阅读说明：本技术 缩合单宁在制备鲈鱼黄曲霉毒素中毒治疗药物、制剂或饲料中的应用 (Application of condensed tannin in preparation of medicine, preparation or feed for treating aflatoxin poisoning of weever ) 是由 彭凯 郑春田 王国霞 赵红霞 于 2021-01-21 设计创作，主要内容包括：本发明公开了缩合单宁在制备鲈鱼黄曲霉毒素中毒治疗药物、制剂或饲料中的应用,所述缩合单宁中原花青定单宁：原翠雀定单宁的质量比大于等于3.3；所述缩合单宁中延伸单元表儿茶素含量大于等于68.8％；所述缩合单宁中延伸单元表没食子儿茶素含量大于等于28.0％；所述缩合单宁的分子量为1～20kDa。发明人发现0.2％的缩合单宁能够有效的治疗或缓解黄曲霉毒素对鲈鱼肝脏及肠道的伤害,从而避免鲈鱼因黄曲霉毒素中毒导致的营养不良、生长缓慢等问题,降低水产养殖中黄曲霉毒素对养殖业的危害和经济损失。(The invention discloses an application of condensed tannin in preparing medicines, preparations or feeds for treating aflatoxin poisoning of weever, wherein the condensed tannin is procyanidine tannin: the mass ratio of the raw delphinidin tannin is more than or equal to 3.3; the content of extension unit epicatechin in the condensed tannin is more than or equal to 68.8 percent; the content of epigallocatechin as an extension unit in the condensed tannin is more than or equal to 28.0 percent; the molecular weight of the condensed tannin is 1-20 kDa. The inventor finds that 0.2% of condensed tannin can effectively treat or relieve the damage of aflatoxin to liver and intestinal tract of weever, thereby avoiding the problems of malnutrition, slow growth and the like of weever caused by aflatoxin poisoning, and reducing the harm and economic loss of aflatoxin to aquaculture.)

1. The application of the condensed tannin in preparing the medicine or preparation for treating aflatoxin poisoning of aquatic animals;

wherein the condensed tannin has a structural formula shown in formula I:

in the formula I, n is selected from any integer of more than or equal to 14;

the R group is-OH or-H and comprises cis and trans structures.

2. Use according to claim 1, characterized in that the procyanidin tannin of the condensed tannin: the mass ratio of the raw delphinidin tannin is more than or equal to 3.3; the content of extension unit epicatechin in the condensed tannin is more than or equal to 68.8 percent; the content of epigallocatechin as an extension unit in the condensed tannin is more than or equal to 28.0 percent; the molecular weight of the condensed tannin is 1-20 kDa.

3. The use of claim 1, wherein the mass concentration of the condensed tannin in the therapeutic medicament or preparation for aflatoxin poisoning of aquatic animals is less than 0.3%; the mass concentration of the condensed tannin in the aquatic animal aflatoxin poisoning treatment medicine or preparation is preferably 0.1-0.2%.

4. The use of claim 1, wherein the aflatoxins comprise aflatoxins B1, B2, G1, G2, M1, M2, GM, P1, Q1, aflatoxin-carbinol and derivatives thereof; the aflatoxin is preferably aflatoxin B1.

5. An aquatic feed, which is characterized in that the fish feed contains imported fish meal, soybean meal, rapeseed meal, flour, monocalcium phosphate, soybean oil, fish oil, soybean lecithin, vitamin premix, mineral premix, VC phosphate, choline chloride, betaine, lysine, methionine, microcrystalline cellulose and condensed tannin;

wherein the vitamin premix contains at least one of VA, VB, VD, VE, VK, calcium pantothenate, inositol or biotin; the vitamin premix preferably contains VA and VB₁，VB₂，VB₆Nicotinic acid, folic acid, VB₁₂VD, VE, VK, calcium pantothenate, inositol, biotin;

the mineral premix contains at least one of magnesium, calcium, iodine, potassium, copper, zinc, iron, cobalt or selenium; the mineral premix preferably contains MgSO₄·H₂O，Ca(IO₃)₂KCl, methionine Cu, ZnSO₄·H₂O，FeSO₄·H₂O, methionine Co, NaSeO₃。

6. The aquatic feed according to claim 5, wherein the fish feed comprises, by mass, 25-30 parts of imported fish meal, 25-28 parts of soybean meal, 8-12 parts of rapeseed meal, 25-30 parts of flour, 1-2 parts of monocalcium phosphate, 1-4 parts of soybean oil, 1-3 parts of fish oil, 1-3 parts of soybean lecithin, 0.1-0.5 part of vitamin premix, 0.1-1 part of mineral premix, 0.1-0.2 part of VC phosphate, 0.1-1 part of choline chloride, 0.1-1 part of betaine, 0.01-0.1 part of lysine, 0.1-1 part of methionine, 1-2 parts of microcrystalline cellulose and 0.1-0.3 part of condensed tannin.

