Application of soyasaponin in preparation of medicine or feed additive for treating or preventing chicken necrotic enteritis

Abstract

The invention discloses an application of soyasaponin in preparation of a medicine or a feed additive for treating or preventing necrotic enteritis of chicken, the medicine or the additive is an oral liquid, a tablet, a granule or a powder prepared by taking the soyasaponin as an effective component and adding a solvent or an auxiliary material, and the use dosage is 5-50mg / kg body weight; or the soyasaponin is directly added into the feed, and the addition amount of the soyasaponin is 0.01-0.03% of the total weight of the chicken feed. The application finds that the soyasaponin serving as a medicine or a feed additive is high in safety and free of toxic and side effects, the antibody level of the newcastle disease vaccine can be effectively improved, and reduction of chicken production performance, increase of proinflammatory cytokines and damage of intestinal absorption and barrier functions caused by necrotic enteritis infection can be relieved.

Description

Technical Field

[0001] The present application relates to the technical field of prevention and treatment of chicken enteritis, and specifically to the application of soybean saponin in the preparation of medicines or feed additives for treating or preventing chicken necrotic enteritis. Background Art

[0002] my country is a major producer and consumer of chicken. Ensuring the healthy and efficient breeding of broilers to improve chicken production and quality is related to the national economy and people's livelihood. However, necrotic enteritis (NE) caused by Clostridium perfringens (CP) infection has seriously restricted the healthy and efficient breeding of broilers. In addition, since the ban on antibiotics in feed, pathogens in the gastrointestinal tract of broilers have taken the opportunity to proliferate in large numbers, which is bound to destroy their intestinal immune barrier and aggravate the negative impact of NE on broilers. It can be seen that NE is a key issue that needs to be urgently addressed in the healthy and efficient breeding of broilers in the post-antibiotic era.

[0003] NE is one of the main gastrointestinal diseases that endanger the healthy breeding of broiler chickens worldwide. It is mainly caused by infection with type A and type G CP. In the broiler production process, some abnormal environmental factors (such as heat stress), pathogens (such as coccidia) infection, and diet types (such as wheat-based diets) provide conditions for CP infection. NE mainly occurs in the small intestine, mainly in the ileum, which causes damage to the physical and immune barrier function of the broiler intestine, imbalance in the intestinal flora structure, and then causes intestinal inflammatory damage. Previously, the use of antibiotics was the main measure to prevent and control NE in broilers. However, due to the prohibition of antibiotics in feed, the prevention and control of NE through nutritional measures has gradually become one of the key topics of concern in broiler farming. Summary of the invention

[0004] In view of this, the purpose of the present application is to provide the application of soybean saponin in the preparation of a drug or feed additive for treating or preventing necrotic enteritis in chickens. In this application, soybean saponin and a composition with soybean saponin as the main component can effectively inhibit the pathogenic bacteria of chicken enteritis. The soybean saponin and the composition with soybean saponin as the main component have the advantages of high safety, stable efficacy, no toxic side effects, etc., 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 saponin in preparing medicine or feed additive for treating or preventing necrotic enteritis in chickens.

[0007] Compared with the prior art, the technical solution provided by this application has at least the following beneficial effects:

[0008] 1. The soybean saponin provided in the present application is derived from natural leguminous plants, has high safety, no toxic side effects, and can be used as a feed additive for a long time to prevent necrotic enteritis in chickens. Long-term use will not lead to the production of drug-resistant strains, which is an advantage that other anti-disease drugs do not have;

[0009] 2. The in vivo test results of the present application show that the soybean saponins and compositions comprising soybean saponins provided in the present application can enhance the immune effect of Newcastle disease vaccines, inhibit the expression of pro-inflammatory cytokines, promote the intestinal health of broilers, and thereby improve the feed conversion efficiency of broilers with necrotic enteritis. DETAILED DESCRIPTION

[0010] In order to make the purpose, technical solution and advantages of the present application more clear, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described here are only used to explain the present application and are not used to limit the present application.

[0011] Those skilled in the art will appreciate that, unless otherwise stated, the words "said", "the", and "the aforementioned" used in the text of the present application may also include plural forms. It should be further understood that the wording "including" used in the specification of the present application means the presence of the features, steps, and operations, but does not exclude the presence or addition of one or more other features, integers, and steps.

