Traditional Chinese medicine feed additive prepared by liquid fermentation of composite strains and preparation method of traditional Chinese medicine feed additive

Abstract

The invention discloses a traditional Chinese medicine feed additive prepared by liquid fermentation of composite strains and a preparation method of the traditional Chinese medicine feed additive. The additive is prepared by the following method: respectively crushing traditional Chinese medicines and compost raw materials, mixing according to a required ratio, adding water, sterilizing to prepare a fermentation liquid, inoculating a mixed bacterium liquid consisting of clostridium butyricum, bacillus coagulans, bacillus velezensis and kluyveromyces marxianus, and performing liquid fermentation, and then concentrating and drying the fermentation liquor to obtain the product. The traditional Chinese medicines comprise liquorice, astragalus membranaceus and acanthopanax, the culture materials comprise bran, corn flour, soybean meal and inorganic salt, and the mass ratio of the culture materials to the traditional Chinese medicine composition is (60-80): (20-40). The feed additive disclosed by the invention has the probiotic effects of the probiotics and the traditional Chinese medicines, and can increase the feed intake of livestock and poultry and reduce the feed conversion ratio and the feed-egg ratio. Meanwhile, the livestock and poultry morbidity can be reduced, the defecation amount is reduced, and the excrement odor is relieved.

Description

Technical Field

[0001] This invention belongs to the field of biotechnology, specifically relating to a traditional Chinese medicine feed additive prepared by liquid fermentation of compound microorganisms and its preparation method. Background Technology

[0002] In modern livestock farming, animals face various stressors and disease threats, necessitating effective health management to improve production performance and product quality. Fermented traditional Chinese medicine (TCM) combines the pharmacological effects of TCM herbs with the probiotic functions of probiotics. The fermentation process breaks down the large active molecules in TCM herbs into smaller molecules, facilitating animal absorption and reducing the toxic side effects. Furthermore, the microbial metabolites produced during fermentation, such as short-chain fatty acids and organic acids, can regulate the animal's gut microbiota, enhance immunity, and improve growth performance, meeting the market demand for green and efficient feed additives. Consumers are increasingly demanding higher safety and quality standards for animal-derived foods, preferring antibiotic-free, green, and healthy options. Fermented TCM feed additives help produce green foods that better meet consumer needs and can address the spread of drug-resistant bacteria and genes in the environment caused by antibiotic abuse or irrational use, making them ideal antibiotic alternatives.

[0003] In the process of fermenting traditional Chinese medicine (TCM) using probiotics, the enzymatic hydrolysis of probiotics increases the release of active ingredients from the TCM; the metabolites of probiotics enrich the active ingredients in the fermented TCM product. Meanwhile, the TCM provides nutrients to the probiotics, promoting their proliferation. New medicinal substances may also be produced during fermentation. Polysaccharides and alkaloids in TCM herbs have antibacterial and anti-inflammatory effects, which can improve animal immunity and reduce disease incidence. Some TCM herbs contain special aromas that can improve feed flavor and enhance animal appetite. TCM herbs can effectively alleviate various stress responses in animals during the breeding process and improve their stress resistance.

[0004] Patent application number CN202010373332.X discloses a method for preparing a fermented natural plant microecological feed additive. This method utilizes Bacillus subtilis, Bacillus licheniformis, and Saccharomyces cerevisiae powder combined with Clostridium butyricum and lactic acid bacteria in different combinations to conduct solid-state fermentation of a mixture of natural plants and culture medium to prepare the feed additive. Feeding this additive to pigs and laying hens resulted in a significant reduction in mortality. However, the solid-state fermentation process leads to heat accumulation and limited nutrient diffusion, which to some extent affects the growth of the fermenting bacteria. Summary of the Invention

