Composition and application thereof in preparation of feed for preventing and treating African swine fever

Abstract

The invention provides a composition which comprises the following components in parts by mass: a biological fermentation base material and a functional auxiliary material, the biological fermentation base material comprises 30-50 parts of corn flour, 15-20 parts of soybean meal, 3-8 parts of fish meal, 3-10 parts of whey powder, 10-20 parts of wheat flour, 4-12 parts of brown sugar, 1-5 parts of a complex microbial inoculant and 18-25 parts of water; the functional auxiliary materials comprise 5-10 parts of citric acid, 2-5 parts of a vitamin mineral premix and 1-3 parts of a plant extract. According to the technical scheme, through a multi-way synergistic mechanism of synergistic fermentation of the complex microbial inoculants, multi-acid staged dissociation, interference of virus replication by the active peptide and infection blocking by the adsorbent, the ASFV is efficiently inactivated, meanwhile, complete nutritional ingredients of the feed are kept, the immunity of live pigs and the utilization rate of the feed are remarkably improved, and double breakthrough of prevention and control effects and breeding benefits is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of feeds, and particularly relates to a composition and its application in preparing feeds with the function of preventing and controlling African swine fever. Background Art

[0002] African swine fever (ASF) is a highly contagious disease caused by African swine fever virus (ASFV). Since it was introduced into China in 2018, it has caused tens of millions of live pigs to die, with direct economic losses exceeding 100 billion yuan. ASFV can be transmitted through multiple routes such as feeds, drinking water, and tick bites. The virus has extremely strong viability in the environment. For example, it can survive for several years in frozen meat and more than 30 days in untreated feeds. At present, there is no effective vaccine or treatment drug, and prevention and control mainly rely on biosecurity measures such as culling and disinfection. However, ordinary feeds lack antiviral functions, becoming a key loophole for virus transmission.

[0003] In the prior art, the following methods are mainly used to attempt to prevent and control the spread of ASFV through feeds: Chinese patent CN112544765A uses high-temperature granulation, treating the feed at a temperature above 85°C for 3 minutes to inactivate the virus. However, high temperature easily destroys heat-sensitive components such as vitamins and enzymes, resulting in nutrient loss of the feed. Chinese patent CN113142416A uses the addition of acidifying agents and discloses a single acidification scheme with citric acid. However, the pH of the gastric juice of live pigs is 1.5 - 3.5, and exogenous acidifying agents are easily neutralized and cannot inhibit the survival of the virus in the intestine. Chinese patent CN112273438A uses lactic acid bacteria fermentation to reduce the pH to 4.5 - 5.0, but this pH range can only delay the virus activity and cannot quickly inactivate ASFV. Research shows that the virus is inactivated within 10 minutes when the pH ≤ 4.0. Some people generate antibacterial peptides by proteolytically hydrolyzing soybean meal, but do not combine with the fermentation process, resulting in a low yield of small peptides and a lack of immune regulatory components.

[0004] The above technologies still have the following defects: Single means such as high temperature or acidification cannot balance virus inactivation and retention of nutrient components, and the inactivation efficiency is insufficient; only targeting the virus envelope or nucleic acid, the action target is single, and there is a lack of a multi-path collaborative inactivation mechanism; excessive addition of acidifying agents makes the feed sour and astringent, with poor palatability, and the feed intake of live pigs decreases by 20% - 30%; long-term use of antibiotic substitutes may disrupt the balance of the intestinal flora and there is a risk of immunosuppression.

[0005] Therefore, it is necessary to design a composition and its application in preparing feeds with the function of preventing and controlling African swine fever. Summary of the Invention

[0006] In order to overcome the defects in the prior art, the present invention provides a composition and its application in preparing feeds with the function of preventing and controlling African swine fever.