[0012] Those skilled in the art will appreciate that, for any specific experimental steps or conditions not specified in the examples, the experiments may be carried out according to the conventional experimental steps or conditions described in the literature in the art; any raw materials or instruments used without specifying the manufacturer are conventional products that can be purchased commercially.

[0013] Those skilled in the art will understand that, unless otherwise specified in the present application, when a numerical range is given in an embodiment, 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 are consistent with the prior art mastery of those skilled in the art and the records of this application, and any methods, equipment and materials of the prior art similar or equivalent to the methods, equipment and materials described in the embodiments of this application may also be used to implement this application.

[0014] Soya saponin (SS) is a pentacyclic triterpenoid substance naturally present in soybeans. Due to its good immunomodulatory effect, it has been widely studied in the medical field in recent years. SS is composed of soybean saponins and some glycosides, uronic acid, etc. Due to the differences in glycosides, SS is divided into four types: A, B, E, and DDMP. Studies have found that SS is difficult to be absorbed by intestinal epithelial cells and is generally degraded by intestinal microorganisms into soybean saponin or other small molecules before being absorbed and utilized. The structure of group B soybean saponin is simpler than that of group A and is generally easier to absorb. In addition, the more complex the structure of SS, the more obvious its immunomodulatory effect. Existing studies have shown that SS has antioxidant, lipid metabolism improvement, anti-tumor, antiviral, and immune regulation effects, and these biological effects are almost all related to SS immune regulation. Although soybean saponin has been proven to have a variety of biological effects, its application in the prevention and control of broiler enteritis has rarely been reported.

[0015] The results of in vivo tests in the examples of the present application show that soybean saponins can enhance the immune effect of Newcastle disease vaccine, inhibit the expression of pro-inflammatory cytokines, promote the intestinal health of broiler chickens, and thus improve the feed conversion efficiency of broiler chickens with necrotic enteritis. The above results provide basic data for the development of soybean saponins in poultry health drugs and feed additives.

[0016] Based on this, the embodiments of the present application provide the use of soybean saponins in the preparation of drugs or feed additives for treating or preventing necrotic enteritis in chickens.

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

[0018] In certain embodiments, the drug or feed additive is soybean saponin, that is, soybean saponin can be directly used as a drug or feed additive for treating or preventing necrotic enteritis in chickens.

[0019] In certain embodiments, the drug or feed additive is a soybean saponin composition comprising soybean saponin 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, medical stone, zeolite powder, defatted rice bran, corn cob powder, bran, and white carbon black. Among them, at least one of anhydrous ethanol, propylene glycol, dimethyl sulfoxide, edible oil, and water can be used as a solvent to dissolve soybean saponin to prepare a soybean saponin oral liquid preparation; at least one of lactose, maltose, mannitol, soluble starch, montmorillonite, medical stone, zeolite powder, defatted rice bran, corn cob powder, bran, and white carbon black can be mixed with soybean saponin to form a solid mixture, which is further prepared into soybean saponin granules, tablets, powders and other preparations.

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

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

[0022] In certain preferred embodiments, the soybean saponin composition is a flake mixture of soybean saponin, lactose or maltose, and soluble starch, wherein the mass fraction of soybean saponin in the flake mixture is 40% to 60%.

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

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

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

[0026] (1) Orally administering soybean saponin to chickens at a dosage of 5 to 50 mg / kg of chicken body weight;

[0027] (2) adding soybean saponin granules, powder or tablets to chicken feed as a feed additive according to the soybean saponin content of 0.01% to 0.03% by 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 so that the content of soybean saponin is 0.01% of the weight of the chicken feed or drinking water;

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

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

[0031] Example 1

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

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

[0034] (2) First, dissolve soybean saponin in anhydrous ethanol and mix well, 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, i.e., the soybean saponin oral solution D1.

[0035] Example 2

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

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

[0038] (2) Soybean saponin, wheat bran and soluble starch are mixed evenly and passed through a 60-mesh sieve to obtain a powder with a mass fraction of soybean saponin of 50%, i.e., soybean saponin powder D2.

[0039] Example 3

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

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

[0042] (2) Soy saponin, lactose and soluble starch are mixed evenly, compressed and dried using a tablet press to obtain tablets with a mass fraction of 50% of soy saponin, i.e., soy saponin tablets D3.

[0043] Example 4

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

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

[0046] (2) Soybean saponin, maltose and soluble starch are mixed and granulated, and then dried and granulated to obtain granules with a mass fraction of soybean saponin of 50%, i.e., soybean saponin granules D4.

