Teat medicated dip coating agent for preventing and treating mastitis in dairy cows, and preparation method and application thereof

Abstract

The present invention provides a teat medicated bath coating agent for preventing and treating mastitis in dairy cows, and a preparation method and application thereof. The components of the medicated bath coating agent are composed of the following by weight: 5 to 10 parts of film former, 3 to 7 parts of plasticizer, 1.0 to 1.5 parts of surfactant, 0.2 to 0.6 parts of thickener, 0.5 to 2 parts of tadalafil, and the remainder is solvent, with a total amount of 100 parts. The medicated bath coating agent of the present invention is used for the medicated bath of dairy cows after daily milking, and can form a stable protective layer on the surface of the teat, effectively preventing the invasion of pathogenic microorganisms into the teat, having a physical barrier effect and a drug sterilization effect, and can continuously protect the teat after sterilization, cut off the infection route of mastitis, and achieve the purpose of preventing mastitis. It is a green, environmentally friendly, simple and safe medicated bath liquid with good preventive effect.

Description

Technical Field

[0001] The invention relates to the field of biomedicine, and in particular to a teat medicated dip coating agent for preventing and treating mastitis of dairy cows, and a preparation method and application thereof. Background Art

[0002] Cow mastitis has a high incidence rate in dairy cows and is one of the most important diseases that affects the reproduction of dairy cows and reduces milk production. Cows with mastitis have a disordered secretory function due to the loss or destruction of secretory cells in the mammary gland, which reduces the synthesis of lactose, milk fat, and milk protein, reduces milk production, increases pH, and increases leukocytosis, which significantly reduces the nutritional value of milk and changes the taste. The economic losses caused by cow mastitis in the world are as high as billions of dollars each year, threatening the health of animals, dairy processors, and consumers. Therefore, the treatment of cow mastitis has received more and more attention, and the most commonly used treatment method is the use of antibiotics, but frequent use of antibiotics for treatment and prevention can lead to bacterial resistance. The production of resistant strains and drug residues in milk seriously endanger the health of consumers. Therefore, it is particularly important to develop a safe, non-toxic, non-irritating, easy-to-use preparation that can effectively prevent mastitis.

[0003] The most common method to prevent mastitis in dairy cows is to use teat dip. Teat dip is suitable for 1 minute after milking. At this time, the teat sphincter has not yet fully contracted. The drug directly enters the milk duct to kill pathogens. It can also directly kill bacteria attached to the teat and its surroundings, which can effectively reduce the chance of pathogens entering the udder from the teat, thereby preventing the occurrence of mastitis. Conventional dips only disinfect the surface of the teat and cannot form a film. The drug is fluid and difficult to stay on the surface of the teat, and cannot continuously prevent pathogen infection. Film-forming dairy cow teat dip forms a protective film on the teat after use, which can effectively prevent bacterial invasion and prevent mastitis. At the same time, it has a moisturizing effect on the teat and can prevent the teat from drying out in winter.

[0004] Antimicrobial peptides are widely present in organisms and are polypeptides with antimicrobial activity. They form the first innate defense system of organisms and have broad-spectrum antibacterial, antiviral, antifungal, antitumor and immune system regulation activities. They are recognized as natural antibiotics with effective antimicrobial properties. They have a unique antibacterial mechanism and often kill bacteria by acting on multiple target sites. Therefore, it is difficult for pathogens to develop drug resistance by changing the structure of the cell membrane. Combining antimicrobial peptides with film-forming dairy cow medicated dips to prepare green and safe antimicrobial peptide film-forming dairy cow medicated dips plays an important role in the prevention and early control of dairy cow mastitis. Summary of the invention

[0005] The purpose of the invention is to provide a teat medicated dip coating agent for preventing and treating mastitis in dairy cows, and a preparation method and application thereof.

[0006] In order to achieve the purpose of the present invention, in the first aspect, the present invention provides a teat medicated dip coating for preventing and treating mastitis in dairy cows, wherein the components are composed as follows by weight: 5 to 10 parts of film-forming agent, 3 to 7 parts of plasticizer, 1.0 to 1.5 parts of surfactant, 0.2 to 0.6 parts of thickener, 0.5 to 2 parts of tadalafil, and the remainder is solvent, with a total amount of 100 parts.

