Application of soybean saponins in the preparation of drugs or feed additives for the treatment or prevention of necrotizing enteritis in chickens

Abstract

This application discloses the use of soybean saponins in the preparation of drugs or feed additives for the treatment or prevention of necrotic enteritis in chickens. The drugs or additives are soybean saponins or oral liquids, tablets, granules, or powders made with soybean saponins as the active ingredient and added solvents or excipients, with a dosage of 5–50 mg / kg body weight; or soybean saponins can be directly added to the feed at a dosage of 0.01%–0.03% of the total weight of the chicken feed. This application finds that soybean saponins, as drugs or feed additives, have high safety, no toxic side effects, can effectively increase antibody levels in chickens infected with Newcastle disease vaccine, and can alleviate the reduction in chicken production performance, the increase in pro-inflammatory cytokines, and impaired intestinal absorption and barrier function caused by necrotic enteritis infection.

Description

Technical Field

[0001] This application relates to the field of chicken enteritis prevention and control technology, specifically to the application of soybean saponins in the preparation of drugs or feed additives for the treatment or prevention of necrotizing enteritis in chickens. Background Technology

[0002] my country is a major producer and consumer of chicken meat, and ensuring the healthy and efficient breeding of broilers to improve chicken yield and quality is crucial to the national economy and people's livelihood. However, necrotic enteritis (NE) caused by Clostridium perfringens (CP) infection severely restricts the healthy and efficient breeding of broilers. Furthermore, since the ban on antibiotics in feed, pathogens in the gastrointestinal tract of broilers have proliferated rapidly, inevitably damaging their intestinal immune barrier and exacerbating the negative impact of NE on broilers. Therefore, NE is a key issue that urgently needs to be addressed for the healthy and efficient breeding of broilers in the post-antibiotic era.

[0003] Nocturnal emission (NE) is one of the major gastrointestinal diseases threatening the health of broiler chickens worldwide, primarily caused by infection with type A and type G coccidia. Abnormal environmental factors (such as heat stress), pathogenic factors (such as coccidiosis), and dietary types (such as wheat-based diets) during broiler production create conditions conducive to coccidia infection. NE mainly occurs in the small intestine, primarily the ileum, leading to impaired physical and immune barrier function of the broiler's intestines, dysbiosis of the intestinal flora, and consequently, intestinal inflammatory damage. Previously, antibiotic use was the main measure for controlling NE in broilers; however, due to the ban on antibiotics in feed, controlling NE through nutritional measures has gradually become one of the key issues of concern in broiler farming. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide the use of soybean saponins in the preparation of drugs or feed additives for the treatment or prevention of necrotic enteritis in chickens. In this application, soybean saponins and compositions with soybean saponins as the main component can effectively inhibit pathogenic bacteria causing enteritis in chickens. These soybean saponins and compositions with soybean saponins as the main component have advantages such as high safety, stable efficacy, and no toxic side effects, and have a significant preventive and control effect on necrotic enteritis in chickens.

[0005] To achieve the above objectives, this application provides at least the following technical solutions:

[0006] Application of soybean saponins in the preparation of drugs or feed additives for the treatment or prevention of necrotizing enteritis in chickens.

[0007] The technical solution provided in this application has at least the following advantages compared with the prior art:

[0008] 1. The soybean saponins provided in this application are derived from natural legumes. They are highly safe and have no toxic side effects. They can be used as feed additives for a long time to prevent necrotizing enteritis in chickens. Long-term use will not lead to the emergence of drug-resistant strains, which is an advantage that other anti-disease drugs do not have.

[0009] 2. The in vivo test results of this application show that the soybean saponins and compositions including soybean saponins provided in this application can enhance the immune effect of Newcastle disease vaccine, inhibit the expression of pro-inflammatory cytokines, improve the intestinal health of broilers, and thus improve the feed conversion efficiency of broilers with necrotizing enteritis. Detailed Implementation

[0010] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0011] Those skilled in the art will understand that, unless otherwise stated, the terms "the," "the," and "the foregoing" used in this application may also include plural forms. It should be further understood that the word "comprising" as used in the specification of this application means the presence of the stated features, steps, or operations, but does not exclude the presence or addition of one or more other features, integers, or steps.

