Compound aquatic feed capable of improving immunity of fishes and preparation method of compound aquatic feed

Abstract

The invention provides a compound aquatic feed for improving fish immunity and a preparation method thereof, and belongs to the technical field of aquatic feeds. The compound aquatic feed comprises the following raw materials in percentage by weight: 9-13% of soybean meal, 2-6% of palm meal, 7-12% of rice bran, 2-5% of brewer's grains, 9-13% of flour, 1-4% of soybean oil, 2-5% of soybean lecithin, 5-8% of shrimp meal, 1-1.5% of a plant extract A, 2-2.5% of a plant extract B, 0.2-0.6% of a complex microbial inoculant, 1-3% of palm oil, 2-3% of monocalcium phosphate and the balance of rapeseed cakes. The prepared compound aquatic feed can improve the immunity of fishes and improve the meat quality of grass carps.

Description

Technical Field

[0001] The invention belongs to the technical field of aquatic feed, and particularly relates to a composite aquatic feed for improving the immunity of fish and a preparation method thereof. Background Art

[0002] Grass carp is a common freshwater fish belonging to the family Cyprinidae. It is named because it mainly feeds on aquatic plants. It is one of the four famous fishes in China and is widely farmed and consumed in China and surrounding areas. Grass carp has tender meat and is rich in high-quality protein. These proteins are rich in all essential amino acids. Grass carp has delicate meat and is easily digested and absorbed by the human body. It is suitable for people of all ages, especially for the elderly and children. It is a very good source of protein.

[0003] With the increasing demand for grass carp, the increase in stocking density and intensiveness, the breeding environment has deteriorated, the growth rate and immunity of grass carp have gradually decreased, and fish diseases have occurred frequently. How to reduce breeding costs, improve disease prevention and control effects, and produce qualified pollution-free food is one of the key issues that need to be urgently solved in grass carp breeding and production. Although adding antibiotics to feed can effectively improve its growth performance and control the occurrence of diseases, the abuse of antibiotics can easily lead to the development of pathogenic microorganisms resistance, drug residues that endanger human health, and excrement polluting the environment.

[0004] In recent years, Chinese herbal medicine preparations have been gradually applied in aquaculture to accelerate growth, improve production performance and enhance immunity. However, there is currently no feed containing Chinese herbal plant ingredients specifically for grass carp growth and immunity enhancement.

[0005] Therefore, there is an urgent need for a composite aquatic feed for improving the immunity of grass carp and a preparation method thereof. Summary of the invention

[0006] The purpose of the present invention is to provide a composite aquatic feed for improving the immunity of fish and a preparation method thereof.

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

[0008] A composite aquatic feed for improving fish immunity comprises the following raw materials in percentage by weight: 9-13% soybean meal, 2-6% palm meal, 7-12% rice bran, 2-5% brewer's grains, 9-13% flour, 1-4% soybean oil, 2-5% soybean lecithin, 5-8% shrimp meal, 1-1.5% plant extract A, 2-2.5% plant extract B, 0.2-0.6% composite bacterial agent, 1-3% palm oil, 2-3% calcium dihydrogen phosphate, and the balance is vegetable cake.

[0009] Furthermore, the preparation method of the plant extract A comprises the following steps:

[0010] (1) mixing green tea, lotus leaves, scutellaria baicalensis and knotweed, and crushing to obtain mixed micro powder;

[0011] (2) adding 7-10 times the weight of water to the mixed micropowder to obtain a fermentation raw material, adding Lactobacillus brevis to the fermentation raw material, and performing anaerobically fermentation at 35-38° C. for 1-2 days, and sterilizing; continuing to add Lactobacillus casei, and performing anaerobically fermentation at 35-38° C. for 2-3 days, and sterilizing; continuing to add Lactobacillus rhamnosus, and performing anaerobically fermentation at 35-38° C. for 1-2 days, and sterilizing; and ultrasonicating at 400-600 W for 30-40 min; after completion, filtering, and drying the filtrate to obtain plant extract A.