[0005] This invention provides a traditional Chinese medicine feed additive prepared by liquid fermentation of compound microorganisms and its preparation method, which solves the problems of existing products using solid-state fermentation, such as easy heat accumulation, limited nutrient diffusion, and to some extent affecting the growth of fermenting bacteria.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A traditional Chinese medicine feed additive prepared by liquid fermentation of a compound strain is produced by the following method: the traditional Chinese medicine and culture medium raw materials are crushed separately and mixed in the required proportion. After sterilization with water, a fermentation broth is prepared. The broth is then inoculated with a mixed bacterial broth composed of Clostridium butyricum, Bacillus coagulans, Bacillus belye and Kluyveromyces for liquid fermentation. Finally, the fermentation broth is concentrated and dried to obtain the product. The traditional Chinese medicines include licorice, astragalus, and eleutherococcus senticosus. The culture medium consists of wheat bran, corn flour, soybean meal, and inorganic salts. The mass ratio of the culture medium to the traditional Chinese medicine composition is 60-80:20-40.

[0007] Furthermore, the mass ratio of licorice, astragalus and Acanthopanax senticosus is 10-20:5-10:5-10; and / or the mass ratio of wheat bran, corn flour, soybean meal and inorganic salts in the culture medium is 40-60:20-30:15-5:5-10.

[0008] Furthermore, the Clostridium butyricum is Clostridium butyricum JBHBIO-BD23, with accession number CGMCC NO.32217; The Bacillus coagulans preservation number is CGMCC NO.32216; The Bacillus species is Bacillus belyssus JBHBBLS3, with accession number CGMCC No. 28883; the Kluyveromyces martensii is Kluyveromyces martensii JBH-BJM4, with accession number CGMCC No. 24455.

[0009] Furthermore, the concentration of Clostridium butyricum in the dried feed additive is (2-6) × 10⁻⁶. 8 CFU / g, the total concentration of other probiotics is (0.7~5)×10 10 CFU / g.

[0010] The method for preparing the feed additive of the present invention includes the following steps: (1) Clostridium butyricum, Bacillus coagulans, Bacillus belliesi, and Kluyveromyces were subjected to liquid fermentation to obtain Clostridium butyricum seed liquid, Bacillus coagulans seed liquid, Bacillus belliesi seed liquid, and Kluyveromyces seed liquid, respectively. The viable cell concentrations of the Bacillus coagulans, Bacillus belliesi, and Kluyveromyces seed liquids were 3–8 × 10⁻⁶, respectively. 9CFU / mL, 2~7×10 9 CFU / mL and 3~6×10 8 CFU / mL; (2) Add 3-5 g / L glucose to the Clostridium butyricum seed liquid, and then inoculate the seed liquid of Bacillus coagulans, Bacillus vesiculosus and Kluyveromyces max-Kluyveromyces at 1%-3% (v / v) of the Clostridium butyricum seed liquid respectively, and ferment at 37℃ for 48 h to obtain the fermented seed liquid of traditional Chinese medicine. (3) Dry and crush the Chinese medicine and culture medium raw materials, mix them according to the required ratio, add water to sterilize and make fermentation liquid, inoculate the Chinese medicine fermentation seed liquid prepared in step (2) for liquid fermentation, and then concentrate and dry the fermentation liquid to obtain feed additive.

[0011] Furthermore, the drying temperature of the Chinese herbal medicine and culture medium raw materials is 50℃~80℃, and they are pulverized and passed through a 60~100 mesh sieve.

[0012] Furthermore, the inoculation amount of the fermented seed liquid of traditional Chinese medicine is 4% to 8% (v / v).

[0013] Furthermore, the solid content of the fermentation broth is 10-15:85-90.

[0014] Furthermore, the fermentation temperature of the liquid fermentation of the traditional Chinese medicine is 30℃~40℃, the time is 48~72 h, and the rotation speed is 80~150 rpm. Beneficial effects

[0015] 1. In this invention, Astragalus membranaceus is slightly warm in nature and sweet in taste, possessing diuretic, qi-tonifying, and exterior-strengthening effects; Acanthopanax senticosus has the effects of tonifying qi and strengthening the spleen, enhancing immunity, and improving the stress state of animals; Glycyrrhiza uralensis can effectively remove excess free radicals produced by heat stress, enhance the antioxidant function of the animal body, increase feed intake, and improve the stress state of animals. In addition, Glycyrrhiza uralensis plays a harmonizing role among the various drugs in the whole system. The combination of these three can enhance the animal's immunity, improve disease resistance, and alleviate stress.