[0007] To achieve the above object, the present invention provides the following technical solutions: A composition, calculated by mass, the composition comprises the following components: a biological fermentation substrate and a functional auxiliary material; The biological fermentation substrate comprises 30 - 50 parts of corn flour, 15 - 20 parts of soybean meal, 3 - 8 parts of fish meal, 3 - 10 parts of whey powder, 10 - 20 parts of wheat flour, 4 - 12 parts of brown sugar, 1 - 5 parts of a compound bacterial agent, and 18 - 25 parts of water; The functional auxiliary material comprises 5 - 10 parts of citric acid, 2 - 5 parts of a vitamin and mineral premix, and 1 - 3 parts of a plant extract.

[0008] The compound bacterial agent comprises Enterococcus faecalis, Bacillus subtilis, Bacillus licheniformis, Saccharomyces cerevisiae, and Clostridium butyricum, and the viable bacteria number ratio thereof is 3 - 9:3 - 9:2 - 6:1 - 3:1 - 3, and the total number of colonies of the compound bacterial agent is 1×10 9 to 5×10 10 CFU per gram.

[0009] The plant extract comprises camellia seed extract, astragalus polysaccharide, and glycyrrhizic acid, and the mass ratio thereof is 1:2 - 4:2 - 4.

[0010] The content of saccharide - terpenoid in the camellia seed extract is ≥40%, the purity of astragalus polysaccharide is ≥90%, and the purity of glycyrrhizic acid is ≥98%.

[0011] The vitamin and mineral premix comprises the following components: 8000 - 12000 IU / kg of vitamin A, 2000 - 3000 IU / kg of vitamin D3, 50 - 80 mg / kg of vitamin E, 100 - 150 mg / kg of ferrous sulfate, 80 - 120 mg / kg of zinc sulfate, and 0.2 - 0.5 mg / kg of sodium selenite.

[0012] The preparation of the biological fermentation substrate comprises the following steps: (1) Crushing corn flour, soybean meal, and wheat flour to a particle size of 0.15 mm to 0.35 mm, and the sieving rate is ≥95%; (2) Mixing the raw materials in step (1) with fish meal, whey powder, and brown sugar, and adding water to adjust the water content to 35% to 45%; (3) Inoculating the compound bacterial agent, and carrying out closed - fermentation at 32°C to 37°C and an initial pH of 5.5 to 6.5 for 72 hours to 120 hours. During the fermentation process, ultrasonic treatment with a frequency of 20 kHz to 40 kHz is applied every 12 hours for 10 minutes to 20 minutes, and the power density is 50 W / L to 100 W / L; (4) After the fermentation is completed, the pH of the material drops to 4.0 to 4.5, the lactic acid content is ≥4%, and the ethanol content is ≥0.5%.

[0013] The soybean meal is subjected to enzymatic hydrolysis before being pulverized: 500 - 800 U / g of neutral protease is added, and hydrolysis is carried out at 45°C to 50°C for 2 to 4 hours, with a degree of hydrolysis ≥ 15%.

[0014] The steps for adding the functional auxiliary materials include: mixing citric acid with a vitamin and mineral premix and a plant extract, then adding the mixture to the biological fermentation base material, and carrying out secondary fermentation at 25°C to 30°C for 48 to 96 hours, with the final pH being 3.8 to 4.2; during the secondary fermentation process, 1 - 2%wt of montmorillonite with a particle size less than 50 microns and 0.5 - 1%wt of activated carbon with a specific surface area greater than 800 m 2 / g are added.

[0015] The functional auxiliary materials also include 1 - 3 parts of fumaric acid and 0.5 - 1.5 parts of malic acid, and the mass ratio of citric acid, fumaric acid, and malic acid is 3 - 5:1 - 2:1.

[0016] Use of a composition in the preparation of a feed for preventing and treating African swine fever, wherein the composition is used for preparing a feed for preventing and treating African swine fever.

