Breeding method for improving disease resistance of carassius auratus var pengze myxosporidium

Abstract

The invention provides a breeding method for improving disease resistance of carassius auratus var pengze myxosporidium. The breeding method comprises the following steps of S1, breeding environment treatment, S2, healthy fry selection and purchase, S3, fry disinfection, S4, fry putting, S5, feeding management, S6, water quality management, S7, disease prevention and detection and S8, emergency treatment. In the fry disinfection link, a biological disinfectant composed of tea saponin, a photosensitive component, carvacrol, artesunate and choline-lactic acid ionic liquid is used for soaking carassius auratus var pengze fry, meanwhile, LED light irradiation is used for assistance, the disinfection components can jointly play a role after penetrating into myxosporidium, growth and reproduction of the myxosporidium are inhibited, and therefore the carassius auratus var pengze fry can be prevented from being damaged by the carassius auratus var pengze. Therefore, the effect of effectively killing myxosporidia is achieved. In the emergency treatment link, an insect-resistant agent composed of a glycan-mercaptosuccinic acid conjugate, antibacterial peptide, artesunate, nano-zinc oxide, triptolide and carvacrol is used, and through the synergistic effect of the components, multi-target efficient killing of myxosporidium is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of aquaculture, and in particular to a breeding method for improving the disease resistance of myxosporeans of Pengze crucian carp. Background Art

[0002] Myxosporidiosis is a parasitic disease caused by pathogenic myxosporids parasitizing fish. Myxosporidiosis belongs to the protist kingdom and is widely parasitic on a variety of marine and freshwater fish. It can also invade amphibians and reptiles. It is one of the most common parasites of fish. Myxosporidiosis has no obvious seasonality and can occur all year round, but it is prone to occur in late spring and early summer and late autumn and winter, and is suitable for breeding in water temperatures of 8-25℃. Myxosporidiosis is extremely harmful to fish farming. Cysts will appear on the surface of the diseased fish or the parasitic parts, affecting the growth of the fish, and in severe cases, it can cause the death of the fish. In addition, myxosporidiosis will reduce the commercial value of the diseased fish, or even completely lose its edible value. In the breeding process of Pengze crucian carp, myxosporidiosis can cause a large number of deaths of fry and adult fish, causing huge economic losses to farmers. The biggest difficulty in preventing and controlling myxosporean disease during Pengze crucian carp farming is that myxosporeans parasitize in the fish's body and develop into cysts with a hard chitin shell, making it difficult for drugs to penetrate into the cysts, making it difficult to kill the insects. Summary of the invention

[0003] In view of this, the present invention proposes a breeding method for improving the disease resistance of Pengze crucian carp myxosporea to solve the above problems.

[0004] The technical solution of the present invention is achieved in this way:

[0005] A breeding method for improving the disease resistance of Pengze crucian carp myxosporea comprises the following steps:

[0006] S1. Aquaculture environment treatment: Use quicklime to spray the bottom and surrounding areas of the pond, mix compound bacterial agent I into the pond mud after 2-4 days, and then plant aquatic plants in the pond mud;

[0007] S2. Purchase healthy fish fry: Purchase Pengze crucian carp fry with normal luster, vitality, normal appearance and no injuries from areas not affected by myxosporean diseases;

[0008] S3. Fry disinfection: The purchased fry are immersed in a biological disinfectant for 25-35 minutes, and while soaking, they are irradiated with LED light having a wavelength of 400-700nm and a light intensity of 1000-3000Lus, wherein the biological disinfectant is composed of tea saponin, a photosensitive component, carvacrol, artesunate, and choline-lactic acid ionic liquid;

[0009] S4. Fish fry release: The disinfected Pengze crucian carp fry is released into the pond, and the disinfected silver carp fry, bighead carp fry, and grass carp fry are released into the pond for mixed culture;

[0010] S5. Feeding management: Pengze crucian carp are fed compound feed I in the seedling stage and immune modulators are fed once every 7-10 days, Pengze crucian carp are fed compound feed II in the juvenile stage and immune modulators are fed once every 10-15 days, Pengze crucian carp are fed compound feed III in the adult stage and immune modulators are fed once every 15-20 days;

[0011] S6. Water quality management: Spray trichlorfon in the pond for disinfection every 25-35 days, change water every 10-20 days, and replace 20-30% of the water in the pond each time. The dissolved oxygen in the water should be maintained at ≥5.0mg / L, the pH value should be maintained at 7.2-8.5, the ammonia nitrogen should be maintained at ≤0.2mg / L, and the nitrite should be maintained at ≤0.1mg / L;

[0012] S7. Disease prevention and detection: Observe the fish for abnormal symptoms every day, and test the fish or water samples for pathogens of myxosporean disease every 30-40 days;

[0013] S8. Emergency treatment: Detect abnormal fish bodies, isolate them, and then soak and disinfect them according to the method in S1. After soaking and disinfection, take insecticides at a rate of 40-60 mg / kg based on the body weight of Pengze crucian carp for 4-6 consecutive days.

[0014] Furthermore, the amount of quicklime used in S1 is 100-150 kg / mu, the composite bacterial agent I is composed of Bacillus subtilis, Bdellovibrio, photosynthetic bacteria, and yeast, and the mass ratio of Bacillus subtilis, Bdellovibrio, photosynthetic bacteria, and yeast is (1.0-3.0):(0.4-1.0):(0.5-1.5):(2.0-4.0), and the amount of composite bacterial agent I used is 1-2 kg / mu.

[0015] Furthermore, the aquatic plant is one or a combination of Elodea, Ceratophyllum, Hydrilla verticillata, Vallisneria, and Water Fern.

[0016] Furthermore, the mass volume ratio g / L of tea saponin, photosensitizing component, carvacrol, artesunate, and choline-lactic acid ionic liquid in S3 biological disinfectant is (1.0-2.0):(0.3-0.5):(0.5-1.5):(0.5-1.5):(4.0-6.0).

[0017] Furthermore, the photosensitizing component is one of chlorophyll a, rose bengal, and eosin Y.

[0018] Furthermore, the choline-lactic acid ionic liquid is prepared by the following method: adding choline chloride to deionized water, stirring at 300-600 r / min for 5-10 min to obtain a choline chloride solution, wherein the mass volume ratio of choline chloride to deionized water is (3-5) to (8-12) in kg / L; pouring the choline chloride solution into a container containing a hydroxide anion exchange resin, performing an ion exchange reaction for 2-4 hours, and collecting the effluent after the reaction is completed to obtain a hydroxide choline solution; adding lactic acid to the hydroxide choline solution, stirring at 100-200 r / min for 24-48 hours at 20-30° C., and obtaining the choline-lactic acid ionic liquid.

[0019] Furthermore, in S4, the number of Pengze crucian carp fry released is 1500-2500 per mu, and the number of silver carp fry, bighead carp fry and grass carp fry is 200-300 per mu in total.

[0020] Furthermore, the specifications of Pengze crucian carp fry are 30-50g / tail, the specifications of silver carp fry are 50-100g / tail, the specifications of bighead carp fry are 80-150g / tail, and the specifications of grass carp fry are 100-200g / tail.

