Functional feed additive for relieving clostridial enteritis of meat poultry as well as preparation method and application of functional feed additive

Abstract

The invention provides a functional feed additive for relieving clostridial enteritis of meat poultry as well as a preparation method and application of the functional feed additive. The functional feed additive is prepared from the following components in parts by weight: 30 to 50 parts of plant extract, 0.5 to 2 parts of monatomic microelement-mesoporous silicon dioxide nanoparticles, 0.1 to 2 parts of momordica saponin and 1 to 3 parts of sarcandra glabra polysaccharide. The product provided by the invention can relieve chicken intestinal structure damage caused by clostridium perfringens and protect normal structures and functions of intestinal tracts; inflammatory factors in jejunum are reduced, inflammatory response is improved, clostridium perfringens colonization is reduced, and the intestinal health level is maintained; furthermore, clostridial enteritis of meat poultry is reduced, and the production performance of broilers is improved.

Description

Technical Field

[0001] This invention belongs to the field of feed preparation technology, specifically relating to a functional feed additive for alleviating clostridial enteritis in poultry, its preparation method, and its application. Background Technology

[0002] Clostridium perfringens can cause necrotic enteritis in chickens, a common disease in poultry farming. Broilers aged 3-6 weeks are particularly susceptible. After entering the chicken's intestines, the bacteria feed on intestinal nutrients, multiply rapidly, and produce large amounts of toxins, causing significant damage to the broiler's intestinal health. This leads to a rapid decline in poultry productivity and has a major impact on the global livestock industry.

[0003] To prevent and treat diseases such as clostridial enteritis in poultry, farmers typically add antibiotics like amoxicillin to feed or drinking water. However, with the complete ban on antibiotics in feed, preventing and controlling this disease has become a pressing problem for the poultry industry.

[0004] CN119257187A discloses a feed additive for preventing necrotic enteritis in broilers, its preparation method, and its application. The additive comprises the following raw materials in parts by weight: 15-30 parts of vegetable essential oil, 40-60 parts of deoxycholic acid, and vitamin D. This feed additive has clearly defined components, stable properties, is easy to operate and control, and is readily industrialized, facilitating its widespread application. Using the feed additive provided by this invention can improve the integrity of the intestinal epithelial barrier, improve the intestinal flora structure, enhance the body's immunity, and effectively prevent the occurrence of necrotic enteritis in broilers.

[0005] CN105770355A discloses a compound preparation for preventing necrotic enteritis in broilers and its application. This compound preparation is composed of different strains and carriers, including butyric acid bacteria with a content of not less than 2 × 10⁻⁶. 9 The content of *Lactobacillus salivarius* in the sample, with CFU / g and accession number CGMCC No. 11386, is not less than 5 × 10⁻⁶. 9 The compound preparation contains CFU / g, garlic extract, and mulberry leaf extract. This invention exhibits significant inhibitory effects against chicken-derived Escherichia coli, Clostridium perfringens, and Salmonella. When applied to broiler farming, it can significantly reduce the morbidity and mortality of necrotizing enteritis caused by Clostridium perfringens and promote broiler growth.

[0006] CN104171375A discloses a traditional Chinese medicine feed additive for preventing necrotizing enteritis in chickens and its preparation method. The commonly used weight ratio is: 17-21 parts Polygonatum sibiricum, 14-18 parts Polygonum multiflorum, 10-14 parts cactus, 10-14 parts pine needles, 7-11 parts Sophora flavescens, 6-10 parts Pulsatilla chinensis, 6-10 parts Dioscorea bulbifera, 5-11 parts Lonicera japonica, and 5-11 parts Schisandra chinensis. The herbs are mixed in the specified ratio and processed into a 50-70 mesh powder. The powder is then mixed with 30% purified water and an appropriate amount of brown sugar and naturally fermented to form an enzyme. After extracting the enzyme liquid, the remaining residue is ground into a paste using a high-speed grinder. This paste is mixed with other feed ingredients in the specified ratio, and then thoroughly mixed with purified high-quality Bacillus subtilis and high-quality yeast. After a second fermentation of 36 hours, the traditional Chinese medicine feed additive for preventing necrotizing enteritis in chickens is produced. This invention has the effects of being mild in nature, easily absorbed, significantly reducing the incidence and mortality of necrotizing enteritis in chickens, and reducing the feed conversion ratio.

