Targeted gill immunopotentiator for high-density cultured trachinotus ovatus as well as preparation method and application thereof

Abstract

The invention discloses a targeted gill immunopotentiator for high-density cultured trachinotus ovatus as well as a preparation method and application of the targeted gill immunopotentiator, and belongs to the technical field of aquaculture. According to the invention, centella asiatica, dried orange peel, dandelion, common carpesium fruit, dried ginger, mangnolia officinalis, vitamin and guanidinoacetic acid are used as a formula to prepare the immunopotentiator capable of enhancing fish immunity. The immunopotentiator can protect the completeness of the gill, acts on the gill part, plays an immunoregulation role, and reduces the occurrence rate of gill diseases; the immunopotentiator contains bacteriostatic and anti-inflammatory components, and can inhibit reproduction of pathogenic bacteria and reduce inflammatory injury. Vitamin C, vitamin E and guanidinoacetic acid in the immunopotentiator can further enhance the ability of fishes to resist pathogenic microorganisms; the guanidinoacetic acid can also reduce the energy supply demand of protein decomposition, indirectly promote muscle protein synthesis, and improve the nutritional value of the trachinotus ovatus.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aquaculture, in particular to a high-density cultured Trachinotus blochii targeted gill immune enhancer, and a preparation method and application thereof. BACKGROUND

[0002] Trachinotus blochii is a high economic value marine fish, which has become a high-end food material in the consumer market and a supporting variety in the aquaculture industry due to its fast growth rate, tender meat, high-quality protein, unsaturated fatty acids and essential trace elements (selenium and zinc).

[0003] To improve economic benefits, the breeding density of Trachinotus blochii is continuously increased, but high feeding amount leads to a sharp increase in residual feed and excrement, causing the ammonia nitrogen and nitrite content in the water to exceed the safety threshold. High concentration of ammonia nitrogen can interfere with the osmoregulation system of fish, damage the mucous membrane of the gill, and reduce the oxygen carrying capacity of red blood cells, resulting in chronic poisoning of Trachinotus blochii and slow growth. In addition, high ammonia nitrogen can damage the epithelium, stomach and intestinal mucosa of fish, causing bleeding on the body surface and internal organs. It can also harm the brain and central nervous system, and even directly cause the death of the organism. The gill is not only a respiratory organ, but also a core component of the mucosal immune system of fish. The epithelial layer is rich in immune effector cells, immune active molecules and immune recognition receptors. Damage to the gill leads to immune collapse, resulting in loss of physical barrier, inhibition of immune cell function and immune recognition disorder, and ultimately leading to the death of the fish.

[0004] Gill tissue is the core organ for achieving the trinity function of respiratory metabolism, ammonia nitrogen excretion and immune defense of golden pompano. The structural integrity and functional stability of gill tissue directly affect the health level and economic benefits of fish. Maintaining the health of gill can not only ensure the stability of blood oxygen saturation and plasma osmotic pressure, but also prevent acute death caused by hypoxia. Moreover, through the intact gill mucosa immune barrier, the invasion of pathogens can be blocked, and the incidence of bacterial sepsis can be reduced. From the perspective of industrial economy, healthy gill tissue can increase the survival rate of aquaculture, significantly shorten the breeding cycle, reduce the loss of live fish transportation, and directly improve the economic benefits. Therefore, developing a technology that targets to repair gill damage and synchronously enhances immunity is the key to solving the problem of high-density breeding of golden pompano, and has urgent significance for ensuring the sustainable development of the hundred-billion-level industry chain. At present, the prevention and treatment of gill erosion mainly depends on water adjustment, water disinfection and drug intervention. In high-density breeding of golden pompano, the rapid accumulation of residual feed and feces leads to a sharp increase in the concentration of pollutants such as ammonia nitrogen and nitrite in the water, which is sudden and spreads quickly. Farmers often fail to respond in time, and acute damage such as gill filament hyperemia and epithelial shedding occurs before they can adjust the water, which directly damages the respiratory and immune barriers and can cause large-scale death in a short period of time. Frequent water disinfection can weaken the natural immune system of fish, making them less resistant to disease. Drug treatment often uses antibiotics, chemical agents or single Chinese medicine components, which can suppress symptoms in the short term, but are prone to induce drug resistance and drug residues, which endanger food safety and the ecological environment. SUMMARY