[0021] Furthermore, in S5, the feeding amount of compound feed I is 1.0-1.5 kg / mu each time, and it is fed twice / day; the feeding amount of compound feed II is 2.0-4.0 kg / mu each time, and it is fed 3 times / day; the feeding amount of compound feed III is 5.0-10.0 kg / mu each time, and it is fed 3 times / day.

[0022] Further, compound feed I includes the following raw materials in parts by weight: 20-30 parts of soybean meal, 5-15 parts of fish meal, 10-20 parts of corn gluten meal, 10-15 parts of wheat flour, 2-5 parts of yeast powder, 2-4 parts of fish oil, 1-2 parts of monocalcium phosphate, 0.5-1 parts of choline chloride, 0.5-1 parts of vitamin premix, 1-2 parts of mineral premix, 0.5-1.0 parts of amino acid additives, and compound feed II includes the following raw materials in parts by weight: 30-40 parts of soybean meal, 10-15 parts of fish meal, 15-25 parts of corn flour, 5-10 parts of spirulina powder, 3-5 parts of fish oil, 1-2 parts of monocalcium phosphate, 0.5-1 parts of choline chloride, 0.5-1 parts of vitamin premix, 1-2 parts of mineral premix, 0.5-1.0 parts of amino acid additives. Compound feed III includes the following raw materials in parts by weight: 45-60 parts of soybean meal, 10-20 parts of fish meal, 20-25 parts of corn flour, 10-15 parts of wheat bran, 2-4 parts of phospholipid oil, 1-2 parts of monocalcium phosphate, 0.5-1 parts of choline chloride, 0.5-1 parts of vitamin premix, 1-2 parts of mineral premix, 0.5-1.0 parts of amino acid additives.

[0023] Furthermore, in S5, the feeding amount of the immune regulator for Pengze crucian carp seedlings is 0.3-0.5 Kg / mu, the feeding amount of the immune regulator for Pengze crucian carp juveniles is 0.6-1.0 Kg / mu, and the feeding amount of the immune regulator for Pengze crucian carp adult fish is 1.5-2.5 Kg / mu.

[0024] Furthermore, the immunomodulator includes the following raw materials in parts by weight: 5-15 parts of peptidoglycan, 3-10 parts of saccharoterpenoids, 4-8 parts of garlic powder, 2-6 parts of ginger powder, 1-3 parts of astragalus powder, 1-3 parts of licorice powder, 1-3 parts of adenosine, 4-10 parts of β-glucan, 3-6 parts of mannan, 5-12 parts of Schizochytrium powder, and 3-6 parts of Clostridium butyricum fermentation broth.

[0025] Furthermore, the immunomodulator is mixed into the feed and fed or made into 1.5-2.5 mm granules and fed separately.

[0026] Furthermore, the insecticide in S8 comprises the following raw materials in parts by weight: 20-30 parts of chitosan-mercaptosuccinic acid conjugate, 5-10 parts of antimicrobial peptides, 15-25 parts of artesunate, 8-12 parts of nano zinc oxide, 5-8 parts of triptolide, and 3-5 parts of carvacrol.

[0027] Furthermore, the insecticide is prepared by the following method: antimicrobial peptides, artesunate, nano zinc oxide, triptolide and carvacrol are mixed, and stirred at 500-1000r / min for 10-30min to obtain an insecticide core; chitosan-mercaptosuccinic acid conjugate is added to acetic acid with a concentration of 1.5-2.5wt%, and stirred at 500-1000r / min for 2-4h to obtain a chitosan-mercaptosuccinic acid conjugate solution, and then the chitosan-mercaptosuccinic acid conjugate solution is sprayed onto the surface of the insecticide core at a spray pressure of 10-20psi, and then dried at 55-65°C for 2-4h to obtain the insecticide.

[0028] Further, the chitosan-mercaptosuccinic acid conjugate is prepared by the following method: adding chitosan to acetic acid with a concentration of 1.5-2.5%wt, stirring at 500-1000 / min for 2-4h to obtain a chitosan solution, wherein the mass volume ratio of chitosan to acetic acid is (0.8-1.2) g / ml: (90-110); adding mercaptosuccinic acid to deionized water, stirring at 500-1000r / min for 10-20min, then adding 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide, stirring at 400-600r / min for activation at 20-30°C for 25-35min, and obtaining an activated mercaptosuccinic acid solution, wherein mercaptosuccinic acid, deionized water, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, and N-hydroxysuccinimide are stirred at 400-600r / min for activation for 25-35min. The volume ratio g / mL is (0.4-0.6):(30-50):(0.2-0.4):(0.1-0.3); the activated mercaptosuccinic acid solution is added dropwise to the chitosan solution, and the pH of the reaction system is adjusted to 4.9-5.1 using a 1M sodium hydroxide solution, and the reaction is stirred at 400-600r / min at 55-65°C for 18-22h to obtain a reaction solution, and the volume ratio of the activated mercaptosuccinic acid solution and the chitosan solution is (1.8-2.2):1.0; the reaction solution is transferred to a dialysis bag, dialyzed with deionized water for 70-75h, during which the water is changed every 8h to obtain a dialyzed solution; the dialyzed solution is concentrated by rotary evaporation, and evaporated for 10-12h at an evaporation temperature of 55-65°C and an evaporation pressure of 8-12mbar to obtain a chitosan-mercaptosuccinic acid conjugate.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The present invention soaks Pengze crucian carp fry in a biological disinfectant composed of tea saponin, photosensitive components, carvacrol, artesunate, and choline-lactic acid ionic liquid, and simultaneously irradiates with LED light, wherein tea saponin can destroy the integrity of the cell membrane of myxosporeans, causing the substances inside to leak, thereby achieving the effect of killing. The photosensitive component generates active oxygen species, which attack the β-1,4-glycosidic bonds and acetylamino groups of the chitin molecular chain of myxosporeans, causing the chemical structure of the shell to break, forming micropores or cracks, which are conducive to the penetration of other components. Carvacrol can interfere with the metabolic process of myxosporeans and inhibit their growth and reproduction. Artesunate has good solubility and penetration, and can quickly enter the body of myxosporeans to inhibit their growth and reproduction. Choline-lactic acid ionic liquids expand and soften the outer shell of myxosporeans by destroying the intermolecular hydrogen bonds of chitin, providing favorable conditions for the penetration of other disinfectant components. After penetrating into the interior of the myxosporeans, these disinfecting ingredients can work together to inhibit their growth and reproduction, thereby effectively killing the myxosporeans.