[0012] Those skilled in the art will understand that, where specific experimental steps or conditions are not specified in the embodiments, they can be performed according to the conventional experimental steps or conditions described in the literature in this field; and where the manufacturers of the raw materials or instruments and equipment used are not specified, they are all conventional products that can be obtained commercially.

[0013] Those skilled in the art will understand that, unless otherwise stated in this application, when numerical ranges are given in the embodiments, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this application, as well as the prior art known to those skilled in the art and the descriptions in this application, can be implemented using any prior art methods, devices, and materials similar to or equivalent to those described, used, or made by means of methods, devices, and materials in the embodiments of this application.

[0014] Soy saponins (SS) are naturally occurring pentacyclic triterpenoids found in soybeans. Due to their potent immunomodulatory effects, they have been extensively studied in the medical field in recent years. SS is composed of soy saponins and some glycosides and uronic acids. Based on differences in glycosides, SS is classified into four types: A, B, E, and DDMP. Studies have found that SS is poorly absorbed by intestinal epithelial cells and is generally absorbed and utilized after being degraded by intestinal microorganisms into soy saponin alcohols or other small molecules. Group B soy saponin alcohols have a simpler structure than group A and are generally more easily absorbed. Furthermore, the more complex the structure of SS, the more pronounced its immunomodulatory effect. Existing research indicates that SS possesses antioxidant, lipid metabolism-improving, antitumor, antiviral, and immunomodulatory effects; almost all of these biological effects are related to SS's immunomodulatory function. Although soy saponins have been proven to have various biological functions, their application in the prevention and control of enteritis in broilers is rarely reported.

[0015] The in vivo test results of the embodiments of this application show that soybean saponins can enhance the immune effect of Newcastle disease vaccine, inhibit the expression of pro-inflammatory cytokines, improve the intestinal health of broilers, and thus improve the feed conversion efficiency of broilers with necrotizing enteritis. The above results provide basic information for the development of soybean saponins in poultry health care drugs and feed additives.

[0016] Based on this, embodiments of this application provide the use of soybean saponins in the preparation of drugs or feed additives for the treatment or prevention of necrotizing enteritis in chickens.

[0017] In some embodiments, the necrotizing enteritis in chickens is caused by Clostridium perfringens infection alone or in combination with coccidia.

[0018] In some embodiments, the drug or feed additive is soybean saponin, that is, soybean saponin can be directly used as a drug or feed additive to treat or prevent necrotic enteritis in chickens.

[0019] In some embodiments, the drug or feed additive is a soy saponin composition comprising soy saponins and excipients. The excipients include at least one of anhydrous ethanol, propylene glycol, dimethyl sulfoxide, edible oil, water, lactose, maltose, mannitol, soluble starch, montmorillonite, maifanite, zeolite powder, defatted rice bran, corn cob powder, wheat bran, and silica. At least one of anhydrous ethanol, propylene glycol, dimethyl sulfoxide, edible oil, and water can be used as a solvent to dissolve the soy saponins and prepare an oral liquid formulation of soy saponins. At least one of lactose, maltose, mannitol, soluble starch, montmorillonite, maifanite, zeolite powder, defatted rice bran, corn cob powder, wheat bran, and silica can be mixed with the soy saponins to form a solid mixture, which can be further prepared into soy saponin granules, tablets, powders, or other formulations.

[0020] In some preferred embodiments, the soy saponin composition is a solution of soy saponins mixed with anhydrous ethanol and water, wherein the concentration of soy saponins is 10-120 mg / mL.