[0007] However, the aforementioned technical solutions have not effectively solved the problems caused by Clostridium perfringens. Therefore, how to provide a method that can effectively alleviate clostridial enteritis in poultry has become an urgent problem to be solved. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the present invention aims to provide a functional feed additive for alleviating clostridial enteritis in poultry, along with its preparation method and application. The product provided by this invention can alleviate intestinal structural damage in chickens caused by Clostridium perfringens, protecting the normal structure and function of the intestine; reduce inflammatory factors in the jejunum, improve inflammatory responses, reduce Clostridium perfringens colonization, and maintain intestinal health; thereby reducing clostridial enteritis in poultry and improving broiler production performance.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a functional feed additive for alleviating clostridial enteritis in poultry, wherein the functional feed additive comprises, by weight, 30-50 parts of plant extract, 0.5-2 parts of single-atom trace element-mesoporous silica nanoparticles, 0.1-2 parts of bitter melon saponins, and 1-3 parts of *Sarcandra glabra* polysaccharide.

[0011] The plant extracts can be in quantities of 30, 35, 40, 45, or 50 parts, etc.; the single-atom trace element-mesoporous silica nanoparticles can be in quantities of 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2 parts, etc.; bitter melon saponins can be in quantities of 0.1, 0.5, 1, 1.5, or 2 parts, etc.; and *Sarcandra glabra* polysaccharides can be in quantities of 1, 1.5, 2, 2.5, or 3 parts, etc., but are not limited to the values ​​listed above. Other unlisted values ​​within the above range are also applicable.

[0012] Single-atom trace elements have small particle sizes, which can quickly enter the interior of bacterial cells, interfere with cell metabolism, and cause them to lose their proper biological functions, eventually leading to bacterial cell death, thereby achieving a bactericidal effect. However, their strong catalytic activity makes them prone to reacting with other substances in the body, preventing them from reaching the intestines well. Mesoporous silica nanoparticles can prevent them from dissolving in the stomach and reacting with other substances, thus preventing them from failing to reach the intestines, and can also play a good role in slow release.

[0013] Ironwood flower extract contains active substances such as flavonoids, coumarins, terpenes, and phenolic acids, and studies have shown that it has an inhibitory effect on a variety of pathogenic bacteria.

[0014] Artemisia annua extract contains a variety of flavonoids, which have antiviral and immune-regulating effects.

[0015] Hydrangea vine extract contains saponins, flavonoids, lignans, coumarins, and alkaloids, and has good anti-inflammatory activity.

[0016] Bitter melon saponins possess antibacterial, antiviral, and antitumor biological activities. However, bitter melon saponins are hygroscopic and their antibacterial activity is unstable. This invention combines bitter melon saponins with single-atom trace elements—mesoporous silica nanoparticles—in a specific ratio, which can effectively improve the antibacterial effect of the product and maintain intestinal health.

[0017] *Sarcandra glabra* polysaccharide possesses good anti-inflammatory and immunomodulatory activities, effectively inhibiting the release of inflammatory factors and enhancing the body's immune function. Flavonoids and other substances in plant extracts (such as *Imperata cylindrica* flower extract, *Hydrangea macrophylla* extract, and *Artemisia scoparia* extract) help the body scavenge free radicals and reduce oxidative stress on cells, thereby protecting the body from disease. The effects of *Sarcandra glabra* polysaccharide and plant extracts complement each other, enhancing their respective biological activities. The combined use of these two ingredients has a synergistic effect, significantly reducing inflammation and enhancing the body's immunity.

[0018] The above-mentioned products utilize a compound of plant extracts, single-atom trace elements (mesoporous silica nanoparticles), bitter melon saponins, and coral polysaccharides. Through synergistic effects, these products can effectively alleviate the damage to the chicken intestinal structure caused by Clostridium perfringens, protect the normal structure and function of the intestine, reduce inflammatory factors in the jejunum, improve the inflammatory response, reduce Clostridium perfringens colonization, and maintain intestinal health. In turn, they can reduce clostridial enteritis in poultry and improve the production performance of broilers.