[0016] 2. The probiotics introduced through secondary fermentation in the Clostridium butyricum fermentation supernatant enhance the product's probiotic effects. Clostridium butyricum produces organic acids such as butyric acid, lactic acid, acetic acid, and propionic acid, lowering the intestinal pH, inhibiting the growth of harmful pathogens, promoting the reproduction of beneficial bacteria, and maintaining intestinal microecological balance. The aroma produced by butyric acid has a good palatability-enhancing effect. Bacillus coagulans produces lactic acid with antibacterial properties and lowers the product's pH. Bacillus belye secretes various digestive enzymes such as protease, lipase, and amylase, improving feed conversion ratio. Kluyveromyces marsupialis secretes more than ten hydrolytic enzymes, including inulinase, xylanase, β-galactosidase, and carboxypeptidase; yeast cell wall polysaccharides are highly effective growth factors for probiotics. This product combines the probiotic effects of both probiotics and traditional Chinese medicine, increasing feed intake in livestock and poultry, and reducing the feed conversion ratio and feed-to-egg ratio. It also reduces livestock and poultry morbidity, decreases fecal volume, and lessens fecal odor.

[0017] 3. This invention uses liquid fermentation to avoid the problems of limited mass and heat transfer, resulting in a higher concentration of live bacteria in the product. Biological preservation instructions for Clostridium butyricum JBHBIO-BD23: Preservation institution: China General Microbiological Culture Collection Center, China Committee on the Preservation and Management of Microbial Cultures; Accession number: CGMCC No. 32217; Deposit date: October 15, 2024; Address: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing; Taxonomic name: Clostridium butyricum. Detailed Implementation

[0018] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] The culture medium formulation used in the embodiments of this invention is as follows: Ferrous sulfite agar medium: tryptone 15.0 g / L, soybean peptone 5.0 g / L, yeast extract 5.0 g / L, sodium metabisulfite 1.0 g / L, ferric ammonium citrate 1.0 g / L, agar 20.0 g / L, pH 7.5±0.2.

[0020] Ordinary broth culture medium: peptone 20 g / L, beef extract 5 g / L, sodium chloride 5 g / L, pH 7.5±0.2.

[0021] Clostridium butyricum activation medium: peptone 10 g / L, beef extract 10 g / L, yeast extract 3 g / L, glucose 5 g / L, soluble starch 1 g / L, sodium chloride 5 g / L, sodium acetate 3 g / L, L-cysteine ​​hydrochloride 0.5 g / L, pH 6.8. Fermentation medium components include molasses 20 g / L, glucose 10 g / L, yeast extract 10 g / L, peptone 20 g / L, magnesium sulfate 1 g / L, dipotassium hydrogen phosphate 0.5 g / L, and sodium citrate 1 g / L.

[0022] Both the activation medium and seed medium for Bacillus coagulans were MRS medium, with the following composition: 10 g / L peptone, 10 g / L beef extract, 5 g / L yeast extract, 2 g / L K₂HPO₄, 2 g / L diammonium citrate, 5 g / L sodium acetate, 20 g / L glucose, 80 mL / L Tween, 0.5 g / L MgSO₄·7H₂O, 0.2 g / L MnSO₄·4H₂O, and a natural pH of 6.3.

[0023] The activation and seed culture media for Bacillus belyssus consisted of: 10 g / L tryptone, 5 g / L NaCl, 10 g / L yeast extract, and pH 7.0.

[0024] The Kluwer Maximilian activation and seed culture medium consisted of 20 g / L glucose, 20 g / L peptone, and 10 g / L yeast extract, with a pH of 6.8.

[0025] The viable bacterial concentration was measured by the dilution plating count method. The viable bacterial concentration measured after heating at 85°C for 10 min was the spore concentration (the concentration of Clostridium butyricum was analyzed using ferrous sulfite agar medium, and the total concentration of other bacteria was analyzed using ordinary broth medium).