[0031] The present invention uses an insecticide composed of a polysaccharide-mercaptosuccinic acid conjugate, an antimicrobial peptide, artesunate, nano zinc oxide, triptolide, and carvacrol, wherein the polysaccharide-mercaptosuccinic acid conjugate targets and anchors the chitin shell of myxosporeans and destroys the dense structure of the shell, so that the pores of the shell are increased, thereby facilitating the penetration of other components into the cyst. The artesunate produces reactive oxygen in the insect body, destroys the mitochondrial membrane potential, and causes energy metabolism to collapse. Artesunate also has a long half-life and can maintain an effective concentration in the insect body for a long time, thereby improving the therapeutic effect. Triptolide blocks the division of the insect body by inhibiting tubulin polymerization. The antimicrobial peptide inhibits the growth and reproduction of the insect body by destroying the cell membrane structure of the insect body. Nano zinc oxide inhibits the enzyme activity in the insect body and interferes with the metabolic process by releasing zinc ions, thereby further inhibiting the growth and reproduction of the insect body. Carvacrol affects its normal physiological function by destroying the nerve conduction mechanism of the insect body, thereby achieving the purpose of killing myxosporeans. Through the synergistic effects of polysaccharide-mercaptosuccinic acid conjugates, antimicrobial peptides, artesunate, nano-zinc oxide, triptolide, and carvacrol, the insecticide achieves multi-target and efficient killing of myxosporeans. DETAILED DESCRIPTION

[0032] In order to better understand the technical content of the present invention, specific embodiments are provided below to further illustrate the present invention.

[0033] Unless otherwise specified, the experimental methods used in the embodiments of the present invention are all conventional methods.

[0034] Unless otherwise specified, the materials, reagents, etc. used in the embodiments of the present invention can be obtained from commercial sources.

[0035] Example 1

[0036] A breeding method for improving the disease resistance of Pengze crucian carp myxosporea comprises the following steps:

[0037] S1. Aquaculture environment treatment: Use quicklime to spray the bottom and around the pond, the usage amount is 100Kg / mu, and after 2 days, mix the composite bacterial agent I into the pond mud. The composite bacterial agent I is composed of Bacillus subtilis, Bdellovibrio, photosynthetic bacteria and yeast in a mass ratio of 1.0:0.4:0.5:2.0, and the usage amount is 1Kg / mu. Then, Elodea is planted in the pond mud.

[0038] S2. Purchase healthy fish fry: Purchase Pengze crucian carp fry with normal luster, vitality, normal appearance and no injuries from non-myxosporidial epidemic areas.

[0039] S3. Fry disinfection: The purchased fry were immersed in a biological disinfectant for 25 minutes. The biological disinfectant consisted of tea saponin, photosensitizing components, carvacrol, artesunate, and choline-lactic acid ionic liquid in a mass volume ratio of 1.0:0.3:0.5:0.5:4.0 g / L. While immersing, LED light with a wavelength of 450nm and a light intensity of 1000Lus was used for irradiation. The photosensitizing component was chlorophyll a. The choline-lactic acid ionic liquid was prepared by the following method: adding choline chloride to The mixture was added into deionized water and stirred at 300 r / min for 10 min to obtain a choline chloride solution, wherein the mass volume ratio of choline chloride to deionized water was 3:8 (kg / L); the choline chloride solution was poured into a container containing a hydroxide anion exchange resin to carry out an ion exchange reaction for 2 h. After the reaction was completed, the effluent was collected to obtain a hydroxide choline solution; lactic acid was added to the hydroxide choline solution, and the mixture was stirred at 100 r / min for 48 h at 20°C to obtain a choline-lactic acid ionic liquid.

[0040] S4. Fish fry release: The disinfected Pengze crucian carp fry are released into the pond, with a release quantity of 1,500 per mu, and the disinfected silver carp fry, bighead carp fry, and grass carp fry are released into the pond for mixed breeding, with a total release quantity of 200 silver carp fry, bighead carp fry, and grass carp fry per mu. Among them, the Pengze crucian carp fry specifications are 30g / tail, silver carp fry specifications are 50g / tail, silver carp fry specifications are 80g / tail, and grass carp fry specifications are 100g / tail.

[0041] S5. Feeding management: Pengze crucian carp are fed compound feed I in the seedling stage, with a feeding amount of 1.0 kg / mu each time and fed twice a day. Compound feed I includes the following raw materials in parts by weight: 20 parts of soybean meal, 5 parts of fish meal, 10 parts of corn protein meal, 10 parts of wheat flour, 2 parts of yeast powder, 2 parts of fish oil, 1 part of calcium dihydrogen phosphate, 0.5 parts of choline chloride, 0.5 parts of vitamin premix, 1 part of mineral premix, and 0.5 parts of amino acid additives. Immune regulators are fed once every 7 days, with a feeding amount of 0.3 kg / mu each time. Pengze crucian carp fry are fed with compound feed II, with each feeding amount of 2.0 kg / mu, and fed 3 times / d. Compound feed II includes the following raw materials in parts by weight: 30 parts of soybean meal, 10 parts of fish meal, 15 parts of corn meal, 5 parts of spirulina powder, 3 parts of fish oil, 1 part of calcium dihydrogen phosphate, 0.5 parts of choline chloride, 0.5 parts of vitamin premix, 1 part of mineral premix, and 0.5 parts of amino acid additives. Immune regulators are fed once every 10 days, with each feeding amount of 0.6 kg / mu. Pengze crucian carp are fed compound feed III during adult stage, with each feeding amount of 5.0 kg / mu, and fed 3 times / d. Compound feed III includes the following raw materials by weight: 45 parts of soybean meal, 10 parts of fish meal, 20 parts of corn flour, 10 parts of wheat bran, 2 parts of phospholipid oil, 1 part of calcium dihydrogen phosphate, 0.5-1 parts of choline chloride, 0.5 parts of vitamin premix, 1 part of mineral premix, 0.5 parts of amino acid additives, and immune modulators are fed once every 15 days, with each feeding amount of 1.5 kg / mu. The immune modulators include the following raw materials by weight: 5 parts of peptidoglycan, 3 parts of saccharoterpenoids, 4 parts of garlic powder, 2 parts of ginger powder, 1 part of astragalus powder, 1 part of licorice powder, 1 part of adenosine, 4 parts of β-glucan, 3 parts of mannan, 5 parts of schizochytrium powder, and 3 parts of Clostridium butyricum fermentation broth. The immune modulators are mixed into the feed and fed.

[0042] S6. Water quality management: Spray trichlorfon into the pond for disinfection every 25 days, change the water every 10 days, and replace 20% of the water in the pond each time. The dissolved oxygen in the water should be maintained at 5.0 mg / L, the pH value should be maintained at 7.2, the ammonia nitrogen should be maintained at 0.2 mg / L, and the nitrite should be maintained at 0.1 mg / L.

[0043] S7. Disease prevention and detection: Observe the fish for abnormal symptoms every day, and test the fish or water samples for the pathogen of myxosporean disease every 30 days.

