Application of coated sodium butyrate in preparation of feed additive for preventing and improving duck serositis

Abstract

The invention relates to the technical field of poultry feed additive application, in particular to application of coated sodium butyrate in preparation of a feed additive for preventing and improving duck serositis. The invention provides a new application of the coated sodium butyrate in preparation of the feed additive for preventing and improving the duck serositis, and a new way is provided for preventing and improving the duck serositis. According to the designed coated sodium butyrate with the double-layer coating structure, the outer coating is an enteric coating and can help the coated sodium butyrate to be released in the intestinal tract at a fixed point, and the inner coating contains a small amount of sodium butyrate and can help the formation of gradient slow release of the sodium butyrate, so that the front part, the middle part and the rear part of the intestinal tract can effectively absorb the sodium butyrate; the effective absorption amount of the intestinal tract to sodium butyrate is greatly improved, and the duck is helped to enhance the immunity and recover health more quickly.

Description

Technical Field

[0001] The invention relates to the technical field of application of poultry feed additives, and in particular to application of coated sodium butyrate in preparing a feed additive for preventing and improving duck serositis. Background Art

[0002] Serositis is an acute or chronic, contact infectious disease caused by Riemerella anatipestifer that mainly affects young poultry. It is mainly manifested by clinical symptoms such as increased eye and nasal secretions, coughing, diarrhea, ataxia, head and neck tremors, and even head and neck crookedness. Anatomical lesions can show pericarditis, perihepatitis, air sac inflammation, salpingitis, peritonitis, meningitis, etc. It mainly affects young poultry aged 1 to 8 weeks, especially young poultry aged 2 to 4 weeks. The characteristics of the disease are rapid transmission, short course of disease, high mortality rate, high morbidity, and mortality rate of 20-40%, or even as high as 80%. Even if the sick poultry survives, it will lead to slow growth and development and affect weight gain. It is mainly transmitted through feces, contaminated feed, body contact, and air, and can also be infected through the respiratory tract and injured wounds.

[0003] Riemerella anatipestifer has many serotypes, and these serotypes lack cross-protection. In addition, the bacterium is prone to multi-drug resistance, and the resistance rate of its strains often exceeds 80%, or even as high as 90%. Therefore, due to the differences in strains prevalent in different regions, the clinical application effect of vaccines is often poor. At the same time, drug addition may not only aggravate the problem of drug resistance, but also cause drug residues, which makes the prevention and control of the disease quite difficult and brings huge economic losses to farmers. Therefore, it is of great significance to find a green and healthy feed additive to prevent duck serositis.

[0004] Sodium butyrate, as a deacetylase inhibitor, can increase the level of histone acetylation. Studies have found that sodium butyrate can inhibit tumor cell proliferation, promote tumor cell aging and apoptosis, etc., which may be related to sodium butyrate increasing histone acetylation. Sodium butyrate has been used in clinical research on tumors. It can be widely used as a feed additive for livestock and poultry.

[0005] At present, there are no reports on the use of sodium butyrate to improve duck serositis. Summary of the invention

[0006] The present invention provides the use of coated sodium butyrate in preparing a feed additive for preventing and improving duck serositis. The present invention aims to discover a new use of coated sodium butyrate and provide a new way for preventing and improving duck serositis.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] The invention finds the application of coated sodium butyrate in preparing a feed additive for preventing and improving duck serositis.

[0009] Encapsulated sodium butyrate is a new type of feed additive that is made by coating sodium butyrate with intelligent microencapsulation technology based on the specific digestive physiological characteristics of meat ducks. It can provide a stable, direct and continuous energy source for intestinal cells. It can not only achieve intestinal sustained release effect, but also effectively reach the posterior part of the intestine and nourish the entire intestine.

[0010] At the same time, sodium butyrate can promote the function of nonspecific immune system and specific immune system, improve the overall immunity of meat ducks, and thus enhance their resistance to serositis. In addition, sodium butyrate can promote the growth of beneficial bacteria and inhibit harmful bacteria, improve the intestinal environment, reduce the invasion of harmful bacteria to the intestine, and thus reduce the incidence of serositis. At the same time, it also overcomes the shortcomings of sodium butyrate such as its strange smell, large loss in the stomach, easy moisture absorption, and difficult processing.