7. The aquatic feed according to claim 5, wherein the fish feed comprises, by mass, 25-30 parts of imported fish meal, 25-28 parts of soybean meal, 8-10 parts of rapeseed meal, 25-26 parts of strong flour, 1-1.5 parts of monocalcium phosphate, 1-3 parts of soybean oil, 1-2 parts of fish oil, 2-3 parts of soybean lecithin, 0.1-0.2 part of vitamin premix, 0.1-0.5 part of mineral premix, 0.1-0.15 part of VC phosphate, 0.1-0.5 part of choline chloride, 0.1-0.5 part of betaine, 0.01-0.05 part of lysine, 0.1-0.25 part of coated methionine, 1-2 parts of microcrystalline cellulose and 0.1-0.2 part of condensed tannin.

8. A method of producing an aquaculture feed product according to any one of claims 5 to 7 including the steps of:

(1) weighing the components of the aquatic feed according to any one of claims 5 to 7, crushing, and mixing;

(2) carrying out microwave tempering, high-temperature puffing and cooling on the mixed components to obtain the product;

wherein, the power of the microwave hardening and tempering in the step (2) is 800-.

9. Use of an aquaculture feed according to any one of claims 5 to 7 or an aquaculture feed prepared by the method of claim 8 for aquaculture of aquatic animals; wherein the aquatic animal is preferably a weever.

10. The condensed tannin is used as a feed additive to be applied to the preparation of feed for preventing or treating aflatoxin poisoning of aquatic animals;

wherein the aquatic animal is preferably a weever.

Technical Field

The invention relates to the field of aquaculture, in particular to application of condensed tannin in preparation of medicines, preparations or feeds for treating aflatoxin poisoning of weever.

Background

Aflatoxins are a very toxic, mutagenic and carcinogenic substance produced by aspergillus flavus and aspergillus parasiticus. The toxigenic aspergillus flavus can produce aflatoxins B1 and B2, and the toxigenic parasitic aspergillus flavus can produce aflatoxins B1, B2, G1 and G2. Often the consequences of intoxication in animals are slow growth, anemia, the production of blood clots, blood stasis, damaged liver and some organs, reduced immune function, and increased mortality. The raw materials of soybean, wheat, corn and the like are main components of fish feed, and are also plant-derived feed raw materials which are likely to carry more aflatoxin, for example, the corn can contain 6000 mug/kg of aflatoxin at most. In addition, the feed is easy to mildew and generate aflatoxin when being stored in a damp and hot environment (particularly in the south), so that the possibility of aflatoxin infection to fishes is high.

In the related technology, the detection of all raw materials related to mycotoxin is the only method for preventing aflatoxin poisoning of aquatic animals at present, and because the sensitivity of fish fries to aflatoxin is high, the requirement on detection accuracy is extremely high, so that a large amount of manpower and material resources are consumed in the early work of preventing aflatoxin poisoning of aquatic animals, and the cost is extremely high.

Therefore, it is urgently needed to develop a preparation which can directly prevent and treat aflatoxin poisoning of aquatic animals, so as to reduce a large amount of preliminary work, improve the safety of aquaculture and reduce loss.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art described above. Therefore, the invention provides the application of the condensed tannin in preparing the medicine or the preparation for treating the aflatoxin poisoning of the aquatic animals, and the condensed tannin accounting for 0.1 to 0.2 percent is added into the feed or other preparations, so that the aflatoxin poisoning of the aquatic animals is effectively relieved or treated.

The first aspect of the invention provides application of condensed tannin in preparing a medicine or a preparation for treating aflatoxin poisoning of aquatic animals.