[0012] Further, the weight ratio of green tea, lotus leaf, scutellaria baicalensis and knotweed is 10:(1-3):(6-8):(12-15).

[0013] Furthermore, the amount of Lactobacillus brevis in the fermentation raw material is 10 7 -10 8 CFU / mL; the amount of Lactobacillus casei in the fermentation raw material is 10 6 -10 7 CFU / mL; the amount of Lactobacillus rhamnosus in the fermentation raw material is 10 8 -10 9 CFU / mL.

[0014] At present, the addition of Chinese herbal medicine components to aquatic feed is generally directly added after crushing, or water extraction is used. The active components of the products obtained by these methods are less, resulting in poor effects. The present invention extracts four natural plants of green tea, lotus leaf, scutellaria and knotweed in a specific ratio, first uses different bacteria for gradient fermentation, and then ultrasonic extraction. The prepared plant extract A can reduce the liver body index of grass carp, improve the spleen body index and the head kidney body index, and can reduce the accumulation of fat in the liver. Improving the spleen body index means that the function of the spleen is enhanced, and more immune cells are involved in the immune response. The head kidney assumes a hematopoietic function similar to that of mammalian bone marrow in fish, and is responsible for producing a variety of blood cells, including immune-related cells. Improving the head kidney body index means that the function of the head kidney is enhanced, and more immune cells can be produced. The present invention selects suitable strains for fermentation. Through the metabolism of microorganisms, fermentation can be carried out in gradients, the biological activity of the extract can be optimized, and certain components in the plant can be converted to make it easier to be absorbed and utilized by grass carp. The multiple active ingredients extracted from green tea, lotus leaves, scutellaria baicalensis and knotweed in a specific ratio can work synergistically to regulate and improve the immune system of grass carp and enhance its resistance to disease.

[0015] Furthermore, the preparation method of the plant extract B comprises the following steps: mixing Acanthopanax senticosus, Licorice, Sophora flavescens and Lycium barbarum, crushing to obtain a mixture, adding water 6-9 times the weight of the mixture to the mixture to obtain a mixed liquid, adding a complex enzyme to the mixed liquid, performing enzymolysis at 30-35°C for 4-7h, and after inactivating the enzyme, obtaining an enzymolysis product, placing the enzymolysis product into a microwave reactor for microwave extraction, filtering with a filter membrane after the extraction is completed, and drying the filtrate to obtain the plant extract B.

[0016] Furthermore, the weight ratio of Acanthopanax senticosus, Glycyrrhiza uralensis, Sophora flavescens and Lycium barbarum is (11-14):10:(4-7):(1-3).

[0017] Furthermore, the complex enzyme comprises cellulase, pectinase and bromelain.

[0018] Furthermore, the amount of cellulase in the mixed liquid is 100-110 U / mL; the amount of pectinase in the mixed liquid is 130-140 U / mL; and the amount of bromelain in the mixed liquid is 80-90 U / mL.

[0019] Furthermore, the conditions for microwave extraction are: microwave power 250-280W, temperature 70-75°C, and extraction time 1.5-2h.

[0020] The present invention performs enzymatic hydrolysis and microwave extraction on acanthopanax senticosus, licorice, sophora flavescens and wolfberry in a specific ratio, and the obtained plant extract B can synergize with the plant extract A, and has a good effect on the weight gain of grass carp. The plant extract A and the plant extract B contain a variety of biologically active ingredients, which can promote the growth and development of grass carp through a variety of mechanisms. Plants such as lotus leaves, scutellaria baicalensis, and sophora flavescens contain rich flavonoids, which have anti-inflammatory and antioxidant effects, can improve the health of intestinal mucosa, enhance intestinal barrier function, reduce the absorption of harmful substances, and thus improve the absorption efficiency of nutrients; catechins and other ingredients in green tea can promote the secretion of digestive enzymes, improve the digestibility of food, and thus increase the absorption of nutrients; polysaccharides, carotene and other ingredients in wolfberry can enhance the function of immune cells and improve the body's immune response ability. The biologically active ingredients in plant extracts A and B can not only improve the digestion and absorption function of grass carp, enhance immunity, anti-oxidation and promote protein synthesis, but also reduce stress response, thereby acting together on the weight gain of grass carp.