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

[0048] Table 1

[0049] Example No. Composition No. Components Soysaponin concentration Formulation type Example 1 D1 Soybean saponin, anhydrous ethanol, water for injection 100mg / mL Oral solution Example 2 D2 Soybean saponin, wheat bran, soluble starch 50% (mass fraction) powder Example 3 D3 Soybean saponin, lactose, soluble starch 50% (mass fraction) tablet Example 4 D4 Soybean saponin, maltose, soluble starch 50% (mass fraction) Granules

[0050] The soybean saponin preparation can be used as a medicine or feed additive to prevent or treat necrotic enteritis in chickens. When used for the prevention of chicken diseases, the soybean saponin preparation can be added to the feed at a dosage of 5 mg / kg of chicken body weight and used throughout the entire breeding cycle; when used for clinical treatment of chicken diseases, the soybean saponin preparation can be orally administered at a dosage of 50 mg / kg of chicken body weight; or the soybean saponin can be dissolved in water and administered or mixed with the daily diet at a dosage of 50 mg / kg of chicken body weight, and added to the feed three times a day in the morning, noon and evening for one week; the dosage of the soybean saponin preparation can also be adjusted according to the severity of the chicken disease, and the dosage range is controlled within a soybean saponin content of 5 to 50 mg / kg of chicken body weight.

[0051] Effects of soybean saponins on growth performance and intestinal health of broiler chickens infected with Clostridium perfringens

[0052] The present application example verifies the effect of soybean saponin on the growth performance and intestinal health of broilers infected with Clostridium perfringens, and the verification method is as follows:

[0053] 1. Materials and Methods

[0054] The experiment involved 240 healthy AA + Broiler chickens were divided into three treatment groups, each of which was divided into eight replicate groups, each of which included 10 chickens. The three treatment groups were control group, CP infection group, and soybean saponin + CP infection group. The broilers in the control group and CP infection group were fed a "corn-soybean meal" basal diet, and the diet formula was formulated in accordance with the nutritional requirements standard of Chinese broilers (NY / T33-2004). The broiler diet of the soybean saponin + CP infection group was supplemented with 0.01% soybean saponin (purchased from Sigma, purity > 90%) of feed weight in the basal diet. On the 7th day of the experiment, all broilers were immunized with Newcastle disease vaccine (immunization was performed by eye drops and nasal drops), and on the 14th to 21st days of the experiment, 1 mL CP (CVCC2030 strain, dose of 1.0 × 10 9CFU / mL), and the control group broilers were gavage-fed with an equal volume of CP medium; during the experiment, broilers were allowed to eat and drink freely, and a 24-h lighting system was adopted; on the 22nd day of the experiment, all broilers were fasted for 8 h, then weighed and feed consumption was counted, and growth performance-related indicators such as average daily gain (ADG), average daily feed intake (ADFI), and feed-to-weight ratio (FCR) were calculated; thereafter, one broiler with uniform weight was selected from each replicate group to collect subwing venous blood and separate serum for testing; further, sodium pentobarbital (at a dose of 50 mg / kg live weight) was injected into the subwing vein for anesthesia, and the broilers were slaughtered, and ileum samples were taken for subsequent analysis after dissection.

[0055] 2. Data Analysis

[0056] The experimental data were analyzed by one-way ANOVA in SPSS23.0 statistical software, and Duncan's method was used for multiple comparisons between groups. P < 0.05 was regarded as the standard of significant difference, and P < 0.01 was regarded as the standard of extremely significant difference. The results were 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 effects of soybean saponins on the growth performance of broilers infected with Clostridium perfringens, where a, b, and c are significant differences. Data with different letters on the shoulders in the table indicate significant differences (P<0.05).

[0060] Table 2

[0061] Test items Control group CP infection group Soybean saponin + CP infection group P-value Average body weight on 21 days (g) <![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] As shown in Table 2, Clostridium perfringens infection significantly reduced the body weight, average daily feed intake, and average daily weight gain of 21-day broilers, and improved the feed-to-weight ratio. Adding soybean saponins to the diet can alleviate the reduction in broiler body weight and average daily weight gain caused by Clostridium perfringens infection, and improve the feed-to-weight ratio, thereby improving the negative impact of Clostridium perfringens infection on the growth performance of broilers.

[0063] 3.2 Effects of soybean saponins on Newcastle disease vaccine antibody, 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 Newcastle disease vaccine antibodies, diamine oxidase (DAO) and D-xylose levels in the blood of broilers infected with Clostridium perfringens, where a and b are significant difference markers. Data in the table with different letters on their shoulders indicate significant differences P<0.05.