[0021] In some preferred embodiments, the soy saponin composition is a powdered mixture of soy saponins, wheat bran, and soluble starch, wherein the mass fraction of soy saponins in the powdered mixture is 40% to 60%.

[0022] In some preferred embodiments, the soy saponin composition is a sheet-like mixture of soy saponins, lactose or maltose, and soluble starch, wherein the mass fraction of soy saponins in the sheet-like mixture is 40% to 60%.

[0023] In some preferred embodiments, the soy saponin composition is a granular mixture of soy saponins, lactose or maltose, and soluble starch, wherein the mass fraction of soy saponins in the granular mixture is 40% to 60%.

[0024] In some embodiments, when the drug or feed additive is a soybean saponin composition, its formulation type includes at least one of oral liquid, granules, tablets, and powders, and the formulation can be prepared using conventional pharmaceutical formulation methods.

[0025] In some embodiments, the method of using the drug or feed additive includes at least one of the following methods:

[0026] (1) Administer the drug orally to chickens at a dose of 5-50 mg / kg of chicken body weight containing soybean saponins;

[0027] (2) Soybean saponins are added to chicken feed as feed additives at a content of 0.01%-0.03% of the weight of chicken feed.

[0028] (3) When used for daily prevention of chicken enteritis, the soybean saponin powder, granules or tablets are crushed and added to the feed or drinking water at a soybean saponin content of 0.01% of the weight of chicken feed or drinking water.

[0029] (4) When used for the clinical treatment of chicken enteritis: administer the drug orally to chickens at a dose of 50 mg / kg chicken body weight of soy saponins; or crush the granules, powders or tablets and feed them directly at a dose of 50 mg / kg chicken body weight of soy saponins; or crush the granules, powders or tablets and add them to the feed at a soy saponin content of 0.03% of the chicken feed weight; or crush the granules, powders or tablets and use them at a soy saponin content of 0.03% of the drinking water weight, adding them three times a day in the morning, noon and evening for one week.

[0030] The technical solution of this application and the technical effects achieved will be described in detail below through more specific embodiments.

[0031] Example 1

[0032] This embodiment provides a method for preparing a soybean saponin oral liquid, including the following steps:

[0033] (1) Weigh out 10g of soybean saponins and 30mL of anhydrous ethanol;

[0034] (2) First, dissolve soybean saponins in anhydrous ethanol, mix well, and then slowly add water for injection to make up to 100 mL, to obtain a soybean saponin oral solution with a concentration of 100 mg / mL, namely the soybean saponin oral solution D1.

[0035] Example 2

[0036] This embodiment provides a method for preparing soybean saponin powder, including the following steps:

[0037] (1) Weigh out 50g of soybean saponins, 20g of wheat bran, and 30g of soluble starch;

[0038] (2) Mix soybean saponins, wheat bran and soluble starch evenly, and pass through a 60-mesh sieve to obtain a powder with a soybean saponin mass fraction of 50%, namely soybean saponin powder D2.

[0039] Example 3

[0040] This embodiment provides a method for preparing soybean saponin tablets, including the following steps:

[0041] (1) Weigh out 50g of soybean saponins, 20g of lactose and 30g of soluble starch, and set aside;

[0042] (2) Mix soybean saponins, lactose and soluble starch evenly, compress and dry them with a tablet press to obtain tablets with a soybean saponin mass fraction of 50%, namely soybean saponin tablets D3.

[0043] Example 4

[0044] This embodiment provides a method for preparing soybean saponin granules, including the following steps:

[0045] (1) Weigh out 50g of soybean saponins, 20g of maltose and 30g of soluble starch, and set aside;

[0046] (2) Mix soybean saponins, maltose and soluble starch, granulate, dry and granulate to obtain granules with a soybean saponin mass fraction of 50%, namely soybean saponin granules D4.

