Fish feed containing traditional Chinese medicine fermentation product and preparation method thereof

Abstract

The application discloses fish feed containing traditional Chinese medicine fermentation and a preparation method thereof. The method comprises the following steps: (1) crushing soybean powder, secondary powder and corn straw powder and sieving to obtain conventional fish feed; (2) sieving vitamin premix and mineral premix and uniformly mixing; (3) adding traditional Chinese medicine fermentation to the mixture obtained in the step (2); (4) uniformly mixing the mixture in the step (3) and the conventional fish feed in the step (1) according to a formula proportion; (5) adding fish oil to the mixture in the step (4); (6) adding water to the mixture in the step (5), granulating and drying. The application adopts a combined synergistic treatment method of enzymolysis and fermentation to replace the previous decoction and extraction method for the traditional Chinese medicine components, effectively improves the content of active components such as curcumin, free anthraquinone and ginsenoside in the feed particles, reduces the production cost and energy consumption, and the prepared fish feed particles have better quality stability. Meanwhile, the fish feed has better effects in improving the growth and immunity of fishes.

Description

Technical Field

[0001] This invention belongs to the field of aquaculture, specifically relating to a fish feed containing fermented Chinese medicine and its preparation method. Background Technology

[0002] CN 114304445 B discloses a fish feed containing traditional Chinese medicine components. Its formula consists of a combination of traditional Chinese medicine, minerals, vitamins, and other raw materials, prepared using modern spray granulation technology. It is said to improve fish growth and meat quality. However, this invention uses a traditional water decoction method to extract the traditional Chinese medicine components, followed by filtration and concentration. This process is complex and involves expensive equipment such as micro-pressure decoction machines, multi-stage filtration systems, and steam recompression systems, resulting in high production costs, high energy consumption, and demanding high skill levels from operators, thus hindering the industrial production of this feed. Furthermore, during the prolonged decoction and extraction process, the active ingredients of the relevant traditional Chinese medicine may be degraded or destroyed, or even produce toxic components, thereby reducing its efficacy in promoting fish growth and improving meat quality. Additionally, fish feed containing traditional Chinese medicine extracts is often bitter, leading to poor palatability, thus presenting certain limitations and shortcomings.

[0003] Currently, fermentation technology is widely used in the food, feed, and biopharmaceutical industries, offering numerous advantages such as relatively mature technology, simple methods, mild conditions, and high degree of automation in industrial equipment. Based on this, this invention improves the preparation process of the traditional Chinese medicine components contained in the fish feed formula. Taking into account the high cellulose content of the medicinal herbs, it employs a synergistic enzymatic hydrolysis and fermentation technique to replace the original decoction and concentration method. This approach offers advantages such as energy saving, environmental protection, cost reduction, and efficiency improvement, making it more convenient for industrial production. Furthermore, the resulting feed has higher value in increasing the content of active ingredients in the traditional Chinese medicine and promoting fish growth and health. Summary of the Invention

[0004] The purpose of this invention is to provide a fish feed containing fermented traditional Chinese medicine and its preparation method. This invention targets the unique traditional Chinese medicine components in the fish feed formula, employing a combined enzymatic hydrolysis and fermentation technique to process them, replacing the original decoction and concentration process. The aim is to overcome the limitations and shortcomings of existing preparation methods, making them more suitable for industrial production and enhancing their medicinal value.

[0005] The fish feed containing fermented traditional Chinese medicine of the present invention is prepared by the following method, including the following steps:

[0006] (1) Crush and sieve soybean flour, wheat middlings and corn stalk flour to obtain conventional fish feed;

[0007] (2) Sift the vitamin premix and mineral premix and mix them evenly;

[0008] (3) Add fermented Chinese medicine to the mixture obtained in step (2);

[0009] (4) Mix the mixture in step (3) with the conventional fish feed in step (1) according to the formula ratio;

[0010] (5) Add fish oil to the mixture from step (4);

[0011] (6) Add water to the mixture in step (5), granulate, and dry;

[0012] The aforementioned fermented Chinese medicine is prepared by pulverizing and mixing turmeric, Panax notoginseng, rhubarb, mulberry leaves, and roasted licorice to form a fermentation culture medium, adding cellulase for enzymatic hydrolysis, and then adding Bacillus cereus culture for fermentation.