In some embodiments, the condensed tannins have the formula I:

in the formula I, n is selected from any integer of more than or equal to 14;

the R group is hydroxyl (-OH) or hydrogen (-H), and comprises cis and trans structures.

Depending on the choice of the R group, the repeat unit in formula I may include one or more of catechin, epicatechin, gallocatechin, or epigallocatechin.

According to the first aspect of the present invention, in a specific embodiment, at least the following advantages are provided:

the invention discloses that 0.1-0.2% of condensed tannin can effectively treat or relieve the damage of aflatoxin to liver and intestinal tract of weever, thereby avoiding the problems of malnutrition, slow growth and the like of weever caused by aflatoxin poisoning, improving the survival rate of weever after aflatoxin poisoning, and reducing the harm and economic loss of aflatoxin in aquaculture to aquaculture.

According to a first aspect of the present invention, in some preferred embodiments of the present invention, said condensed tannins are derived from plants comprising one or more of dalmatian purple, vitis vinifera marc, stylosanthes guianensis.

According to a first aspect of the invention, in some preferred embodiments of the invention, n in formula I is taken from 14, 15 or 17, such that the degree of polymerization of the compound in formula I reaches 17, 18 or 20.

In some more preferred embodiments of the present invention, the condensed tannin has a degree of polymerization of 17.

According to a first aspect of the present invention, in some preferred embodiments of the present invention, the above condensed tannins are procyanidin tannins: the mass ratio of the raw delphinidin tannin is more than 3.3.

In some more preferred embodiments of the present invention, the procyanidin tannin of the condensed tannins described above: the mass ratio of the raw delphinidin tannin is more than 4.2.

In some preferred embodiments of the present invention, the condensed tannins have an epicatechin extender content of greater than 62.3%.

In some more preferred embodiments of the present invention, the condensed tannins have an epicatechin extender content of greater than 68.8%.

In some preferred embodiments of the present invention, the condensed tannins have an epigallocatechin gallate extension unit content of greater than 23.5%.

In some more preferred embodiments of the present invention, the condensed tannins have an epigallocatechin gallate extension unit content of greater than 28.0%.

In some preferred embodiments of the present invention, the condensed tannin has a molecular weight of 1 to 20 kDa.

According to the first aspect of the present invention, in some preferred embodiments of the present invention, the mass concentration of the condensed tannin in the medicine, preparation or feed for treating aflatoxin poisoning of aquatic animals is less than 0.3%.

In some preferred embodiments of the present invention, the mass concentration of the condensed tannin in the medicine, preparation or feed for treating aflatoxin poisoning of aquatic animals is 0.1-0.2%.

In some more preferred embodiments of the present invention, the concentration of the condensed tannin in the therapeutic agent, preparation or feed for aflatoxin poisoning of aquatic animals is 0.2% by mass.

In some preferred embodiments according to the first aspect of the invention, the aflatoxins include aflatoxins B1, B2, G1, G2, M1, M2, GM, P1, Q1, aflatoxin-hydrin and derivatives thereof.

In some more preferred embodiments of the invention, the aflatoxin described above is aflatoxin B1.

In a second aspect of the invention, there is provided an aquaculture feed comprising imported fish meal, soybean meal, rapeseed meal, flour, monocalcium phosphate, soybean oil, fish oil, soybean lecithin, a vitamin premix, a mineral premix, VC phosphate, choline chloride, betaine, lysine, methionine, microcrystalline cellulose and condensed tannin.

Wherein the vitamin premix contains at least one of VA, VB, VD, VE, VK, calcium pantothenate, inositol or biotin; the mineral premix contains at least one of magnesium, calcium, iodine, potassium, copper, zinc, iron, cobalt or selenium.