[0019] Preferably, the plant extract includes any one or a combination of at least two of the following: ironwood flower extract, hydrangea extract, or Artemisia annua extract, with a preferred combination of ironwood flower extract, hydrangea extract, and Artemisia annua extract.

[0020] The combination of these specific plant extracts can further enhance the product's effectiveness.

[0021] Preferably, the mass ratio of the ironwood flower extract, hydrangea extract, and Artemisia extract is (1-3):(3-5):(2-4), wherein the number of parts of the ironwood flower extract can be 1 part, 1.5 parts, 2 parts, 2.5 parts, or 3 parts, etc.; the number of parts of the hydrangea extract can be 3 parts, 3.5 parts, 4 parts, 4.5 parts, or 5 parts, etc.; and the number of parts of the Artemisia extract can be 2 parts, 2.5 parts, 3 parts, 3.5 parts, or 4 parts, etc., but is not limited to the values ​​listed above. Other unlisted values ​​within the above range are also applicable.

[0022] Preferably, the plant extract is prepared by a method comprising the following steps:

[0023] The plant raw materials were dried, pulverized, mixed with an alcohol solution for extraction, and then subjected to ultrasonic extraction, concentration, and drying to obtain the plant extract.

[0024] The plant materials include ironwood flowers, hydrangea vines, or sand wormwood.

[0025] Preferably, the alcohol solution includes an ethanol solution with a volume fraction of 60-80%, such as 60%, 65%, 70%, 75%, or 80%, but not limited to the values ​​listed above. Other unlisted values ​​within the above range are also applicable.

[0026] Preferably, the ratio of the plant material to the alcohol solution is 1:(10-15)g / mL, for example, 1:10g / mL, 1:11g / mL, 1:12g / mL, 1:13g / mL, 1:14g / mL or 1:15g / mL, but not limited to the values ​​listed above. Other unlisted values ​​within the above range are also applicable.

[0027] Preferably, the extraction time with the alcohol solution is 30-60 min, such as 30 min, 35 min, 40 min, 45 min, 50 min, 55 min or 60 min, but not limited to the values ​​listed above. Other values ​​not listed in the above range are also applicable.

[0028] Preferably, the ultrasonic extraction time is 30-50 min, such as 30 min, 35 min, 40 min, 45 min or 50 min, but not limited to the values ​​listed above. Other values ​​not listed in the above range are also applicable.

[0029] The specific preparation methods and parameter limitations described above can further enhance the efficacy of plant extracts.

[0030] Preferably, the single-atom trace element-mesoporous silica nanoparticles are prepared by a method comprising the following steps:

[0031] Water is mixed with single-atom trace elements, and then mixed and stirred with mesoporous silica nanoparticles. The single-atom trace elements-mesoporous silica nanoparticles are obtained by solid-liquid separation.

[0032] The above preparation method enables the effective adsorption of single-atom trace elements by mesoporous silica nanoparticles, improving the sustained-release effect and thus enhancing the product efficacy.

[0033] Preferably, the water is further adjusted to pH 2-3 before being mixed with the single-atom trace elements.

[0034] Preferably, the mass ratio of the single-atom trace element to the mesoporous silica nanoparticles is (1-3):(5-6).

[0035] Preferably, the single-atom trace elements include single-atom copper and / or single-atom zinc, with single-atom copper and single-atom zinc being more preferred.

[0036] Preferably, the mass ratio of the single-atom copper to the single-atom zinc is 1:(2-5), such as 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5 or 1:5, but not limited to the values ​​listed above. Other unlisted values ​​within the above range are also applicable.

[0037] The aforementioned specific single-atom trace elements and their ratios have a large specific surface area and atomic-level precision, which can maximize reactivity, enhance antibacterial and antiviral effects, and effectively alleviate inflammation.

[0038] Preferably, the functional feed additive further includes 1-5 parts by weight of glyceryl monolaurate, such as 1 part, 2 parts, 3 parts, 4 parts or 5 parts, but not limited to the values ​​listed above. Other unlisted values ​​within the above range are also applicable.