[0017] Compared with the prior art, the advantages and beneficial effects of the present invention are: 1. The composition of the present application is co - fermented by a compound bacterium agent to produce a large amount of lactic acid and ethanol, making the pH value at the end of fermentation acidic. The acidic environment can inactivate ASFV within 10 minutes. Compared with the prior art where citric acid is used alone or the fermentation pH only reaches 4.5 - 5.0, this technology shortens the inactivation time from several hours to the minute level and avoids the loss of vitamins and enzymes caused by high - temperature treatment. The lactic acid content generated during fermentation ≥ 4%, which not only directly destroys the virus envelope but also can continuously maintain a low - pH environment in the digestive tract of live pigs, inhibiting the survival of the virus in the intestine. In addition, the ethanol content greater than 0.5% forms a synergistic effect with organic acids, achieving a dual inactivation mechanism by dissolving the virus lipid outer membrane and denaturing the virus protein.

[0018] 2. The soybean meal in the present application is pretreated by hydrolysis with neutral protease, with a degree of hydrolysis ≥ 15%, and the generated small peptides and the antibacterial peptides produced by fermentation form active components with a molecular weight of 500 - 2000 Da. These small peptides can penetrate the virus capsid and interfere with the DNA replication enzyme activity of ASFV, forming a complementary effect with acidification inactivation. Compared with the process of directly fermenting without enzymatic hydrolysis, the yield of small peptides in this scheme is significantly increased, and it contains immune - regulating components such as glutamine peptides, which can enhance the intestinal mucosal immunity of live pigs. At the same time, lactoferrin is provided by whey powder in the fermentation base material, and together with astragalus polysaccharide in the plant extract, it activates macrophages and enhances the non - specific immune response ability of the body.

[0019] 3. The functional excipients of this application adopt a combined ratio of citric acid, fumaric acid, and malic acid of 3-5:1-2:1. The dissociation constants of the three organic acids are different, and they can continuously release hydrogen ions at different stages of the stomach and intestine of live pigs. Compared with the defect that a single acidifier is quickly neutralized in gastric juice, this composite acid system dissociates in stages, enabling the feed to maintain an effective antiviral concentration throughout the digestive tract. The addition of montmorillonite and activated carbon further adsorbs free virus particles and reduces the infection dose. Experiments show that this combination reduces the survival rate of ASFV in simulated gastrointestinal fluid by more than 85% compared with single acidification treatment.

[0020] 4. Ultrasonic treatment is introduced in the fermentation process of this application. Through the cavitation effect, it promotes the metabolic activity of the composite bacterial agent, increasing the germination rate of Bacillus subtilis spores by 40% and the lactic acid production of Enterococcus faecalis by 25%. This not only shortens the fermentation cycle but also promotes the increase in ethanol concentration and enhances the virus inactivation effect. At the same time, the mechanical vibration generated by ultrasound makes the materials mix evenly, avoiding inactivation dead angles caused by too high local pH and ensuring that the pH fluctuation of each batch of fermentation products is reduced.

[0021] 5. The sugar terpenoids, astragalus polysaccharides, and glycyrrhizic acid in the plant extract form a triple immune enhancement effect. Sugar terpenoids block the invasion of ASFV by inhibiting the binding of viral envelope glycoproteins to host cell receptors; astragalus polysaccharides upregulate the expression of interferon-γ and promote lymphocyte proliferation; glycyrrhizic acid inhibits the topoisomerase encoded by the virus and prevents viral DNA replication. The three work together to increase the IgG antibody level in the serum of live pigs by 50%, while reducing the expression level of inflammatory factor IL-6 by 30% and alleviating the excessive immune response caused by the virus. Compared with the scheme of simply using antimicrobial peptides, this combination significantly reduces the risk of secondary bacterial infection.

[0022] 6. The ratio of vitamin E to selenium is particularly increased in the vitamin and mineral premix. Through antioxidant effects, it protects the unsaturated fatty acids in the fermentation products from acidolysis damage. Ferrous sulfate combines with lactic acid to form a soluble complex, increasing the biological utilization rate of iron by 60% and improving the anemia state of live pigs. This design makes up for the problem of mineral loss caused by too low pH in traditional fermented feed, increasing the daily weight gain, decreasing the feed-to-meat ratio, and improving the feed intake compared with ordinary acidified feed.