[0011] Preferably, the duck is a meat duck aged 1 to 8 weeks.

[0012] The coated sodium butyrate provided in the present application has good effects on preventing and improving duck serositis in 1 to 8-week-old meat ducks.

[0013] Preferably, the amount of the coated sodium butyrate added to the feed is 300-500 g / t.

[0014] Preferably, the content of sodium butyrate in the coated sodium butyrate is 25-32 wt%.

[0015] Further preferably, the content of sodium butyrate in the coated sodium butyrate is 28-31 wt%.

[0016] Further preferably, the content of sodium butyrate in the coated sodium butyrate is 30 wt%.

[0017] Preferably, the coated sodium butyrate comprises sodium butyrate particles, a polysaccharide inner coating, and an enteric outer coating from the inside to the outside.

[0018] The release of sodium butyrate in the duck intestine is delayed by double-layer coating, and the transportation stability of the coated sodium butyrate is enhanced.

[0019] The use of enteric materials to prepare the enteric outer coating can ensure that sodium butyrate does not dissolve in the stomach and is gradually released in the intestine. Similarly, the polysaccharide inner coating contains polysaccharides, which can produce a gel barrier after hydration when in contact with water. This gel barrier can also prevent the release of sodium butyrate, while remaining stable in the acidic environment of the stomach and slowly degrading after entering the alkaline environment of the intestine. Therefore, when the enteric outer coating is accidentally damaged, it can also ensure that most of the sodium butyrate is released in the intestine. When the enteric outer coating structure is stable, sodium butyrate has double-layer protection, so the effective absorption by the intestine is greatly increased.

[0020] In addition, the double-layer coating design can provide additional physical protection and reduce the impact of the external environment (such as humidity, temperature, and pH changes) on sodium butyrate. In general, the enteric outer coating ensures the release of sodium butyrate in the intestine, while the inner polysaccharide inner coating has a sustained-release property that ensures that sodium butyrate continues to work in the intestine and prolongs its efficacy.

[0021] Preferably, the particle size of the coated sodium butyrate is 0.3-0.8 mm.

[0022] Preferably, the sodium butyrate particles include sodium butyrate, β-cyclodextrin, pregelatinized starch and hydroxypropyl methylcellulose, the polysaccharide inner coating includes sodium alginate, hydroxypropyl methylcellulose and sodium butyrate, and the enteric outer coating includes ethyl cellulose, acrylic resin IV and hydroxypropyl methylcellulose phthalate.

[0023] Preferably, in parts by weight, the sodium butyrate particles include 25 to 30 parts of sodium butyrate, 30 to 35 parts of β-cyclodextrin, 13 to 18 parts of pregelatinized starch and 9 to 12 parts of hydroxypropyl methylcellulose, the polysaccharide inner coating includes 4 to 7 parts of sodium alginate, 5 to 8 parts of hydroxypropyl methylcellulose and 2 to 3 parts of sodium butyrate, and the enteric outer coating includes 5 to 8 parts of ethyl cellulose, 4 to 6 parts of acrylic resin IV and 6 to 10 parts of hydroxypropyl methylcellulose phthalate.

[0024] A small amount of sodium butyrate is added to the inner polysaccharide coating. After the enteric outer coating dissolves, the inner polysaccharide coating begins to dissolve in the front of the intestine, and a small amount of sodium butyrate is released in the front of the intestine, which can help mobilize the intestinal function of the duck. As the inner polysaccharide coating is transported to the middle and rear of the intestine along the rolling path and slowly dissolves in the process, a large amount of sodium butyrate particles are released in the middle and rear of the intestine. Under the stimulation of a small amount of sodium butyrate, the intestine can quickly absorb sodium butyrate, thereby completing the effective absorption of sodium butyrate by the duck intestine.