[0013] Preferably, the fermented Chinese medicine is prepared by mixing 24 parts by weight of turmeric, 8 parts by weight of Panax notoginseng, 8 parts by weight of rhubarb, 8 parts by weight of mulberry leaf and 8 parts by weight of prepared licorice root to form a fermentation culture medium, adding cellulase for enzymatic hydrolysis, and then adding Bacillus spp. bacterial solution for fermentation.

[0014] Preferably, the traditional Chinese medicine fermentation culture medium is prepared by pulverizing and mixing 24 parts of turmeric, 8 parts of Panax notoginseng, 8 parts of rhubarb, 8 parts of mulberry leaf, and 8 parts of prepared licorice root by weight to obtain the traditional Chinese medicine components. The components are then mixed in the following weight ratios: 80-100 parts of traditional Chinese medicine components, 3-6 parts of wheat bran, 2-4 parts of glucose, 1-2 parts of urea, 0.5-1 parts of ammonium sulfate, 0.1-0.2 parts of potassium dihydrogen phosphate, and 0.07-0.15 parts of magnesium sulfate heptahydrate.

[0015] Further preferred, the composition ratio of the traditional Chinese medicine fermentation culture medium, in order of weight ratio, is as follows: traditional Chinese medicine components 90, wheat bran 5, glucose 3, urea 1, ammonium sulfate 1, potassium dihydrogen phosphate 0.2, and magnesium sulfate heptahydrate 0.1.

[0016] Furthermore, the amount of cellulase added to the fermentation medium of the traditional Chinese medicine is 15 u / g ~ 40 u / g (enzyme activity units).

[0017] Preferably, the amount of cellulase added to the fermentation medium of the traditional Chinese medicine is 30 u / g (enzyme activity units).

[0018] Furthermore, after the cellulase is added, Bacillus spp. is inoculated with the bacterial culture for fermentation 2-4 hours later.

[0019] Preferably, the cellulase is added for 4 hours before the Bacillus spores are inoculated for fermentation.

[0020] Furthermore, the fermentation conditions are: temperature 28-36℃, stirring speed 80-130 r / min, and fermentation time 48-72 h.

[0021] Preferably, the optimal fermentation conditions are: temperature 34℃, stirring speed 110 r / min, and fermentation time 60 h.

[0022] Preferably, the Bacillus bacterial culture is obtained by the following steps: inoculating Bacillus in a seed culture medium and then culturing it at 25-35°C for 24-36 h; the seed culture medium comprises peptone, yeast extract and sodium chloride.

[0023] Furthermore, the amount of Bacillus bacterial inoculum is 3-10% of the mass of the traditional Chinese medicine fermentation culture medium.

[0024] Preferably, the amount of Bacillus bacterial inoculum accounts for 5% of the mass of the traditional Chinese medicine fermentation culture medium.

[0025] Preferably, the mass ratio of each ingredient in the fish feed is 30 parts of fermented Chinese medicine, 30 parts of soybean flour, 15 parts of fish oil, 15 parts of wheat bran, 15 parts of corn stalk powder, 5 parts of vitamin premix, and 5 parts of mineral premix.

[0026] The vitamin premix comprises, by weight, 5 parts vitamin C, 2 parts vitamin B6, 2 parts retinol, 2 parts pantothenic acid, 2 parts niacin, 2 parts biotin, 2 parts vitamin D, and 1 part inositol.

[0027] The mineral premix comprises, by weight, 3 parts magnesium sulfate heptahydrate, 3 parts potassium dihydrogen phosphate, 3 parts zinc sulfate heptahydrate, 3 parts calcium hydrogen phosphate, 2 parts sodium chloride, 2 parts potassium iodide, 2 parts copper chloride dihydrate, 2 parts cobalt chloride hexahydrate, and 1 part sodium selenite pentahydrate.

