Feed additive for resisting intestinal stress of largemouth bass
By adding seaweed polysaccharides to largemouth bass feed, the problem of largemouth bass being susceptible to oxidative stress under intensive breeding conditions is solved, its antioxidant ability and immunity are improved, and the effect of green and healthy feed additives is achieved.
Patent Information
- Application Number
- CN202411871376.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-18
- Publication Date
- 2025-04-04
AI Technical Summary
Largemouth bass is susceptible to oxidative stress under intensive breeding conditions, resulting in reduced immunity, slow growth and prone to disease. The abuse of chemical drugs such as antibiotics in the prior art also has food safety and drug resistance problems.
Seaweed polysaccharides are used as feed additives, extracted by ultrasonic-assisted hot water method and added to the feed of largemouth black bass to improve its antioxidant ability and immunity.
Seaweed polysaccharides effectively reduce the oxidative stress state of largemouth bass, improve their antioxidant enzyme activity, enhance immunity, improve intestinal health, have no toxic side effects, and are environmentally friendly.
Smart Images
Figure CN119744979A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of aquatic feed additives, and in particular relates to a feed additive for resisting intestinal stress of largemouth bass. Background Art
[0002] Under intensive farming conditions, fish are stimulated by a variety of stress factors, which can lead to stress reactions. For farmed fish, a variety of factors such as farming density, temperature, human operation, pathogenic microorganisms, etc. can lead to excessive production of ROS in the fish, causing oxidative stress and endangering the health of fish. Oxidative stress can cause apoptosis of immune cells and inhibit the activity of immune-related proteins or enzymes, thereby reducing the body's immunity and resistance to pathogens and diseases. Under oxidative stress, excessive ROS destroys the antioxidant system, attacks biofilms, proteins and nucleic acids, and causes oxidative damage to the body's lipids, DNA, proteins and other biological macromolecules, thereby reducing the body's resistance and inducing various diseases.
[0003] At present, it is a trend to add feed additives of natural origin to aquaculture to combat oxidative stress. In the breeding process, in order to improve the immunity and antioxidant capacity of fish and reduce the risk of infection, chemical drugs such as antibiotics are often overused. The abuse of chemical drugs such as antibiotics, on the one hand, will lead to drug residues in aquatic organisms, causing food safety problems; on the other hand, it will also make pathogens resistant to drugs, hindering the sustainable development of aquaculture.
[0004] Largemouth bass has firm meat, delicious taste, few bone spurs, and high nutritional value. It is very popular in the market and is known as China's "fifth largest fish". Largemouth bass has strong disease resistance and few diseases. It can be raised alone or mixed with other species in ponds. It is also suitable for high-density breeding in factory breeding systems, and has high economic benefits. With the development of intensive breeding, largemouth bass are prone to stress during breeding, such as high temperature stress, hypoxia stress, disease stress, etc. Long-term or excessive oxidative stress can significantly affect the normal physiological and behavioral activities of fish, leading to slow growth, reduced immunity, and even death of fish, causing great harm to actual production. Largemouth bass are prone to enteritis, especially during the feed transition period. As people's requirements for food quality and safety become increasingly stringent, green and pollution-free aquatic products are more popular. Therefore, the research and development and application of efficient, healthy and environmentally friendly plant-based feed additives or fishery drugs are one of the key measures to promote the sustainable development of aquaculture. Summary of the invention
[0005] One of the purposes of the present invention is to provide application of seaweed polysaccharide in largemouth bass breeding.
[0006] Specifically, it relates to the application of seaweed polysaccharide in the preparation of feed additives for largemouth bass to resist intestinal stress, and to the application method of seaweed polysaccharide in largemouth bass breeding.
[0007] The seaweed polysaccharide is brown algae polysaccharide, red algae polysaccharide or green algae polysaccharide; among them, green algae polysaccharide is preferred.
[0008] In one embodiment, the chlorella polysaccharide is from Ulva ulvae.
[0009] In the present invention, in the method for applying seaweed polysaccharide in largemouth bass breeding, when feeding feed, seaweed polysaccharide of 0.08% to 0.14% of the total weight of feed is added to the feed.
[0010] The second object of the present invention is to provide a feed additive for largemouth bass to resist intestinal stress.
[0011] Specifically, the feed additive for largemouth bass against intestinal stress is composed of seaweed polysaccharides.