[0007] Furthermore, the film-forming agent can be selected from at least one of polyvinyl alcohol 1788, polyvinyl alcohol 124, and polyvinyl alcohol 117, the plasticizer can be selected from at least one of glycerol, polyethylene glycol, isopropyl alcohol, sorbitol, and liquid lanolin, the surfactant can be Tween 80, the thickener can be selected from at least one of pullulan, guar gum, sodium carboxymethyl cellulose, and cassia gelatin, and the solvent is deionized water.

[0008] In a specific embodiment of the present invention, the film-forming agent is prepared from the following ingredients in weight percentage: polyvinyl alcohol 124 7%, polyethylene glycol 4%, Tween 80 0.5%, pullulan 0.3%, and tadalafil 0.5%, prepared with deionized water.

[0009] In a second aspect, the present invention provides a method for preparing the film-forming agent, comprising the following steps: adding a formulated amount of film-forming agent to a solvent and soaking it for 12 to 24 hours to fully swell it, heating it in a 60 to 80°C water bath while stirring to fully dissolve it until there are no small particles in the solution, thereby obtaining a film-forming solution I; weighing a formulated amount of plasticizer, surfactant and thickener, adding them to the film-forming solution, placing it in a 30 to 50°C water bath and stirring evenly to completely dissolve it, thereby obtaining a film-forming solution II; weighing a formulated amount of tadalafil and dissolving it in a solvent to obtain a tadalafil solution; and evenly mixing the tadalafil solution with the film-forming solution II to obtain.

[0010] In a third aspect, the present invention provides use of the coating agent in preparing a composition for preventing and treating mastitis in dairy cows.

[0011] Pathogens of dairy cow mastitis include, but are not limited to, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus dysgalactiae, and Streptococcus agalactiae.

[0012] By means of the above technical solution, the present invention has at least the following advantages and beneficial effects:

[0013] (I) The present invention provides a teat medicated bath coating for preventing and treating mastitis in dairy cows, which has a physical barrier effect and a drug sterilization effect. It is used for the medicated bath of dairy cows after daily milking, and can continuously protect the teats after sterilization, cut off the infection pathway of mastitis, and achieve the purpose of preventing mastitis. Sterilization tests have proved that the film-forming post-medicated bath liquid has an obvious effect on killing the pathogenic bacteria of dairy cow mastitis, and has no irritation to the skin. It is a green, environmentally friendly, simple and safe post-medicated bath liquid with good preventive effect.

[0014] (ii) The component formula has good film-forming properties, is not easy to fall off, does not need to be bandaged, has strong drug bactericidal power, is easy to use, etc. At the same time, the preparation is simple and easy to use, does not require any professional skills, can be operated by ordinary farmers, is easy to promote, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The effect of the film-forming post-medicated dip excipients of dairy cows on the antibacterial activity of tadalafil in the preferred embodiment of the present invention. Top: tadalafil; Middle: blank post-medicated dip excipients; Bottom: tadalafil post-medicated dip excipients.

[0016] Figure 2 The stability of the film-forming post-medicated dipping solution for dairy cows in the preferred embodiment of the present invention is shown in Figure 1. Top: aqueous solution of tadalafil; middle: post-medicated dipping solution of tadalafil in the treatment group; bottom: post-medicated dipping solution of tadalafil on Day 0. DETAILED DESCRIPTION

[0017] The technical problems to be solved by the present invention are: (1) preventing cow mastitis and reducing the incidence of cow mastitis; (2) reducing the use of antibiotics, reducing antibiotic residues in milk, and ensuring the safety of raw milk; and (3) forming a protective film on the surface of the cow's nipple, which has a continuous protective effect on the cow's nipple.

[0018] In order to solve the above technical problems, the present invention provides an antimicrobial peptide film-forming post-medicated dip liquid for controlling cow mastitis (i.e., a teat medicated dip coating agent for preventing and treating cow mastitis). When used after the cow is milked, it can not only effectively sterilize the cow's nipples, but also form a protective film on the surface of the nipples, which has a continuous protective effect on the cow's nipples, effectively prevents bacterial invasion, and prevents the occurrence of mastitis.