[0023] 7. In the secondary fermentation stage, Clostridium butyricum is promoted to produce butyric acid with a concentration of 0.3%, which directly nourishes the colonic epithelial cells and repairs the intestinal barrier damage caused by ASFV infection. At the same time, this process enables ion exchange between citric acid and montmorillonite to form a pH-responsive slow-release structure, releasing the adsorbed organic acids in the alkaline environment of the intestine and extending the antiviral action time to more than 12 hours. The high specific surface area of activated carbon effectively adsorbs the endotoxin produced by virus metabolism, reducing clinical symptoms such as fever in live pigs and decreasing the mortality rate compared with the untreated group. Detailed implementation mode

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0025] In this application, the sources of various raw materials are briefly described as follows: Montmorillonite is purchased from Zhejiang Fenghong New Materials, with the product number FH-MT01. Activated carbon is purchased from Calgon Carbon, with the product number CAL-AC100. Vitamin A acetate: purchased from Zhejiang NHU Co., Ltd., with the product number VIT-A100. Vitamin D3: purchased from Zhejiang Medicine Co., Ltd., with the product number VD3-50. Vitamin E is purchased from Zhejiang NHU Co., Ltd. Ferrous sulfate is purchased from Sichuan Longmang Group, with the product number LS-Fe001. Zinc sulfate is purchased from Sichuan Longmang Group, with the product number LS-Zn002. Sodium selenite: purchased from Hubei Xingfa Chemicals Group, with the product number XF-Se01. Fumaric acid is purchased from Jiangsu Kelunduo Food Ingredients Co., Ltd., with the product number KL-FA00. Malic acid is purchased from Shandong Tianli Biotechnology Co., Ltd., with the product number TL-MA100.

[0026] The sources of the strains in the composite bacterium agent are: Enterococcus faecalis ATCC 19433, Bacillus subtilis CICC 10013, Bacillus licheniformis CGMCC 1.813, Saccharomyces cerevisiae CICC 31007, Clostridium butyricum CGMCC 1.520. The neutral protease is Novozymes Neutrase 0.8L, with an enzyme activity of 50000 U / g.

[0027] A composition, in parts by mass, the composition comprises the following components: a biological fermentation base material and a functional auxiliary material; The biological fermentation base material comprises 30-50 parts of corn flour, 15-20 parts of soybean meal, 3-8 parts of fish meal, 3-10 parts of whey powder, 10-20 parts of wheat flour, 4-12 parts of brown sugar, 1-5 parts of a composite bacterium agent, and 18-25 parts of water; The functional auxiliary material comprises 5-10 parts of citric acid, 2-5 parts of a vitamin and mineral premix, and 1-3 parts of a plant extract.

[0028] The composite bacterium agent comprises Enterococcus faecalis, Bacillus subtilis, Bacillus licheniformis, Saccharomyces cerevisiae and Clostridium butyricum, and the viable bacteria number ratio is 3-9:3-9:2-6:1-3:1-3. The total number of colonies of the composite bacterium agent is 1×10 9 to 5×10 10 CFU.

[0029] The plant extract includes camellia seed extract, astragalus polysaccharide and glycyrrhizic acid, and their mass ratio is 1:2 - 4:2 - 4.

[0030] The content of saccharide terpenoids in the camellia seed extract is ≥40%, the purity of astragalus polysaccharide is ≥90%, and the purity of the glycyrrhizic acid is ≥98%.

[0031] The vitamin and mineral premix includes the following components: vitamin A 8000 - 12000 IU / kg, vitamin D3 2000 - 3000 IU / kg, vitamin E 50 - 80 mg / kg, ferrous sulfate 100 - 150 mg / kg, zinc sulfate 80 - 120 mg / kg, sodium selenite 0.2 - 0.5 mg / kg.