[0021] Furthermore, the composite bacterial agent includes Lactobacillus acidophilus, Lactobacillus helveticus, Bifidobacterium longum and Bifidobacterium lactis; the bacterial activity of Lactobacillus acidophilus in the composite bacterial agent is 10 6 -10 7 CFU / g; the bacterial activity of Lactobacillus helveticus in the composite bacterial agent is 10 8 -109 CFU / g; the activity of Bifidobacterium longum in the composite bacterial agent is 10 7 -10 8 CFU / g; the activity of Bifidobacterium lactis in the composite bacterial agent is 10 9 -10 10 CFU / g.

[0022] Grass carp has higher nutritional value and healthier dietary characteristics. The protein in grass carp is a high-quality animal protein source. At the same time, low-fat grass carp can reduce the intake of saturated fat and cholesterol, which helps to reduce the risk of cardiovascular disease. The present invention can increase the protein content in grass carp and reduce the fat content by adding a composite bacterial agent to a composite aquatic feed. The composite bacterial agent of a specific type of the present invention helps to improve the intestinal health of grass carp and enhance the function of its digestive system. A healthy intestine can better absorb nutrients, thereby increasing the growth rate and protein accumulation of grass carp. The microorganisms in the composite bacterial agent of the present invention can also reduce the accumulation of fat by regulating the fat metabolism pathway in the grass carp, and can produce some enzyme substances to promote the decomposition of fat and the utilization of energy, thereby reducing the fat content. And by adding a composite bacterial agent prepared by a specific type of bacteria of the present invention, the weight gain of grass carp can also be promoted in coordination with plant extract A and plant extract B.

[0023] The present invention also provides a method for preparing a composite aquatic feed for improving fish immunity, comprising the following steps: feeding raw materials into a mixer according to proportion and mixing them evenly, and then feeding them into a grinder and grinding them to obtain the composite aquatic feed for improving fish immunity.

[0024] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0025] 1. The present invention extracts four natural plants of green tea, lotus leaf, scutellaria baicalensis and knotweed in a specific ratio, first uses different bacteria for gradient fermentation, and then ultrasonicates, and the obtained plant extract A can reduce the liver-body index of grass carp, increase the spleen-body index and the head-kidney-body index, and enhance the immune ability of grass carp.

[0026] 2. The plant extract B obtained by enzymolysis and microwave extraction of Acanthopanax senticosus, Licorice, Sophora flavescens and Lycium barbarum in a specific ratio can synergize with the plant extract A and has a good effect on weight gain of grass carp.

[0027] 3. The present invention can increase the protein content of grass carp and reduce the fat content by adding the composite bacterial agent to the composite aquatic feed. In addition, by adding the composite bacterial agent prepared by the specific type of bacteria of the present invention, the plant extract A and the plant extract B can also be used to promote the weight gain of grass carp. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The bacterial agent used in the present invention is a commercially available product, and the specific purchase conditions are as follows:

[0030] Lactobacillus brevis, accession number: SHBCCD14346, was purchased from Shanghai Microbiological Collection Center.

[0031] Lactobacillus casei, accession number: SHBCCD24737, was purchased from Shanghai Microbiological Collection Center.

[0032] Lactobacillus rhamnosus, accession number: SHBCCD73158, was purchased from Shanghai Microbiological Collection Center.

[0033] Lactobacillus acidophilus, accession number: CCTCCAB2010208, was purchased from China Center for Type Culture Collection.

[0034] Lactobacillus helveticus, accession number: CCTCCAB2010205, was purchased from China Center for Type Culture Collection.

[0035] Bifidobacterium longum, accession number: SHBCCD24310, was purchased from Shanghai Microbiological Collection Center.