[0005] The purpose of the present application is to provide a high-density breeding golden pompano targeted gill immune enhancer and its preparation method and application, in order to solve the problems existing in the prior art. The present application uses Yunnan snowbell root, tangerine or orange peel, dandelion, hirudinea, dried ginger, magnolia officinalis, vitamins and guanidino acetic acid as the formula to prepare an immune enhancer that can enhance the immunity of fish. The immune enhancer can protect the integrity of the fish gill, act on the gill, play an immune regulation role, and reduce the incidence of fish gill disease; the immune enhancer contains antibacterial and anti-inflammatory components, which can inhibit the reproduction of pathogenic bacteria and reduce inflammation damage. Vitamin C, vitamin E and guanidino acetic acid in the immune enhancer can further enhance the resistance of fish to pathogenic microorganisms; guanidino acetic acid can also reduce the demand for protein decomposition for energy, indirectly promote muscle protein synthesis, and improve the nutritional value of golden pompano.

[0006] To achieve the above purpose, the present application provides the following scheme:

[0007] The present application provides a high-density breeding golden pompano targeted gill immune enhancer, which comprises the following raw materials by weight: Chinese herbal medicine extract 2-4 parts, vitamin C 2-5 parts, vitamin E 2-5 parts and guanidino acetic acid 0.5-3 parts;

[0008] The Chinese herbal medicine extract comprises raw materials in the following weight parts: 15-30 parts of Gotukoa, 5-15 parts of dried tangerine or orange peel, 5-10 parts of dandelion, 5-10 parts of Herba Lycopi, 3-8 parts of dried ginger and 3-6 parts of Magnolia officinalis.

[0009] Further, the immune enhancer comprises raw materials in the following weight parts: 2 parts of Chinese herbal medicine extract, 2 parts of vitamin C, 2 parts of vitamin E and 2 parts of guanidino acetic acid.

[0010] The Chinese herbal medicine extract comprises raw materials in the following weight parts: 30 parts of Gotukoa, 5 parts of dried tangerine or orange peel, 5 parts of dandelion, 8 parts of Herba Lycopi, 8 parts of dried ginger and 6 parts of Magnolia officinalis.

[0011] Further, the immune enhancer comprises raw materials in the following weight parts: 2 parts of Chinese herbal medicine extract, 2 parts of vitamin C, 2 parts of vitamin E and 2 parts of guanidino acetic acid.

[0012] The application also provides a preparation method of the above-mentioned immune enhancer, comprising the following steps:

[0013] The Gotukoa, dried tangerine or orange peel, dandelion, Herba Lycopi, dried ginger and Magnolia officinalis are dried, crushed, extracted with water, precipitated with alcohol, and freeze-dried to obtain the Chinese herbal medicine extract;

[0014] The Chinese herbal medicine extract is mixed with vitamin C, vitamin E and guanidino acetic acid to obtain the immune enhancer.

[0015] Further, the water extraction and alcohol precipitation step is as follows:

[0016] (1) The crushed raw materials are mixed with water, and after 100-150 min of water bath extraction at 95℃, the mixture is filtered;

[0017] (2) The extraction of step (1) is repeated twice, and the filtrates are combined;

[0018] (3) The obtained filtrate is concentrated by rotary evaporation, and then 95% ethanol solution is added in a volume ratio of 1:5, and the precipitate is obtained by precipitation, and the supernatant is discarded and the precipitate is washed.

[0019] Optionally, the ratio of the crushed raw materials to water is 1 g:10 mL.

[0020] Optionally, the volume fraction of the ethanol solution is 95%.

[0021] The application also provides the use of the above-mentioned immune enhancer in the preparation of goldfish feed.