[0026] Example 1: Preparation of Fermented Seed Liquid of Traditional Chinese Medicine

[0027] Preparation method of Clostridium butyricum fermentation supernatant: An appropriate amount of slant culture was inoculated into an activation medium and statically cultured at 37℃ for 16 h in an anaerobic incubator to obtain the seed culture. Clostridium butyricum fermentation was carried out in a 50 L fermenter under the following conditions: 70% loading coefficient, 4% inoculum (v / v), fermentation at 37℃ for 36 h, rotation speed of 100 rpm, fermenter pressure of 0.05 MPa, and nitrogen flow rate of 0.2 VVM. After fermentation, the obtained fermentation broth was centrifuged at 5000 rpm for 10 min to prepare the supernatant. The effective viable concentration of Clostridium butyricum in the obtained supernatant was 5.3 × 10⁻⁶.7 CFU / mL.

[0028] Preparation method of Bacillus coagulans seed culture: Bacillus coagulans slant culture was inoculated into sterile MRS medium, with a liquid volume of 40% in a shake flask, and activated by incubation at 180 rpm and 42℃ for 24 h. The activated solution was then inoculated into MRS medium at a 4% inoculation rate and fermented under activated conditions for 8 h to obtain an effective viable cell concentration of 4.4 × 10⁻⁶. 9 CFU / mL Bacillus coagulans seed culture.

[0029] Preparation method of Bacillus belye seed culture: Bacillus belye slant culture was inoculated into activation medium at a volume of 20%, and cultured at 37℃ and 220 rpm for 18 h for activation. The activated solution was then inoculated into seed culture medium at a volume of 4%, and cultured under activation conditions for 8 h to obtain an effective viable bacterial concentration of 3.2 × 10⁻⁶. 9 CFU / mL Bacillus belye seed culture.

[0030] Kluyveromyces martensii culture method: Kluyveromyces martensii slant culture was inoculated into activation medium (30% capacity) and cultured at 30℃ and 180 rpm for 24 h to obtain the activated solution. Then, 4% of the inoculum was inoculated into expansion medium and cultured under activation conditions for 18 h to obtain an effective viable cell concentration of 3.6 × 10⁻⁶. 8 CFU / mL Max Kluyveromyces seed culture.

[0031] Preparation method of mixed bacterial culture: Add 3 g / L glucose to the Clostridium butyricum fermentation supernatant, then inoculate Bacillus coagulans fermentation broth, Bacillus bellies fermentation broth, and Kluyveromyces seed culture at 2% (v / v) of the Clostridium butyricum fermentation supernatant, respectively, and incubate at 37℃ for 48 h. Secondary fermentation can fully utilize the residual nutrients in the Clostridium butyricum fermentation supernatant, transforming pollution into resources and realizing "turning waste into treasure".

[0032] Example 2: Optimization of Traditional Chinese Medicine Formulation

[0033] The Chinese herbal medicine and culture medium raw materials are pulverized and passed through a 100-mesh sieve, then mixed in the required proportions, sterilized with water to prepare a fermentation broth. The broth is then inoculated with a mixed bacterial solution consisting of Clostridium butyricum, Bacillus coagulans, Bacillus belye, and Kluyveromyces martensii for liquid fermentation. Finally, the fermentation broth is concentrated and dried to obtain the final product.

[0034] The initial conditions were as follows: the culture medium consisted of wheat bran, corn flour, soybean meal, and inorganic salts in a ratio of 60:25:10:5. The traditional Chinese medicine composition was licorice, astragalus, and eleutherococcus senticosus in a ratio of 2:1:1. The ratio of culture medium to traditional Chinese medicine was 60:40. Water was added and sterilized to obtain a liquid culture medium with a solid content of 10%. The inoculum size of the compound bacterial solution was 4%, and the fermentation conditions were as follows: temperature 37℃, rotation speed 100 rpm, fermentation time 48 h, and tank pressure 0.03 MPa. Based on the initial conditions, the proportions of the Chinese medicinal materials licorice, astragalus, and eleutherococcus senticosus, the ratio of Chinese medicinal materials to culture medium, and the inoculation amount of mixed bacterial solution were optimized sequentially. One condition was optimized at a time, and the optimization results were used for subsequent optimization work. The evaluation criteria for the optimization process were the concentration of Clostridium butyricum and the total concentration of other probiotics.