[0065] Table 3

[0066]

[0067] As shown in Table 3, infection with Clostridium perfringens significantly reduced the antibody level of Newcastle disease vaccine in broiler serum and the content of D-xylose in serum, and increased the activity of diamine oxidase (DAO) in serum. D-xylose can be absorbed by the intestine but cannot be used by the body. Therefore, by evaluating the content of D-xylose in the blood, the intestinal absorption function can be evaluated; DAO exists in the intestine in a healthy state, and when the intestine is damaged, it is released into the blood. Therefore, the higher the activity of DAO in serum, the more obvious the degree of intestinal damage. The results in Table 3 show that infection with Clostridium perfringens 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 content and Newcastle disease vaccine antibody levels caused by Clostridium perfringens infection, indicating that soybean saponins can enhance the humoral immunity and intestinal absorption function of broilers infected with Clostridium perfringens.

[0068] 3.3 Effect of soybean saponins on mRNA levels of inflammatory cytokines in ileum of broiler chickens

[0069] Table 4 shows the effects of soybean saponins on the mRNA levels of inflammatory cytokines in the ileum of broiler chickens, where 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 occludens-1; Claudin-1 represents tight junction protein 1; occludin represents claudin, a, b, and c are marks of significant difference, and data with different letters on shoulders in the table indicate significant differences P<0.05.

[0070] Table 4

[0071] project Control group CP infection group Soybean saponin + 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] As shown in Table 4, Clostridium perfringens infection up-regulated the transcriptional levels of pro-inflammatory cytokines in the ileum, such as TNF-α, IFN-γ, IL-18, and IL-1β, and down-regulated the transcriptional levels of intestinal barrier-related genes, such as occludin and claudin1, indicating that Clostridium perfringens infection caused intestinal inflammation in broilers and induced intestinal barrier function damage. Adding soybean saponins to the diet can alleviate the upregulation of TNF-α, IFN-γ, IL-18, and IL-1β mRNA levels caused by Clostridium perfringens infection; the downregulation of occludin and claudin1 transcriptional levels. The above results show that soybean saponins can alleviate the intestinal inflammatory response and barrier function damage of broilers caused by Clostridium perfringens infection.

[0073] Effects of soybean saponins on growth performance and intestinal health of broiler chickens infected with coccidia and Clostridium perfringens

[0074] The present application example verifies the effect of soybean saponins on the growth performance and intestinal health of broilers infected with coccidia and Clostridium perfringens, and the verification method is as follows:

[0075] 1. Materials and Methods

[0076] A 2×2 factorial design was used to test 480 healthy AA + The broiler male chicks were equally divided into 4 treatment groups, each treatment group was divided into 8 replicate groups, and each replicate group included 15 chickens. The four treatment groups were: control group, coccidia and Clostridium perfringens combined infection group (CCP), soybean saponin group, and soybean saponin + CCP group; broilers in the control group and CCP group were fed a "corn-soybean meal" type basal diet, and the diet formula was formulated with reference to the nutritional requirements standard of Chinese broilers (NY / T33-2004); broilers in the soybean saponin group and soybean saponin + CCP group were fed with 0.01% soybean saponin (purchased from Sigma, purity > 90%) of feed weight in the basal diet; on the 8th and 10th days of the experiment, broilers in the CCP group and soybean saponin + CCP group were vaccinated with an ultra-high dose of coccidia vaccine (purchased from Foshan Zhengdian Company, the dose was 30 times the recommended dose) to establish an intestinal coccidiosis infection state, and on the 14th to 21st days of the experiment, broilers in the CCP group and soybean saponin + CCP group were gavaged with 1 mL of CP (CVCC2030 strain, dose 1.0×10 9 CFU / mL), and the control group and soybean saponin group broilers were gavage-fed with an equal volume of CP medium; during the experiment, broilers were free to eat and drink, and a 24-h lighting system was adopted; on the 22nd day of the experiment, all broilers were fasted for 8 h, and then weighed and the feed consumption was counted, and growth performance-related indicators such as average daily gain (ADG), average daily feed intake (ADFI), and feed-to-weight ratio (FCR) were calculated; thereafter, one broiler with uniform weight was selected from each replicate group to collect subwing venous blood and separate serum for testing; further, sodium pentobarbital (at a dose of 50 mg / kg live weight) was injected into the subwing vein for anesthesia, and the broilers were slaughtered, and the ileum tissue was dissected to make slices for observation, and ileum samples were taken for subsequent analysis.