[0022] The application also provides a goldfish feed for enhancing the immunity of high-density cultured goldfish, wherein the goldfish feed comprises the above-mentioned immune enhancer.

[0023] Optionally, the immune enhancer accounts for 0.3wt%-0.5wt% in the gold pomfret feed.

[0024] The application also provides a method for enhancing the immunity of high-density cultured gold pomfret, which utilizes the gold pomfret feed described above to feed the gold pomfret.

[0025] The application discloses the following technical effects:

[0026] The application discloses an immune enhancer for enhancing the immunity of fish, which is prepared from Centella asiatica, dried tangerine or orange peel, dandelion, hawkthorn, dried ginger, magnolia, vitamins and guanidoacetic acid. The immune enhancer can protect the integrity of fish gills, act on the gills, play an immune regulation role, and reduce the incidence of fish gill diseases. The immune enhancer contains bacteriostatic and anti-inflammatory components, and can inhibit the reproduction of pathogenic bacteria and reduce inflammatory damage. Vitamin C, vitamin E and guanidoacetic acid in the immune enhancer can further enhance the resistance of fish to pathogenic microorganisms. Guanidoacetic acid can also reduce the demand for protein decomposition for energy, indirectly promote muscle protein synthesis, and improve the nutritional value of gold pomfret.

[0027] The application provides an effective immune enhancer for high-density culture of gold pomfret, which can reduce bacterial infection problems in the high-density culture process from two aspects of improving the immunity of fish and inhibiting the reproduction of bacteria in water, reduce fish gill erosion problems, improve the survival rate and growth performance of fish, and provide technical support for reducing the culture cost of gold pomfret and improving the culture benefit. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings in the following description only constitute some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0029] Figure 1 The results of the bacteriostatic effect determination of the medicinal extract in Example 1;

[0030] Figure 2 The death conditions of gold pomfret in each group in the pre-experiment of Test Example 1;

[0031] Figure 3 The death conditions of gold pomfret in each group in the formal experiment of Test Example 1;

[0032] Figure 4 The observation diagram of the gills of gold pomfret in each group in the formal experiment of Test Example 1. DETAILED DESCRIPTION

[0033] The detailed description set forth below of various illustrative embodiments explains the principles of the application and demonstrates the practical application of the application. It is to be understood that the detailed description and specific examples described herein are merely intended to describe certain aspects of the application and are not intended to limit the scope of the application.

[0034] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Additionally, it is to be understood that where the application is herein described as comprising or having particular elements, this is intended to mean that the application comprises or has at least one of the particular elements. Furthermore, where the application is herein described as comprising or having particular components, this is intended to mean that the application comprises or has at least one of the particular components.

[0035] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Although preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application. All documents mentioned herein are incorporated by reference to disclose and describe in detail the methods and / or materials useful in connection to the documents. In the case of conflict between the present specification and any document incorporated herein by reference, the present specification will control.

[0036] Various modifications and changes can be made to the specific embodiments described herein without departing from the scope or spirit of the application. Other embodiments of the application will be apparent to those of ordinary skill in the art from the description and examples herein. The description and examples are illustrative of the application and are not intended to limit the scope of the application.

[0037] As used herein, the terms "comprises", "comprising", "includes", "including", "has", "having", "contains", "containing", or variations thereof, are intended to be open-ended terms that mean including, but not limited to.

[0038] Example 1

[0039] The Chinese medicine extract was prepared according to the following formula: Centella asiatica 25 parts, Citrus reticulata 10 parts, Taraxacum officinale 5 parts, Herba Lycopi 8 parts, Zingiber officinale 6 parts, Magnolia officinalis 6 parts.