[0035] Table 1. Effect of Chinese herbal medicine ratio on the fermentation results of Chinese herbal medicine Of the three options mentioned above, the product with the ratio of licorice:astragalus:eleutherococcus senticosus 2:1:1 had the highest concentration of Clostridium butyricum and the total concentration of other probiotic live bacteria.

[0036] Example 3: Optimization of the ratio of traditional Chinese medicine to culture medium

[0037] The optimal mass ratios of Chinese herbal medicine to culture medium were 60:40, 50:50, 40:60, 30:70, and 20:80. The results are shown in Table 2.

[0038] Table 2. Effects of the ratio of culture medium to traditional Chinese medicine on the fermentation results of traditional Chinese medicine. Chinese medicine / culture material <![CDATA[Concentration of Clostridium butyricum (×10 8 CFU / mL)]]> <![CDATA[Total concentration of other viable bacteria (×10 10 CFU / mL)]]> 60:40 2.32 0.72 50:50 3.67 0.93 40:60 5.36 1.75 30:70 5.76 2.84 20:80 5.44 2.45 The total concentration of probiotic live bacteria in the products obtained by the above three ratios of 30:70 and 20:80 is greater than that of 40:60, and the ratios of 30:70 and 20:80 are not much different. Considering the cost, the optimal ratio of Chinese medicine to culture medium is 20:80.

[0039] Example 4: Optimization of inoculum size

[0040] The inoculum amounts were optimized to 2%, 4%, 6%, 8%, and 10%, respectively.

[0041] Table 3. Effect of mixed inoculum size on the fermentation results of traditional Chinese medicine Inoculation amount (%) <![CDATA[Clostridium butyricum concentration (×10 8 CFU / mL)]]> <![CDATA[Total viable cell concentration (×10 10 CFU / mL)]]> 2 3.31 1.98 4 5.38 2.62 6 5.66 3.71 8 5.79 3.96 10 5.87 4.05 Among the three methods mentioned above, the concentrations of Clostridium butyricum and other probiotic live bacteria were relatively high and similar at inoculum levels of 6%, 8%, and 10%. A 6% inoculum level was the optimal choice.

[0042] Example 5: Component Analysis of Spray-Dried Products

[0043] Liquid fermentation was carried out under the optimized conditions obtained in the aforementioned examples (a ratio of licorice, astragalus, and eleutherococcus senticosus of 2:1:1; a ratio of Chinese medicine to culture medium of 20:80; and an inoculum size of 6% for the mixed bacterial solution). The resulting fermentation broth was spray-dried at an inlet temperature of 160°C to obtain the final product, and several indicators were analyzed. Butyric acid and acetic acid were detected by gas chromatography, with contents of 1.5% and 1.22%, respectively. Lactic acid content was determined by high-performance liquid chromatography (HPLC) according to the T / NAIA 002-2020 standard, and was 3.23%. Total saponins of Astragalus membranaceus were determined using the national standard method outlined in the 2020 edition of the Pharmacopoeia of the People's Republic of China, Part IV, General Chapter 2304, "Determination of Total Saponins in Feed," and GB / T30522-2014, "Determination of Total Saponins in Feed." The colorimetric determination was performed at a wavelength of 560 nm using a vanillin-perchloric acid chromogenic system. The content before fermentation was 0.67%, and the content after fermentation was 1.14%, indicating a certain increase in total saponins. Total saponins of Acanthopanax senticosus were measured using ultraviolet spectrophotometry. The content before and after fermentation was 1.02% and 2.17%, respectively, showing a significant increase. Glycyrrhiza polysaccharides were detected using the phenol-sulfuric acid method according to T / CFIAS 6001-2022, "Determination of Polysaccharides in Natural Plant Feed Raw Materials and Their Extracts—Spectrophotometric Method." The content before and after fermentation was 2.37% and 3.82%, respectively, showing a significant increase. The viable concentrations of Clostridium butyricum and other total viable bacteria were 5.66 × 10⁻⁶. 8 and 6.97×10 9 CFU / g. Example 6: Experimental Animals and Experimental Design