[0025] Preferably, the particle size of sodium butyrate in the sodium butyrate particles is 0.1-0.5 μm, and the particle size of sodium butyrate in the polysaccharide inner layer coating is 0.05-0.1 μm.

[0026] The particle size of sodium butyrate in the inner polysaccharide coating is smaller than that in the sodium butyrate particles. This is because small particles of sodium butyrate are easier to fuse with sodium alginate and hydroxypropyl methylcellulose to form a uniform coating liquid, which can improve the stability of the inner polysaccharide coating.

[0027] Preferably, the method for preparing the coated sodium butyrate comprises:

[0028] S1. Sodium butyrate, β-cyclodextrin, pregelatinized starch and hypromellose are mixed, water is added, stirred and granulated to obtain sodium butyrate granules;

[0029] S2. Sodium butyrate and water were mixed and then sodium alginate and hydroxypropyl methylcellulose were added to obtain an inner coating solution, and ethyl cellulose, acrylic resin IV and hydroxypropyl methylcellulose phthalate were dissolved in water to obtain an outer coating solution;

[0030] S3. Spray the inner coating liquid on the surface of the sodium butyrate particles to form a polysaccharide inner coating, and continue to spray the outer coating liquid on the surface of the polysaccharide inner coating to form an enteric outer coating to obtain coated sodium butyrate.

[0031] Preferably, in S2, the mass ratio of sodium butyrate to water is 1:(8-12).

[0032] Further preferably, in S2, the mass ratio of sodium butyrate to water is 1:10.

[0033] Dissolving sodium butyrate in water first can help the sodium butyrate to be evenly distributed in the inner layer of the polysaccharide coating.

[0034] Therefore, the present invention has the following beneficial effects:

[0035] (1) The present invention provides a new use of coated sodium butyrate in the preparation of a feed additive for preventing and improving duck serositis, thereby providing a new approach for preventing and improving duck serositis.

[0036] (2) The present invention provides a coated sodium butyrate with a double-layer coating structure, which can help sodium butyrate to achieve effective sustained release in the intestine of ducks and improve the effective absorption of sodium butyrate by the intestine.

[0037] (3) The double-layer coating structure of the coated sodium butyrate designed by the present invention has an outer coating that is an enteric coating that can help the coated sodium butyrate to be released at a specific point in the intestine, and an inner coating that contains a small amount of sodium butyrate that can help form a gradient sustained release of sodium butyrate, so that the front, middle and back parts of the intestine can effectively absorb sodium butyrate, greatly improving the effective absorption of sodium butyrate by the intestine, and helping ducks to enhance their resistance and restore health faster. DETAILED DESCRIPTION

[0038] The present invention is further described below in conjunction with specific embodiments. Those of ordinary skill in the art will be able to implement the present invention based on these descriptions. In addition, the embodiments of the present invention involved in the following description are generally only embodiments of a part of the present invention, rather than all embodiments. Therefore, based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work should fall within the scope of protection of the present invention.

[0039]

Preparation of coated sodium butyrate

[0040] Example 1 Preparation of 30wt% coated sodium butyrate

[0041] S1. Mix 37 g of sodium butyrate (average particle size 0.25 μm), 33 g of β-cyclodextrin, 17 g of pregelatinized starch and 80 g of water in a 20 rpm mixer to obtain a uniform product, and then perform wet granulation. Then, dry the product in a vacuum drying oven at 60° C. for 4 h to obtain sodium butyrate granules.

[0042] S2, 2 g of sodium butyrate (average particle size 0.07 μm) and 20 g of water were mixed evenly in a 20 rpm mixer, and then 5 g of sodium alginate and 6 g of hydroxypropyl methylcellulose were added to obtain an inner coating solution.

[0043] S3, 7 g of ethyl cellulose, 5 g of acrylic resin IV, 8 g of hydroxypropyl methylcellulose phthalate and 30 g of water were mixed in a 20 rpm mixer to obtain an outer coating solution.