[0040] The preparation method of the Chinese medicine extract is as follows:

[0041] (1) Centella asiatica, Citrus reticulata, Taraxacum officinale, Herba Lycopi, Zingiber officinale and Magnolia officinalis were dried according to the proportion, and then crushed;

[0042] (2) Water extraction and alcohol precipitation was performed on Radix Rehmanniae Glutinosae, Pericarpium Citri Reticulatae, Herba Taraxaci, Herba Lycopi, Rhizoma Zingiberis Recens, and Magnoliae Officinalis: distilled water was added at a solid-liquid ratio of 1:10 (g / mL), and the mixture was extracted at 95°C for 120 min in a water bath, and then filtered. The residue was extracted twice more, and the filtrates were combined, filtered, and centrifuged at 12,000 g for 5 min. The supernatant was concentrated to dryness in a rotary evaporator, and then 5 times the volume of 95% ethanol was added to the concentrate, followed by precipitation for 12 h. The precipitate was then centrifuged at 10,000 g for 5 min, and the supernatant was discarded. The precipitate was precipitated twice more with anhydrous ethanol, and then dried in a vacuum. The precipitate was ground in a pulverizer and passed through a 100-mesh screen to obtain the extract of traditional Chinese medicine.

[0043] The prepared traditional Chinese medicine extract was tested for antibacterial effect on Streptococcus agalactiae using the BHIA plate diffusion method and the Oxford cup punch method. The antibacterial effect was evaluated by the size of the inhibition zone. The operation method was as follows: 0.1 mL of Streptococcus agalactiae liquid with a concentration of 1×10 7 CFU / mL was spread on a BHIA plate, and then dried. Three holes were punched in each plate using an Oxford cup. Five times and ten times dilutions of the traditional Chinese medicine extract and sterilized saline were added to the three holes, respectively, at 0.1 mL per hole, ensuring that the holes were filled but not overflowing. Each type of liquid was tested three times. The results are shown in Table 1. Figure 1 As can be seen from Table 1, the traditional Chinese medicine extract had an antibacterial effect on Streptococcus agalactiae. After being diluted five times, the diameter of the inhibition zone was the largest, and the antibacterial effect was the best.

[0044] Example 2

[0045] This example is an optimization of the formulation of the traditional Chinese medicine extract in Example 1. The specific optimization process is as follows:

[0046] Experimental group A: Radix Rehmanniae Glutinosae 25 parts, Pericarpium Citri Reticulatae 10 parts, Herba Taraxaci 5 parts, Herba Lycopi 8 parts, Rhizoma Zingiberis Recens 6 parts, and Magnoliae Officinalis 6 parts;

[0047] Experimental group B: Radix Rehmanniae Glutinosae 15 parts, Pericarpium Citri Reticulatae 15 parts, Herba Taraxaci 10 parts, Herba Lycopi 8 parts, Rhizoma Zingiberis Recens 6 parts, and Magnoliae Officinalis 4 parts;

[0048] Experimental group C: Radix Rehmanniae Glutinosae 30 parts, Pericarpium Citri Reticulatae 5 parts, Herba Taraxaci 5 parts, Herba Lycopi 8 parts, Rhizoma Zingiberis Recens 8 parts, and Magnoliae Officinalis 6 parts;

[0049] Experimental group D: Radix Rehmanniae Glutinosae 30 parts, Pericarpium Citri Reticulatae 5 parts, Herba Taraxaci 10 parts, Herba Lycopi 8 parts, Rhizoma Zingiberis Recens 3 parts, and Magnoliae Officinalis 4 parts;

[0050] Experimental group E: Radix Rehmanniae Glutinosae 25 parts, Pericarpium Citri Reticulatae 5 parts, Herba Taraxaci 8 parts, Herba Lycopi 10 parts, Rhizoma Zingiberis Recens 8 parts, and Magnoliae Officinalis 4 parts;

[0051] Experimental group F: Radix Rehmanniae Glutinosae 15 parts, Pericarpium Citri Reticulatae 10 parts, Herba Taraxaci 5 parts, Herba Lycopi 10 parts, Rhizoma Zingiberis Recens 8 parts, and Magnoliae Officinalis 4 parts.