[0028] Furthermore, after fermentation, the fermentation products need to be dried and pulverized.

[0029] Furthermore, the fermentation product is dried at a temperature of 55-80℃ until the moisture content is no higher than 12%.

[0030] Compared with the existing preparation method disclosed in CN 114304445 B, the advantages and positive effects of the present invention are as follows:

[0031] (1) The content of active ingredients in traditional Chinese medicine is increased, enhancing the medicinal value of the feed. This fish feed contains characteristic traditional Chinese medicine components such as turmeric, Panax notoginseng, rhubarb, and mulberry leaves. The series of active ingredients contained in these herbs, such as curcumin, ginsenosides, Panax notoginseng saponins, and free anthraquinones, have important functions such as antioxidation, liver protection, and immunity enhancement. They can promote fish growth, improve fish stress resistance and overall health, and are an important material basis for the value of this fish feed. In the current preparation method, the combination of traditional Chinese medicine is extracted by decoction and concentration. The long-term high-temperature treatment in this process degrades and transforms the relevant active ingredients, thereby reducing their content and even producing side effects, especially for heat-instantaneous components. This invention uses a combination of enzymatic hydrolysis and fermentation to treat the combination of traditional Chinese medicine, replacing the decoction and concentration processes. The treatment conditions are milder, avoiding the impact of high temperature on the relevant active ingredients, thus maximizing the medicinal value of the fish feed.

[0032] (2) Reduced energy consumption and preparation costs, which is beneficial for industrial production. Current preparation processes involve equipment lines such as micro-pressure decoction machines, micro-pressure step-by-step filtration systems, and steam recompression systems. These equipment lines are expensive, energy-intensive, and have stringent operating parameters. The process transfer steps are complex, and the skill requirements for industrial workers are relatively high, which is not conducive to industrial promotion and large-scale production. In the embodiments of this invention, a combined enzymatic hydrolysis and fermentation synergistic process is adopted. The reaction conditions are relatively mild, the industrialization technology is mature, the equipment requirements are low, the degree of automation is high, which can effectively reduce production costs, reduce dependence on manual labor, and has the advantages of being green and environmentally friendly.

[0033] (3) The synergistic effect of cellulase and probiotics with traditional Chinese medicine improves the utilization value of feed. Given that the cell walls of traditional Chinese medicine components such as Panax notoginseng, rhubarb, and mulberry leaves contain a large amount of cellulose, this invention utilizes the similarity between the enzymatic hydrolysis conditions of cellulase and the fermentation conditions of Bacillus subtilis to synergistically combine enzymatic hydrolysis and fermentation. Through cellulase hydrolysis, the release and exposure of the internal components of the traditional Chinese medicine cells are facilitated, thereby improving the fermentation effect of Bacillus subtilis. Simultaneously, cellulose is decomposed into a series of sugar sources such as oligosaccharides, cellobiose, and monosaccharides (glucose, etc.), which can serve as important nutrients in feed and are beneficial for fish absorption and utilization. Furthermore, Bacillus subtilis is a probiotic that promotes animal growth and development and enhances immunity. It can complement traditional Chinese medicine to promote the proliferation of probiotics, while fermentation by probiotics can improve the absorption efficiency of traditional Chinese medicine. Therefore, this invention, through the synergistic effect of cellulase and probiotics with traditional Chinese medicine, can effectively improve the nutritional and medicinal value of the fish feed and has good application prospects.

[0034] (4) Improved feed compliance and increased feed pellet stability. In current preparation methods, the extract obtained by decocting and concentrating the Chinese herbal medicine components with water is granulated with other components. The resulting feed is often bitter, especially rhubarb, which is bitter and cold in nature, resulting in poor palatability and strong medicinal properties. In addition, because the Chinese herbal medicine extract powder contains water, it is easy to absorb moisture, resulting in poor feed stability. Therefore, there are certain requirements for the packaging and storage of the feed. In the embodiments of this invention, the Chinese herbal medicines that have undergone enzymatic hydrolysis and fermentation treatment have significantly reduced bitterness and a milder medicinal properties while ensuring efficacy, thus improving the fish's compliance with feeding and resulting in better feed pellet stability.