[0044] S4. In a fluidized bed coater, the inner coating liquid obtained in S2 is evenly sprayed on the surface of the sodium butyrate particles in S1 at a flow rate of 1 L / min, an inlet air temperature of 80°C, and a time of 3 h to form a uniform polysaccharide inner coating on the surface of the sodium butyrate particles to obtain the expected coated sodium butyrate.

[0045] S5. In a fluidized bed coating machine, the outer coating liquid obtained in S3 is evenly sprayed on the surface of the expected coated sodium butyrate in S4 at a flow rate of 1 L / min, an inlet air temperature of 80°C, and a time of 3 h to form a uniform enteric outer coating on the surface of the expected coated sodium butyrate to obtain coated sodium butyrate.

[0046] Table 1 Ingredients / g

[0047]

[0048] Comparative Example 1

[0049] This comparative example is basically the same as Example 1, except that: referring to Table 1, the addition of sodium butyrate (average particle size 0.07 μm) in the polysaccharide inner coating formula is omitted.

[0050] Comparative Example 2

[0051] This comparative example is basically the same as Example 1, except that: referring to Table 1, the inner polysaccharide coating is eliminated.

[0052] The sustained release effect of the coated sodium butyrate obtained in Example 1 and Comparative Examples 1-2 was measured under artificial intestinal fluid.

[0053] Liquid preparation method: Prepare artificial intestinal fluid as the release medium in accordance with the requirements of the 2020 edition of the Chinese Pharmacopoeia of Veterinary Medicine.

[0054] Artificial intestinal fluid operation plan: Take coated sodium butyrate (0.2g), accurate to 0.0002g, place it in a dissolution cup, use a rotating basket, and refer to the first method (basket method) of Part 0931 of the 2020 edition of the "Chinese Pharmacopoeia of Veterinary Medicine". Add 400mL of artificial intestinal fluid, set the temperature to 38°C, and the speed to 100r / min. After rotating for 4h, use a high performance liquid chromatography to determine the residue content.

[0055] The test results recorded in artificial intestinal fluid are shown in Table 2.

[0056] Table 2 Release of coated sodium butyrate in artificial intestinal fluid / %

[0057] Group 0.5h 1h 1.5h 2h 2.5h 3h 3.5h 4h Example 1 18.11c 35.23c 43.27c 52.65c 65.24b 78.91c 89.58c 95.65b Comparative Example 1 14.27b 30.19b 39.45b 47.62b 64.96b 81.13b 94.31b 95.69b Comparative Example 2 29.34a 45.87a 63.14a 89.85a 97.13a 97.34a 97.50a 97.55a

[0058] It can be seen from Table 2 that the sodium butyrate in the inner coating is removed in Comparative Example 1, and its early release is slightly lower than that in Example 1, and the release time is earlier than that in Example 1. In addition, the release time of Comparative Example 2 is earlier. From this result, it can be seen that the double-layer coating structure proposed in Example 1 can effectively prolong the release time of sodium butyrate, achieve the effect of gradient sustained release, and play a role in long-term supply.

[0059]

Serositis test

[0060] Application Example 1 Meat duck serositis experiment / Example 1

[0061] 480 1-day-old, healthy ducks with similar body weight were randomly divided into 8 groups, with 6 replicates in each group and 10 ducks in each replicate. They were divided into blank control group, positive control group and experimental groups 1 to 6. The experimental design is shown in Table 3. All treatment groups were fed the same diet and had free access to food and water. The feed formula and nutritional level are shown in Table 4. After one week of feeding, the positive control group and experimental groups 1 to 6 were injected with 0.2 mL of 10 9 CFU / mL of Riemerella anatipestifer, and the blank control group was injected with an equal amount of normal saline; after the infection, the subjects were observed for 2 weeks.

[0062] During the trial, the incidence of serositis in meat ducks was observed and counted. When the ducks showed symptoms such as increased eye and nasal secretions, coughing, diarrhea, ataxia, head and neck tremors, and even head and neck tilt, they were determined to have serositis. At the same time, the mortality rate of meat ducks was recorded in a timely manner during the trial. The results are shown in Table 5.