[0052] Comparative Example A: Centella asiatica 30 parts, dried tangerine or orange peel 15 parts, dandelion 15 parts, caper 10 parts, dried ginger 8 parts;

[0053] Comparative Example B: Centella asiatica 30 parts, dried tangerine or orange peel 15 parts, dandelion 15 parts, caper 10 parts;

[0054] Comparative Example C: Centella asiatica 30 parts, dried tangerine or orange peel 15 parts, dandelion 15 parts;

[0055] Comparative Example D: Centella asiatica 30 parts, dried tangerine or orange peel 15 parts;

[0056] Comparative Example E: Centella asiatica 30 parts;

[0057] Comparative Example F: zero addition.

[0058] The preparation method of the Chinese medicine extract is the same as that in Example 1. The bacteriostatic effect determination method is the same as that in Example 1, with sterilized physiological saline as the control group. The results are shown in Table 1. It can be seen that the bacteriostatic diameters of the experimental groups are significantly higher than that of the control group, indicating that the synergistic effect of multiple Chinese medicine components on the inhibition of Streptococcus agalactiae is more effective. Among them, the bacteriostatic circle diameter of experimental group C is the largest and significantly higher than that of other experimental groups. Therefore, the bacteriostatic effect of the formula of experimental group C: Centella asiatica 30 parts, dried tangerine or orange peel 5 parts, dandelion 5 parts, caper 8 parts, dried ginger 8 parts, and magnolia officinalis 6 parts is the best.

[0059] Table 1 Comparison of bacteriostatic effects of different formula Chinese medicine extracts

[0060]

[0061] Example 3

[0062] This example is a further optimization based on experimental group C of Example 2, and the specific optimization process is as follows:

[0063] Different formula feed additives are prepared:

[0064] Experimental group G: Chinese herbal medicine extract 4 parts + vitamin C 4 parts, the composition and ratio of Chinese herbal medicine extract are the same as those of experimental group C of Example 2;

[0065] Experimental group H: Chinese herbal medicine extract 4 parts + vitamin E 4 parts, the composition and ratio of Chinese herbal medicine extract are the same as those of experimental group C of Example 2;

[0066] Experimental group I: Chinese herbal medicine extract 4 parts + guanidoacetic acid 4 parts, the composition and ratio of Chinese herbal medicine extract are the same as those of experimental group C of Example 2;

[0067] Experimental group J: Chinese herbal medicine extract 2 parts + vitamin C 2 parts + vitamin E 2 parts + guanidoacetic acid 2 parts, the composition and ratio of Chinese herbal medicine extract are the same as those of experimental group C of Example 2;

[0068] Control group A: Chinese herbal medicine extract 8 parts, same as experimental group C of Example 2;

[0069] Control group B: Vitamin C 8 parts;

[0070] Control group C: Vitamin E 8 parts;

[0071] Control group D: base formula.

[0072] Taking gold pomfret as the test object, the effect of the above feed additive on the growth of gold pomfret was tested. The test process is as follows:

[0073] The gold pomfret fry was temporarily raised in a temporary raising barrel for two weeks, and was starved for 24 h before experimental grouping, and then was anesthetized, and healthy fry was selected and randomly divided into 8 groups, 3 replicates in each group, 30 tails in each replicate were placed in a net cage (1.0 m x 1.0 m x 1.5 m), and the average initial weight of the fry was (10.0 ± 0.5) g. The test feed was fed twice a day at 8:00 and 16:00, and was fed to satiation. The fish's feed intake, mortality and other data were recorded every day. During the test, the water temperature was (26.9 ± 2.1) ℃, the dissolved oxygen was > 6.0 mg / L, the ammonia nitrogen was < 0.1 mg / L, the pH value was 7.7-8.0, the salinity was 15‰~20‰, and the light cycle was natural light. The test lasted for 61 days.

[0074] The test feed formula of each group is as follows:

[0075] Table 2 Feed formula (g / kg of feed)

[0076]

[0077] After the experimental fish was raised for 61 days, the final body weight was weighed, and the survival rate, individual weight gain rate, and specific growth rate were calculated. The relevant growth performance indicators were calculated according to the following formula.