[0035] This invention employs a combined enzymatic hydrolysis and fermentation process to replace the previous water decoction extraction method for traditional Chinese medicine components. This effectively increases the content of active ingredients such as curcumin, free anthraquinones, and ginsenosides in the feed pellets, while reducing production costs and energy consumption. The resulting fish feed pellets exhibit better quality stability. Furthermore, the fish feed provided by this invention demonstrates superior effects in improving fish growth and immunity. Attached Figure Description

[0036] Figure 1 This is a flowchart of the preparation process of fermented Chinese medicine. Detailed Implementation

[0037] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention.

[0038] Example 1: Comparison of preparation methods for traditional Chinese medicine components

[0039] For details regarding the other components and preparation steps of this fish feed, please refer to the implementation instructions in the above case study. This case study provides a detailed comparison of the processing method for the traditional Chinese medicine components with the current preparation method (CN 114304445 B), as follows:

[0040] Traditional Chinese Medicine Premix (Preparation Method): According to the proportions of the traditional Chinese medicine components (24 parts turmeric, 8 parts Panax notoginseng, 8 parts rhubarb, 8 parts mulberry leaf, and 8 parts prepared licorice root by mass), weigh each herb separately. Mix the raw materials of turmeric, Panax notoginseng, rhubarb, mulberry leaf, and prepared licorice root, add 10 times the amount of water and soak for 0.5 h. Use a micro-pressure decoction machine (rated pressure 0.15~0.20 MPa, safety valve opening pressure 0.15~0.25 MPa, decoction tank temperature 100~110℃) for decoction extraction, controlling the heat source to maintain a gentle boil for 90 min, followed by vortex sedimentation to obtain the decoction liquid. Filter the decoction liquid using a micro-pressure stepwise filtration system (filter mesh size approximately 300 μm), and then concentrate it using a centrifugal steam compressor system (temperature 65~85℃) until the relative density is 1.08~1.25 (55~60℃), thus obtaining the traditional Chinese medicine premix.

[0041] Traditional Chinese Medicine Fermentation Product (Preparation Method of this Invention): According to the proportion of traditional Chinese medicine components (24 parts by weight of turmeric, 8 parts of Panax notoginseng, 8 parts of rhubarb, 8 parts of mulberry leaf, and 8 parts of prepared licorice root), each herb is weighed, pulverized and mixed, and passed through a 40-mesh sieve. 90 parts by weight are taken and mixed with 5 parts by weight of wheat bran, 3 parts by weight of glucose, 1 part by weight of urea, 1 part by weight of ammonium sulfate, 0.2 parts by weight of potassium dihydrogen phosphate, and 0.1 parts by weight of magnesium sulfate heptahydrate in a fermentation tank. Water is added to prepare a traditional Chinese medicine fermentation culture medium. Cellulase is added at a rate of 30 u / g. The fermentation tank temperature is set at 34℃ and the stirring speed is 110 r / min. After 4 h, 5% of the fermentation culture medium weight of Bacillus belye (deposited at Guangdong Provincial Microbial Culture Collection Center, accession number GDMCC.1.1835) seed liquid is inoculated. After fermentation for 60 h, the mixture is filtered, and the fermentation product is dried (at a temperature of about 60℃) until the moisture content is less than 12%. The product is then pulverized to obtain the traditional Chinese medicine fermentation product. The seed culture of Bacillus refers to the culture of Bacillus inoculated into a seed culture medium (containing peptone, yeast extract, and sodium chloride, such as LB medium) and incubated at 32°C for 36 hours. The preparation process is as follows: Figure 1 As shown.