[0063] Table 3 Experimental design

[0064]

[0065] Table 4 Diet formulation and nutrient level (air-dried basis)

[0066]

[0067] Note: 1. Premix provides per kg of diet (1-21 days): VA 4.50 mg, cholecalciferol 0.10 mg, VE 3.0 mg, VK 3.0 mg, thiamine (VB1) 3.0 mg, riboflavin (VB2) 9.0 mg, pyridoxine (VB6) 3.0 mg, cyanocobalamin 0.02 mg, pantothenic acid 15.0 mg, niacin 39.0 mg, folic acid 1.5 mg, biotin 0.22 mg, choline 700 mg, Cu 8.0 mg, iron 40.0 mg, manganese 100 mg, zinc 50 mg, iodine 0.35 mg, selenium 0.15 mg; 2. Premix provides per kg of diet (22-42 days): VA 3.0 mg, cholecalciferol 0.075 mg, VE 2.0mg, menadione 2.0mg, thiamine (VB1) 2.0mg, riboflavin (VB2) 6.4mg, pyridoxine (VB6) 2.0mg, cyanocobalamin 0.02mg, pantothenic acid 10.0mg, niacin 26.0mg, folic acid 1.0mg, biotin 0.10mg, choline 500mg, copper 8.0mg, iron 30.0mg, manganese 80mg, zinc 40mg, iodine 0.35mg, selenium 0.15mg.

[0068] Table 5 Death of meat ducks

[0069] Treatment Group Total number, group Death / Survival / Survival rate / % Blank control 60 0 0 100 Positive Control 60 42 18 <![CDATA[30.00 d ]]> Test Group 1 60 13 47 <![CDATA[78.33 c ]]> Test Group 2 60 8 52 <![CDATA[86.67 a ]]> Experiment 3 groups 60 7 53 <![CDATA[88.33 a ]]> Test 4 groups 60 8 52 <![CDATA[86.67 a ]]> Test 5 groups 60 11 49 <![CDATA[81.67 b <!-- 5 -->]]> Experiment 6 groups 60 14 46 <![CDATA[76.67 c ]]>

[0070] From the data in Table 5, it can be seen that the addition of coated sodium butyrate can significantly reduce the mortality rate of broiler ducks. The appropriate addition amount is 300-500g / t, and the best effect is achieved when 400g of coated sodium butyrate is added per ton of complete feed.

[0071] Application Example 2 Meat duck serositis experiment / Example 1, Comparative Examples 1-2

[0072] 300 1-day-old, healthy meat ducks of similar weight were selected and randomly divided into 5 groups, with 6 replicates in each group and 10 meat ducks in each replicate. They were divided into blank control group, positive control group and experimental groups 1 to 3. The experimental design is shown in Table 6. All treatment groups were fed the same diet and had free access to food and water. The feed formula and nutritional level are shown in Table 4. After one week of feeding, the positive control group and experimental groups 1 to 3 were injected with 0.2 mL of 10 9 CFU / mL of Riemerella anatipestifer, and the blank control group was injected with an equal amount of normal saline; after the infection, the subjects were observed for 2 weeks.

[0073] During the trial, the incidence of serositis in meat ducks was observed and counted. When the ducks showed symptoms such as increased eye and nasal secretions, coughing, diarrhea, ataxia, head and neck tremors, and even head and neck tilt, they were determined to have serositis. At the same time, the mortality rate of meat ducks was recorded in a timely manner during the trial. The results are shown in Table 7.

[0074] Table 6 Experimental design

[0075]

[0076] Table 7 Death of meat ducks

[0077] Treatment Group Total number, group Death / Survival / Survival rate / % Blank control 60 0 0 100 Positive Control 60 40 20 33.33c Test Group 1 60 7 53 88.33a Test Group 2 60 8 52 86.67a Experiment 3 groups 60 15 45 75.00b

[0078] From the data in Table 7, it can be seen that the coated sodium butyrate prepared in Example 1 and Comparative Example 1 may not have much difference in the survival rate, but both have played a role in improving the survival rate of diseased ducks, proving that the coated sodium butyrate does have an improving effect on duck serositis.