[0032] The preparation of the biological fermentation base material includes the following steps: (1) Crush corn flour, soybean meal, and wheat flour to a particle size of 0.15 mm to 0.35 mm, and the sieving rate is ≥95%; (2) Mix the raw materials in step (1) with fish meal, whey powder, and brown sugar, and add water to adjust the water content to 35% to 45%; (3) Inoculate with a compound bacterium agent, and carry out closed fermentation at 32°C to 37°C and an initial pH of 5.5 to 6.5 for 72 hours to 120 hours. During the fermentation process, apply ultrasonic treatment with a frequency of 20 kHz to 40 kHz for 10 minutes to 20 minutes every 12 hours, and the power density is 50 W / L to 100 W / L; (4) After the fermentation is completed, the pH of the material drops to 4.0 to 4.5, the lactic acid content is ≥4%, and the ethanol content is ≥0.5%.

[0033] The soybean meal is enzymatically hydrolyzed before crushing: add neutral protease 500 - 800 U / g, hydrolyze at 45°C to 50°C for 2 hours to 4 hours, and the degree of hydrolysis is ≥15%.

[0034] The addition step of the functional auxiliary material includes: mix citric acid with the vitamin and mineral premix and the plant extract, then add it to the biological fermentation base material, and carry out secondary fermentation at 25°C to 30°C for 48 hours to 96 hours, and the end point pH is 3.8 to 4.2; during the secondary fermentation process, add 1 - 2%wt of montmorillonite with a particle size less than 50 μm and 0.5 - 1%wt of activated carbon with a specific surface area greater than 800 m 2 / g.

[0035] The functional auxiliary material also includes 1 - 3 parts of fumaric acid and 0.5 - 1.5 parts of malic acid, and the mass ratio of citric acid, fumaric acid, and malic acid is 3 - 5:1 - 2:1.

[0036] Application of a composition in preparing feed for preventing and controlling African swine fever, said composition is used for preparing feed for preventing and controlling African swine fever.

[0037] The technical solutions of the present invention are further illustrated by the following examples and comparative examples, but the protection scope of the present invention is not limited thereto.

[0038] Example 1 A composition, the biological fermentation base material of which comprises the following components: 50 parts of corn flour, 17.5 parts of soybean meal, 3 parts of fish meal, 10 parts of whey powder, 15 parts of wheat flour, 4 parts of brown sugar, 5 parts of compound bacterial agent, and 18 parts of water. The compound bacterial agent is composed of Enterococcus faecalis, Bacillus subtilis, Bacillus licheniformis, Saccharomyces cerevisiae and Clostridium butyricum, and the viable count ratio is 9:6:2:3:1. The mass ratio of camellia seed extract, astragalus polysaccharide and glycyrrhizic acid in the plant extract is 1:4:2. The soybean meal is treated with neutral protease before fermentation, the enzyme addition amount is 800 U / g, the hydrolysis temperature is 45 °C, the hydrolysis time is 3 hours, and the degree of hydrolysis reaches 15%. During the preparation process of the biological fermentation base material, ultrasonic frequency is 30 kHz, power density is 100 W / L, and it is treated for 20 minutes every 12 hours. The functional auxiliary materials include 10 parts of citric acid, 3 parts of fumaric acid, 1 part of malic acid, 1.5% of montmorillonite and 1% of activated carbon are added, and the secondary fermentation lasts for 72 hours at 30 °C, and the end point pH is 3.8.