[0039] Secondly, the present invention provides a method for preparing the functional feed additive for alleviating clostridial enteritis in poultry as described above, the preparation method comprising the following steps:

[0040] The functional feed additive for relieving clostridial enteritis in broilers and poultry is obtained by mixing plant extracts, single-atom trace elements (mesoporous silica nanoparticles), bitter melon saponins, and coral polysaccharides.

[0041] Preferably, the mixture further includes mixing with monoglyceride lauryl ester.

[0042] Thirdly, the present invention also provides the application of the functional feed additive described above for alleviating clostridial enteritis in poultry in the preparation of poultry feed.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] This invention provides a functional feed additive that alleviates clostridial enteritis in poultry. It utilizes a compound of plant extracts, single-atom trace elements (mesoporous silica nanoparticles), bitter melon saponins, and *Clerodendrum trichotomum* polysaccharides. Through synergistic effects, this additive effectively alleviates intestinal structural damage caused by *Clostridium perfringens*, protecting normal intestinal structure and function; reduces inflammatory factors in the jejunum, improves inflammatory responses, reduces *Clostridium perfringens* colonization, and maintains intestinal health; thereby reducing clostridial enteritis in poultry and improving broiler production performance. Detailed Implementation

[0045] To further illustrate the technical means and effects of the present invention, the following describes the technical solution of the present invention in conjunction with preferred embodiments of the present invention. However, the present invention is not limited to the scope of the embodiments.

[0046] In the following examples, the single-atom copper and single-atom zinc were purchased from Guangxi Liankehua New Materials Co., Ltd.

[0047] Mesoporous silica nanoparticles were purchased from Beijing Zhongke Keyou Technology Co., Ltd.

[0048] Bitter melon saponins were purchased from Xinyang Mufan Biotechnology Co., Ltd.

[0049] The herbicide *Gnaphalium affine* was purchased from Fufeng Sinote Biotechnology Co., Ltd.

[0050] Preparation Example 1

[0051] This preparation example provides a plant extract, prepared by the following method:

[0052] After weighing the ironwood flowers, they were placed in a far-infrared drying oven and dried until they were completely dry. The moisture content was measured to be less than 10%. The powder was then ground in a grinder and passed through an 80-mesh sieve to obtain powder. The powder was extracted with 70% ethanol at a material-to-liquid ratio of 1:13 g / mL for 50 min. The extracted sample was then placed in an ultrasonic device and ultrasonically assisted for 40 min. After filtration with filter paper, the filtrate was concentrated in a vacuum rotary evaporator at 50°C for 40 min. After drying at a low temperature of 20°C and grinding in a mortar, the ironwood flower extract was obtained.

[0053] Following the same method described above, replace the ironwood flowers with equal amounts of hydrangea vine and Artemisia scoparia to obtain hydrangea vine extract and Artemisia scoparia extract;

[0054] The plant extract was obtained by mixing ironwood flower extract, hydrangea extract, and Artemisia annua extract in a mass ratio of 2:4:3.

[0055] Preparation Example 2

[0056] This preparation example provides a plant extract, prepared by the following method:

[0057] After weighing the ironwood flowers, they were placed in a far-infrared drying oven and dried until they were completely dry. The moisture content was measured to be less than 10%. The powder was then ground in a grinder and passed through an 80-mesh sieve to obtain a powder. The powder was extracted with 60% ethanol at a material-to-liquid ratio of 1:10 g / mL for 60 min. The extracted sample was then placed in an ultrasonic device for ultrasonic-assisted extraction for 30 min. After filtration with filter paper, the filtrate was concentrated in a vacuum rotary evaporator at 50°C for 40 min. After drying at a low temperature of 20°C and grinding in a mortar, the ironwood flower extract was obtained.

[0058] Following the same method described above, replace the ironwood flowers with equal amounts of hydrangea vine and Artemisia scoparia to obtain hydrangea vine extract and Artemisia scoparia extract;

[0059] The plant extract was obtained by mixing ironwood flower extract, hydrangea extract, and Artemisia annua extract in a mass ratio of 1:3:2.