In some preferred embodiments of the present invention, the vitamin premix contains VA and VB₁，VB₂，VB₆Nicotinic acid, folic acid, VB₁₂VD, VE, VK, calcium pantothenate, inositol, biotin; the mineral premix contains MgSO₄·H₂O， Ca(IO₃)₂KCl, methionine Cu, ZnSO₄·H₂O，FeSO₄·H₂O, methionine Co, NaSeO₃。

According to the second aspect of the invention, in some preferred embodiments of the invention, the aquatic feed comprises, by mass, 25 to 30 parts of imported fish meal, 25 to 28 parts of soybean meal, 8 to 12 parts of rapeseed meal, 25 to 30 parts of flour, 1 to 2 parts of monocalcium phosphate, 1 to 4 parts of soybean oil, 1 to 3 parts of fish oil, 1 to 3 parts of soybean lecithin, 0.1 to 0.5 part of vitamin premix, 0.1 to 1 part of mineral premix, 0.1 to 0.2 part of VC phosphate, 0.1 to 1 part of choline chloride, 0.1 to 1 part of betaine, 0.01 to 0.1 part of lysine, 0.1 to 1 part of methionine, 1 to 2 parts of microcrystalline cellulose, and 0.1 to 0.3 part of condensed tannin.

According to the second aspect of the invention, in some preferred embodiments of the invention, the aquatic feed comprises, by mass, 25 to 30 parts of imported fish meal, 25 to 28 parts of soybean meal, 8 to 10 parts of rapeseed meal, 25 to 26 parts of high gluten flour, 1 to 1.5 parts of monocalcium phosphate, 1 to 3 parts of soybean oil, 1 to 2 parts of fish oil, 2 to 3 parts of soybean lecithin, 0.1 to 0.2 part of vitamin premix, 0.1 to 0.5 part of mineral premix, 0.1 to 0.15 part of VC phosphate, 0.1 to 0.5 part of choline chloride, 0.1 to 0.5 part of betaine, 0.01 to 0.05 part of lysine, 0.1 to 0.25 part of coated methionine, 1 to 2 parts of microcrystalline cellulose, and 0.1 to 0.2 part of condensed tannin.

In some more preferred embodiments of the invention, the aquatic feed product comprises: 28% of imported fish meal, 24% of soybean meal, 10% of rapeseed meal, 26% of high gluten flour, 1.5% of monocalcium phosphate, 3% of soybean oil, 2% of fish oil, 2% of soybean lecithin, 0.1% of vitamin premix, 0.5% of mineral premix, 0.14% of VC phosphate, 0.5% of choline chloride, 0.5% of betaine, 0.03% of lysine, 0.22% of enveloped methionine, 1.31% of microcrystalline cellulose powder and 0.2% of condensed tannin.

According to the second aspect of the present invention, in a specific embodiment, at least the following advantageous effects are provided:

according to the invention, 0.2% of condensed tannin is added into the feed, so that the damage of aflatoxin to liver and intestinal tract of weever can be effectively treated or relieved, thereby avoiding the problems of malnutrition, slow growth and the like of weever caused by aflatoxin poisoning, improving the survival rate of weever after aflatoxin poisoning, and reducing the harm and economic loss of aflatoxin in aquaculture to aquaculture.

In a third aspect of the invention, there is provided a process for the preparation of an aquaculture feed product according to the second aspect of the invention, comprising the steps of:

(1) weighing the components in the formula of the aquatic feed of the second aspect of the invention, crushing and mixing;

(2) and (3) carrying out microwave tempering, high-temperature puffing and cooling on the mixed components to obtain the product.

Wherein, the power of the microwave hardening and tempering in the step (2) is 800-.

The puffing temperature in the step (2) is 110 ℃, and the pressure in the puffing cavity is 1.83 Mpa.

Microwave tempering is the improvement of feed quality by utilizing the thermal effect generated by the microwave electromagnetic field. Compared with the traditional steam conditioning method, the method has the advantages that:

(1) the hardening and tempering time is shortened. Microwave heating belongs to an internal heating mode, electromagnetic energy directly acts on medium molecules to be converted into heat energy, the medium is heated inside and outside simultaneously through transmission, heat conduction is not needed, and therefore the purpose of rapid and uniform heating can be achieved.

(2) And (4) uniformly heating. The microwave conditioning does not limit the shape of the feed, and the microwave can uniformly permeate regardless of the shape of the microwave, so the heating uniformity is greatly improved.

(3) Energy conservation and high efficiency. The heating chamber for microwave tempering is a closed cavity for electromagnetic waves, the electromagnetic waves cannot leak out and can only be absorbed by a heated object, and air in the heating chamber and a metal wall surface cannot be heated, so that the heat efficiency is high. Meanwhile, the environmental temperature outside the conditioner is not increased, so that the energy conservation and the environmental protection are achieved.