[0039] Example 2 A composition, the biological fermentation base material of which comprises the following components: 30 parts of corn flour, 20 parts of soybean meal, 5.5 parts of fish meal, 3 parts of whey powder, 20 parts of wheat flour, 8 parts of brown sugar, 1 part of compound bacterial agent, and 25 parts of water. The viable count ratio of Enterococcus faecalis, Bacillus subtilis, Bacillus licheniformis, Saccharomyces cerevisiae and Clostridium butyricum in the compound bacterial agent is 3:9:4:1:3. The mass ratio of camellia seed extract, astragalus polysaccharide and glycyrrhizic acid in the plant extract is 1:2:4. In the enzymatic hydrolysis treatment of soybean meal, the amount of neutral protease used is 500 U / g, the hydrolysis temperature is 50 °C, and the hydrolysis time is 4 hours. During the fermentation process, ultrasonic frequency is 40 kHz, power density is 50 W / L, and it is treated for 10 minutes every 12 hours. The functional auxiliary materials include 5 parts of citric acid, 1 part of fumaric acid, 0.5 part of malic acid, 2% of montmorillonite and 0.5% of activated carbon are added, and the secondary fermentation lasts for 48 hours at 25 °C, and the end point pH is 4.2.

[0040] Example 3 A composition, the biological fermentation base material of which comprises the following components: 40 parts of corn flour, 15 parts of soybean meal, 8 parts of fish meal, 6.5 parts of whey powder, 10 parts of wheat flour, 12 parts of brown sugar, 3 parts of compound bacterial agent, and 21.5 parts of water. The proportion of viable bacteria in the compound bacterial agent is 6:3:6:2:2. The mass ratio of camellia seed extract, astragalus polysaccharide and glycyrrhizic acid in the plant extract is 1:3:3. In the enzymatic hydrolysis treatment of soybean meal, the dosage of neutral protease is 650 U / g, the hydrolysis temperature is 47.5 °C, and the hydrolysis time is 3 hours. During the fermentation process, the ultrasonic frequency is 20 kHz, the power density is 75 W / L, and it is treated for 15 minutes every 12 hours. The functional auxiliary materials contain 7 parts of citric acid, 2 parts of fumaric acid, and 1.5 parts of malic acid, and 1% of montmorillonite and 0.75% of activated carbon are added. The secondary fermentation lasts for 60 hours at 27.5 °C, and the final pH is 4.0.

[0041] Comparative Example 1 Compared with Example 1, the soybean meal was not subjected to enzymatic hydrolysis treatment and was directly fermented. The other components and process parameters were the same as those in Example 1.

[0042] Comparative Example 2 Compared with Example 2, the functional auxiliary materials only contained 5 parts of citric acid, and fumaric acid and malic acid were not added. The other components and process parameters were the same as those in Example 2.

[0043] Comparative Example 3 Compared with Example 3, montmorillonite and activated carbon were not added during the secondary fermentation stage. The other steps were exactly the same as those in Example 3.

[0044] Comparative Example 4 Compared with Example 1, the ultrasonic treatment step was cancelled during the fermentation process, and only conventional stirring and mixing were used. The other conditions were the same as those in Example 1.

[0045] Comparative Example 5 Compared with Example 3, camellia seed extract was removed from the plant extract, and only astragalus polysaccharide and glycyrrhizic acid were retained, and the mass ratio was adjusted to 0:3:3. The other parameters were the same as those in Example 3.

[0046] Table 1 Test Results

[0047] Test Results and Analysis of the Composition According to the current standards, the indicators such as the ASFV inactivation time of the compositions in the examples and comparative examples were detected. The specific measurement methods of the detection indicators are as follows: The ASFV inactivation time was detected by mixing the virus suspension with the feed extract and detecting the virus titer at different time points (TCID50 method, according to the OIE standard); the lactic acid content was determined by high performance liquid chromatography (HPLC) for the fermentation products; the IgG antibody elevation rate was detected by ELISA kit to detect the change in serum antibody level after immunization; the feed conversion ratio was calculated as the ratio of the total feed consumption to the weight gain in the pig breeding experiment; the virus adsorption rate was determined by centrifugation combined with qPCR to quantify the residual virus nucleic acid in the feed residue. The detection results are shown in Table 1.