[0042] The above-mentioned Chinese herbal premix and fermented Chinese herbal products are combined with other components to form fish feed pellets. The formula and preparation method of this fish feed are as follows:

[0043] Fish feed formula: by weight, it includes 30 parts of Chinese medicine premix or fermented Chinese medicine, 30 parts of soybean flour, 15 parts of fish oil, 15 parts of wheat middlings, 15 parts of corn stalk powder, 5 parts of vitamin premix and 5 parts of mineral premix.

[0044] The vitamin premix consists of: 5 parts vitamin C, 2 parts vitamin B6, 2 parts retinol, 2 parts pantothenic acid, 2 parts niacin, 2 parts biotin, 2 parts vitamin D, and 1 part inositol, mixed evenly.

[0045] The mineral premix includes: 3 parts magnesium sulfate heptahydrate, 3 parts potassium dihydrogen phosphate, 3 parts zinc sulfate heptahydrate, 3 parts calcium hydrogen phosphate, 2 parts sodium chloride, 2 parts potassium iodide, 2 parts copper chloride dihydrate, 2 parts cobalt chloride hexahydrate, and 1 part sodium selenite pentahydrate, which are mixed evenly to obtain the final product.

[0046] The preparation method includes the following steps:

[0047] Step 1: Using ultra-fine grinding technology, soybean flour, wheat middlings, and corn stalks are ground and sieved to obtain conventional fish feed;

[0048] Step 2: Mix the vitamin premix and mineral premix evenly and pass them through a 40-mesh sieve.

[0049] Step 3: Add the fermented Chinese medicine to the mixture obtained in Step 2.

[0050] Step 4: Using a three-dimensional mixer, mix the mixture from Step 3 with the conventional fish feed from Step 1 according to the formula ratio.

[0051] Step 5: The powder mixed in Step 4 is fed into the airflow distribution plate of the fluidized bed granulation chamber, and the blower is turned on to send in hot air to preheat the mixed powder at a temperature of 65°C.

[0052] Step Six: Dissolve the fish oil in an appropriate amount of drinking water, start the spray program, spray it into the fluidized bed granulation chamber, granulate, and dry. The spray granulation conditions are: atomization pressure 0.12 MPa, inlet temperature 85~90℃, outlet temperature 55~60℃, and spray rate 240 Hz. During granulation, to achieve better particle quality, a small amount of drinking water can be sprayed in as needed. After spray granulation, dry and granulate at the material drying temperature. The material drying temperature is 75℃, the drying time is 30 minutes, and the granules are finished to a 40 mesh.

[0053] This yielded feeds for the control group and the experimental group, prepared using traditional Chinese medicine premix and fermented traditional Chinese medicine, respectively. The following tests were then conducted:

[0054] Curcumin content: The content of the two types of fish feed pellets was calculated according to the detection method disclosed in CN 114304445 B.

[0055] Saponin content: The total amount of ginsenoside Rg1, ginsenoside Rb1 and notoginsenoside R1 is used as the test method, which refers to the measurement and determination method of Panax notoginseng in the 2020 edition of the Chinese Pharmacopoeia.

[0056] Free anthraquinone content: Calculated as the total amount of aloe-emodin, rhein, emodin, chrysophanol, and emodin methyl ether. The detection method refers to the measurement and determination method under the rhubarb medicinal material section of the 2020 edition of the Chinese Pharmacopoeia.

[0057] The experimental results are shown in Table 1 below.

[0058] Table 1. Detection results of some active ingredients of traditional Chinese medicine in feed pellets

[0059]

[0060] The test results showed that the contents of curcumin, saponins, and free anthraquinones in the experimental group were significantly higher than those in the control group, especially saponins and free anthraquinones, which were nearly three times higher than those in the control group. The experiment indicates that the current preparation method, which uses decoction and concentration to process the herbal components, destroys some of their active ingredients, especially heat-instantaneous components such as saponins and free anthraquinones. In contrast, the gentle enzymatic fermentation method can effectively maintain a higher content of active ingredients from the herbal components in the feed.

[0061] Example 2: Stability Study of Feed Pellet

[0062] The quality stability of the two feed samples in Example 1 under normal room temperature conditions was investigated, as follows:

[0063] Experimental conditions: The samples were placed in commercially available feed packaging materials and examined at normal room temperature (25℃ ± 2℃, RH 60% ± 10%).