(4) Easy to control. The control of the microwave power is adjusted by a switch and a knob, and the microwave power is ready to use when being started, has no thermal inertia, is continuously adjustable in power and is easy to automate.

(5) Reducing the loss rate of nutrient substances. Compared with the traditional steam conditioning, the microwave conditioning time is greatly shortened, the protection of vitamins, trace elements, condensed tannin and other nutrients in the feed is facilitated, and the feed quality is improved.

In a fourth aspect of the invention there is provided the use of an aquaculture feed product according to the second aspect of the invention or prepared according to the method of the third aspect of the invention in aquaculture.

In some preferred embodiments of the invention, the aquatic animal is a weever.

In a fifth aspect of the invention, the condensed tannin is used as a feed additive in the preparation of feed for preventing or treating aflatoxin poisoning of aquatic animals.

In some preferred embodiments of the invention, the aquatic animal is a weever.

Drawings

FIG. 1 is a nuclear magnetic resonance spectrum of condensed tannins in an example of the present invention;

FIG. 2 shows HE stained sections (X200 times) of G0 group weever hepatocytes in examples of the present invention;

FIG. 3 is a G1 group weever hepatocyte HE stained section (x 200 fold) in an example of the present invention;

FIG. 4 is a G2 group weever hepatocyte HE stained section (x 200 fold) in an example of the present invention;

FIG. 5 shows HE stained sections (X200 times) of G3 group weever hepatocytes in examples of the present invention;

FIG. 6 is a G4 group weever hepatocyte HE stained section (x 200 fold) in an example of the present invention;

FIG. 7 is a G0 group of weever colon histopathological HE stained section (x 40 fold) in an example of the present invention;

FIG. 8 is a G1 group of weever colon histopathological HE stained section (x 40 fold) in an example of the present invention;

FIG. 9 is a G2 group of weever colon histopathological HE stained section (x 40 fold) in an example of the present invention;

FIG. 10 is a G3 group of weever colon histopathological HE stained section (x 40 fold) in an example of the present invention;

FIG. 11 is a G4 group of weever colon histopathological HE stained section (x 40 fold) in an example of the present invention.

Detailed Description

In order to make the objects, technical solutions and technical effects of the present invention more clear, the present invention will be described in further detail with reference to specific embodiments. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

The experimental materials and reagents used are, unless otherwise specified, all consumables and reagents which are conventionally available from commercial sources.

Experimental Material

(1) Preparation of condensed tannin:

freeze-drying the plant sample, and crushing until all the plant sample passes through a 1.0mm standard sieve.

② adding extracting solution (laccase 10U/mL, cellulase 150U/mL, pectinase 20U/mL) for extraction for 40min, wherein the extracting temperature is 45 ℃, the pH value of the extracting solution is 5.0, and the material-liquid ratio is 1:20 g/mL. And carrying out vacuum filtration and freeze-drying on the extracting solution to obtain a crude extract.

Dissolving the crude extract in 80% methanol solution, filtering to remove impurities, adding the filtrate into a cross-linked dextran column, stirring thoroughly, standing for 30min, and vacuum filtering. Repeating the steps for a plurality of times until the solution obtained after vacuum filtration becomes colorless. The filtrate was discarded.

(iv) repeatedly washing the Sephadex column with 50% acetone solution (containing 0.1% ascorbic acid) until the eluate turns colorless.

Fifthly, evaporating and concentrating the eluent (40 ℃, 30min), and freeze-drying to obtain the high-purity plant condensed tannin.

Wherein the plants in the step (i) comprise one or more of purple dalbergia, wine grape residues and stylosanthes guianensis.

(2) Identification of condensed tannins:

by using¹H-¹³The high purity plant condensed tannin prepared in the above example was identified by C HSQC NMR spectrum, and the identification results are shown in FIG. 1.

The results showed that the condensed tannin prepared in the above example had a purity of 96.5%. The degree of polymerization of the condensed tannin was 17, the mass ratio of procyanidin tannin to procyanidin tannin in the condensed tannin was 3.3, the content of epicatechin as an extension unit was 68.8%, and the content of epigallocatechin as an extension unit was 28.0%.