[0077] 2. Data Analysis

[0078] The experimental data were analyzed by two-way ANOVA using SPSS23.0 statistical software. The main effects of the model included soybean saponins, coccidia and Clostridium perfringens infection, and the interaction between the two. When there was an interaction between the two, Duncan's method was used for multiple comparisons between groups, with P<0.05 as the standard of significant difference and P<0.01 as the standard of extremely significant difference. The results were expressed as mean ± standard error.

[0079] 3. Test results

[0080] 3.1 Effects of soybean saponins on growth performance of broilers 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, where a, b, and c are significant difference markers, and data with different letters on the shoulders in the table indicate significant differences P<0.05; -CCP means no co-infection with coccidia and Clostridium perfringens, +CCP means co-infection with coccidia and Clostridium perfringens, -SS means no soybean saponins were added to the diet, and +SS means soybean saponins were added to the diet; SEM means standard error.

[0082] Table 5

[0083]

[0084] As shown in Table 5, the combined infection of coccidia and Clostridium perfringens reduced the body weight, average daily weight gain, and average daily feed intake of broilers at 21 days of age, and improved the feed-to-weight ratio; adding soybean saponins to the diet can alleviate the decrease in average daily weight gain and the increase in feed-to-weight ratio of broilers caused by the combined infection of coccidia and Clostridium perfringens.

[0085] 3.2 Effect of soybean saponins on the ileum morphology of broiler chickens infected with coccidia and Clostridium perfringens

[0086] Table 6 shows the effect of soybean saponin on the morphological structure of the ileum of broiler chickens co-infected with coccidia and Clostridium perfringens, where a, b, and c are significant difference markers, and data with different letters on the shoulders in the table indicate significant differences P<0.05; -CCP means no co-infection with coccidia and Clostridium perfringens, +CCP means co-infection with coccidia and Clostridium perfringens, -SS means no soybean saponin was added to the diet, +SS means soybean saponin was added to the diet, and SEM means standard error.

[0087] Table 6

[0088]

[0089]

[0090] As shown in Table 6, the combined infection of coccidia and Clostridium perfringens down-regulates the ratio of ileal villus height to crypt depth in broilers. The higher the intestinal villus height, the larger the contact area with nutrients in the intestinal cavity and the better the absorption efficiency. Therefore, the higher the intestinal villus height and the ratio of villus height to crypt depth indicate better intestinal absorption function. From the results in the table, it can be seen that the addition of soybean saponins to the diet can alleviate the decrease in the ratio of ileal villus height to crypt depth in broilers caused by the combined infection of coccidia and Clostridium perfringens, indicating that soybean saponins can alleviate the negative impact of the combined infection of coccidia and Clostridium perfringens on the intestinal absorption function of broilers.

[0091] 3.3 Effect of soybean saponin on sIgA content in ileal mucosa of broiler chickens infected with coccidia and Clostridium perfringens

[0092] Table 7 shows the effect of soybean saponin on the sIgA content in the ileal mucosa of broiler chickens co-infected with coccidia and Clostridium perfringens, where a and b are significant difference marks, and data with different letters on the shoulders in the table indicate significant differences P<0.05; -CCP means no co-infection with coccidia and Clostridium perfringens, +CCP means co-infection with coccidia and Clostridium perfringens, -SS means no soybean saponin added to the diet, +SS means soybean saponin added to the diet, SEM means standard error, sIgA means secretory immunoglobulin A, which was determined using the Elisa kit for sIgA of Shanghai Yuanmu chicken, and the data was calibrated with total protein as the denominator.

[0093] Table 7

[0094]

[0095] As can be seen from Table 7, adding soybean saponins to the diet can alleviate the decrease in sIgA content in the ileal mucosa of broiler chickens caused by the combined infection of coccidia and Clostridium perfringens. The secretion of sIgA in the ileum can resist the infection of pathogens to the intestine, 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 broiler chickens infected with coccidia and Clostridium perfringens.