[0047] The formulations and parameters of the various soybean saponin preparations prepared in the above embodiments are shown in Table 1 below:

[0048] Table 1

[0049] Example number Composition Number Components Soy saponin concentration Formulation type Example 1 D1 Soy saponins, anhydrous ethanol, water for injection 100mg / mL oral liquid Example 2 D2 Soy saponins, wheat bran, soluble starch 50% (mass fraction) powder Example 3 D3 Soy saponins, lactose, soluble starch 50% (mass fraction) tablet Example 4 D4 Soy saponins, maltose, soluble starch 50% (mass fraction) Granules

[0050] The aforementioned soy saponin preparations can be used as drugs or feed additives to prevent or treat necrotic enteritis in chickens. When used for routine disease prevention, the soy saponin preparations can be added to the feed at a dosage of 5 mg / kg of chicken body weight, and used throughout the feeding cycle. When used for clinical treatment of chicken diseases, the soy saponin preparations can be administered orally at a dosage of 50 mg / kg of chicken body weight; or the soy saponins can be dissolved in water and administered orally at a dosage of 50 mg / kg of chicken body weight, or mixed with the daily diet and added to the feed, three times a day (morning, noon, and evening) for one week. The dosage of the soy saponin preparations can also be adjusted according to the severity of the chicken disease, with the dosage range controlled between 5 and 50 mg / kg of chicken body weight.

[0051] Effects of soybean saponins on growth performance and gut health in broilers infected with Clostridium perfringens

[0052] This application's embodiments verified the effects of soybean saponins on the growth performance and intestinal health of broilers infected with Clostridium perfringens. The verification method is as follows:

[0053] 1. Materials and Methods

[0054] The experiment used 240 one-day-old healthy AA birds with uniform weight. + Broiler chicks were randomly divided into three treatment groups, each with eight replicates, and each replicate consisting of 10 chicks. The three treatment groups were: a control group, a CP infection group, and a soybean saponin + CP infection group. The control and CP infection groups were fed a corn-soybean meal basal diet formulated according to the Chinese broiler nutritional requirements standard (NY / T33-2004). The soybean saponin + CP infection group received a diet supplemented with 0.01% soybean saponin (purchased from Sigma, purity >90%) by weight of feed added to their basal diet. On day 7 of the experiment, all broilers were vaccinated against Newcastle disease (via eye drops or nasal drops). From day 14 to day 21 of the experiment, the CP infection group and the soybean saponin + CP infection group were administered 1 mL of CP (CVCC2030 strain, dose 1.0 × 10⁻⁶) daily by gavage. 9The control group was fed an equal volume of CP medium (CFU / mL). During the experiment, the broilers had free access to feed and water and were under a 24-hour light regime. On day 22, all broilers were fasted for 8 hours, then weighed and their feed consumption was recorded. Growth performance indicators such as average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR) were calculated. Subsequently, one broiler of uniform weight was selected from each replicate group to collect blood from the subwing vein and separate the serum for testing. The broilers were then anesthetized by injecting sodium pentobarbital (50 mg / kg live body weight) into the subwing vein, slaughtered, and ileal samples were obtained for further analysis.

[0055] 2. Data Analysis

[0056] The experimental data were analyzed by one-way ANOVA in SPSS 23.0 statistical software. Duncan's method was used to perform multiple comparisons between groups. P < 0.05 was used as the significance criterion, and P < 0.01 was used as the extremely significant criterion. The results are expressed as mean ± standard deviation.

[0057] 3. Test Results

[0058] 3.1 Effects of soybean saponins on growth performance of broilers infected with Clostridium perfringens

[0059] Table 2 shows the effect of soybean saponins on the growth performance of broilers infected with Clostridium perfringens. In the table, a, b, and c are indicators of significant differences. Different letters on the data indicate significant differences (P < 0.05).