Example 1

An aquatic feed, the aquatic formula is: 28% of imported fish meal, 24% of soybean meal, 10% of rapeseed meal, 26% of high gluten flour, 1.5% of monocalcium phosphate, 3% of soybean oil, 2% of fish oil, 2% of soybean lecithin, 0.1% of vitamin premix, 0.5% of mineral premix, 0.14% of VC phosphate, 0.5% of choline chloride, 0.5% of betaine, 0.03% of lysine, 0.22% of enveloped methionine, 1.31% of microcrystalline cellulose powder and 0.2% of condensed tannin.

Wherein the vitamin premix is a conventional vitamin premix for meat fish in the field, and comprises VA and VB₁，VB₂， VB₆Nicotinic acid, folic acid, VB₁₂VD, VE, VK, calcium pantothenate, inositol, biotin. The mineral premix is also conventional in the art, and comprises MgSO₄·H₂O，Ca(IO₃)₂KCl, methionine Cu, ZnSO₄·H₂O，FeSO₄·H₂O, methionine Co, NaSeO₃。

Weighing the raw materials of the components according to the content of the components, and uniformly mixing the raw materials after being crushed by a crusher. And (3) carrying out microwave tempering on the mixed raw materials of the components, wherein the microwave power is 1000W, and the microwave treatment time is 90 s. Then placing the raw materials after the microwave treatment into a bulking machine, bulking at the temperature of 110 ℃ and the pressure of a bulking cavity of 1.83Mpa, and cooling to obtain the feed for preventing or treating aflatoxin poisoning of aquatic animals.

Example 2

An aquatic feed, the aquatic formula is: 28 percent of imported fish meal, 24 percent of soybean meal, 10 percent of rapeseed meal, 26 percent of high gluten flour, 1.5 percent of calcium dihydrogen phosphate, 3 percent of soybean oil, 2 percent of fish oil, 2 percent of soybean lecithin, 0.1 percent of vitamin premix, 0.5 percent of mineral premix, 0.14 percent of VC phosphate, 0.5 percent of choline chloride, 0.5 percent of betaine, 0.03 percent of lysine, 0.22 percent of enveloped methionine, 1.41 percent of microcrystalline cellulose powder and 0.1 percent of condensed tannin.

Wherein the vitamin premix is a conventional vitamin premix for meat fish in the field, and comprises VA and VB₁，VB₂， VB₆Nicotinic acid, folic acid, VB₁₂VD, VE, VK, calcium pantothenate, inositol, biotin. The mineral premix is also conventional in the art, and comprises MgSO₄·H₂O，Ca(IO₃)₂KCl, methionine Cu, ZnSO₄·H₂O，FeSO₄·H₂O, methionine Co, NaSeO₃。

Weighing the raw materials of the components according to the content of the components, and uniformly mixing the raw materials after being crushed by a crusher. And (3) carrying out microwave tempering on the mixed raw materials of the components, wherein the microwave power is 1000W, and the microwave treatment time is 90 s. Then placing the raw materials after the microwave treatment into a bulking machine, bulking at the temperature of 110 ℃ and the pressure of a bulking cavity of 1.83Mpa, and cooling to obtain the feed for preventing or treating aflatoxin poisoning of aquatic animals.

Comparative example 1

An aquatic feed, the aquatic formula is: 28 percent of imported fish meal, 24 percent of soybean meal, 10 percent of rapeseed meal, 26 percent of high gluten flour, 1.5 percent of calcium dihydrogen phosphate, 3 percent of soybean oil, 2 percent of fish oil, 2 percent of soybean lecithin, 0.1 percent of vitamin premix, 0.5 percent of mineral premix, 0.14 percent of VC phosphate, 0.5 percent of choline chloride, 0.5 percent of betaine, 0.03 percent of lysine, 0.22 percent of enveloped methionine and 1.51 percent of microcrystalline cellulose powder.

The preparation is as in example 1.

Comparative example 2

An aquatic feed, the aquatic formula is: 28 percent of imported fish meal, 24 percent of soybean meal, 10 percent of rapeseed meal, 26 percent of high gluten flour, 1.5 percent of calcium dihydrogen phosphate, 3 percent of soybean oil, 2 percent of fish oil, 2 percent of soybean lecithin, 0.1 percent of vitamin premix, 0.5 percent of mineral premix, 0.14 percent of VC phosphate, 0.5 percent of choline chloride, 0.5 percent of betaine, 0.03 percent of lysine, 0.22 percent of enveloped methionine, 1.21 percent of microcrystalline cellulose powder and 0.3 percent of condensed tannin.