[0060] Preparation Example 3

[0061] This preparation example provides a plant extract, prepared by the following method:

[0062] After weighing the ironwood flowers, they were placed in a far-infrared drying oven and dried until they were completely dry. The moisture content was measured to be less than 10%. The powder was then ground in a grinder and passed through an 80-mesh sieve. The powder was extracted with 80% ethanol at a material-to-liquid ratio of 1:15 g / mL for 30 min. The extracted sample was then placed in an ultrasonic device and ultrasonically extracted for 60 min. After filtration with filter paper, the filtrate was concentrated in a vacuum rotary evaporator at 50°C for 40 min. After drying at a low temperature of 20°C and grinding in a mortar, the ironwood flower extract was obtained.

[0063] Following the same method described above, replace the ironwood flowers with equal amounts of hydrangea vine and Artemisia scoparia to obtain hydrangea vine extract and Artemisia scoparia extract;

[0064] The plant extract was obtained by mixing ironwood flower extract, hydrangea extract, and Artemisia annua extract in a mass ratio of 3:5:4.

[0065] Preparation Example 4

[0066] This preparation example provides a plant extract. The preparation method is the same as in Example 1, except that it does not include the ironwood flower extract and the portion is reduced and allocated proportionally to the hydrangea extract and artemisia extract.

[0067] Preparation Example 5

[0068] This preparation example provides a plant extract. The preparation method is the same as in Example 1, except that it does not include the hydrangea extract and the portion is reduced and allocated proportionally to the ironwood flower extract and the artemisia extract.

[0069] Preparation Example 6

[0070] This preparation example provides a plant extract. The preparation method is the same as in Example 1, except that it does not include Artemisia annua extract and the reduced portion is allocated proportionally to Hydrangea chinensis extract and Ironwood flower extract.

[0071] Preparation Example 7

[0072] This preparation example provides a single-atom copper-zinc mesoporous silica nanoparticle, prepared by the following method:

[0073] Take 200mL of water and adjust the pH to between 2 and 3 with glacial acetic acid. Dissolve 2g of monoatomic copper and monoatomic zinc (mass ratio 1:3) in the water. After they are completely dissolved, add 5.5g of mesoporous silica nanoparticles and stir continuously for 4 hours. After all the monoatomic copper and zinc are adsorbed by the mesoporous silica nanoparticles, use a centrifuge to separate the solid and liquid components. Dry the solid part to remove moisture to obtain monoatomic copper-zinc-mesoporous silica nanoparticles.

[0074] Preparation Example 8

[0075] This preparation example provides a single-atom copper-zinc mesoporous silica nanoparticle, prepared by the following method:

[0076] Take 200mL of water and adjust the pH to between 2 and 3 with glacial acetic acid. Dissolve 1g of monatomic copper and monatomic zinc (mass ratio 1:2) in the water. After they are completely dissolved, add 5g of mesoporous silica nanoparticles and stir continuously for 2 hours. After all the monatomic copper and zinc are adsorbed by the mesoporous silica nanoparticles, use a centrifuge to separate the solid and liquid components. Dry the solid part to remove moisture to obtain monatomic copper-zinc-mesoporous silica nanoparticles.

[0077] Preparation Example 9

[0078] This preparation example provides a single-atom copper-zinc mesoporous silica nanoparticle, prepared by the following method:

[0079] Take 200mL of water and adjust the pH to between 2 and 3 with glacial acetic acid. Dissolve 3g of monoatomic copper and monoatomic zinc (mass ratio 1:5) in the water. After they are completely dissolved, add 6g of mesoporous silica nanoparticles and stir continuously for 5 hours. After all the monoatomic copper and zinc are adsorbed by the mesoporous silica nanoparticles, use a centrifuge to separate the solid and liquid. Dry the solid part to remove the water to obtain monoatomic copper-zinc-mesoporous silica nanoparticles.

[0080] Preparation Example 10

[0081] This preparation example provides a single-atom copper-mesoporous silica nanoparticle. The preparation method is the same as that in Preparation Example 7, except that the single-atom zinc is replaced with an equal amount of single-atom copper.

[0082] Preparation Example 11

[0083] This preparation example provides a single-atom zinc-mesoporous silica nanoparticle. The preparation method is the same as that in Preparation Example 7, except that the single-atom copper is replaced with an equal amount of single-atom zinc.