[0079] Five ducks were randomly selected from each of the six groups of surviving ducks, namely the blank control group, the positive control group and test groups 1 to 3, and weighed. The difference between their weights and that in the healthy state before the test was calculated, and the weight gain of the five ducks before and after the test was recorded. The average weight gain of the blank control group was calculated as Ag, and the average weight gain of the positive control group (or any one of the test groups 1 to 3) was calculated as B g. Relative weight gain = B / A*100%. The results are shown in Table 8.

[0080] Table 8 Weight gain of surviving ducks

[0081]

[0082] From the data in Table 8, it can be seen that the weight gain of the surviving ducks in Test Group 1 and Test Group 2 corresponding to Example 1 and Comparative Example 1 is significantly different. The use of the coated sodium butyrate with the structure of Example 1 provided in the present application can not only significantly reduce the mortality rate of sick ducks, but also the surviving ducks are in good health, close to those of healthy ducks.

Claims

1. Application of coated sodium butyrate in the preparation of feed additives for preventing and improving duck serositis.

2. The use according to claim 1, characterized in that The ducks are meat ducks aged 1 to 8 weeks.

3. The use according to claim 1, characterized in that The added amount of the coated sodium butyrate in the feed is 300-500g / t.

4. The use according to claim 1, characterized in that The content of sodium butyrate in the coated sodium butyrate is 25-32 wt %.

5. The use according to any one of claims 1 to 4, characterized in that: The coated sodium butyrate comprises sodium butyrate particles, a polysaccharide inner coating and an enteric outer coating from the inside to the outside.

6. The use according to claim 5, characterized in that The average particle size of the coated sodium butyrate is 0.3-0.8 mm.

7. The use according to claim 5, characterized in that The sodium butyrate particles include sodium butyrate, beta-cyclodextrin, pregelatinized starch and hydroxypropyl methylcellulose, the polysaccharide inner coating includes sodium alginate, hydroxypropyl methylcellulose and sodium butyrate, and the enteric outer coating includes ethyl cellulose, acrylic resin IV and hydroxypropyl methylcellulose phthalate.

8. The use according to claim 7, characterized in that The average particle size of the sodium butyrate in the sodium butyrate particles is 0.1-0.5 μm, and the average particle size of the sodium butyrate in the polysaccharide inner layer coating is 0.05-0.1 μm.

9. The use according to claim 5, characterized in that In parts by weight, the sodium butyrate particles include 25 to 30 parts of sodium butyrate, 30 to 35 parts of beta-cyclodextrin, 13 to 18 parts of pregelatinized starch and 9 to 12 parts of hydroxypropyl methylcellulose, the polysaccharide inner coating includes 4 to 7 parts of sodium alginate, 5 to 8 parts of hydroxypropyl methylcellulose and 2 to 3 parts of sodium butyrate, and the enteric outer coating includes 5 to 8 parts of ethyl cellulose, 4 to 6 parts of acrylic resin IV and 6 to 10 parts of hydroxypropyl methylcellulose phthalate.

10. The use according to claim 5, characterized in that The preparation method of the coated sodium butyrate comprises: S1. Sodium butyrate, β-cyclodextrin, pregelatinized starch and hypromellose are mixed, water is added, stirred and granulated to obtain sodium butyrate granules; S2. Sodium butyrate and water were mixed and then sodium alginate and hydroxypropyl methylcellulose were added to obtain an inner coating solution, and ethyl cellulose, acrylic resin IV and hydroxypropyl methylcellulose phthalate were dissolved in water to obtain an outer coating solution; S3. Spray the inner coating liquid on the surface of the sodium butyrate particles to form a polysaccharide inner coating, and continue to spray the outer coating liquid on the surface of the inner coating to form an enteric outer coating to obtain coated sodium butyrate.

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