[0044] 1. Fattening pig experiment One hundred and eighty healthy pigs with an average weight of 40 ± 2.5 kg from Henan Ping'an Pig Farm were randomly divided into three groups, with three replicates per group and 20 pigs per replicate. These included one blank control group and two experimental groups. The blank control group received no additives in their diet. Experimental group one (finishing pigs) received a fermented traditional Chinese medicine additive prepared according to the optimized method described in the aforementioned example, at a rate of 1‰ in their diet. Experimental group two received a commercially available additive (Baomu brand live probiotics) in their diet. Both additives were added at a rate of 1 kg / ton. The pigs had free access to feed and water, and were routinely immunized and dewormed. The incidence of disease and the mental state of each pig were observed and recorded daily during the 45-day experiment. During the experiment, the difference between the daily feed intake and uneaten feed for each pig was recorded, and the average value was calculated (from 7:00 AM to 7:00 PM daily). The weight of each experimental pig at the beginning and end of the experiment was recorded, and the daily weight gain during the experiment was calculated (from 7:00 AM on the first day of the experiment to 7:00 AM on the last day, weighed on an empty stomach). The feed conversion ratio (FCR) was calculated based on daily feed intake and daily weight gain. Simultaneously, the incidence of disease in the pigs was recorded, observing for symptoms such as fever exceeding 40°C, lethargy, decreased appetite, drowsiness, slow movement, cyanosis, dry or wet cough, wheezing, purulent or bloody nasal discharge, diarrhea, vomiting, and alternating constipation and diarrhea.

[0045] Table 4. Fattening Pig Trial Testing items control group Experimental Group 1 Experimental Group 2 Feed intake / g 1754 1877 1814 Daily weight gain / g 779 876 826 Meat-to-fat ratio 2.25 2.14 2.19 Incidence rate / % 25.2% 1.6% 3.7% Stool volume / g 2152 2041 2076 As shown in Table 4, the feed additive prepared according to this invention can increase the daily weight gain of pigs, promote pig growth, and reduce fecal volume. Furthermore, the product of this invention can also improve pig immunity and reduce the incidence of disease in pigs.

[0046] 2. Laying hen experiment The experiment selected 240 healthy laying hens with no significant weight difference from a poultry farm in Pitiao Town, Taihe County. They were randomly divided into 4 groups, with 6 replicates per group and 10 healthy laying hens per replicate, including one blank control group and two experimental groups. The blank control group received no additives in their diet. Experimental group one received a fermented traditional Chinese medicine additive prepared according to the optimized method described in the previous embodiment, while experimental group two received a commercially available feed additive (Baomu brand live probiotics) in their diet. Both additives were added at a dosage of 1 kg / ton. The experimental laying hens were cage-housed with free access to feed, maintaining a constant temperature of 25℃, 16 hours of light, 8 hours of darkness, and 50% humidity. All replicates had identical rearing conditions (cage space, ventilation, water). Routine immunization and deworming were administered. Mortality and culling were observed and recorded daily during the experiment. The experiment lasted 25 days. Daily feed intake, total egg production, and total egg weight were recorded for each treatment group. Total feed intake, feed conversion ratio, and egg production rate were calculated.