[0044] S8. Emergency treatment: Detect abnormal fish bodies, isolate them, and then soak and disinfect them according to the method in S1. After soaking and disinfection, take insecticides at a rate of 40 mg / kg based on the body weight of Pengze crucian carp for 6 consecutive days. The insecticide comprises the following raw materials in parts by weight: 20 parts of chitosan-mercaptosuccinic acid conjugate, 5 parts of antimicrobial peptide, 15 parts of artesunate, 8 parts of nano zinc oxide, 5 parts of triptolide and 3 parts of carvacrol. The insecticide is prepared by the following method: antimicrobial peptide, artesunate, nano zinc oxide, triptolide and carvacrol are mixed, and stirred at 500 r / min for 30 minutes to obtain an insecticide core; chitosan-mercaptosuccinic acid conjugate is added to acetic acid with a concentration of 1.5wt%, and stirred at 500 r / min for 4 hours to obtain a chitosan-mercaptosuccinic acid conjugate solution; then the chitosan-mercaptosuccinic acid conjugate solution is sprayed onto the surface of the insecticide core at a spray pressure of 10 psi, and then dried at 55°C for 4 hours to obtain the insecticide. The chitosan-mercaptosuccinic acid conjugate is prepared by the following method: adding chitosan to acetic acid with a concentration of 1.5%wt, stirring at 500 / min for 4h to obtain a chitosan solution, wherein the mass volume ratio of chitosan to acetic acid is 0.8:90 g / ml; adding mercaptosuccinic acid to deionized water, stirring at 500r / min for 20min, then adding 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide, stirring at 400r / min for 35min at 20°C to activate, to obtain an activated mercaptosuccinic acid solution, mercaptosuccinic acid, deionized water, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide. The mass volume ratio of amber imide is 0.4:30:0.2:0.1 g / mL; the activated mercaptosuccinic acid solution is added dropwise to the chitosan solution, and the pH of the reaction system is adjusted to 4.9 with a 1M sodium hydroxide solution, and the reaction is stirred at 400r / min at 55°C for 22h to obtain a reaction solution, and the volume ratio of the activated mercaptosuccinic acid solution and the chitosan solution is 1.8:1.0; the reaction solution is transferred to a dialysis bag, and dialyzed with deionized water for 70h, during which the water is changed every 8h to obtain a dialyzed solution; the dialyzed solution is concentrated by rotary evaporation, and evaporated at an evaporation temperature of 55°C and an evaporation pressure of 8mbar for 12h to obtain a chitosan-mercaptosuccinic acid conjugate.

[0045] Example 2

[0046] A breeding method for improving the disease resistance of Pengze crucian carp myxosporea comprises the following steps:

[0047] S1. Treatment of aquaculture environment: Use quicklime to spray the bottom and around the pond, the usage amount is 125Kg / mu, and after 3 days, mix the composite bacterial agent I into the pond mud. The composite bacterial agent I is composed of Bacillus subtilis, Bdellovibrio, photosynthetic bacteria and yeast in a mass ratio of 2.0:0.7:1.0:3.0, and the usage amount is 1.5Kg / mu. Then, plant duckweed, Hydrilla verticillata and Vallisneria in the pond mud.

[0048] S2. Purchase healthy fish fry: Purchase Pengze crucian carp fry with normal luster, vitality, normal appearance and no injuries from non-myxosporidial epidemic areas.

[0049] S3. Fry disinfection: The purchased fry were immersed in a biological disinfectant for 30 minutes. The biological disinfectant consisted of tea saponin, photosensitizing components, carvacrol, artesunate, and choline-lactic acid ionic liquid in a mass volume ratio of 1.5:0.4:1.0:1.0:5.0 g / L. While immersing, LED light with a wavelength of 550nm and a light intensity of 2000Lus was used for irradiation. The photosensitizing component was rose bengal. The choline-lactic acid ionic liquid was prepared by the following method: adding choline chloride to In deionized water, stir at 450r / min for 7.5min to obtain a choline chloride solution, and the mass volume ratio of choline chloride to deionized water is 4:10. Pour the choline chloride solution into a container filled with a hydroxide anion exchange resin to carry out an ion exchange reaction for 3h. After the reaction is completed, collect the effluent to obtain a hydroxide choline solution. Add lactic acid to the hydroxide choline solution, stir at 150r / min for 36h at 25°C to obtain a choline-lactic acid ionic liquid.

[0050] S4. Fish fry release: The disinfected Pengze crucian carp fry are released into the pond, with a release quantity of 2,000 per mu, and the disinfected silver carp fry, bighead carp fry, and grass carp fry are released into the pond for mixed breeding, with a total release quantity of 250 silver carp fry, bighead carp fry, and grass carp fry per mu. Among them, the Pengze crucian carp fry specifications are 40g / tail, silver carp fry specifications are 80g / tail, silver carp fry specifications are 120g / tail, and grass carp fry specifications are 150g / tail.

[0051] S5. Feeding management: Pengze crucian carp are fed compound feed I in the seedling stage, with a feeding amount of 1.2 kg / mu each time and fed twice a day. Compound feed I includes the following raw materials in parts by weight: 25 parts of soybean meal, 10 parts of fish meal, 15 parts of corn protein meal, 12.5 parts of wheat flour, 3.5 parts of yeast powder, 3 parts of fish oil, 1.5 parts of calcium dihydrogen phosphate, 0.8 parts of choline chloride, 0.8 parts of vitamin premix, 1.5 parts of mineral premix, and 0.8 parts of amino acid additives. Immune regulators are fed once every 8 days, with a feeding amount of 0.4 kg / mu each time. Pengze crucian carp fry are fed with compound feed II, with each feeding amount of 3.0 kg / mu, and fed 3 times / d. Compound feed II includes the following raw materials in parts by weight: 35 parts of soybean meal, 12.5 parts of fish meal, 20 parts of corn flour, 7.5 parts of spirulina powder, 4 parts of fish oil, 1.5 parts of calcium dihydrogen phosphate, 0.8 parts of choline chloride, 0.8 parts of vitamin premix, 1.5 parts of mineral premix, and 0.8 parts of amino acid additives. Immune regulators are fed once every 10-15 days, with each feeding amount of 0.8 kg / mu. Pengze crucian carp were fed compound feed III in the adult stage, with a feeding amount of 7.5 kg / mu each time, and fed 3 times / d. Compound feed III included the following raw materials by weight: 52.5 parts of soybean meal, 15 parts of fish meal, 22.5 parts of corn flour, 12.5 parts of wheat bran, 3 parts of phospholipid oil, 1.5 parts of calcium dihydrogen phosphate, 0.8 parts of choline chloride, 0.8 parts of vitamin premix, 1.5 parts of mineral premix, 0.8 parts of amino acid additives, and immune modulators were fed once every 18 days, with a feeding amount of 2.0 kg / mu each time. The immune modulators included the following raw materials by weight: 10 parts of peptidoglycan, 6.5 parts of saccharoterpenoids, 6 parts of garlic powder, 4 parts of ginger powder, 2 parts of astragalus powder, 2 parts of licorice powder, 2 parts of adenosine, 7 parts of β-glucan, 4.5 parts of mannan, 8.5 parts of schizochytrium powder, and 4.5 parts of Clostridium butyricum fermentation broth. The immune modulator was prepared into 2.0 mm granules and fed individually.

[0052] S6. Water quality management: Spray trichlorfon into the pond for disinfection every 30 days, change the water every 15 days, and replace 25% of the water in the pond each time. The dissolved oxygen in the water should be maintained at 5.5 mg / L, the pH value should be maintained at 7.9, the ammonia nitrogen should be maintained at 0.1 mg / L, and the nitrite should be maintained at 0.05 mg / L.