[0060] Table 2

[0061] Testing items control group CP infection group Soy saponins + CP infection group P-value Average weight (g) on ​​the 21st <![CDATA[724.96±31.02 a ]]> <![CDATA[605.31±12.98 c ]]> <![CDATA[647.22±29.88 b ]]> <0.001 ADFI(g) <![CDATA[51.12±1.12 a ]]> <![CDATA[47.11±2.12 b ]]> <![CDATA[48.03±2.08 b ]]> 0.011 ADG(g) <![CDATA[36.12±1.98 a ]]> <![CDATA[30.25±1.23 c ]]> <![CDATA[32.35±0.91 b ]]> <0.001 FCR <![CDATA[1.43±0.03 c ]]> <![CDATA[1.58±0.06 a ]]> <![CDATA[1.48±0.04 b ]]> 0.021

[0062] Table 2 shows that Clostridium perfringens infection significantly reduced 21-day broiler body weight, average daily feed intake, and average daily weight gain, while increasing the feed conversion ratio. Adding soybean saponins to the diet can alleviate the reduction in broiler body weight and average daily weight gain, and the increase in feed conversion ratio caused by Clostridium perfringens infection, thereby mitigating the negative impact of Clostridium perfringens infection on broiler growth performance.

[0063] 3.2 Effects of soybean saponins on Newcastle disease vaccine antibodies, diamine oxidase, and D-xylose levels in the blood of broilers infected with Clostridium perfringens

[0064] Table 3 shows the effects of soybean saponins on the levels of Newcastle disease vaccine antibodies, diamine oxidase (DAO), and D-xylose in the blood of broilers infected with Clostridium perfringens. In the table, a and b are indicators of significant differences, and different letters on the data indicate significant differences (P < 0.05).

[0065] Table 3

[0066]

[0067] Table 3 shows that *Clostridium perfringens* infection significantly downregulated the levels of Newcastle disease vaccine antibodies and D-xylose in broiler serum, while increasing the activity of diamine oxidase (DAO). D-xylose can be absorbed by the intestines but cannot be utilized by the body; therefore, evaluating blood D-xylose levels can assess intestinal absorption function. In healthy individuals, DAO exists in the intestines; when the intestines are damaged, it is released into the bloodstream. Therefore, higher serum DAO activity indicates more significant intestinal damage. Table 3 results indicate that *Clostridium perfringens* infection causes intestinal damage, reduced absorption function, and weakened humoral immunity in broilers. Adding soybean saponins to the diet can alleviate the decrease in serum D-xylose and Newcastle disease vaccine antibody levels caused by *Clostridium perfringens* infection, indicating that soybean saponins can enhance humoral immunity and intestinal absorption function in broilers infected with *Clostridium perfringens*.

[0068] 3.3 Effects of soybean saponins on the mRNA levels of inflammatory cytokines in the ileum of broilers

[0069] Table 4 shows the effects of soybean saponins on the mRNA levels of inflammatory cytokines in the ileum of broilers. In this table, TNF-α represents tumor necrosis factor-α; IFN-γ represents interferon-γ; IL-18 represents interleukin-18; IL-1β represents interleukin-1β; ZO-1 represents occludin-1; Claudin-1 represents tight junction protein 1; and occludin represents occludin. a, b, and c are statistical markers, and different letters in the superscript indicate statistically significant differences (P < 0.05).

[0070] Table 4

[0071] project control group CP infection group Soy saponins + CP infection group P-value TNF-α <![CDATA[1.00±0.12 b ]]> <![CDATA[2.42±0.25 a ]]> <![CDATA[1.12±0.25 b ]]> 0.003 IFN-γ <![CDATA[1.00±0.28 b ]]> <![CDATA[2.50±0.52 a ]]> <![CDATA[1.35±0.33 b ]]> <0.001 IL-18 <![CDATA[1.00±0.24 b ]]> <![CDATA[1.82±0.19 a ]]> <![CDATA[1.61±0.21 a ]]> 0.134 IL-1β <![CDATA[1.00±0.27 c ]]> <![CDATA[3.12±0.30 a ]]> <![CDATA[1.86±0.36 b ]]> <0.001 ZO-1 1.00±0.30 1.09±0.34 0.94±0.24 0.316 occludin <![CDATA[1.00±0.26 a ]]> <![CDATA[0.41±0.20 c ]]> <![CDATA[0.79±0.16 b ]]> 0.043 claudin1 <![CDATA[1.00±0.24 a ]]> <![CDATA[0.68±0.19 b ]]> <![CDATA[0.86±0.18 ab ]]> 0.014