[0084] Example 1

[0085] This embodiment provides a functional feed additive for alleviating clostridial enteritis in poultry, and the raw materials for preparation are as follows (by weight):

[0086] Preparation Example 1: 40 parts of plant extract, Preparation Example 7: 1.2 parts of single-atom copper-zinc-mesoporous silica nanoparticles, 1 part of bitter melon saponin, 2 parts of *Sarcandra glabra* polysaccharide, and 3 parts of monoglyceride laurate.

[0087] The preparation method is as follows:

[0088] The functional feed additive is obtained by mixing plant extracts, single-atom copper-zinc-mesoporous silica nanoparticles, bitter melon saponins, coral polysaccharides, and monoglycerides of laurate.

[0089] Example 2

[0090] This embodiment provides a functional feed additive for alleviating clostridial enteritis in poultry, and the raw materials for preparation are as follows (by weight):

[0091] Preparation Example 2 provided 30 parts of plant extract, Preparation Example 8 provided 2 parts of single-atom copper-zinc-mesoporous silica nanoparticles, 0.1 parts of bitter melon saponin, 3 parts of *Sarcandra glabra* polysaccharide and 1 part of monoglyceride laurate.

[0092] The preparation method is the same as in Example 1.

[0093] Example 3

[0094] This embodiment provides a functional feed additive for alleviating clostridial enteritis in poultry, and the raw materials for preparation are as follows (by weight):

[0095] Preparation Example 3 provided 50 parts of plant extract, Preparation Example 9 provided 0.5 parts of single-atom copper-zinc-mesoporous silica nanoparticles, 2 parts of bitter melon saponins, and 1 part of *Sarcandra glabra* polysaccharide.

[0096] The preparation method is the same as in Example 1.

[0097] Examples 4-6

[0098] Examples 4-6 provide functional feed additives for alleviating clostridial enteritis in poultry. The raw materials used in their preparation are the same as in Example 1, except that the plant extract provided in Preparation Example 1 is replaced with an equal amount of the plant extract provided in Preparation Examples 4-6.

[0099] The preparation method is the same as in Example 1.

[0100] Examples 7-8

[0101] Examples 7-8 provide functional feed additives for alleviating clostridial enteritis in poultry. The raw materials are the same as in Example 1, except that the single-atom copper-zinc-mesoporous silica nanoparticles are replaced with equal amounts of the single-atom copper-mesoporous silica nanoparticles and single-atom zinc-mesoporous silica nanoparticles provided in Examples 10-11.

[0102] The preparation method is the same as in Example 1.

[0103] Comparative Example 1

[0104] This comparative example provides a functional feed additive for alleviating clostridial enteritis in poultry. The raw materials used in its preparation are identical to those in Example 1, except that they do not contain plant extracts, and a portion of the raw materials is proportionally allocated to monoatomic copper-zinc-mesoporous silica nanoparticles, bitter melon saponins, and coral polysaccharides.

[0105] The preparation method is the same as in Example 1.

[0106] Comparative Example 2

[0107] This comparative example provides a functional feed additive for alleviating clostridial enteritis in poultry. The raw materials used in its preparation are identical to those in Example 1, except that they do not contain single-atom copper-zinc-mesoporous silica nanoparticles and a portion of the raw materials is allocated proportionally to plant extracts, bitter melon saponins, and coral polysaccharides.

[0108] The preparation method is the same as in Example 1.

[0109] Comparative Example 3

[0110] This comparative example provides a functional feed additive for alleviating clostridial enteritis in poultry. The raw materials used in its preparation are identical to those in Example 1, except that they do not contain bitter melon saponins, a portion of which is proportionally allocated to monoatomic copper-zinc-mesoporous silica nanoparticles, plant extracts, and *Sarcandra glabra* polysaccharide.

[0111] The preparation method is the same as in Example 1.

[0112] Comparative Example 4

[0113] This comparative example provides a functional feed additive for alleviating clostridial enteritis in poultry. The raw materials used in its preparation are identical to those in Example 1, except that they do not contain *Gnaphalium affine* polysaccharide, and a portion of it is proportionally allocated to monoatomic copper-zinc-mesoporous silica nanoparticles, bitter melon saponins, and plant extracts.

[0114] The preparation method is the same as in Example 1.