[0036] Bifidobacterium lactis, accession number: SHBCCD24728, was purchased from Shanghai Microbiological Collection Center.

[0037] Lactobacillus plantarum, accession number: SHBCCD17052, was purchased from Shanghai Microbiological Collection Center.

[0038] Bifidobacterium breve, accession number: SHBCCD24425JCM7019, was purchased from Shanghai Microbiological Collection Center.

[0039] Lactobacillus johnsonii, accession number: SHBCCD71369, was purchased from Shanghai Microbiological Collection Center.

[0040] Lactobacillus reuteri, accession number: SHBCCD12901, was purchased from Shanghai Microbiological Collection Center.

[0041] Soybean meal was purchased from Shijiazhuang Lvwan Agricultural and Sideline Products Co., Ltd.

[0042] Palm meal was purchased from Huamo (Shandong) Biotechnology Co., Ltd.

[0043] Rice bran was purchased from Hebei Taide Agriculture Co., Ltd.

[0044] Brewer's grains were purchased from Lixian Houde Agricultural Technology Co., Ltd.

[0045] Shrimp powder was purchased from Shaanxi Chenming Biotechnology Co., Ltd.

[0046] Example 1

[0047] The present embodiment provides a composite aquatic feed for improving the immunity of fish, comprising the following raw materials in percentage by weight: 11% soybean meal, 4% palm meal, 9% rice bran, 3% brewer's grains, 10% flour, 3% soybean oil, 4% soybean lecithin, 6% shrimp meal, 1.2% plant extract A, 2.3% plant extract B, 0.5% composite bacterial agent, 2% palm oil, 2.6% monocalcium phosphate, and the balance is vegetable cake;

[0048] The preparation method of the plant extract A comprises the following steps:

[0049] (1) mixing green tea, lotus leaf, scutellaria baicalensis and knotweed in a weight ratio of 10:2:7:13, and crushing to less than 100 meshes to obtain mixed fine powder;

[0050] (2) adding water 8 times the weight of the mixed micropowder to the mixed micropowder to obtain a fermentation raw material, and adding Lactobacillus brevis to the fermentation raw material, wherein the amount of Lactobacillus brevis in the fermentation raw material is 10 7 CFU / mL; anaerobic fermentation at 37℃ for 2 days, after sterilization; continue to add Lactobacillus casei, the amount of Lactobacillus casei in the fermentation raw material is 10 7 CFU / mL; 36℃ anaerobic fermentation for 3 days, after sterilization, continue to add Lactobacillus rhamnosus, the amount of Lactobacillus rhamnosus in the fermentation raw material is 10 8 CFU / mL, anaerobic fermentation at 36°C for 1 day, sterilization, 500W ultrasound for 35 minutes; after completion, filtration using a 0.22 micron filter membrane, and drying the filtrate to obtain plant extract A.

[0051] The preparation method of the plant extract B comprises the following steps: mixing Acanthopanax senticosus, Glycyrrhiza uralensis, Sophora flavescens and Lycium barbarum in a weight ratio of 12:10:5:2, crushing to less than 50 meshes to obtain a mixture, adding water 7 times the weight of the mixture to the mixture to obtain a mixed liquid, adding a composite enzyme to the mixed liquid, wherein the composite enzyme comprises cellulase, pectinase and bromelain; the amount of the cellulase in the mixed liquid is 105 U / mL; the amount of the pectinase in the mixed liquid is 135 U / mL; the amount of the bromelain in the mixed liquid is 85 U / mL; performing enzymolysis at 32°C for 6 hours, and obtaining an enzymolysis product after inactivation of the enzyme, and placing the enzymolysis product in a microwave reactor for microwave extraction, wherein the microwave extraction conditions are as follows: microwave power 260 W, temperature 72°C, and extraction time 1.7 hours; after the extraction is completed, filtering with a 0.22 micron filter membrane, and drying the filtrate to obtain the plant extract B.