[0053] S7. Disease prevention and detection: Observe the fish for abnormal symptoms every day, and test the fish or water samples for the pathogen of myxosporidiosis every 35 days.

[0054] S8. Emergency treatment: Detect abnormal fish bodies, isolate them, and then soak and disinfect them according to the method in S1. After soaking and disinfection, take insecticides at a rate of 50 mg / kg based on the body weight of Pengze crucian carp for 5 consecutive days. The insecticide comprises the following raw materials in parts by weight: 25 parts of chitosan-mercaptosuccinic acid conjugate, 7.5 parts of antimicrobial peptide, 20 parts of artesunate, 10 parts of nano zinc oxide, 6.5 parts of triptolide and 4 parts of carvacrol. The insecticide is prepared by the following method: antimicrobial peptide, artesunate, nano zinc oxide, triptolide and carvacrol are mixed, and stirred at 750 r / min for 20 minutes to obtain an insecticide core; chitosan-mercaptosuccinic acid conjugate is added to acetic acid with a concentration of 2.0wt%, and stirred at 750 r / min for 3 hours to obtain a chitosan-mercaptosuccinic acid conjugate solution, and then the chitosan-mercaptosuccinic acid conjugate solution is sprayed onto the surface of the insecticide core at a spray pressure of 15 psi, and then dried at 60°C for 3 hours to obtain the insecticide. The chitosan-mercaptosuccinic acid conjugate is prepared by the following method: adding chitosan to acetic acid with a concentration of 2.0%wt, stirring at 750 / min for 3h to obtain a chitosan solution, wherein the mass volume ratio of chitosan to acetic acid is 1.0:100 g / ml; adding mercaptosuccinic acid to deionized water, stirring at 750r / min for 15min, then adding 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide, stirring at 25°C at 500r / min for 30min to activate, to obtain an activated mercaptosuccinic acid solution, mercaptosuccinic acid, deionized water, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide The mass volume ratio of amber imide is 0.5:45:0.3:0.2 g / mL; the activated mercaptosuccinic acid solution is added dropwise to the chitosan solution, and the pH of the reaction system is adjusted to 5.0 with a 1M sodium hydroxide solution, and the reaction is stirred at 500r / min at 60°C for 20 hours to obtain a reaction solution, and the volume ratio of the activated mercaptosuccinic acid solution and the chitosan solution is 2.0:1.0; the reaction solution is transferred to a dialysis bag, and dialyzed with deionized water for 72 hours, during which the water is changed every 8 hours to obtain a dialyzed solution; the dialyzed solution is concentrated by rotary evaporation, and evaporated for 11 hours at an evaporation temperature of 60°C and an evaporation pressure of 10mbar to obtain a chitosan-mercaptosuccinic acid conjugate.

[0055] Example 3

[0056] A breeding method for improving the disease resistance of Pengze crucian carp myxosporea comprises the following steps:

[0057] S1. Treatment of aquaculture environment: Use quicklime to spray the bottom and around the pond, the usage amount is 150Kg / mu, and after 4 days, mix the compound bacterial agent I into the pond mud. The compound bacterial agent I is composed of Bacillus subtilis, Bdellovibrio, photosynthetic bacteria and yeast in a mass ratio of 3.0:1.0:1.5:4.0, and the usage amount is 2Kg / mu. Then, duckweed, hydrilla verticillaster and water fern are planted in combination in the pond mud.

[0058] S2. Purchase healthy fish fry: Purchase Pengze crucian carp fry with normal luster, vitality, normal appearance and no injuries from non-myxosporidial epidemic areas.

[0059] S3. Fry disinfection: The purchased fry were immersed in a biological disinfectant for 35 minutes. The biological disinfectant consisted of tea saponin, photosensitizing components, carvacrol, artesunate, and choline-lactic acid ionic liquid in a mass volume ratio of 2.0:0.5:1.5:1.5:6.0 g / L. While soaking, LED light with a wavelength of 700nm and a light intensity of 3000Lus was used for irradiation. The photosensitizing component was eosin Y. The choline-lactic acid ionic liquid was prepared by the following method: adding choline chloride to The mixture was added into deionized water and stirred at 600 r / min for 5 min to obtain a choline chloride solution, wherein the mass volume ratio of choline chloride to deionized water was 5:12 (kg / L); the choline chloride solution was poured into a container containing a hydroxide anion exchange resin to carry out an ion exchange reaction for 2 h. After the reaction was completed, the effluent was collected to obtain a hydroxide choline solution; lactic acid was added to the hydroxide choline solution, and the mixture was stirred at 200 r / min for 24 h at 30 °C to obtain a choline-lactic acid ionic liquid.

[0060] S4. Fish fry release: The disinfected Pengze crucian carp fry are released into the pond, with a release quantity of 2,500 per mu, and the disinfected silver carp fry, bighead carp fry, and grass carp fry are released into the pond for mixed breeding, with a total release quantity of 300 silver carp fry, bighead carp fry, and grass carp fry per mu. Among them, the Pengze crucian carp fry specifications are 50g / tail, silver carp fry specifications are 100g / tail, silver carp fry specifications are 150g / tail, and grass carp fry specifications are 200g / tail.

[0061] S5. Feeding management: Pengze crucian carp are fed compound feed I in the seedling stage, with a feeding amount of 1.5 kg / mu each time and fed twice a day. Compound feed I includes the following raw materials in parts by weight: 30 parts of soybean meal, 15 parts of fish meal, 20 parts of corn protein meal, 15 parts of wheat flour, 5 parts of yeast powder, 4 parts of fish oil, 2 parts of monocalcium phosphate, 1 part of choline chloride, 1 part of vitamin premix, 2 parts of mineral premix, and 1.0 part of amino acid additives. Immune regulators are fed once every 10 days, with a feeding amount of 0.5 kg / mu each time. Pengze crucian carp fry are fed with compound feed II, with each feeding amount of 24.0 kg / mu, and fed 3 times / d. Compound feed II includes the following raw materials in parts by weight: 40 parts of soybean meal, 15 parts of fish meal, 25 parts of corn meal, 10 parts of spirulina powder, 5 parts of fish oil, 2 parts of monocalcium phosphate, 1 part of choline chloride, 1 part of vitamin premix, 2 parts of mineral premix, and 1.0 part of amino acid additive. Immune regulators are fed once every 15 days, with each feeding amount of 1.0 kg / mu. Pengze crucian carp were fed compound feed III during adult stage, with each feeding amount of 10.0 kg / mu, and fed 3 times / d. Compound feed III included the following raw materials by weight: 60 parts of soybean meal, 20 parts of fish meal, 25 parts of corn flour, 15 parts of wheat bran, 4 parts of phospholipid oil, 2 parts of calcium dihydrogen phosphate, 1 part of choline chloride, 1 part of vitamin premix, 2 parts of mineral premix, 1.0 part of amino acid additive, and immune modulators were fed once every 20 days, with each feeding amount of 2.5 kg / mu. The immune modulators included the following raw materials by weight: 15 parts of peptidoglycan, 10 parts of saccharoterpenoids, 8 parts of garlic powder, 6 parts of ginger powder, 3 parts of astragalus powder, 3 parts of licorice powder, 3 parts of adenosine, 10 parts of β-glucan, 6 parts of mannan, 12 parts of schizochytrium powder, and 6 parts of Clostridium butyricum fermentation broth. The immune modulators were made into 2.5 mm granules and fed separately.