[0115] Effect test:

[0116] Five hundred and fourteen 1-day-old Sanhuang broiler chickens were randomly divided into 14 groups. Each group had six replicates, with six chickens per replicate. The design of the 14 groups was as follows: (1) The control group was fed a basal diet without bacterial challenge throughout the experiment; (2) The control group was fed a basal diet with bacterial challenge throughout the experiment; (3) The experimental group (12 groups) was fed a basal diet with bacterial challenge throughout the experiment, and was provided with 500 mg / kg of the products of Examples 1-8 and Comparative Examples 1-4 from day 14 to day 21.

[0117] Challenge method: Clostridium perfringens (purchased from Beijing Bio-Biotech Biotechnology Co., Ltd., strain number: bio-52850) bacterial suspension was administered via gavage for 7 days (days 14 to 21). The challenge dose was 1×10⁻⁶. 8 CFU / mL / animal).

[0118] On day 21, four chickens were randomly selected from each column of each treatment group. After weighing, blood samples were collected from the wing vein of each chicken, placed in 10 mL centrifuge tubes, and centrifuged at 3000 rpm for 15 min at 4°C to obtain serum samples, which were stored at -20°C for further research. After euthanasia, the broilers were immediately dissected after cervical dislocation, and the jejunum of each group was collected and preserved for analysis.

[0119] Growth performance

[0120] Throughout the experiment, the body weight of broilers in each group was measured on days 1, 14, and 21. Feed intake and weight gain during this period were calculated on days 14 and 21. Feed conversion ratio (FCR) was calculated on days 1-14, 14-21, and 1-21. FCR = feed intake / weight gain × 100%. The results are as follows:

[0121]

[0122] Serum immunoglobulin content measurement

[0123] The levels of immunoglobulin A, immunoglobulin M, and immunoglobulin Y (IgA, IgM, IgY) in serum were determined using a chicken-specific ELISA kit (Jiangsu Enzyme Immunoassay Co., Ltd., Jiangsu, China) according to the instruction manual.

[0124]

[0125] Intestinal lesion score

[0126] Blinded assessment of jejunal lesions was conducted by three independent observers. The jejunal lesion scoring followed a 0-4 scale: 0 indicated normal, healthy tissue without major lesions; 1 indicated thin-walled or fragile tissue with a gray appearance; 2 indicated thin-walled tissue with focal necrosis, a gray appearance, and a small amount of gas production; 3 indicated thin-walled tissue with considerable necrotic plaques, the intestine filled with gas, and a small amount of blood; 4 indicated severe, extensive necrosis, significant hemorrhage, and a large amount of gas in the intestine.

[0127] Observation of intestinal morphology

[0128] Jejunum was fixed with 4% paraformaldehyde and then embedded in paraffin to prepare 5 μm tissue sections. Morphological analysis was performed using hematoxylin and eosin staining. The sections were imaged using a digital trinocular camera microscope system, and six intact intestinal villi were randomly selected from each section. The height of each villus and its corresponding crypt depth were determined using image analysis software, and the ratio between the two was calculated. Villus height was defined as the vertical distance from the villus tip to the villus-crypt junction, while crypt depth was defined as the vertical distance from the villus-crypt junction to the crypt floor.

[0129]

[0130]

[0131] Jejunal inflammatory cytokine content measurement

[0132] The levels of tumor necrosis factor (TNF-α), interleukin-6 (IL-6), interleukin-10 (IL-10), and interferon-gamma (IFN-γ) in the jejunum were determined using a chicken-specific ELISA kit (Jiangsu Enzyme Immunoassay Co., Ltd., Jiangsu, China) according to the instruction manual.

[0133]

[0134] The data above show that the product provided by this invention can effectively alleviate intestinal inflammation in poultry and improve production performance. Comparative Examples 1-8 show that this invention, by using a specific combination of plant extracts and specific single-atom trace elements—mesoporous silica nanoparticles, can further improve the product's effectiveness. Comparative Examples 1 and 1-5 show that this invention, by using a compound of plant extracts, single-atom trace elements—mesoporous silica nanoparticles, bitter melon saponins, and *Clostridium perfringens* polysaccharides, works synergistically to effectively alleviate the damage to the chicken's intestinal structure caused by *Clostridium perfringens*, protect the normal structure and function of the intestine, reduce inflammatory factors in the jejunum, improve inflammatory response, reduce *Clostridium perfringens* colonization, and maintain intestinal health. This, in turn, reduces clostridial enteritis in poultry and improves the production performance of broilers.