[0047] Table 5. Data from the laying hen experiment Testing items 25-day feed intake / kg 25-day mortality rate / % Egg ratio Total egg weight / kg Egg production / Egg production rate / % control group 644.59 0.32 2.02 319.1 5425 90.42 Experimental Group 1 651.32 0.04 1.93 337.9 5701 95.02 Experimental Group 2 648.65 0.13 1.99 325.6 5633 93.89 The results in Table 5 show that the egg production rate of the experimental animal group was significantly higher than that of the control group, and the mortality rate was significantly lower. Furthermore, feed intake increased, but the feed conversion ratio decreased.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A traditional Chinese medicine feed additive prepared by liquid fermentation of a compound microbial strain, characterized in that, It is prepared by the following method: the Chinese medicine and culture medium raw materials are crushed separately and mixed in the required proportion. After sterilization with water, a fermentation liquid is prepared. A mixed bacterial liquid composed of Clostridium butyricum, Bacillus coagulans, Bacillus belye and Kluyveromyces masculinus is inoculated for liquid fermentation. Then the fermentation liquid is concentrated and dried to obtain the product. The traditional Chinese medicines include licorice, astragalus, and eleutherococcus senticosus. The culture medium consists of wheat bran, corn flour, soybean meal, and inorganic salts. The mass ratio of the culture medium to the traditional Chinese medicine composition is 60-80:20-40.

2. The feed additive according to claim 1, characterized in that: The mass ratio of licorice, astragalus and eleutherococcus senticosus is 10-20:5-10:5-10; and / or the mass ratio of wheat bran, corn flour, soybean meal and inorganic salts in the culture medium is 40-60:20-30:15-5:5-10.

3. The feed additive according to claim 1, characterized in that: The Clostridium butyricum is Clostridium butyricum JBHBIO-BD23, with accession number CGMCC NO.32217; The Bacillus coagulans preservation number is CGMCC NO.32216; The Bacillus species is Bacillus belyssus JBHBBLS3, with accession number CGMCC No. 28883; the Kluyveromyces martensii is Kluyveromyces martensii JBH-BJM4, with accession number CGMCC No. 24455.

4. The feed additive according to claim 1, characterized in that: The concentration of Clostridium butyricum in the dried feed additive is 2-6 × 10⁻⁶. 8 CFU / g, and the total concentration of other probiotics is 0.7–5 × 10⁻⁶. 10 CFU / g.

5. A method for preparing a feed additive as described in any one of claims 1-4, characterized in that, Includes the following steps: (1) Clostridium butyricum, Bacillus coagulans, Bacillus belliesi, and Kluyveromyces were subjected to liquid fermentation to obtain Clostridium butyricum seed liquid, Bacillus coagulans seed liquid, Bacillus belliesi seed liquid, and Kluyveromyces seed liquid, respectively. The viable cell concentrations of the Bacillus coagulans, Bacillus belliesi, and Kluyveromyces seed liquids were 3–8 × 10⁻⁶, respectively. 9 CFU / mL, 2~7×10 9 CFU / mL and 3~6×10 8 CFU / mL; (2) Add 3-5 g / L glucose to the Clostridium butyricum seed liquid, and then inoculate the Bacillus coagulans seed liquid, Bacillus vesiculosus seed liquid and Kluyveromyces masculinus seed liquid at 1%-3% (v / v) of the Clostridium butyricum seed liquid respectively, and let it ferment at 37℃ for 48 h to obtain the fermented seed liquid of traditional Chinese medicine. (3) Dry and crush the Chinese medicine and culture medium raw materials, mix them according to the required ratio, add water to sterilize and make fermentation liquid, inoculate the Chinese medicine fermentation seed liquid prepared in step (2) for liquid fermentation, and then concentrate and dry the fermentation liquid to obtain feed additive.

6. The preparation method according to claim 6, characterized in that: The Chinese herbal medicine and culture medium raw materials are dried at a temperature of 50℃~80℃ and then pulverized and passed through a 60~100 mesh sieve.

7. The preparation method according to claim 6, characterized in that: The inoculation amount of the fermented seed liquid of traditional Chinese medicine is 4% to 8% v / v.

8. The preparation method according to claim 6, characterized in that: The solid content of the fermentation broth is 10-15:85-90.

9. The preparation method according to claim 6, characterized in that: The fermentation temperature of the liquid fermentation of the traditional Chinese medicine is 30℃~40℃, the time is 48~72 h, and the rotation speed is 80~150 rpm.