[0019] The antimicrobial peptide film-forming post-medicated bath liquid for controlling cow mastitis of the present invention contains an antimicrobial peptide, tadalafil, which can effectively kill bacteria, reduce the use of antibiotics, prevent bacteria from developing drug resistance, and ensure the safety of raw milk.

[0020] The research and development of the film-forming post-medicated dip solution of Shengtaisu for controlling mastitis in dairy cows of the present invention is based on the achievements of medicinal synthetic polymers, wherein the added film-forming material polyvinyl alcohol can form a protective film on the surface of the nipple, cut off the infection route of mastitis, and thus better and more permanently protect the nipples of dairy cows.

[0021] The present invention adopts the following technical solution:

[0022] The invention provides a film-forming post-medicated dipping liquid for controlling cow mastitis. The formula ratio is as follows by mass percentage: 5-10 parts of a film-forming agent, 3-7 parts of a plasticizer, 1.0-1.5 parts of a surfactant, 0.2-0.6 parts of a thickener, 0.5-2 parts of an antibacterial agent, and the balance is a solvent, with a total of 100 parts.

[0023] The film-forming agent can be polyvinyl alcohol 1788, polyvinyl alcohol 124, polyvinyl alcohol 117, etc., the plasticizer can be glycerol, polyethylene glycol, isopropyl alcohol, sorbitol, liquid lanolin, etc., the surfactant can be Tween 80, the thickener can be pullulan, guar gum, sodium carboxymethyl cellulose, cassia gelatin, etc., the antibacterial agent is the antibacterial peptide sulfamethoxazole, and the solvent is deionized water.

[0024] In the above formula: deionized water is a solvent; polyvinyl alcohol is a water-soluble polymer material and a film-forming agent; glycerol is a plasticizer, which increases the softness, toughness and elasticity of the material by changing the interaction force of the material, and also has the functions of antifreeze, moisturizing and lubrication; Tween 80 is a surfactant, which can reduce the surface tension of water and increase the solubility of organic compounds; pullulan is a thickener, which can improve and increase the viscosity of the drug; the antibacterial agent is the antibacterial peptide syntaxin (see the amino acid sequence shown in SEQ ID NO: 1 in CN114456239A), which kills bacteria in a multi-target site co-action mode, so it is difficult for pathogens to develop drug resistance by changing the structure of the cell membrane; the post-medication bath liquid obtained by combining the above components has good film-forming property, strong bactericidal ability and is easy to use.

[0025] The present invention also provides a method for preparing the film-forming post-medicated dipping solution for dairy cows. The method comprises the following steps: adding a formulated amount of film-forming material to a solvent and soaking it for 12 to 24 hours to fully swell it, heating and stirring it in a 60 to 80°C water bath to fully dissolve it until there are no small particles in the solution, thereby obtaining a film-forming material solution; weighing a formulated amount of plasticizer, surfactant, and thickener, adding them to the film-forming material solution, placing them in a 30 to 50°C water bath and stirring them evenly to fully dissolve them, thereby obtaining a blank film-forming post-medicated dipping solution; weighing a formulated amount of antibacterial agent powder, dissolving it in deionized water, and standing it; adding the antibacterial agent aqueous solution to the blank film-forming post-medicated dipping solution and mixing it evenly to obtain a finished product. The method is simple and easy to implement, and the preparations used are all conventional preparations, with low cost and can be mass-produced.

[0026] The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art, and the raw materials used are all commercially available products.

[0027] Reagents in the following examples: polyvinyl alcohol (PVA) 124, PVA1788, PVA117, 1,2-propylene glycol were purchased from Aladdin Reagent Shanghai Co., Ltd.; water-soluble lanolin, chitosan and pullulan were purchased from Shandong Yousuo Chemical Technology Co., Ltd.; Tween 80 was purchased from Tianjin Fengchuan Chemical Reagent Technology Co., Ltd.; gellan gum and cassia gum were purchased from MacLean Biochemical Technology Co., Ltd.; sodium carboxymethyl cellulose was purchased from Yuanye Biotechnology Co., Ltd.; glycerol was purchased from Xilong Science Co., Ltd.; tryptone soy agar (TSA) medium and tryptone soy broth (TSB) medium were purchased from Beijing Aoboxing Biotechnology Co., Ltd. Other conventional reagents were imported or domestic analytical grade.