[0062] S6. Water quality management: Spray trichlorfon into the pond for disinfection every 35 days, change the water every 20 days, and replace 30% of the water in the pond each time. The dissolved oxygen in the water should be maintained at 6.0 mg / L, the pH value should be maintained at 8.5, the ammonia nitrogen should be maintained at 0.1 mg / L, and the nitrite should be maintained at 0.1 mg / L.

[0063] S7. Disease prevention and detection: Observe the fish for abnormal symptoms every day, and test the fish or water samples for pathogens of myxosporidiosis every 40 days.

[0064] S8. Emergency treatment: Detect abnormal fish bodies, isolate them, and then soak and disinfect them according to the method in S1. After soaking and disinfection, take insecticides at a rate of 60 mg / kg based on the body weight of Pengze crucian carp for 4 consecutive days. The insecticide comprises the following raw materials in parts by weight: 30 parts of chitosan-mercaptosuccinic acid conjugate, 10 parts of antimicrobial peptide, 25 parts of artesunate, 12 parts of nano zinc oxide, 8 parts of triptolide and 5 parts of carvacrol. The insecticide is prepared by the following method: antimicrobial peptide, artesunate, nano zinc oxide, triptolide and carvacrol are mixed, and stirred at 1000 r / min for 10 minutes to obtain an insecticide core; chitosan-mercaptosuccinic acid conjugate is added to acetic acid with a concentration of 2.5wt%, and stirred at 1000 r / min for 2 hours to obtain a chitosan-mercaptosuccinic acid conjugate solution, and then the chitosan-mercaptosuccinic acid conjugate solution is sprayed onto the surface of the insecticide core at a spray pressure of 20 psi, and then dried at 65°C for 2 hours to obtain the insecticide. The chitosan-mercaptosuccinic acid conjugate is prepared by the following method: adding chitosan to acetic acid with a concentration of 2.5%wt, stirring at 1000 / min for 2h to obtain a chitosan solution, wherein the mass volume ratio of chitosan to acetic acid is 1.2:110 g / ml; adding mercaptosuccinic acid to deionized water, stirring at 1000r / min for 10min, then adding 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide, stirring at 30°C and 600r / min for 25min to activate, to obtain an activated mercaptosuccinic acid solution, mercaptosuccinic acid, deionized water, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide The mass volume ratio of succinimide g / mL is 0.6:50:0.4:0.3; the activated mercaptosuccinic acid solution is added dropwise to the chitosan solution, and the pH of the reaction system is adjusted to 5.1 with a 1M sodium hydroxide solution, and the reaction is stirred at 600r / min at 65°C for 22h to obtain a reaction solution, and the volume ratio of the activated mercaptosuccinic acid solution and the chitosan solution is 2.2:1.0; the reaction solution is transferred to a dialysis bag, dialyzed with deionized water for 75h, during which the water is changed every 8h to obtain a dialyzed solution; the dialyzed solution is concentrated by rotary evaporation, and evaporated at an evaporation temperature of 65°C and an evaporation pressure of 12mbar for 10h to obtain a chitosan-mercaptosuccinic acid conjugate.

[0065] Comparative Example 1

[0066] The difference between this comparative example and Example 2 is that an equal volume of deionized water is used in the biological disinfectant in step S3 instead of the choline-lactic acid ionic liquid.

[0067] Comparative Example 2

[0068] The difference between this comparative example and Example 2 is that the biological disinfectant in step S3 does not contain any photosensitive components, and no LED light is used for immersion in the biological disinfectant.

[0069] Comparative Example 3

[0070] The difference between this comparative example and Example 2 is that no immune modulator is fed in step S5.

[0071] Comparative Example 4

[0072] The difference between this comparative example and Example 2 is that the insecticide in step S8 does not contain chitosan-mercaptosuccinic acid conjugate.

[0073] Comparative Example 5

[0074] The difference between this comparative example and Example 2 is that the insecticide in step S8 uses chitosan of equal mass instead of chitosan-mercaptosuccinic acid conjugate.

[0075] Effect verification

[0076] Set up 8 ponds of 1 mu with the same length, width and height, inject the same amount of water, and culture according to the culture methods of Examples 1-3 and Comparative Examples 1-5, respectively, for 200 days. Record the initial total weight of the Pengze crucian carp placed in each pond before the fry are placed, record the number of Pengze crucian carp infected with myxosporean disease in each pond during the culture process, and record the number of Pengze crucian carp cured when treating Pengze crucian carp infected with myxosporean disease. After the culture is completed, weigh and record the final total weight of the Pengze crucian carp. The infection rate of myxosporean disease, the cure rate of myxosporean disease, and the weight gain rate of the Pengze crucian carp in each pond are counted, and the statistical results are shown in Table 1. Calculate according to the following formula:

[0077] Myxosporidiosis infection rate = (number of fish infected with myxosporidiosis / total number of fish released) × 100%;

[0078] Myxosporidiosis cure rate = (number of fish cured of myxosporidiosis / number of fish infected with myxosporidiosis) × 100%;

[0079] Weight gain rate = (final total body weight / initial total body weight) × 100%.

[0080] Table 1

[0081] Myxosporidiosis infection rate / % Myxosporidiosis cure rate / % Weight gain rate / % Example 1 2.3 95 231 Example 2 2.0 98 235 Example 3 2.1 96 229 Comparative Example 1 11.4 65 187 Comparative Example 2 11.2 67 182 Comparative Example 3 10.9 80 163 Comparative Example 4 2.2 61 190 Comparative Example 5 2.1 77 201

[0082] It can be seen from Table 1 that the breeding methods of Examples 1-3 of the present invention have low myxosporean infection rates, high cure rates, and high weight gain rates, among which Example 2 has the best effect.

[0083] Compared with Comparative Example 1 by Example 2, there are a large number of hydrogen bonds between the chitin shell molecular chains of myxosporeans, and the choline cations and lactic acid anions contained in the choline-lactic acid ionic liquid can be combined with the hydroxyl and acetylamino groups on the chitin shell molecular chains of myxosporeans to form competitive hydrogen bonds, destroying the hydrogen bond network between the original chitin molecular chains, causing the shell structure to be loose, which is conducive to the penetration of choline-lactic acid ionic liquid into the chitin shell. And after penetrating into the chitin shell, the distance between the chitin molecular chains is increased by solvation. The hydrogen bond network destruction and the increase in the distance between the molecular chains of the chitin shell cause the shell to form micropores, which provide channels for the penetration of tea saponin, photosensitive components, carvacrol, and artesunate, thereby effectively eliminating myxosporeans, thereby reducing the infection rate of myxosporean disease and improving the cure rate of myxosporean disease. Due to the reduction of the infection rate of myxosporeans and the improvement of the cure rate of myxosporean disease, Pengze crucian carp can grow and develop better during the breeding process. The fish body grows faster and the feed conversion rate is improved, so that the total weight of Pengze crucian carp increases more in the same breeding cycle. Therefore, at the end of breeding, the growth rate of harvested Pengze crucian carp is higher, and the breeding efficiency is significantly improved.