[0135] The applicant declares that this invention illustrates the functional feed additive for alleviating clostridial enteritis in poultry, its preparation method, and its application through the above embodiments. However, this invention is not limited to the above embodiments, meaning that this invention does not necessarily rely on the above embodiments for implementation. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of the raw materials in the product, addition of auxiliary components, and selection of specific methods all fall within the protection and disclosure scope of this invention.

[0136] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0137] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

Claims

1. A functional feed additive for alleviating clostridial enteritis in poultry, characterized in that, The functional feed additive comprises, by weight, 30-50 parts of plant extract, 0.5-2 parts of single-atom trace element-mesoporous silica nanoparticles, 0.1-2 parts of bitter melon saponins, and 1-3 parts of *Sarcandra glabra* polysaccharide.

2. The functional feed additive for alleviating clostridial enteritis in poultry according to claim 1, characterized in that, The plant extract includes any one or a combination of at least two of the following: ironwood flower extract, hydrangea extract, or Artemisia annua extract, preferably a combination of ironwood flower extract, hydrangea extract, and Artemisia annua extract.

3. The functional feed additive for alleviating clostridial enteritis in poultry according to claim 2, characterized in that, The mass ratio of the ironwood flower extract, hydrangea extract and Artemisia annua extract is (1-3):(3-5):(2-4).

4. The functional feed additive for alleviating clostridial enteritis in poultry according to any one of claims 1-3, characterized in that, The plant extract was prepared by a method comprising the following steps: The plant raw materials were dried, pulverized, mixed with an alcohol solution for extraction, and then subjected to ultrasonic extraction, concentration, and drying to obtain the plant extract. The plant materials include ironwood flowers, hydrangea vines, or sand wormwood.

5. The functional feed additive for alleviating clostridial enteritis in poultry according to claim 4, characterized in that, The alcohol solution includes an ethanol solution, wherein the volume fraction of the ethanol solution is 60-80%. Preferably, the ratio of the plant material to the alcohol solution is 1:(10-15)g / mL; Preferably, the extraction time with the alcohol solution is 30-60 minutes.

6. The functional feed additive for alleviating clostridial enteritis in poultry according to claim 4 or 5, characterized in that, The ultrasonic extraction time is 30-50 minutes.

7. The functional feed additive for alleviating clostridial enteritis in poultry according to any one of claims 1-6, characterized in that, The single-atom trace element-mesoporous silica nanoparticles are prepared by a method comprising the following steps: Water was mixed with a single-atom trace element, and then mixed and stirred with mesoporous silica nanoparticles. The single-atom trace element-mesoporous silica nanoparticles were obtained by solid-liquid separation. Preferably, the water is further adjusted to pH 2-3 before being mixed with the single-atom trace elements; Preferably, the mass ratio of the single-atom trace element to the mesoporous silica nanoparticles is (1-3):(5-6); Preferably, the single-atom trace element includes single-atom copper and / or single-atom zinc, with single-atom copper and single-atom zinc being more preferred; Preferably, the mass ratio of the single-atom copper to the single-atom zinc is 1:(2-5).

8. The functional feed additive for alleviating clostridial enteritis in poultry according to any one of claims 1-7, characterized in that, The functional feed additive also includes 1-5 parts by weight of lauric acid monoglyceride.

9. A method for preparing a functional feed additive for alleviating clostridial enteritis in poultry according to any one of claims 1-8, characterized in that, The preparation method includes the following steps: The functional feed additive for relieving clostridial enteritis in broilers and poultry is obtained by mixing plant extracts, single-atom trace elements-mesoporous silica nanoparticles, bitter melon saponins and coral polysaccharides. Preferably, the mixture further includes mixing with monoglyceride lauryl ester.

10. The application of a functional feed additive for alleviating clostridial enteritis in poultry according to any one of claims 1-8 in the preparation of poultry feed.

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