Comparative example 3

An aquatic feed, the aquatic formula is: 28 percent of imported fish meal, 24 percent of soybean meal, 10 percent of rapeseed meal, 26 percent of high gluten flour, 1.5 percent of calcium dihydrogen phosphate, 3 percent of soybean oil, 2 percent of fish oil, 2 percent of soybean lecithin, 0.1 percent of vitamin premix, 0.5 percent of mineral premix, 0.14 percent of VC phosphate, 0.5 percent of choline chloride, 0.5 percent of betaine, 0.03 percent of lysine, 0.22 percent of enveloped methionine, 1.41 percent of microcrystalline cellulose powder and 0.1 percent of hydrolyzed tannin.

Comparative example 4

An aquatic feed, the aquatic formula is: 28 percent of imported fish meal, 24 percent of soybean meal, 10 percent of rapeseed meal, 26 percent of high gluten flour, 1.5 percent of calcium dihydrogen phosphate, 3 percent of soybean oil, 2 percent of fish oil, 2 percent of soybean lecithin, 0.1 percent of vitamin premix, 0.5 percent of mineral premix, 0.14 percent of VC phosphate, 0.5 percent of choline chloride, 0.5 percent of betaine, 0.03 percent of lysine, 0.22 percent of enveloped methionine, 1.31 percent of microcrystalline cellulose powder and 0.2 percent of hydrolyzed tannin.

Effect verification

(1) Constructing an aflatoxin poisoning model:

the weever with the average weight of 2.9 g/tail is selected as a test object, the culture test is carried out in a recirculating aquaculture system, the culture test is divided into 5 groups, 15 jars (the volume of water is 300L, the diameter is 80cm, the height is 70cm) are arranged, each group is repeated for 3 times, each group repeats 35 fishes, and the culture period is 8 weeks.

The aquatic feed prepared in the comparative example 1 is fed only by taking the comparative example 1 as a blank control G0, and the aflatoxin B1 is not added.

The test groups were:

test group G1 fed the aquatic feed prepared in comparative example 1, to which was added 1mg/kg aflatoxin B1.

Test group G2 fed the aquatic feed prepared in example 1, to which was added 1mg/kg aflatoxin B1.

Test group G3 fed the aquatic feed prepared in example 2, and 1mg/kg aflatoxin B1 was added to the feed.

Test group G4 fed the aquatic feed prepared in comparative example 2, to which was added 1mg/kg aflatoxin B1.

Test group G5 fed the aquatic feed prepared in comparative example 3, and 1mg/kg aflatoxin B1 was added to the feed.

Test group G6 fed the aquatic feed prepared in comparative example 4, to which was added 1mg/kg aflatoxin B1.

(2) Detecting the growth condition of the weever:

the feeding test is carried out according to the groups in the embodiment, the weight gain condition of the weever is measured after 8 weeks of culture, and the weight gain rate and the specific growth rate are calculated so as to analyze the influence of the aflatoxin on the growth condition of the weever and the relief condition of different groups of feeds on the aflatoxin poisoning.

The results are shown in Table 1.

TABLE 1 Effect of different groups of feeds on the growth of aflatoxin-poisoned weever

Note: the same row of data and marked with different lower case letters indicate significant difference (P < 0.05), and the same or no letter indicates insignificant difference (P > 0.05).

From the table 1, it can be seen that the growth level of the weever can be remarkably reduced by feeding 1mg/kg of aflatoxin B1 into the weever, and the weight gain rate of G1 is reduced by 651.7% compared with that of G0, which indicates that the aflatoxin B1 can seriously hinder the normal growth of the weever. The condensed tannins extracted in the previous embodiment are respectively added in the groups G2 and G3 in an amount of 0.1 percent and 0.2 percent, and under the condition that other nutrient components are the same as G1, the weight gain rates of the groups G2 and G3 are only reduced by 10.3 percent and 69.0 percent, which shows that the condensed tannins can relieve the inhibition effect of aflatoxin B1 on the growth of weever, and the effect is better along with the increase of the content of the condensed tannins. However, when the content of the condensed tannin exceeds 3% (G4), the average weight, the weight gain rate and the specific growth rate of the weever are obviously reduced (P is less than 0.05), which shows that after the limited dosage of more than 3%, the excessive condensed tannin mainly plays a role in anti-nutrition instead, so that the absorption of nutrient components by the weever is weaker, and the growth condition of the weever is worse.