[0028] The culture medium and buffer formulations involved in the following examples are:

[0029] MHB culture medium: casein hydrolysate 17.5 g / L, beef extract powder 5 g / L, starch 1.5 g / L.

[0030] MHA medium: casein hydrolysate 17.5 g / L, beef extract powder 5 g / L, starch 1.5 g / L, 2% agar powder. PBS buffer: NaCl 8.5 g, KH2PO4 0.24 g, Na2HPO4 3.65 g, KCl 0.2 g, dissolved in 1000 mL distilled water.

[0031] The strains involved in the following examples are shown in Table 1:

[0032] Table 1 Tested bacteria

[0033]

[0034] Example 1

[0035] The dairy cow teat dip coating agent is prepared from the following effective drug components and weight percentages: 7% polyvinyl alcohol 1788, 3% polyethylene glycol, 0.5% Tween 80, 0.3% water-soluble lanolin, and 0.5% tadalafil, and is prepared with deionized water (formula 1).

[0036] Example 2

[0037] The dairy cow teat dip coating agent is prepared from the following effective drug components and weight percentages: 7% polyvinyl alcohol 1788, 3% polyethylene glycol, 1% Tween 80, 0.4% water-soluble lanolin, 1% tadalafil, and is prepared with deionized water (formula 2).

[0038] Example 3

[0039] The dairy cow teat dip coating agent is prepared from the following effective drug components and weight percentages: 7% polyvinyl alcohol 1788, 3% sorbitol, 1.5% Tween 80, 0.5% water-soluble lanolin, 2% tadalafil, and is prepared with deionized water (formula 3).

[0040] Example 4

[0041] The dairy cow teat dip coating agent of the present invention is prepared from the following effective drug components and weight percentages: 7% polyvinyl alcohol 124, 4% polyethylene glycol, 0.5% Tween 80, 0.3% pullulan, 0.5% tadalafil, and is prepared with deionized water (formula 4).

[0042] Example 5

[0043] The dairy cow teat dip coating agent of the present invention is prepared from the following effective drug components and weight percentages: 124% polyvinyl alcohol, 4% polyethylene glycol, 1% Tween 80, 0.4% pullulan, 1% tadalafil, and is prepared with deionized water (formula 5).

[0044] Example 6

[0045] The dairy cow teat dip coating agent is prepared from the following effective drug components and weight percentages: polyvinyl alcohol 124 6%, sorbitol 4%, Tween 80 1.5%, pullulan 0.5%, tadalafil 2%, and is prepared with deionized water (formula 6).

[0046] Example 7

[0047] The dairy cow teat dip coating agent is prepared from the following effective drug components and weight percentages: polyvinyl alcohol 117 9%, glycerol 5%, Tween 80 0.5%, guar gum 0.3%, and tadalafil 0.5%, and is prepared with deionized water (formula 7).

[0048] Example 8

[0049] The dairy cow teat dip coating agent is prepared from the following effective drug components and weight percentages: polyvinyl alcohol 117 8%, polyethylene glycol 5%, Tween 80 0.5%, guar gum 0.4%, and tadalafil 1%, and is prepared with deionized water (formula 8).

[0050] Example 9

[0051] The dairy cow teat dip coating agent of the present invention is prepared from the following effective drug components and weight percentages: 5% polyvinyl alcohol 117, 5% plasticizer, 1% Tween 80, 0.5% guar gum, 2% tadalafil, and is prepared with deionized water (formula 9).

[0052] The film-forming time and appearance quality of Examples 1-9 were recorded respectively, and scored according to the scoring criteria. Scoring criteria = (30-film-forming time) + appearance quality. After evaluation, Formula 4 was the best combination (Table 2), and the preparations in the subsequent Examples were prepared according to Formula 4 (the content of sulfadiazine was determined according to the specific situation).