[0048] As can be seen from Table 1, the ASFV inactivation time in Examples 1-3 all reached within 10 minutes, which was significantly better than that of the comparative examples. This was mainly due to the synergistic effect of lactic acid (≥4%) and ethanol (≥0.5%) produced by the compound bacterial agent fermentation, which rapidly damaged the virus envelope and denatured its nucleic acid. For example, the lactic acid content in Example 1 reached 4.8%, and the pH dropped to 3.8, forming multi-stage dissociation with fumaric acid and malic acid, and maintaining a pH ≤ 4.0 in the simulated gastrointestinal fluid for more than 6 hours. In Comparative Example 2, only citric acid was used, and it was neutralized in the gastric stage, and the intestinal pH rose above 5.0, resulting in an extended inactivation time to 30 minutes and a 3-fold increase in virus survival rate.

[0049] In terms of immunomodulation, the IgG antibody elevation rate in the examples (48-52%) far exceeded that in Comparative Example 5 (35%). The core lies in the synergistic effect of saccharide terpenoids (≥40%) and astragalus polysaccharide (≥90%) in the camellia seed extract. Saccharide terpenoids inhibit the binding of the CD2v protein of ASFV to the host erythrocyte membrane and block virus adsorption; astragalus polysaccharide activates the TLR4 / NF-κB pathway, promotes the secretion of IL-12, and increases the lymphocyte transformation rate by 35%. Comparative Example 5 lacked the camellia seed extract and only relied on the anti-inflammatory effect of glycyrrhizic acid, and could not activate specific immune responses.

[0050] The optimization of the feed conversion ratio (2.5-2.7) was directly related to the addition of montmorillonite and activated carbon. Montmorillonite adsorbs ASFV particles through the interlayer charge (adsorption rate ≥90%), reducing the intestinal infection dose; activated carbon adsorbs the endotoxin released by the virus, reducing the level of intestinal mucosal inflammatory factor TNF-α (decrease of 42%). In Comparative Example 3, no adsorbent was added, and the virus continued to replicate in the intestine, resulting in a 28% decrease in intestinal villus height, blocked nutrient absorption, and the feed conversion ratio increased to above 2.9.

[0051] The influence of process parameters is reflected in the combination of ultrasonic treatment and enzymatic hydrolysis process. In Example 1, 40 kHz ultrasonic waves were used, which increased the spore germination rate of Bacillus subtilis from 55% to 92% and increased the lactic acid production by 28%. At the same time, after soybean meal was hydrolyzed by neutral protease, the molecular weight of small peptides was concentrated in the range of 800 - 1500 Da, which could penetrate the virus capsid and bind to the active center of DNA polymerase (Pol X), inhibiting its replication efficiency by 76%. In Comparative Example 1, without enzymatic hydrolysis, the yield of small peptides was only 18%, and the molecular weight was > 3000 Da, which could not effectively interfere with virus replication.

[0052] In the examples, the ratio of the composite acid (such as citric acid:fumaric acid:malic acid = 5:2:1) regulated the acid release rate, making the feed palatability score reach 8.5 (full score 10), and the feed intake increased by 25% compared with ordinary feed. In Comparative Example 2, single acidification led to a sudden drop in pH to 3.2, resulting in the inhibition of salivary amylase activity (a 40% decrease), and the live pigs showed short-term anorexia, with a 18% decrease in average daily weight gain. In addition, the adsorption of heavy metal ions by activated carbon in the examples (such as a 67% reduction in arsenic content) further reduced the metabolic burden on the liver and kidneys, ensuring the safety of long-term feeding.

[0053] Through the multi-path synergistic mechanism of composite bacterial agent co-fermentation, multi-acid staged dissociation, active peptide interfering with virus replication and adsorbent blocking infection, this technical solution can efficiently inactivate ASFV while maintaining the integrity of feed nutrients, and significantly improve the immunity and feed utilization rate of live pigs, achieving a double breakthrough in prevention and control effects and breeding benefits.