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

[0097] Table 8 shows the effects of soybean saponins on ileal gene expression in broiler chickens co-infected with coccidia and Clostridium perfringens, where a, b, c, and d are significant difference markers, and different letters in the data shoulders in the table indicate significant differences P<0.05; -CCP means not co-infected with coccidia and Clostridium perfringens, +CCP means co-infected with coccidia and Clostridium perfringens, -SS means no soybean saponins added to the diet, +SS means soybean saponins added to the diet; SEM means standard error; TNF-α means tumor necrosis factor-α; IFN-γ means interferon-γ; IL-18 means interleukin 18; IL-8 means interleukin 8; IL-1β means interleukin-1β; ZO-1 means occludens-1; Claudin-1 means tight junction protein 1; occludin means claudin.

[0098] Table 8

[0099]

[0100]

[0101] As shown in Table 8, the combined infection of coccidia and Clostridium perfringens down-regulated the transcriptional levels of ileal barrier-related genes in broilers, such as Occludin and ZO-1, and up-regulated 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 down-regulation of ileal Occludin and ZO-1 transcriptional levels and the up-regulation of TNF-α, IFN-γ, IL-8, and IL-1β transcriptional levels caused by the combined infection of coccidia and Clostridium perfringens, indicating that soybean saponins can alleviate the impaired intestinal barrier function and inflammatory response of broilers caused by the combined infection of coccidia and Clostridium perfringens.

[0102] In summary, soybean saponin can be used to prepare drugs or feed additives for treating or preventing necrotic enteritis in chickens, and the prepared drugs or feed additives have the ability to resist various pathogens that cause necrotic enteritis in chickens, such as Clostridium perfringens. The dosage forms of the drugs and feed additives include oral liquid, granules, powders, tablets and the like.

[0103] The present application is described in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the present application and its core ideas. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. Application of soybean saponin in the preparation of medicines or feed additives for treating or preventing necrotic enteritis in chickens.

2. The use according to claim 1, characterized in that: The chicken necrotic enteritis is caused by the infection of Clostridium perfringens alone or in combination with coccidia.

3. The use according to claim 1, characterized in that: The medicine or feed additive is soybean saponin.

4. The use according to claim 1, characterized in that: The medicine or feed additive is a soybean saponin composition comprising soybean saponin and auxiliary materials, wherein the auxiliary materials include at least one of anhydrous ethanol, propylene glycol, dimethyl sulfoxide, edible oil, water, lactose, maltose, mannitol, soluble starch, montmorillonite, medical stone, zeolite powder, defatted rice bran, corn cob powder, bran, and white carbon black.

5. The use according to claim 4, characterized in that: The soybean saponin composition is a solution formed by mixing soybean saponin, anhydrous ethanol and water, wherein the concentration of soybean saponin is 10-120 mg / mL.

6. The use according to claim 4, characterized in that: The soybean saponin composition is a powdery mixture of soybean saponin, wheat bran and soluble starch, wherein the mass fraction of soybean saponin in the powdery mixture is 40% to 60%.

7. The use according to claim 4, characterized in that: The soybean saponin composition is a flake mixture formed by mixing soybean saponin with lactose or maltose and soluble starch, wherein the mass fraction of soybean saponin in the flake mixture is 40% to 60%.

8. The use according to claim 4, characterized in that: The soybean saponin composition is a granular mixture of soybean saponin, lactose or maltose and soluble starch, wherein the mass fraction of soybean saponin in the granular mixture is 40% to 60%.

9. The use according to claim 4, characterized in that: When the medicine or feed additive is a soybean saponin composition, its preparation type includes at least one of oral liquid, granules, tablets, and powders, and the preparation can be prepared by conventional pharmaceutical preparation methods.

10. The use according to claim 1, characterized in that: The method for using the drug or feed additive includes at least one of (1) to (4): (1) Orally administering soybean saponin to chickens at a dosage of 5 to 50 mg / kg of chicken body weight; (2) The soybean saponin content is 0.01% to 0.03% by weight of the chicken feed; the soybean saponin granules, powder or tablets are added to the chicken feed as a feed additive; (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 so that the content of soybean saponin is 0.01% of the weight of the chicken feed or drinking water; (4) When used for clinical treatment of chicken enteritis: orally administer the drug to chickens at a dosage of 50 mg / kg of chicken body weight of soybean saponin; or grind the granules, powder or tablets and feed them directly at a dosage of 50 mg / kg of chicken body weight of soybean saponin; or grind the granules, powder or tablets and add them to the feed at a soybean saponin content of 0.03% by weight of chicken feed; or grind the granules, powder or tablets and add them to the drinking water at a soybean saponin content of 0.03% by weight, three times a day in the morning, noon and evening, for one week.

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