When the hydrolyzed tannin with the same quantity as G2 and G3 is added into the feed as the additive, the action effect of G5 and G6 on weever is not obviously different from that of G1, which indicates that the hydrolyzed tannin has no detoxification effect or that the hydrolyzed tannin has weaker action effect than the condensed tannin, probably because the hydrolyzed tannin has simple structure and small molecular weight and is easy to be degraded in the digestive tract of animals and can not fully exert the bioactivity.

(3) The condensed tannin has the following treatment effects on liver injury caused by aflatoxin poisoning of weever:

according to the results of the above examples, the treatment effect of condensed tannin on liver damage caused by aflatoxin poisoning of weever is further explored, and the experimental design is as follows:

the method in the embodiment is adopted to construct an aflatoxin poisoning model, the schemes from G0 to G4 are adopted to carry out a grouping feeding test, after 8 weeks of feeding, weever in each group is randomly extracted, the liver is taken out, a liver section (HE staining) is prepared by adopting a conventional method in the field, and the morphological structure of the liver cell is observed under a microscope.

The shapes of the hepatocytes G0-G4 are shown in FIGS. 1-5.

Fig. 2 shows the liver of normal fed weever, and after 1mg/kg aflatoxin B1 is added, it can be found that aflatoxin B1 can cause severe pathological changes of weever liver, significant changes of hepatocyte morphology, severe vacuolation and inflammatory infiltration (fig. 3). After 0.1-0.2% of condensed tannin is added, the morphology of the liver cells of the weever is obviously changed, which shows that 0.1-0.2% of condensed tannin can effectively relieve the damage of aflatoxin B1 to the liver of the weever and relieve the poisoning symptom of aflatoxin B1 (fig. 4 and 5). When the addition amount of the condensed tannin is increased to 0.3%, the liver cells of the weever are denatured to generate damage and pathological changes (figure 6), which shows that the addition amount of the condensed tannin is not suitable to be increased to 0.3% or more.

(4) The condensed tannin has the following treatment effects on intestinal injury caused by aflatoxin poisoning of weever:

according to the results of the above examples, the treatment effect of condensed tannin on intestinal tract injury caused by aflatoxin poisoning of weever is further explored, and the experimental design is as follows:

the method in the embodiment is adopted to construct an aflatoxin poisoning model, the schemes from G0 to G4 are adopted to carry out a grouped feeding test, after 8 weeks of feeding, weever in each group is randomly extracted, intestinal tracts are taken out, intestinal tissue sections (HE staining) are prepared by adopting the conventional means in the field, and the intestinal villus morphological structure is observed under a microscope.

The intestinal villus forms of G0-G4 are shown in FIGS. 7-11.

FIG. 6 shows colon tissues of normal fed weever, and after 1mg/kg of aflatoxin B1 is added, it can be found that aflatoxin B1 changes the villus morphological structure of weever intestinal canals, the length of intestinal villus is remarkably reduced (P < 0.05), and the number of goblet cells is remarkably reduced (P < 0.05), which indicates that aflatoxin B1 damages intestinal morphology of weever (FIG. 8). After 0.1-0.2% of condensed tannin is added, the villus morphological structure and the villus length of the weever intestines are close to normal, which shows that 0.1-0.2% of condensed tannin can effectively relieve the damage of aflatoxin B1 to weever intestines and relieve the poisoning symptom of aflatoxin B1 (fig. 9 and fig. 10). When the addition amount of the condensed tannin is increased to 0.3%, the morphology and length of intestinal villi of weever are seriously damaged (fig. 11), and thus, it is demonstrated that the addition amount of the condensed tannin is not preferably increased to 0.3% or more.

In conclusion, 0.1-0.2% of condensed tannin can effectively treat or relieve the damage of aflatoxin to liver and intestinal tract of weever, thereby avoiding the problems of malnutrition, slow growth and the like of weever caused by aflatoxin poisoning, improving the survival rate of weever after aflatoxin poisoning, and reducing the harm and economic loss of aflatoxin in aquaculture to aquaculture.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.