[0078] Survival rate (%) = (number of live experimental fish in each group at the end / total number of experimental fish in each group) x 100%;

[0079] Individual weight gain rate = (final weight of live experimental fish in each group-initial weight of live experimental fish in each group) / initial weight of live experimental fish in each group x 100%;

[0080] Specific growth rate (% / d) = 100% x (ln final weight-ln initial weight) / cultivation days.

[0081] The experimental results are shown in Table 3. It can be seen that the growth performance of the experimental group J is the best, the survival rate is the highest, and through observation, the fish gill color is red and the structure is complete, and the incidence of gill erosion is the lowest. It shows that the combination of vitamin C, vitamin E and guanidoacetic acid with Chinese herbal medicine extract has the best effect on the growth performance and immunity of the golden pompano.

[0082] Table 3 Effect of different feed additives on the growth performance of golden pompano

[0083]

[0084] Example 4

[0085] The feed additive is prepared according to the formula of experimental group J in Example 3. Then, 0% (control group), 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt% and 0.5wt% are added to the basic golden pompano feed (manufacturer: Jiangmen Xinhui Puhui Aquatic Feed Co., Ltd.) respectively to make experimental feed, which are recorded as D0 group (control group), D1 group, D2 group, D3 group, D4 group and D5 group respectively.

[0086] Golden pompano is used as the test object to test the effect of the above-mentioned feed additive on the growth of golden pompano. The test process is as follows:

[0087] Golden pompano larvae are temporarily raised in a temporary raising barrel for two weeks, and are starved for 24 hours before experimental grouping. Then, healthy larvae are selected and randomly divided into 6 groups, each with 3 replicates and 30 tails in each replicate, and placed in net cages (1.0 m x 1.0 m x 1.5 m). The test feed is fed twice a day at 8:00 and 16:00 respectively, and the fish are fed to satiation. The fish's food intake and death number are recorded every day. During the test, the water temperature is (26.9±2.1)℃, the dissolved oxygen is >6.0 mg / L, the ammonia nitrogen is <0.1 mg / L, the pH value is 7.7-8.0, the salinity is 15‰~20‰, and the light cycle is natural light. The test lasts for 61 days. The calculation method of the relevant growth performance indicators is the same as that of Example 3.

[0088] The experimental results are shown in Table 4. It can be seen that the growth performance of the golden pompano is the best when 4wt‰ of the feed additive is added to the feed.

[0089] Table 4 Effect of different proportions of feed additives on the growth performance of golden pompano

[0090]

[0091] Test Example 1

[0092] Streptococcus agalactiae is used as the experimental strain to conduct artificial infection experiment of golden pompano. The experimental process is as follows:

[0093] 1. Pre-experiment:

[0094] One hundred and eighty healthy golden pomfret of uniform size were selected and randomly divided into six groups of 30 fish each, including one control group and five experimental groups. The control group was injected intraperitoneally with 200 μL of PBS, while the experimental groups were injected with 1.0 × 10⁻⁶ PBS. 6 1.0×10 7 1.0×10 8 1.0×10 9 1.0×10 10 CFU / mL agalactiae streptococcal suspensions were designated S1, S2, S3, S4, and S5. Mortality rates were assessed at 1, 2, 3, 4, 5, 6, and 7 days post-infection.

[0095] The results are as follows Figure 2 As shown in the figure, after intraperitoneal injection of *Streptococcus agalactiae* strain, golden pomfret exhibited symptoms such as slowed swimming speed and darkened body color within hours, and subsequently died. The control group of golden pomfret remained normal for 7 days. With increasing bacterial concentration, the mortality rate of the golden pomfret gradually increased, reaching a peak at a bacterial concentration of 1.0 × 10⁻⁶. 8 At that time, the cumulative mortality rate of golden pomfret reached 50% after 7 days. This indicates that the 7-day median lethal dose (LD50) of *Streptococcus agalactiae* for golden pomfret is [not specified]. 50 1.0×10 8 CFU / mL.

