaten feed rate increased to 4.9%, and the nutrient loss rate increased to 8.7%. This indicates that the mass ratio of the three types of particles must be maintained within the range of 5-15:60-85:10-30. Too few feed-inducing lead particles will weaken the feeding initiation, too few main culture particles will reduce the supply of core nutrients, and too many compensating softening particles will increase the risk of softening residue and nutrient loss in the later stages.

[0195] Examples 2 and 3 correspond to the boundary or near-boundary combinations of the three types of particle ratios. In Example 2, the mass ratio of feed-inducing lead particles, delayed sinking main culture particles, and compensating softening particles is 5:85:10. In Example 3, the mass ratio of the three is 15:60:25. Both groups can form an effective three-segment window and achieve a higher aquaculture effect than the comparative example, indicating that the mass ratio range defined by the present invention has feasibility and protection scope. However, the weight gain rate, feed conversion ratio, weight gain rate of weak fish, and residual feed rate of both are slightly lower than those of Example 1, indicating that 10:75:15 is more conducive to achieving a balance between feed induction, core nutrient supply, and subsequent compensation.

[0196] Examples 4 and 5 correspond to the lower and upper limits of the proportion of compensated softened particle size, respectively. In Example 4, the compensated softened particle size is 60% of the particle size of the delayed-sinking main nutrient particles, with an initial softening time of 10.6 min and a 20-min aggregate retention rate of 82.8%. In Example 5, the compensated softened particle size is 85% of the particle size of the delayed-sinking main nutrient particles, with an initial softening time of 12.9 min and a 20-min aggregate retention rate of 87.1%. Both examples fall within the later compensation window and maintain low nutrient loss, indicating that a particle size ratio of 60%-85% can balance the ingestibility in the later stage and the stability of aggregates.

[0197] Examples 6 and 7 correspond to the boundaries of 25 and 45 parts of fermented plant protein substrate, respectively. Their weight gain rates were 196.2% and 204.7%, and their feed conversion ratios were 1.29 and 1.22, respectively, both of which were better than most comparative examples. This shows that the limitation of 25-45 parts of fermented plant protein substrate in the basic nutrient mixture of the present invention can cover the effective implementation at different plant protein substitution levels. However, when the fermented plant protein substrate is at a lower level, the growth-promoting nutritional support is slightly weaker. When it is at a higher level, the overall effect is close to the optimal level. This further proves that the improvement of the present invention does not rely solely on the fermentation of plant protein itself, but on the synergy between the fermented plant protein substrate and the three types of particle feeding window structures.

[0198] Example 8, after changing the composition of the feed-inducing release layer and the softening and retaining layer, still achieved a weight gain rate of 207.2%, a feed conversion ratio of 1.21, a final weight variation of 11.3%, a weight gain rate of 198.1% for weaker fish, and a residual feed rate of 2.6%. This indicates that within the range of optional components defined in the claims, feed-inducing components such as betaine, hydrolyzed fish protein, small peptides, and yeast extract, as well as softening and retaining components such as pregelatinized starch, sodium alginate, and plant gum, can be replaced through similar feed-inducing release and softening and retaining mechanisms, supporting the rationality of the component range of the present invention.

[0199] As can be seen from Tables 1 and 2, Examples 1 to 8 not only achieved stable water inlet window formation, but also demonstrated synergistic improvements in aquaculture results, including high weight gain, low feed conversion ratio, low coefficient of variation in final weight, high weight gain of weaker fish, and low uneaten feed rate. In contrast, the comparative examples showed significant deterioration in at least one key indicator if any of the following key features were missing: three types of particle diversion, nutrient load misalignment, water density transition layer, softening and retention layer, separate loading methods, reasonable particle size ratio, or reasonable mass ratio. This indicates that the technical effect of the present invention has a clear causal chain: structured diversion leads to water inlet behavior misalignment, water inlet behavior misalignment leads to feeding window misalignment, feeding window misalignment improves the distribution of feeding opportunities in the group, feeding opportunity distribution improves the weight gain and final weight uniformity of weaker fish, and softening and retention and nutrient load misalignment reduce nutrient loss and uneaten feed.

[0200] Therefore, this invention achieves technical effects different from existing feeds containing single floating particles, uniformly mixed particles, ordinary sinking particles, or simple attractant additives through a technical route of homogeneous basic nutrient mixture diversion—three types of particle heterogeneous configuration—attractant, main, and compensating nutrient misalignment load—continuous feeding window self-allocation after water introduction. Its superior results are not something that those skilled in the art can directly expect through conventional formula optimization alone, but rather a comprehensive effect resulting from the synergistic effect of multi-particle group behavior, feeding competition regulation, softening maintenance, and active component protection. This further supports the inventiveness and reasonableness of the scope of protection of the proportion of the three types of particles, the particle size ratio of the compensating softening particles, the window time range, and the nutrient load misalignment mode in the claims of this invention.