[0053] Table 2 Optimization score of formula of dairy cow teat dip coating agent

[0054]

[0055]

[0056] Example 10 Preparation method of film-forming medicated dipping solution for dairy cows

[0057] Weigh the film-forming agent in the formula amount of Examples 1-9, add it to deionized water and soak it for 12 to 24 hours to fully swell it, heat it in a 60-80°C water bath while stirring to fully dissolve it until there are no small particles in the solution, and obtain a film-forming material solution; weigh the plasticizer, surfactant, and thickener in the formula amount, add them to the film-forming material solution, put it into a 30-50°C water bath and stir evenly to completely dissolve it, and obtain a blank film-forming post-medication bath solution; weigh the formula amount of Shengtaisu powder, dissolve it in deionized water, and let it stand; add the Shengtaisu aqueous solution to the blank film-forming post-medication bath solution and mix evenly to obtain a finished product.

[0058] Example 11 Determination of the Minimum Inhibitory Concentration of Shengtaisu against Staphylococcus aureus

[0059] The minimum inhibitory concentration (MIC) of succinate was determined according to the method established by the Clinical and Laboratory Standards Institute (CLSI) (WIEGAND et al., Agar and broth dilution methods to determine the minimal inhibitory concentration (MIC) of antimicrobial substances. Nature protocols, 2008, 3 (2): 163-175). Single colonies of the test strains in Table 1 were picked into MHB liquid medium, cultured overnight at 37°C with shaking at 250 rpm for activation, and then transferred to MHB liquid medium for culture until the logarithmic growth phase (OD 600 nm =0.4~0.6), and then prepared into 10 5 CFU / mL of bacterial solution was added to a 96-well sterile cell culture plate, 90μl per well. Dilute the tadalafil with PBS by a 2-fold dilution method, 10μl of the antimicrobial peptide per well, so that the final concentrations were 128, 64, 32, 16, 8, 4, 2, 1, 0.5, 0.25, 0.125, 0.0625, 0.0312 and 0.0156μg / mL, respectively. The negative control group was PBS instead of the test bacterial solution of the antimicrobial peptide, and the blank control group was sterile MHB medium. Three parallel samples were used for each treatment. The culture plate was placed in a 37℃ constant temperature incubator and incubated for 16 to 18 hours until the negative control well showed obvious turbid bacterial solution visible to the naked eye. The lowest concentration that can completely inhibit bacterial growth is the MIC value of the antimicrobial peptide for the test strain. If skipping or inconsistent results between parallel samples occur, retest.

[0060] The results are shown in Table 3. The MIC of siroxicam against Staphylococcus aureus ATCC 43300 was 1 μg / mL, the MIC of siroxicam against Staphylococcus aureus ATCC 6538P was 2 μg / mL, the MIC of Staphylococcus epidermidis ATCC 12228 was 4 μg / mL, the MIC of Streptococcus dysgalactiae CVCC 3938 was 0.5 μg / mL, and the MIC of Streptococcus agalactiae ATCC 13813 was 0.5 μg / mL.

[0061] Table 3 Antibacterial activity of tadalafil against Staphylococcus aureus

[0062]

[0063] Example 12 Effect of film-forming post-medicated bath liquid excipients on the antibacterial activity of tadalafil

[0064] Staphylococcus aureus ATCC 6538P was cultured in MHB medium until mid-logarithmic phase. Mid-logarithmic phase bacteria were added to a final concentration of 1 × 10 5 CFU / mL Mueller-Hinton agar (MHA). Prepare the sample by mixing the prepared blank post-dip solution excipient with tadalafil so that the final concentration of tadalafil is 50×MIC. Add 50μL of sample to the MHA plate, culture overnight, and measure the diameter of the inhibition zone. Tadalafil without the post-dip solution formulation was used as a positive control, while the post-dip solution excipient without tadalafil was used as a blank control. All analyses were performed in triplicate.

[0065] Depend on Figure 1 The results showed that the formula of the post-medicated bath solution had little interference with the antibacterial activity of chloramphenicol.