[0072] Table 4 shows that *Clostridium perfringens* infection upregulates the transcriptional levels of pro-inflammatory cytokines such as TNF-α, IFN-γ, IL-18, and IL-1β in the ileum, and downregulates the transcriptional levels of intestinal barrier-related genes such as occludin and claudin1. This indicates that *Clostridium perfringens* infection causes intestinal inflammation in broilers and induces impaired intestinal barrier function. Adding soybean saponins to the diet can alleviate the upregulation of TNF-α, IFN-γ, IL-18, and IL-1β mRNA levels and the downregulation of occludin and claudin1 transcriptional levels caused by *Clostridium perfringens* infection. These results suggest that soybean saponins can alleviate the intestinal inflammatory response and barrier function impairment in broilers caused by *Clostridium perfringens* infection.

[0073] Effects of soybean saponins on growth performance and gut health in broilers co-infected with coccidia and Clostridium perfringens

[0074] This application's embodiments verified the effects of soybean saponins on the growth performance and intestinal health of broiler chickens co-infected with coccidia and Clostridium perfringens. The verification method is as follows:

[0075] 1. Materials and Methods

[0076] A 2×2 factorial design was used in the experiment, which included 480 one-day-old healthy AA birds with uniform body weight. + Broiler chicks were divided into four treatment groups, each of which was further divided into eight replicates, with each replicate consisting of 15 chicks. The four treatment groups were: control group, coccidia and Clostridium perfringens co-infection group (CCP), soybean saponin group, and soybean saponin + CCP group. Broilers in the control and CCP groups were fed a corn-soybean meal basal diet formulated according to the Chinese broiler nutritional requirements standard (NY / T33-2004). Broilers in the soybean saponin and soybean saponin + CCP groups had 0.01% soybean saponin (purchased from Sigma, purity >90%) added to their basal diet. On days 8 and 10 of the experiment, broilers in the CCP and soybean saponin + CCP groups were vaccinated with an ultra-high dose of coccidia vaccine (purchased from Foshan Zhengdian Company, dose 30 times the recommended dose) to establish an intestinal coccidia infection state. From days 14 to 21 of the experiment, broilers in the CCP and soybean saponin + CCP groups were gavaged with 1 mL of the vaccine daily. CP (CVCC2030 strain, dosage 1.0 × 10⁻⁶) 9 Broilers in the control and soybean saponin groups were fed the same volume of CP medium (CFU / mL). During the experiment, broilers had free access to feed and water and were under a 24-hour light regime. On day 22, all broilers were fasted for 8 hours, then weighed and their feed consumption was recorded. Growth performance indicators such as average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR) were calculated. Subsequently, one broiler of uniform weight was selected from each replicate group to collect blood from the subwing vein and separate the serum for testing. The broilers were then anesthetized by injecting sodium pentobarbital (50 mg / kg live body weight) into the subwing vein, slaughtered, and dissected to obtain ileal tissue for sectioning and observation. Ileal samples were then collected for further analysis.

[0077] 2. Data Analysis

[0078] Experimental data were analyzed using SPSS 23.0 statistical software in a two-way ANOVA. The main effects of the model included soybean saponins, co-infection with coccidia and Clostridium perfringens, and their interaction. When an interaction was found, Duncan's method was used for multiple comparisons between groups. P < 0.05 was considered statistically significant, and P < 0.01 was considered highly significant. Results are expressed as mean ± standard error.