[0201] Based on the preferred embodiments of the present invention described above, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A method for preparing feed that promotes the growth of channel catfish, characterized in that, Includes the following steps: S1. The plant protein raw material is subjected to bacterial and enzyme co-fermentation to obtain fermented plant protein base material; S2. Mix the fermented plant protein base with protein peptide source, energy raw material, mineral raw material and binding raw material to obtain basic nutrient mixture; S3. Divide the basic nutrient mixture into a first mixture, a second mixture, and a third mixture; S4. The first mixture is subjected to light expansion treatment and a feeding-inducing release layer is formed on its surface to obtain feeding-inducing pilot particles. The feeding-inducing pilot particles are used to release feeding-inducing signals in the early stage of water entry. S5. The second mixture is subjected to mesoporous expansion treatment to form a hydration density conversion layer and a growth-promoting active component loading layer, thereby obtaining delayed-sinking main nutrient particles. The delayed-sinking main nutrient particles gradually change from a floating or semi-floating state to a semi-suspended state or a slowly sinking state after entering the water. S6. The third mixture is subjected to small particle size molding treatment to form a softening and retaining layer and an easily digestible growth-promoting component loading layer to obtain compensated softening particles. The compensated softening particles soften after entering water to form small clumps that retain the clump shape. S7. Mix the feed-inducing pilot pellets, delayed sinking main feed pellets, and compensating softening pellets according to the preset mass ratio to obtain feed that promotes the growth of spotted catfish.

2. The method for preparing feed to promote the growth of channel catfish according to claim 1, characterized in that, The plant protein raw materials include at least two of soybean meal, rapeseed meal, cottonseed protein, peanut meal and corn protein powder; the bacterial enzyme co-fermentation uses at least two of Bacillus subtilis, Lactobacillus plantarum and Saccharomyces cerevisiae, and is combined with at least one of neutral protease, phytase and xylanase for fermentation, and the resulting material is dried to a moisture content of no more than 12% after fermentation.

3. The method for preparing feed to promote the growth of channel catfish according to claim 1, characterized in that, The basic nutrient mixture comprises the following components in parts by weight: 25-45 parts fermented plant protein base, 3-10 parts protein peptide source, 3-8 parts fish meal, 12-25 parts wheat flour, 5-12 parts corn gluten powder, 1-4 parts fish oil, 0.5-2 parts phospholipid oil, 1-3 parts calcium dihydrogen phosphate, 0.2-1 parts compound vitamins, 0.2-1 parts compound minerals, and 1-5 parts binding material.

4. The method for preparing feed to promote the growth of channel catfish according to claim 1, characterized in that, The feeding-inducing release layer includes at least two of the following: betaine, hydrolyzed fish protein, small peptides, free amino acids, and yeast extract; the crude protein loading and crude fat loading of the feeding-inducing pilot particles are both lower than those of the delayed-sinking main nutrient particles, so that the feeding-inducing pilot particles release feeding signals in the early stage of entering the water without concentrating on carrying the main nutrient components.

5. The method for preparing feed to promote the growth of channel catfish according to claim 1, characterized in that, The hydration density transition layer includes at least two of the following: hydrophilic colloid, modified starch, alginate, sodium carboxymethyl cellulose, gelatin, and lipid sealing layer; the delayed-sinking main culture particles gradually increase in density after entering the water through pore water intake and hydrophilic colloid hydration, thereby forming a slow-sinking main culture window after the feeding induction lead particles release feeding signals.

6. The method for preparing feed to promote the growth of channel catfish according to claim 1, characterized in that, The growth-promoting active component loading layer includes at least three of the following: fermented plant protein powder, protein peptide source, probiotic protective microcapsules, slow-release acidified microparticles, betaine, and plant-derived polysaccharides; the probiotic protective microcapsules and slow-release acidified microparticles are loaded separately to reduce the impact of acidic components on probiotic activity during the storage and water immersion stages.

7. The method for preparing feed to promote the growth of channel catfish according to claim 1, characterized in that, The particle size of the compensating softening particles is 60%-85% of the particle size of the delayed-sinking main culture particles; the softening retention layer includes at least two of pregelatinized starch, pectin, gelatin, alginate, resistant starch and plant gum, so that the compensating softening particles soften without completely pulverizing in the later compensation window.

8. The method for preparing feed to promote the growth of channel catfish according to claim 1, characterized in that, The mass ratio of the feeding-inducing pilot particles, the delayed-sinking main culture particles, and the compensating softening particles is 5-15:60-85:10-30; the surface feeding-inducing window is 0-3 minutes after water immersion, the delayed-sinking main culture particle window is 3-10 minutes after water immersion, and the subsequent compensation window is 10-20 minutes after water immersion.

9. The method for preparing feed for promoting the growth of channel catfish according to claim 1, characterized in that, The feed-inducing pilot granules, delayed sinking main nutrient granules, and compensating softening granules are prepared using a nutrient loading misalignment method. Among them, the feed-inducing pilot granules are mainly loaded with feed-inducing components, the delayed sinking main nutrient granules are mainly loaded with fermented plant proteins, protein peptides, and lipid energy components, and the compensating softening granules are mainly loaded with easily digestible small peptides, probiotic protective microcapsules, and slow-release acidified microparticles.

10. A feed for promoting the growth of channel catfish, characterized in that, The feed is prepared by the preparation method according to any one of claims 1-9, comprising: The feed includes feed-attracting pilot pellets, delayed-sinking main nutrient pellets, and compensating softening pellets mixed in the same batch. The feed-attracting pilot pellets, delayed-sinking main nutrient pellets, and compensating softening pellets have different release times, floating and sinking states, softening behaviors, and nutrient load structures, so that in the same feeding, a surface feed-attracting window, a slow-sinking main nutrient window, and a subsequent compensating window are formed in sequence.

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