[0052] The composite bacterial agent comprises Lactobacillus acidophilus, Lactobacillus helveticus, Bifidobacterium longum and Bifidobacterium lactis; the bacterial activity of Lactobacillus acidophilus in the composite bacterial agent is 10 7 CFU / g; the bacterial activity of Lactobacillus helveticus in the composite bacterial agent is 10 8 CFU / g; the activity of Bifidobacterium longum in the composite bacterial agent is 10 7 CFU / g; the activity of Bifidobacterium lactis in the composite bacterial agent is 10 10 CFU / g.

[0053] The method for preparing the composite aquatic feed for improving fish immunity comprises the following steps: feeding the raw materials into a mixer in proportion and mixing them evenly, and then feeding them into a grinder and grinding them to a particle size less than 100 meshes to obtain the composite aquatic feed for improving fish immunity.

[0054] Example 2

[0055] The present embodiment provides a composite aquatic feed for improving the immunity of fish, comprising the following raw materials in percentage by weight: 9% soybean meal, 6% palm meal, 7% rice bran, 5% brewer's grains, 9% flour, 4% soybean oil, 2% soybean lecithin, 8% shrimp meal, 1% plant extract A, 2.5% plant extract B, 0.2% composite bacterial agent, 3% palm oil, 2% monocalcium phosphate, and the balance is vegetable cake;

[0056] The preparation method of the plant extract A comprises the following steps:

[0057] (1) mixing green tea, lotus leaf, scutellaria baicalensis and knotweed in a weight ratio of 10:1:6:15, and crushing to less than 100 meshes to obtain mixed fine powder;

[0058] (2) adding water 10 times the weight of the mixed micropowder to the mixed micropowder to obtain a fermentation raw material, and adding Lactobacillus brevis to the fermentation raw material, wherein the amount of Lactobacillus brevis in the fermentation raw material is 10 7 CFU / mL; anaerobic fermentation at 35℃ for 1 day, after sterilization; continue to add Lactobacillus casei, the amount of Lactobacillus casei in the fermentation raw material is 10 7 CFU / mL; 38℃ anaerobic fermentation for 3 days, after sterilization, continue to add Lactobacillus rhamnosus, the amount of Lactobacillus rhamnosus in the fermentation raw material is 10 9 CFU / mL; anaerobic fermentation at 38°C for 2 days, sterilization, and 600W ultrasound for 40 minutes; after completion, filtration was performed using a 0.22 micron filter membrane, and the filtrate was dried to obtain plant extract A.

[0059] The preparation method of the plant extract B comprises the following steps: mixing Acanthopanax senticosus, Licorice, Sophora flavescens and Lycium barbarum in a weight ratio of 11:10:7:1, crushing to less than 50 meshes to obtain a mixture, adding 9 times the weight of water to the mixture to obtain a mixture liquid, adding a composite enzyme to the mixture liquid, wherein the composite enzyme comprises cellulase, pectinase and bromelain. The amount of the cellulase in the mixture liquid is 110U / mL; the amount of the pectinase in the mixture liquid is 130U / mL; the amount of the bromelain in the mixture liquid is 90U / mL; performing enzymolysis at 35°C for 4h, after inactivating the enzyme, obtaining an enzymolysis product, placing the enzymolysis product in a microwave reactor for microwave extraction, and the microwave extraction conditions are: microwave power 250W, temperature 75°C, extraction time 2h; after the extraction is completed, filtering with a 0.22 micron filter membrane, drying the filtrate, and obtaining the plant extract B.

[0060] The composite bacterial agent comprises Lactobacillus acidophilus, Lactobacillus helveticus, Bifidobacterium longum and Bifidobacterium lactis; the bacterial activity of Lactobacillus acidophilus in the composite bacterial agent is 10 6 CFU / g; the bacterial activity of Lactobacillus helveticus in the composite bacterial agent is 10 8 CFU / g; the activity of Bifidobacterium longum in the composite bacterial agent is 10 8 CFU / g; the activity of Bifidobacterium lactis in the composite bacterial agent is 10 9 CFU / g.