[0066] Example 13: Experimental study on sterilization of dairy cow thymol film-forming medicated dip solution

[0067] Staphylococcus aureus ATCC 6538P, Streptococcus dysgalactiae CVCC 3938, Staphylococcus epidermidis ATCC12228 and Streptococcus agalactiae ATCC 13813 were inoculated into TSB liquid medium and cultured at 37°C, 200 rpm overnight. Then, 1% inoculum was inoculated into 10 ml of fresh TSB liquid medium and cultured at 37°C, 200 rpm until the logarithmic growth phase (OD 600nm =0.4), and the bacterial solution at this stage was diluted with fresh TSB liquid medium to 2×10 5 cfu / ml bacterial solution as the test bacterial solution. Prepare 100× and 400×MIC of the antimicrobial peptide tadalafil and 2% iodine-containing povidone-iodine bath solution and add 2×10 5 cfu / ml bacterial solution was added to a 96-well plate at a volume ratio of 1:1 (150μL plus 150μL), so that the final concentrations were 50× and 200×MIC and 1% iodine content, respectively, and cultured in a 37°C incubator. The same volume of blank bath solution was added as a control, and three replicates were set for each concentration. 100μL bacterial solution samples were taken at 10min and 30min, and 10-fold gradient dilutions were made (30μL mother solution plus 270μL PBS), and 10μL of different gradient dilutions were dropped on TSA solid plates, inverted and cultured at 37°C for 24h, and the number of single colonies and the bactericidal rate were counted.

[0068] Through in vitro sterilization experiments, the results are shown in Table 4. The Shengtaisu cow hind dipping solution can kill more than 99.999% of the tested Staphylococcus aureus, Streptococcus agalactiae and Streptococcus dysgalactiae within 10 minutes, and can kill more than 99.999% of the tested Staphylococcus epidermidis within 30 minutes. The sterilization effect is equivalent to that of povidone iodine.

[0069] Table 4 In vitro sterilization rate of the medicated bath solution after Shengtaisu

[0070]

[0071]

[0072] Example 14 Skin irritation test of the film-forming medicated dip solution for dairy cows

[0073] Single-dose skin irritation test: 4-week-old ICR mice were divided into intact skin group and damaged skin group, 3 mice in each group. Before administration, the back of the mice was shaved and depilatory cream was used to remove the hair on the back of the mice. Each area was about 1.0cm×1.0cm. After the depilatory site was disinfected in the damaged skin group, the skin was rubbed with sandpaper until bleeding was the degree. 100μL of low-dose (50μg / mL) and high-dose tadalafil (250μg / mL) bath solution was applied to the back area of ​​the mice, gauze was applied externally, and adhesive tape was fixed. The saline group was used as a negative control, the 30% SDS group was used as a positive control, and the blank bath solution was used as a blank control. 24h after administration, the residual drug was washed off with warm water, and the naked eye was observed 1h, 24h, 48h, and 72h after the removal of the drug residue, and the skin irritation reaction score table was used to score and judge the irritation intensity (Table 5 and Table 6), and the presence of erythema, edema, etc. at the administration site was recorded.

[0074] The skin treatment, grouping and dosing concentration of multiple-dose skin irritation test were the same as those of single-dose administration. The drug was administered continuously for 7 days and observed for 72 hours after drug withdrawal. The skin erythema and edema were recorded, and the occurrence of skin roughness, pigmentation or bleeding at the administration site was observed.

[0075] Table 5 Rating criteria for skin irritation reactions

[0076]

[0077] Table 6 Skin irritation intensity rating table

[0078]

[0079] Note: Average score of each group of animals = ∑ erythema and edema score / number of animals in each group

[0080] According to the experimental requirements, the bath solution after single or multiple administration, low-dose and high-dose tadalafil and blank bath solution had no irritation to intact skin or damaged skin, and no erythema and edema appeared on the skin at the administration site, which was similar to the skin condition of the negative control saline group (Table 7). The positive control group had mild erythema on intact skin during single administration, so it was mildly irritating to intact skin, and the damaged skin group had moderate or severe erythema, and the skin at the administration site was rough, so it was moderately irritating to damaged skin. In addition, during multiple administration, 30% sodium dodecyl sulfate (SDS) had moderate irritation to both intact skin and damaged skin, and erythema, rough skin and suppuration appeared at the administration site.