[0064] The observation period is 12 months, which includes 0, 1, 3, 6 and 12 months.

[0065] Examination items: Properties: appearance, color, shape, odor, etc. Content: moisture, curcumin, saponins, free anthraquinones.

[0066] The experimental results are shown in Table 2 below.

[0067] Table 2 Results of feed pellet stability study

[0068]

[0069] The stability study results showed that, within 12 months of storage at room temperature, the control group exhibited significant moisture absorption, reaching a moisture content of 14.4%. The feed pellets showed marked clumping, and all other content indicators showed significant decreases, with curcumin decreasing by over 5% and free anthraquinone by 22%. While the experimental group also showed some moisture absorption over the 12 months, the moisture content remained below 10%, the overall pellet condition was good, and other content indicators remained generally stable, although slightly decreased, but the decrease did not exceed 3%, significantly better than the control group. This may be because the current preparation method uses a concentrated extract of traditional Chinese medicine premix obtained through decoction, leading to feed pellets that are prone to moisture absorption, mold growth, and poor stability.

[0070] Example 3: Enhancing the Non-specific Immunity of Yellow Catfish

[0071] This embodiment uses yellow catfish as the experimental subject to compare the effects of the two types of feed pellets in Example 1 on their non-specific immunity. The specific scheme is as follows:

[0072] Twenty yellow catfish, each weighing approximately 90 grams, were used in both the control and experimental groups. They were fed twice daily, morning and evening, with a daily feed amount of 3% of the fish's total weight, under natural light. After 56 days of experimentation, the fish were fasted for 24 hours. Five fish were randomly selected from each tank, and blood was collected from their tail veins. The blood was centrifuged at 4000 rpm / min for 5 minutes at 4℃. The serum was then flash-frozen in liquid nitrogen and stored at -80℃ for analysis of non-specific immunity. The experimental results are shown in Table 3.

[0073] Table 3 Results of the non-specific immunity test of yellow catfish

[0074]

[0075] Compared with the control group, under the same experimental conditions, the activities of superoxide dismutase, alkaline phosphatase, total protein, and albumin in the serum of yellow catfish in the experimental group increased by 16.76%, 13.98%, 22.50%, and 9.13%, respectively, all significantly better than those in the control group. This indicates that the feed pellets in the experimental group can improve the non-specific immunity of yellow catfish and enhance its immune performance and disease resistance. The results show that, compared with feed pellets made from traditional Chinese medicine premixes prepared by decoction and concentration, feed pellets made from fermented traditional Chinese medicine products prepared by enzymatic hydrolysis and fermentation can improve the non-specific immunity of yellow catfish.

Claims

1. A method for preparing fish feed containing traditional Chinese medicine fermentation, characterized in that, It comprises the following steps: (1) crushing and sieving soybean powder, secondary powder and corn stalk powder to obtain conventional fish feed; (2) sieving vitamin premix and mineral premix and mixing them uniformly; (3) adding traditional Chinese medicine fermentation product to the mixture obtained in step (2); (4) mixing the mixture in step (3) with the conventional fish feed in step (1) according to the formula proportion and mixing them uniformly; (5) adding fish oil to the mixture in step (4); (6) adding water to the mixture in step (5), granulating and drying; The traditional Chinese medicine fermentation product is prepared by crushing and uniformly mixing curcuma longa, panax notoginseng, rhubarb, mulberry leaf and licorice, adding cellulase for enzymolysis, then adding bacillus subtilis liquid for fermentation. The bacillus subtilis is bacillus velezensis, which is preserved in Guangdong Microbial Culture Collection Center with the preservation number of GDMCC.1.1835. The traditional Chinese medicine fermentation medium is prepared by crushing and uniformly mixing curcuma longa 24 parts, panax notoginseng 8 parts, rhubarb 8 parts, mulberry leaf 8 parts and licorice 8 parts to obtain traditional Chinese medicine components, and then uniformly mixing the traditional Chinese medicine components, bran 3-6, glucose 2-4, urea 1-2, ammonium sulfate 0.5-1, potassium dihydrogen phosphate 0.1-0.2 and magnesium sulfate heptahydrate 0.07-0.15 according to the weight ratio of 80-100:3-6:2-4:1-2:0.5-1:0.1-0.2:0.07-0.