[0079] 3. Test Results

[0080] 3.1 Effects of soybean saponins on growth performance of broilers co-infected with coccidia and Clostridium perfringens

[0081] Table 5 shows the effects of soybean saponins on the growth performance of broilers co-infected with coccidia and Clostridium perfringens. In the table, a, b, and c are indicators of statistical significance. Different letters under the data indicate statistical significance (P < 0.05). -CCP indicates no co-infection with coccidia and Clostridium perfringens, +CCP indicates co-infection with coccidia and Clostridium perfringens, -SS indicates no soybean saponins added to the diet, and +SS indicates soybean saponins added to the diet. SEM represents the standard error.

[0082] Table 5

[0083]

[0084] Table 5 shows that co-infection with coccidia and Clostridium perfringens reduces the 21-day-old body weight, average daily weight gain, and average daily feed intake of broilers, while increasing the feed conversion ratio. Adding soybean saponins to the diet can alleviate the decrease in average daily weight gain and increase in feed conversion ratio of broilers caused by co-infection with coccidia and Clostridium perfringens.

[0085] 3.2 Effects of soybean saponins on the morphology and structure of the ileum in broiler chickens co-infected with coccidia and Clostridium perfringens

[0086] Table 6 shows the effects of soybean saponins on the morphology of the ileum in broilers co-infected with coccidia and Clostridium perfringens. In the table, a, b, and c are significance markers, and different letters on the data indicate significant differences (P < 0.05). -CCP indicates no co-infection with coccidia and Clostridium perfringens, +CCP indicates co-infection with coccidia and Clostridium perfringens, -SS indicates no soybean saponins added to the diet, and +SS indicates soybean saponins added to the diet. SEM represents the standard error.

[0087] Table 6

[0088]

[0089]

[0090] Table 6 shows that co-infection with coccidia and Clostridium perfringens lowers the ratio of ileal villus height to crypt depth in broilers. Higher villus height results in a larger contact area with nutrients in the intestinal lumen, leading to better absorption efficiency. Therefore, higher villus height and a higher villus height-to-crypt depth ratio indicate better intestinal absorption. The results in the table show that dietary supplementation with soybean saponins can alleviate the decrease in the ileal villus height-to-crypt depth ratio caused by co-infection with coccidia and Clostridium perfringens in broilers, indicating that soybean saponins can mitigate the negative impact of co-infection with coccidia and Clostridium perfringens on the intestinal absorption function of broilers.

[0091] 3.3 Effects of soybean saponins on sIgA content in the ileal mucosa of broiler chickens co-infected with coccidia and Clostridium perfringens

[0092] Table 7 shows the effect of soybean saponins on the sIgA content in the ileal mucosa of broilers co-infected with coccidia and Clostridium perfringens. In the table, a and b are statistical markers, and different letters under the data indicate statistical significance (P < 0.05). -CCP indicates no co-infection with coccidia and Clostridium perfringens, +CCP indicates co-infection with coccidia and Clostridium perfringens, -SS indicates no soybean saponins added to the diet, and +SS indicates soybean saponins added to the diet. SEM represents the standard error, and sIgA represents secretory immunoglobulin A, which was determined using the Shanghai Yuanmu Chicken sIgA ELISA kit, with total protein as the denominator after calibration.

[0093] Table 7

[0094]

[0095] As shown in Table 7, the addition of soybean saponins to the diet can alleviate the downregulation of sIgA content in the ileal mucosa of broilers caused by coccidia and Clostridium perfringens co-infection. The secretion of sIgA in the ileum can resist the infection of the intestine by pathogens, thereby enhancing the immune function of the intestine. The results in Table 7 show that soybean saponins can enhance the immune function of the intestine of broilers co-infected with coccidia and Clostridium perfringens.