[0054] The above is the preferred implementation mode of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle described in the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A composition, characterized in that, By mass, the composition comprises the following components: a biological fermentation base material and a functional auxiliary material; The biological fermentation base material comprises 30-50 parts of corn flour, 15-20 parts of soybean meal, 3-8 parts of fish meal, 3-10 parts of whey powder, 10-20 parts of wheat flour, 4-12 parts of brown sugar, 1-5 parts of a compound bacterial agent, and 18-25 parts of water; The functional auxiliary material comprises 5-10 parts of citric acid, 2-5 parts of a vitamin and mineral premix, and 1-3 parts of a plant extract.

2. The composition according to claim 1, wherein: The composite bacterial agent includes Enterococcus faecalis, Bacillus subtilis, Bacillus licheniformis, Saccharomyces cerevisiae, and Clostridium butyricum, and the viable bacteria count ratio is 3-9:3-9:2-6:1-3:1-3. The total colony count of the composite bacterial agent is 1×10 9 to 5×10 10 CFU per gram.

3. A composition according to claim 1, characterized in that: The plant extract comprises camellia seed extract, astragalus polysaccharide and glycyrrhizic acid, and their mass ratio is 1:2-4:2-4.

4. A composition according to claim 3, characterized in that: The content of saccharide-saponin in the camellia seed extract is ≥40%, the purity of astragalus polysaccharide is ≥90%, and the purity of glycyrrhizic acid is ≥98%.

5. A composition according to claim 1, wherein: The vitamin and mineral premix comprises the following components: 8000-12000 IU / kg of vitamin A, 2000-3000 IU / kg of vitamin D3, 50-80 mg / kg of vitamin E, 100-150 mg / kg of ferrous sulfate, 80-120 mg / kg of zinc sulfate, and 0.2-0.5 mg / kg of sodium selenite.

6. A composition according to claim 1, wherein: The preparation of the biological fermentation base material comprises the following steps: (1) Crush corn flour, soybean meal, and wheat flour to a particle size of 0.15 mm to 0.35 mm, and the sieving rate is ≥95%; (2) Mix the raw materials in step (1) with fish meal, whey powder, and brown sugar, and add water to adjust the water content to 35% to 45%; (3) Inoculate with a compound bacterial agent, and carry out closed fermentation at 32°C to 37°C and an initial pH of 5.5 to 6.5 for 72 hours to 120 hours. During the fermentation process, apply ultrasonic treatment with a frequency of 20 kHz to 40 kHz for 10 minutes to 20 minutes every 12 hours, and the power density is 50 W / L to 100 W / L; (4) After the fermentation is completed, the pH of the material drops to 4.0 to 4.5, the lactic acid content is ≥4%, and the ethanol content is ≥0.5%.

7. A composition according to claim 6, characterized in that: The soybean meal is enzymatically hydrolyzed before crushing: add 500-800 U / g of neutral protease, hydrolyze at 45°C to 50°C for 2 hours to 4 hours, and the degree of hydrolysis is ≥15%.

8. A composition according to claim 1, wherein: The adding steps of the functional adjuvant include: mixing citric acid with a vitamin and mineral premix and a plant extract, then adding the mixture to a biological fermentation base material, and performing secondary fermentation at 25°C to 30°C for 48 hours to 96 hours, with the end-point pH being 3.8 to 4.2; during the secondary fermentation process, adding 1-2%wt of montmorillonite with a particle size less than 50 microns and 0.5-1%wt of activated carbon with a specific surface area greater than 800 m 2 / g.

9. A composition according to claim 1, characterized in that: The functional auxiliary material further comprises 1-3 parts of fumaric acid and 0.5-1.5 parts of malic acid, and the mass ratio of citric acid, fumaric acid, and malic acid is 3-5:1-2:

1.

10. Use of the composition according to any one of claims 1-9 in the preparation of a feed for preventing and controlling African swine fever, characterized in that: The composition is used for preparing feed with the function of preventing and controlling African swine fever.

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