[0096] 2. Formal Experiment:

[0097] One hundred healthy golden pomfret were selected from the holding tank. They were randomly divided into two groups: a negative control group and an infection group, with 50 fish in each group; an additional additive + infection group was set up, taken from group D4 of Example 4, which had been pre-treated with feed additives. Each fish in the control group was injected with 200 μL of sterile PBS buffer. Each fish in the infection group and the additive + infection group was injected with 200 μL of agalactococcal suspension (i.e., an injection volume of 1.0 × 10⁻⁶). 9 CFU / fish). Take gills from the infected group and the additive + infected group, and observe the color and morphology of the gill filaments.

[0098] The results are as follows Figure 3 As shown, the feed additive of the present invention can effectively improve the immunity of golden pomfret and reduce the mortality rate caused by Streptococcus agalactiae infection. Figure 4 As can be seen, the gills of the infected fish showed swelling, whitening, and erosion, while the gills of the fish in the additive + infected group were bright red with neatly arranged and clearly defined gill filaments. This indicates that the feed additive (immune enhancer) of the present invention can effectively inhibit gill erosion and maintain gill health.

[0099] The above described embodiments are only to illustrate the preferred modes of the present application, and are not intended to limit the scope of the present application. Any modification and improvement made by those skilled in the art to the technical solutions of the present application without departing from the design spirit of the present application shall fall within the protection scope of the present application.

Claims

1. A high-density cultured Pampus argenteus targeted gill immune enhancer, characterized in that, The immune enhancer comprises raw materials in the following proportions by weight: Chinese herbal medicine extract 2-4 parts, vitamin C 2-5 parts, vitamin E 2-5 parts, and guanidoacetic acid 0.5-3 parts. The Chinese herbal medicine extract comprises raw materials in the following proportions by weight: Centella asiatica 15-30 parts, dried tangerine or orange peel 5-15 parts, dandelion 5-10 parts, Herba crithmi 5-10 parts, dried ginger 3-8 parts, and Magnolia officinalis 3-6 parts.

2. The immune enhancer according to claim 1, characterized by, The immune enhancer comprises raw materials in the following proportions by weight: Chinese herbal medicine extract 2 parts, vitamin C 2 parts, vitamin E 2 parts, and guanidoacetic acid 2 parts. The Chinese herbal medicine extract comprises raw materials in the following proportions by weight: Centella asiatica 30 parts, dried tangerine or orange peel 5 parts, dandelion 5 parts, Herba crithmi 8 parts, dried ginger 8 parts, and Magnolia officinalis 6 parts.

3. The method of producing an immunopotentiator as claimed in claim 1 or 2, characterized by, The method comprises the following steps: The Centella asiatica, dried tangerine or orange peel, dandelion, Herba crithmi, dried ginger, and Magnolia officinalis are dried, crushed, subjected to water extraction and alcohol precipitation, and freeze-dried to obtain the Chinese medicine extract; The Chinese medicine extract is mixed with vitamin C, vitamin E, and guanidoacetic acid to obtain the immune enhancer.

4. The production method according to claim 3, characterized by, The water extraction and alcohol precipitation are performed as follows: (1) The crushed raw materials are mixed with water, and subjected to 100-150 min of water bath extraction at 95℃, followed by suction filtration; (2) The extraction of step (1) is repeated twice, and the filtrates are combined; (3) The obtained filtrate is concentrated by rotary evaporation, and then 95% ethanol solution is added in a volume ratio of 1:5, followed by precipitation, discarding of the supernatant, and washing of the precipitate.

5. The preparation method according to claim 4, characterized in that, The ratio of the crushed raw materials to water is 1 g:10 mL.

6. The preparation method according to claim 4, characterized in that, The volume fraction of the ethanol solution is 95%.

7. Use of the immune enhancer of claim 1 or 2 in the preparation of a goldfish feed.

8. A goldfish feed for enhancing immunity of high-density cultured goldfish, characterized by, The goldfish feed comprises the immune enhancer of claim 1 or 2.

9. The feed for goldfish according to claim 8, characterized by The proportion of the immune enhancer in the goldfish feed is 0.3wt%-0.5wt%.

10. A method of enhancing immunity of high density farmed cobia, characterized in that, The goldfish is fed with the goldfish feed of claim 8 or 9.

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