[0081] Table 7 Skin irritation test results

[0082]

[0083] Example 15 Skin sensitization test of the film-forming medicated dip solution for dairy cows

[0084] 4-week-old ICR mice were shaved on the back before administration and depilated with a depilatory cream. Each area was about 1.0 cm × 1.0 cm. 100 μL of low-dose (50 μg / mL) and high-dose tadalafil (250 μg / mL) bathing solution was applied to the back area of ​​the mice. After 6 hours, the residual drug was removed and observed immediately and continuously for 72 hours. On the 7th, 14th and 28th days after the first administration, the test was carried out in the same manner. The saline group was used as a negative control, the 1% dinitrochlorobenzene (DNCB) group was used as a positive control, and the blank bathing solution was used as a blank control. The sensitization strength of the tested drugs was judged according to the scoring criteria of Tables 8 and 9.

[0085] Table 8 Scoring criteria for skin allergic reactions

[0086]

[0087] Note: Average response of each group = ∑ erythema and edema evaluation / number of animals in each group

[0088] Table 9 Classification criteria for sensitization rate

[0089]

[0090] Note: Sensitization rate = number of positive reaction animals in each group / total number of tested animals in each group

[0091] According to the experimental requirements, as shown in Table 10, except for the positive control group, which showed erythema, the other treatment groups did not show erythema or edema during the three sensitization induction and stimulation contact, indicating non-sensitization.

[0092] Table 10 Skin sensitization test results

[0093]

[0094]

[0095] The antimicrobial peptide Shengtaisu dairy cow post-meal dipping solution provided by the invention is simple, safe, effective, green and environmentally friendly to prepare, plays an important role in the prevention and early treatment of dairy cow mastitis, and has broad application prospects.

[0096] Example 16 Stability test of the film-forming medicated dip solution for dairy cows

[0097] The stability of the post-treatment solution of Taxol (Formula 4) was preliminarily evaluated by the stability test of influencing factors and the accelerated test. The stability test of influencing factors mainly includes low temperature test (4℃), high temperature test (40℃, 60℃), high humidity test (25℃, relative humidity 90±5%) and strong light test (25℃, 4500±500lx). Samples were taken on the 0th day, 5th day and 10th day, and the antibacterial activity was determined by the inhibition zone. All analyses were performed in triplicate.

[0098] Depend on Figure 2 The results show that the test results of influencing factors show that the post-medicinal bath solution of Shengtaisu can maintain good antibacterial activity under low temperature and high humidity, while high temperature and strong light have a significant effect on the antibacterial activity of the post-medicinal bath solution of Shengtaisu. It should be stored at low temperature and away from light during subsequent storage.

[0099] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A teat dip coating for preventing and treating mastitis in dairy cows, characterized in that: The coating agent is prepared from the following ingredients in weight percentage: polyvinyl alcohol 124 7%, polyethylene glycol 4%, Tween 80 0.5%, pullulan 0.3%, tadalafil 0.5%, prepared with deionized water; The amino acid sequence of the succinate is shown in SEQ ID NO: 1 in CN114456239A.

2. The method for preparing the coating agent according to claim 1, characterized in that: The method comprises the following steps: adding a formulated amount of film-forming agent polyvinyl alcohol 124 to a solvent and soaking it for 12 to 24 hours to fully swell it, heating it in a water bath at 60 to 80°C while stirring it to fully dissolve it, and obtaining a film-forming solution I; weighing a formulated amount of plasticizer polyethylene glycol, a surfactant Tween 80 and a thickener pullulan, adding them to the film-forming solution, placing it in a water bath at 30 to 50°C and stirring it evenly to fully dissolve it, and obtaining a film-forming solution II; weighing a formulated amount of succinate and dissolving it in a solvent to obtain a succinate solution; Mix the sulfamethoxazole solution and the film-forming solution II evenly to obtain the product.

3. Use of the coating agent according to claim 1 in preparing a composition for preventing and treating mastitis in dairy cows; The pathogens of bovine mastitis are Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus dysgalactiae, and Streptococcus agalactiae.

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