[0084] By comparing Example 2 with Comparative Example 2, the photosensitive component absorbs LED light energy of a specific wavelength and transitions from the ground state to the excited state. The excited state photosensitizer transfers energy to the surrounding oxygen molecules to generate highly reactive singlet oxygen or generate reactive oxygen species such as superoxide anions and hydroxyl radicals through electron transfer. The generated reactive oxygen species attack the β-1,4-glycosidic bonds and acetylamino groups of the chitin molecular chain, causing the chemical structure of the shell to break and form micropores or cracks, which helps other components to penetrate, thereby effectively eliminating myxosporeans, thereby reducing the infection rate of myxosporean disease and improving the cure rate of myxosporean disease.

[0085] Compared with Comparative Example 3 by Example 2, the peptidoglycan, saccharide terpenoid, garlic powder, ginger powder, astragalus powder, and ginger powder in the immunomodulator can stimulate the nonspecific immune system of Pengze crucian carp and enhance its bactericidal and antiviral capabilities. β-Glucan, mannan, and adenosine can stimulate the specific immune system of Pengze crucian carp, promote its proliferation and differentiation, produce more antibodies and cytokines, and improve the disease resistance of Pengze crucian carp. The beneficial substances in the butyric clostridium fermentation liquid can regulate the intestinal flora of Pengze crucian carp, inhibit the growth of harmful bacteria, and promote the reproduction of beneficial bacteria, thereby enhancing the digestive ability and immunity of Pengze crucian carp. By enhancing the immunity of Pengze crucian carp, the immunomodulator can make Pengze crucian carp better resist the infection of myxosporeans. The enhancement of the immune system can more effectively identify and remove pathogens, thereby reducing the infection rate. When Pengze crucian carp is infected with myxosporeans, the enhanced immune system can start immune response faster, produce more antibodies and cytokines, accelerate the removal of pathogens and the repair of tissues, thereby improving the cure rate. The Schizochytrium powder in the immune modulator is rich in polyunsaturated fatty acids, which can promote the growth and development of Pengze crucian carp. At the same time, the enhanced immune system can enable fish to better utilize nutrients in feed, improve feed conversion rate, and thus increase weight gain rate. The immune modulator significantly improves the immunity of Pengze crucian carp through the synergistic effects of multi-target immune activation, anti-inflammatory repair, intestinal health regulation, and metabolic promotion, achieving the triple goals of reducing infection rate, increasing cure rate, and increasing weight gain rate.

[0086] By comparing Example 2 with Comparative Example 4, the amino group contained in the chitosan-mercaptosuccinic acid conjugate forms a hydrogen bond with the acetyl group of chitin of the myxosporea, anchoring on the surface of the cyst. The thiol contained in the chitosan-mercaptosuccinic acid conjugate undergoes an exchange reaction with the disulfide bond of the chitin coat protein to form a covalent bond, further strengthening the adsorption. The hydrogen bonds and covalent bonds formed at the same time can destroy the original hydrogen bond network and protein structure of the shell, thereby destroying the compactness of the shell, increasing the pores of the shell, so that antimicrobial peptides, artesunate, nano zinc oxide, triptolide, and carvacrol can smoothly enter the cyst, effectively killing myxosporea.

[0087] By comparing Example 2 with Comparative Example 5, the chitosan-mercaptosuccinic acid conjugate further enhances the targeting effect and penetration effect through the exchange reaction between the thiol group and the disulfide bond of the chitin coat protein. Therefore, compared with chitosan, the chitosan-mercaptosuccinic acid conjugate has a better effect.

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for improving the disease resistance of Pengze crucian carp myxosporea, characterized in that: The following steps are involved: S1. Aquaculture environment treatment: Use quicklime to spray the bottom and surrounding areas of the pond, mix compound bacterial agent I into the pond mud after 2-4 days, and then plant aquatic plants in the pond mud; S2. Purchase healthy fish fry: Purchase Pengze crucian carp fry with normal luster, vitality, normal appearance and no injuries from areas not affected by myxosporean diseases; S3. Fry disinfection: The purchased fry are immersed in a biological disinfectant for 25-35 minutes, and while soaking, they are irradiated with LED light having a wavelength of 400-700nm and a light intensity of 1000-3000Lus, wherein the biological disinfectant is composed of tea saponin, a photosensitive component, carvacrol, artesunate, and choline-lactic acid ionic liquid; S4. Fish fry release: The disinfected Pengze crucian carp fry is released into the pond, and the disinfected silver carp fry, bighead carp fry, and grass carp fry are released into the pond for mixed culture; S5. Feeding management: Pengze crucian carp are fed compound feed I in the seedling stage and immune modulators are fed once every 7-10 days, Pengze crucian carp are fed compound feed II in the juvenile stage and immune modulators are fed once every 10-15 days, Pengze crucian carp are fed compound feed III in the adult stage and immune modulators are fed once every 15-20 days; S6. Water quality management: Spray trichlorfon in the pond for disinfection every 25-35 days, change water every 10-20 days, and replace 20-30% of the water in the pond each time. The dissolved oxygen in the water should be maintained at ≥5.0mg / L, the pH value should be maintained at 7.2-8.5, the ammonia nitrogen should be maintained at ≤0.2mg / L, and the nitrite should be maintained at ≤0.1mg / L; S7. Disease prevention and detection: Observe the fish for abnormal symptoms every day, and test the fish or water samples for pathogens of myxosporean disease every 30-40 days; S8. Emergency treatment: Detect abnormal fish bodies, isolate them, and then soak and disinfect them according to the method in S1. After soaking and disinfection, take insecticides at a rate of 40-60 mg / kg based on the body weight of Pengze crucian carp for 4-6 consecutive days.

2. A method for cultivating carp of Pengze crucian carp to improve its disease resistance to myxosporea as claimed in claim 1, characterized in that: The amount of quicklime used in S1 is 100-150 kg / mu, the composite bacterial agent I is composed of Bacillus subtilis, Bdellovibrio, photosynthetic bacteria, and yeast, and the mass ratio of Bacillus subtilis, Bdellovibrio, photosynthetic bacteria, and yeast is (1.0-3.0):(0.4-1.0):(0.5-1.5):(2.0-4.0), and the amount of composite bacterial agent I used is 1-2 kg / mu.

3. A method for cultivating carp of Pengze crucian carp to improve its disease resistance to myxosporea as claimed in claim 1, characterized in that: The mass volume ratios of tea saponin, photosensitizing component, carvacrol, artesunate and choline-lactic acid ionic liquid in the S3 biological disinfectant are (1.0-2.0) g / L: (0.3-0.5) g / L: (0.5-1.5) g / L: (4.0-6.0) g / L.