[0096] 3.4 Effects of soybean saponins on gene expression in the ileum of broiler chickens co-infected with coccidia and Clostridium perfringens

[0097] Table 8 shows the effects of soybean saponins on gene expression in the ileum of broilers co-infected with Coccidia and Clostridium perfringens. In the table, a, b, c, and d are statistically significant markers; different letters above the data indicate statistically significant differences (P < 0.05). -CCP indicates no co-infection with Coccidia and Clostridium perfringens; +CCP indicates co-infection with Coccidia and Clostridium perfringens; -SS indicates no soybean saponins added to the diet; +SS indicates soybean saponins added to the diet; SEM indicates standard error; TNF-α indicates tumor necrosis factor-α; IFN-γ indicates interferon-γ; IL-18 indicates interleukin-18; IL-8 indicates interleukin-8; IL-1β indicates interleukin-1β; ZO-1 indicates occludin-1; Claudin-1 indicates tight junction protein 1; occludin indicates occludin.

[0098] Table 8

[0099]

[0100]

[0101] Table 8 shows that co-infection with coccidia and Clostridium perfringens downregulates the transcriptional levels of ileal barrier-related genes in broilers, such as Occludin and ZO-1, and upregulates the transcriptional levels of pro-inflammatory cytokines, such as TNF-α, IFN-γ, IL-8, and IL-1β. Adding soybean saponins to the diet can alleviate the downregulation of Occludin and ZO-1 transcriptional levels and the upregulation of TNF-α, IFN-γ, IL-8, and IL-1β transcriptional levels in the ileum caused by co-infection with coccidia and Clostridium perfringens, indicating that soybean saponins can alleviate the impaired intestinal barrier function and inflammatory response in broilers caused by co-infection with coccidia and Clostridium perfringens.

[0102] In summary, soybean saponins can be used to prepare drugs or feed additives for the treatment or prevention of necrotic enteritis in chickens. The prepared drugs or feed additives possess resistance to various pathogens that cause necrotic enteritis in chickens, including Clostridium perfringens. The dosage forms of these drugs and feed additives include oral liquids, granules, powders, and tablets.

[0103] The present application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present application. The descriptions of the embodiments above are only for the purpose of helping to understand the present application and its core ideas. It should be noted that those skilled in the art can make several improvements and modifications to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. Application of soybean saponins in the preparation of drugs or feed additives for the treatment or prevention of necrotizing enteritis in chickens.

2. The application according to claim 1, characterized in that, The aforementioned necrotizing enteritis in chickens is caused by Clostridium perfringens infection alone or in combination with coccidia.

3. The application according to claim 1, characterized in that, The drug or feed additive is a soybean saponin composition including soybean saponins and excipients, wherein the excipients include at least one of anhydrous ethanol, propylene glycol, dimethyl sulfoxide, edible oil, water, lactose, maltose, mannitol, soluble starch, montmorillonite, maifanite, zeolite powder, defatted rice bran, corn cob powder, wheat bran, and silica.

4. The application according to claim 3, characterized in that, The soybean saponin composition is a solution formed by mixing soybean saponins with anhydrous ethanol and water, wherein the concentration of soybean saponins is 10~120 mg / mL.

5. The application according to claim 3, characterized in that, The soy saponin composition is a powdered mixture of soy saponins, wheat bran, and soluble starch, wherein the mass fraction of soy saponins in the powdered mixture is 40% to 60%.

6. The application according to claim 3, characterized in that, The soy saponin composition is a sheet-like mixture of soy saponins, lactose or maltose, and soluble starch, wherein the mass fraction of soy saponins in the sheet-like mixture is 40% to 60%.

7. The application according to claim 3, characterized in that, The soy saponin composition is a granular mixture of soy saponins, lactose or maltose, and soluble starch, wherein the mass fraction of soy saponins in the granular mixture is 40% to 60%.

8. The application according to claim 3, characterized in that, When the drug or feed additive is a soybean saponin composition, its formulation type includes at least one of oral liquid, granules, tablets, and powders, and the formulation is prepared using conventional pharmaceutical formulation methods.

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