[0061] The method for preparing the composite aquatic feed for improving fish immunity comprises the following steps: feeding the raw materials into a mixer in proportion and mixing them evenly, and then feeding them into a grinder and grinding them to a particle size less than 100 meshes to obtain the composite aquatic feed for improving fish immunity.

[0062] Comparative Example 1

[0063] The difference between this comparative example and Example 1 is that: plant extract A 1.2%, plant extract B 2.3%, are replaced by: plant extract A 2.3%, plant extract B 1.2%.

[0064] Comparative Example 2

[0065] The difference between this comparative example and Example 1 is that the preparation method of the plant extract A comprises the following steps:

[0066] (1) mixing green tea, lotus leaf, scutellaria baicalensis and knotweed in a weight ratio of 10:2:7:13, and crushing to less than 100 meshes to obtain mixed fine powder;

[0067] (2) Mix the mixed micro powder in a weight ratio of 1:8 and an ethanol aqueous solution with a volume fraction of 70%, heat and reflux for extraction three times, each extraction for 60 minutes, filter with a 0.22 micron filter membrane, and dry the filtrate to obtain plant extract A.

[0068] Comparative Example 3

[0069] The difference between this comparative example and Example 1 is that green tea, lotus leaf, scutellaria baicalensis and knotweed are mixed in a weight ratio of 1:1:1:1.

[0070] Comparative Example 4

[0071] The difference between this comparative example and Example 1 is that Lactobacillus brevis is replaced by Lactobacillus acidophilus, and the amount of Lactobacillus acidophilus in the fermentation raw material is 10 7 CFU / mL; Lactobacillus casei was replaced by Lactobacillus helveticus, and the amount of Lactobacillus helveticus in the fermentation raw material was 10 7 CFU / mL; Lactobacillus rhamnosus was replaced by Bifidobacterium longum, and the amount of Bifidobacterium longum in the fermentation raw material was 10 8 CFU / mL.

[0072] Comparative Example 5

[0073] The difference between this comparative example and Example 1 is that the green tea, lotus leaf, scutellaria baicalensis and knotweed mixed in a weight ratio of 10:2:7:13 is replaced by: honeysuckle, angelica, epimedium and pulsatilla scabra mixed in a weight ratio of 10:2:7:13.

[0074] Comparative Example 6

[0075] The difference between this comparative example and Example 1 is that the mixture of Acanthopanax senticosus, Glycyrrhiza uralensis, Sophora flavescens and Lycium barbarum in a weight ratio of 12:10:5:2 is replaced by the mixture of Tangerine Peel, Codonopsis pilosula, Cornus officinalis and Coriolus versicolor in a weight ratio of 12:10:5:2.

[0076] Comparative Example 7

[0077] The difference between this comparative example and Example 1 is that Acanthopanax senticosus, Glycyrrhiza uralensis, Sophora flavescens and Lycium barbarum are mixed in a weight ratio of 1:1:1:1.

[0078] Comparative Example 8

[0079] The difference between this comparative example and Example 1 is that the composite enzyme includes neutral protease, β-glucanase and ficin; the amount of the neutral protease in the mixed liquid is 105 U / mL; the amount of the β-glucanase in the mixed liquid is 135 U / mL; the amount of the ficin in the mixed liquid is 85 U / mL;

[0080] Comparative Example 9

[0081] The difference between this comparative example and Example 1 is that the composite bacterial agent includes Lactobacillus plantarum, Bifidobacterium breve, Lactobacillus johnsonii and Lactobacillus reuteri; the bacterial activity of Lactobacillus plantarum in the composite bacterial agent is 10 7CFU / g; the bacterial activity of Bifidobacterium breve in the composite bacterial agent is 10 8 CFU / g; the bacterial activity of Lactobacillus johnsonii in the composite bacterial agent is 10 7 CFU / g; the bacterial activity of Lactobacillus reuteri in the composite bacterial agent is 10 10 CFU / g.