15.

2. The production method according to claim 1, characterized by, The traditional Chinese medicine fermentation medium is prepared by crushing and uniformly mixing curcuma longa 24 parts, panax notoginseng 8 parts, rhubarb 8 parts, mulberry leaf 8 parts and licorice 8 parts to obtain traditional Chinese medicine components, and then uniformly mixing the traditional Chinese medicine components, bran 3-6, glucose 2-4, urea 1-2, ammonium sulfate 0.5-1, potassium dihydrogen phosphate 0.1-0.2 and magnesium sulfate heptahydrate 0.07-0.15 according to the weight ratio of 80-100:3-6:2-4:1-2:0.5-1:0.1-0.2:0.07-0.

15.

3. The method of claim 1, wherein, The addition amount of cellulase in the traditional Chinese medicine fermentation medium is 15 u / g-40 u / g.

4. The method of claim 1, wherein, The addition amount of cellulase in the traditional Chinese medicine fermentation medium is 30 u / g.

5. The preparation method according to claim 4, characterized in that, After adding the cellulase, the bacillus subtilis liquid is inoculated for fermentation after 2-4 hours.

6. The preparation method according to claim 5, characterized in that, The cellulase is added for 4 hours, and then the bacillus subtilis liquid is inoculated for fermentation.

7. The preparation method according to claim 1, characterized in that, The fermentation conditions are as follows: temperature 28-36℃, stirring speed 80-130 r / min and fermentation time 48-72 h.

8. The method of claim 1, wherein, The fermentation conditions are as follows: temperature 34℃, stirring speed 110 r / min and fermentation time 60 h.

9. The method of claim 1, wherein, The bacillus subtilis liquid is obtained by the following steps: inoculating bacillus subtilis in seed culture medium and then culturing at 25-35℃ for 24-36 h; the seed culture medium comprises peptone, yeast powder and sodium chloride.

10. The method of claim 9, wherein, The inoculation amount of the bacillus subtilis liquid accounts for 3-10% of the mass of the traditional Chinese medicine fermentation medium.

11. The method of claim 10, wherein, The inoculation amount of the bacillus subtilis liquid accounts for 5% of the mass of the traditional Chinese medicine fermentation medium.

12. The method of claim 1, wherein, The mass ratio of the use amount of each raw material of the fish feed is as follows: traditional Chinese medicine fermentation product 30 parts, soybean powder 30 parts, fish oil 15 parts, secondary powder 15 parts, corn stalk powder 15 parts, vitamin premix 5 parts and mineral premix 5 parts.

13. The method of claim 1, wherein, The vitamin premix comprises, by mass fraction, 5 parts of vitamin C, 2 parts of vitamin B6, 2 parts of retinol, 2 parts of pantothenic acid, 2 parts of nicotinic acid, 2 parts of biotin, 2 parts of vitamin D, and 1 part of inositol; and the mineral premix comprises, by mass fraction, 3 parts of magnesium sulfate heptahydrate, 3 parts of potassium dihydrogen phosphate, 3 parts of zinc sulfate heptahydrate, 3 parts of calcium hydrogen phosphate, 2 parts of sodium chloride, 2 parts of potassium iodide, 2 parts of copper chloride dihydrate, 2 parts of cobalt chloride hexahydrate, and 1 part of sodium selenite pentahydrate.

14. The method of claim 1, wherein, After fermentation, the fermentation product needs to be dried and crushed.

15. The method of claim 14, wherein, The drying temperature of the fermentation product is 55-80℃, and the drying is performed until the moisture content is not higher than 12%.

16. Fish feed prepared according to the preparation method of claim 1.

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