4. A method for cultivating carp of Pengze crucian carp to improve its disease resistance to myxosporea as claimed in claim 3, characterized in that: The photosensitive component is one of chlorophyll a, rose bengal and eosin Y.

5. A method for cultivating carp of Pengze for improving the disease resistance of myxosporeans as claimed in claim 3, characterized in that: The choline-lactic acid ionic liquid is prepared by the following method: adding choline chloride to deionized water, stirring at 300-600 r / min for 5-10 min to obtain a choline chloride solution, wherein the mass volume ratio of the choline chloride to the deionized water is (3-5):(8-12) in kg / L; pouring the choline chloride solution into a container filled with a hydroxide anion exchange resin, performing an ion exchange reaction for 2-4 hours, and collecting an effluent after the reaction is completed to obtain a hydroxide choline solution; adding lactic acid to the hydroxide choline solution, stirring at 100-200 r / min for 24-48 hours at 20-30° C. to obtain the choline-lactic acid ionic liquid.

6. A method for cultivating carp of Pengze crucian carp to improve its disease resistance to myxosporea as claimed in claim 1, characterized in that: The compound feed I in S5 has a feeding amount of 1.0-1.5 kg / mu each time, and is fed twice a day; the compound feed II has a feeding amount of 2.0-4.0 kg / mu each time, and is fed three times a day; the compound feed III has a feeding amount of 5.0-10.0 kg / mu each time, and is fed three times a day; the compound feed I includes the following raw materials in parts by weight: 20-30 parts of soybean meal, 5-15 parts of fish meal, 10-20 parts of corn gluten meal, 10-15 parts of wheat flour, 2-5 parts of yeast powder, 2-4 parts of fish oil, 1-2 parts of monocalcium phosphate, 0.5-1 parts of choline chloride, 0.5-1 parts of vitamin premix, 1-2 parts of mineral premix, 0.5-1.0 parts of amino acid additives, and the compound feed II includes The compound feed III comprises the following raw materials in parts by weight: 30-40 parts of soybean meal, 10-15 parts of fish meal, 15-25 parts of corn flour, 5-10 parts of spirulina powder, 3-5 parts of fish oil, 1-2 parts of monocalcium phosphate, 0.5-1 parts of choline chloride, 0.5-1 parts of vitamin premix, 1-2 parts of mineral premix, and 0.5-1.0 parts of amino acid additives. The compound feed III comprises the following raw materials in parts by weight: 45-60 parts of soybean meal, 10-20 parts of fish meal, 20-25 parts of corn flour, 10-15 parts of wheat bran, 2-4 parts of phospholipid oil, 1-2 parts of monocalcium phosphate, 0.5-1 parts of choline chloride, 0.5-1 parts of vitamin premix, 1-2 parts of mineral premix, and 0.5-1.0 parts of amino acid additives.

7. A method for cultivating carp of Pengze crucian carp to improve its disease resistance to myxosporea as claimed in claim 1, characterized in that: The feeding amount of the immune regulator for Pengze crucian carp seedlings in S5 is 0.3-0.5 kg / mu, the feeding amount of the immune regulator for Pengze crucian carp juveniles is 0.6-1.0 kg / mu, and the feeding amount of the immune regulator for Pengze crucian carp adult fish is 1.5-2.5 kg / mu. The immune regulator comprises the following raw materials in parts by weight: 5-15 parts of peptidoglycan, 3-10 parts of saccharoterpenoids, 4-8 parts of garlic powder, 2-6 parts of ginger powder, 1-3 parts of astragalus powder, 1-3 parts of licorice powder, 1-3 parts of adenosine, 4-10 parts of β-glucan, 3-6 parts of mannan, 5-12 parts of Schizochytrium powder, and 3-6 parts of Clostridium butyricum fermentation broth.

8. A method for cultivating carp of Pengze for improving the disease resistance of myxosporeans as claimed in claim 1, characterized in that: The insecticide in S8 comprises the following raw materials in parts by weight: 20-30 parts of chitosan-mercaptosuccinic acid conjugate, 5-10 parts of antimicrobial peptides, 15-25 parts of artesunate, 8-12 parts of nano zinc oxide, 5-8 parts of triptolide, and 3-5 parts of carvacrol.

9. A method for cultivating carp of Pengze for improving the disease resistance of myxosporeans as claimed in claim 8, characterized in that: The insecticide is prepared by the following method: antimicrobial peptide, artesunate, nano zinc oxide, triptolide and carvacrol are mixed, and stirred at 500-1000r / min for 10-30min to obtain an insecticide core; chitosan-mercaptosuccinic acid conjugate is added to acetic acid with a concentration of 1.5-2.5wt%, and stirred at 500-1000r / min for 2-4h to obtain a chitosan-mercaptosuccinic acid conjugate solution, and then the chitosan-mercaptosuccinic acid conjugate solution is sprayed onto the surface of the insecticide core at a spray pressure of 10-20psi, and then dried at 55-65°C for 2-4h to obtain the insecticide.

10. A method for cultivating carp of Pengze for improving the disease resistance of myxosporeans as claimed in claim 8, characterized in that: The chitosan-mercaptosuccinic acid conjugate is prepared by the following method: adding chitosan to acetic acid with a concentration of 1.5-2.5%wt, stirring at 500-1000 / min for 2-4h to obtain a chitosan solution, wherein the mass volume ratio of chitosan to acetic acid is (0.8-1.2):(90-110) g / ml; adding mercaptosuccinic acid to deionized water, stirring at 500-1000r / min for 10-20min, then adding 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide, stirring at 400-600r / min for activation at 20-30°C for 25-35min, to obtain an activated mercaptosuccinic acid solution, wherein the mass volume ratio of mercaptosuccinic acid, deionized water, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide is (0.8-1.2):(90-110) g / ml; adding mercaptosuccinic acid to deionized water, stirring at 500-1000r / min for 10-20min, then adding 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide, stirring at 400-600r / min for activation at 20-30°C for 25-35min, to obtain an activated mercaptosuccinic acid solution. The ratio of g / mL is (0.4-0.6):(30-50):(0.2-0.4):(0.1-0.3); the activated mercaptosuccinic acid solution is added dropwise to the chitosan solution, and the pH of the reaction system is adjusted to 4.9-5.1 using a 1M sodium hydroxide solution, and the reaction is stirred at 400-600r / min at 55-65°C for 18-22h to obtain a reaction solution, wherein the volume ratio of the activated mercaptosuccinic acid solution to the chitosan solution is (1.8-2.2):1.0; the reaction solution is transferred to a dialysis bag, and dialyzed with deionized water for 70-75h, during which the water is changed every 8h to obtain a dialyzed solution; the dialyzed solution is concentrated by rotary evaporation, and evaporated for 10-12h at an evaporation temperature of 55-65°C and an evaporation pressure of 8-12mbar to obtain a chitosan-mercaptosuccinic acid conjugate.