[0082] Performance Testing

[0083] The performance tests were conducted on the compound aquatic feeds of Examples 1-2 and Comparative Examples 1-9.

[0084] 1. Select healthy and uniform-sized grass carp (100±10.06g), randomly divide them into 12 groups, 40 grass carp in each group, and raise them in a circulating aquarium. Feed them with basic feed (Shandong Miner New Material Co., Ltd., fish feed) until the fish actively grab food, and the acclimation time is 15d; then use the composite aquatic feed and basic feed (Shandong Miner New Material Co., Ltd., fish feed) of Example 1-2 and Comparative Example 1-9 respectively, and formally cultivate them for 45d, feed them 3 times a day, at 9:00, 13:00, and 17:00, respectively, and the feeding rate is 2% of the fish body weight. The feeding rate is adjusted once a week. During the test, the water temperature is 20±3°C, the water pH value is 6.9-7.2, the dissolved oxygen is 6-8mg / L, and the ammonia nitrogen is ≤0.1mg / L.

[0085] Calculate the weight gain rate and immune organ performance indicators.

[0086] Weight gain rate = (final weight - initial weight) / initial weight × 100%.

[0087] Hepatosomatic index = liver weight / final weight × 100%.

[0088] Spleen index = spleen weight / final weight × 100%.

[0089] Head-kidney index = head-kidney weight / final weight × 100%.

[0090] The results are shown in Table 1.

[0091] Table 1 Weight gain rate and immune organ performance index test results (%)

[0092]

[0093]

[0094] 2. Refer to the relevant national testing standards (GB / T9695.7-2008, GB / T9695.18-2008, GB / T9695.15-2008 and GB / T9695.11-2008) to test the meat quality indicators of grass carp after feeding.

[0095] The results are shown in Table 2.

[0096] Table 2 Test results of grass carp meat quality indexes (%)

[0097]

[0098]

[0099] From the above performance test results, it can be seen that the composite aquatic feed of Examples 1-2 can improve the immunity of grass carp, have a good weight gain effect on grass carp, and have higher meat quality. In particular, the comprehensive performance of Example 1 is the most outstanding, which is mainly due to the synergistic effect of the raw materials of the composite aquatic feed.

[0100] However, the comparative examples were significantly inferior to the embodiments in the corresponding performance tests because they did not adopt the necessary technical solutions. Comparative example 1 changed the ratio of plant extract A and plant extract B, and the weight gain of grass carp decreased. Comparative example 2 changed the preparation method of plant extract A, comparative example 3 changed the ratio of green tea, lotus leaf, scutellaria baicalensis and knotweed, comparative example 4 changed the strain used for fermentation of plant extract A, and comparative example 5 changed the types of four natural plants. The above comparative examples all showed that the improvement effect of grass carp liver body index, spleen body index and head kidney body index became worse. Comparative example 6 changed the raw materials of plant extract B; comparative example 7 changed the ratio of Acanthopanax senticosus, Licorice, Sophora flavescens and Lycium barbarum, comparative example 8 changed the composite enzyme used in plant extract B, and the feed prepared in the above comparative examples had a weakened effect on grass carp weight gain. The strain used in the composite bacterial agent of comparative example 9 was changed, and the meat quality of grass carp decreased. The above experimental results further prove the importance of the technical solution defined in the present invention for its technical effect.

[0101] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A composite aquatic feed for improving the immunity of fish, characterized in that: The invention comprises the following raw materials in percentage by weight: 9-13% soybean meal, 2-6% palm meal, 7-12% rice bran, 2-5% brewer's grains, 9-13% flour, 1-4% soybean oil, 2-5% soybean lecithin, 5-8% shrimp meal, 1-1.5% plant extract A, 2-2.5% plant extract B, 0.2-0.6% composite bacterial agent, 1-3% palm oil, 2-3% monocalcium phosphate, and the balance is vegetable cake; The preparation method of the plant extract A comprises the following steps: (1) mixing green tea, lotus leaves, scutellaria baicalensis and knotweed, and crushing to obtain mixed micro powder; (2) adding 7-10 times the weight of water to the mixed micropowder to obtain a fermentation raw material, adding Lactobacillus brevis to the fermentation raw material, and performing anaerobically fermentation at 35-38° C. for 1-2 days, and sterilizing; continuing to add Lactobacillus casei, and performing anaerobically fermentation at 35-38° C. for 2-3 days, and sterilizing; continuing to add Lactobacillus rhamnosus, and performing anaerobically fermentation at 35-38° C. for 1-2 days, and sterilizing; and ultrasonicating at 400-600 W for 30-40 min; after completion, filtering, and drying the filtrate to obtain plant extract A.

2. The composite aquatic feed for improving fish immunity according to claim 1, characterized in that: The weight ratio of green tea, lotus leaf, scutellaria baicalensis and knotweed is 10:(1-3):(6-8):(12-15).

3. The composite aquatic feed for improving fish immunity according to claim 1, characterized in that: The amount of Lactobacillus brevis used in the fermentation raw material is 10 7 -10 8 CFU / mL; the amount of Lactobacillus casei in the fermentation raw material is 10 6 -10 7 CFU / mL; the amount of Lactobacillus rhamnosus in the fermentation raw material is 10 8 -10 9 CFU / mL.

4. The composite aquatic feed for improving fish immunity according to claim 1, characterized in that: The preparation method of the plant extract B comprises the following steps: mixing Acanthopanax senticosus, Glycyrrhiza uralensis, Sophora flavescens and Lycium barbarum, and crushing to obtain a mixture, adding water 6-9 times the weight of the mixture to the mixture to obtain a mixture liquid, adding a complex enzyme to the mixture liquid, performing enzymolysis at 30-35° C. for 4-7 hours, and obtaining an enzymolysis product after inactivating the enzyme, placing the enzymolysis product in a microwave reactor for microwave extraction, filtering with a filter membrane after the extraction is completed, and drying the filtrate to obtain the plant extract B.

5. The composite aquatic feed for improving fish immunity according to claim 4, characterized in that: The weight ratio of Acanthopanax senticosus, Glycyrrhiza uralensis, Sophora flavescens and Lycium barbarum is (11-14):10:(4-7):(1-3).

6. The composite aquatic feed for improving fish immunity according to claim 4, characterized in that: The complex enzyme comprises cellulase, pectinase and bromelain.

7. The composite aquatic feed for improving fish immunity according to claim 6, characterized in that: The amount of cellulase in the mixed liquid is 100-110 U / mL; the amount of pectinase in the mixed liquid is 130-140 U / mL; and the amount of bromelain in the mixed liquid is 80-90 U / mL.

8. The composite aquatic feed for improving fish immunity according to claim 4, characterized in that: The conditions of microwave extraction are: microwave power 250-280W, temperature 70-75°C, and extraction time 1.5-2h.

9. The composite aquatic feed for improving fish immunity according to claim 1, characterized in that: The composite bacterial agent comprises Lactobacillus acidophilus, Lactobacillus helveticus, Bifidobacterium longum and Bifidobacterium lactis; the bacterial activity of Lactobacillus acidophilus in the composite bacterial agent is 10 6 -10 7 CFU / g; the bacterial activity of Lactobacillus helveticus in the composite bacterial agent is 10 8 -10 9 CFU / g; the activity of Bifidobacterium longum in the composite bacterial agent is 10 7 -10 8 CFU / g; the bacterial activity of Bifidobacterium lactis in the composite bacterial agent is 10 9 -10 10 CFU / g.

10. A method for preparing the composite aquatic feed for improving fish immunity according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: feeding the raw materials into a mixer according to a proportion and mixing them evenly, and then feeding the raw materials into a grinder and grinding them to obtain a composite aquatic feed for improving the immunity of fish.

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