[0012] In the present invention, in order to improve the biological activity of seaweed polysaccharides, the following method is used for extraction, which specifically includes the following steps:
[0013] (1) grinding dried seaweed into powder to obtain seaweed powder;
[0014] (2) soaking the seaweed powder in water, ultrasonically treating it, bathing it in hot water, and centrifuging it to obtain the supernatant.
[0015] (3) Add ethanol to the supernatant to precipitate, let it stand, and then centrifuge to collect the precipitate;
[0016] (4) dissolving the precipitate in hot water, repeating step (3), and then freeze-drying to obtain the seaweed polysaccharide.
[0017] The present invention adopts ultrasonic-assisted hot water method to extract seaweed polysaccharides. Compared with the general water extraction method, the extraction rate is higher; compared with the acid / alkali extraction method, the extracted seaweed polysaccharides have better biological activity and are more soluble in water, and the application operation is more convenient and easy.
[0018] Furthermore, the seaweed powder described in step (1) is passed through a 60-mesh sieve.
[0019] Furthermore, the water described in step (2) is ultrapure water, and the mass volume ratio of seaweed powder to ultrapure water is 1 (g):30 (mL); the ultrasonic treatment is performed at a power of 400W for 1 hour; the hot water bath is performed at a temperature of 95°C for 4 hours; and the centrifugation condition is performed at a speed of 5000rpm for 10 minutes.
[0020] Furthermore, in step (3), the ethanol concentration is 95%, and the volume of ethanol is 3 times the volume of the supernatant; the standing condition is standing at 4° C. for 12 hours, and the centrifugation condition is centrifugation at a rotation speed of 5000 rpm for 10 minutes.
[0021] Furthermore, the hot water in step (4) is 95° C., and the freeze drying is performed at a freezing temperature of -60° C. and a vacuum degree of 1 Pa for 24 hours.
[0022] In the present invention, the seaweed polysaccharide is brown algae polysaccharide, red algae polysaccharide or green algae polysaccharide, among which green algae polysaccharide is preferred.
[0023] In one embodiment, the chlorella polysaccharide is from Ulva ulvae.
[0024] The third object of the present invention is to provide a feed for largemouth bass to resist intestinal stress.
[0025] The largemouth bass anti-intestinal stress feed comprises a basic feed and seaweed polysaccharides, wherein the addition amount of the seaweed polysaccharides is 0.08% to 0.14% of the mass of the basic feed.
[0026] In the present invention, the seaweed polysaccharide is brown algae polysaccharide, red algae polysaccharide or green algae polysaccharide, among which green algae polysaccharide is preferred.
[0027] In one embodiment, the chlorella polysaccharide is from Ulva ulvae.
[0028] The preparation method of the largemouth bass anti-intestinal stress feed is as follows: dissolving seaweed polysaccharide in water to obtain seaweed polysaccharide liquid, then pouring it into the basic feed in small amounts and multiple times, stirring continuously during the process until the basic feed is evenly coated with the seaweed polysaccharide liquid; and then drying the mixed seaweed polysaccharide feed.
[0029] Furthermore, the suitable addition amount of the seaweed polysaccharide is 0.08% to 0.14% of the basic feed mass.
[0030] Furthermore, the amount of water is 20% of the mass of the basic feed.
[0031] Furthermore, the drying temperature is 55°C.
[0032] Compared with the prior art, the present invention has the following beneficial effects:
[0033] Seaweed polysaccharides are extracted from large marine algae and have biological activities such as antioxidant, anti-inflammatory, anti-cancer, and anti-bacterial. Applying seaweed polysaccharides to Caco-2 cells induced by hydrogen peroxide can reduce the production of reactive oxygen species (ROS) and malondialdehyde (MDA) in Caco-2 cells. Using seaweed polysaccharides as an anti-stress feed additive for largemouth bass can effectively reduce the malondialdehyde (MDA) content in the serum and intestines of largemouth bass, increase the enzyme activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT), reduce intestinal inflammation, and improve the tight junctions of intestinal epithelial cells, thereby improving antioxidant capacity, improving intestinal health, and resisting stress.
[0034] The present invention uses seaweed polysaccharides as feed additives for largemouth seabass, especially green algae polysaccharides, which can improve the growth performance, antioxidant capacity and immunity of largemouth seabass, has no toxic side effects, is environmentally friendly, is a green and healthy feed additive, conforms to the concept of healthy ecological breeding, and is suitable for the development requirements of current aquaculture. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Figure 1 The effect of fucoidan on hydrogen peroxide-induced oxidative damage in Caco-2 cells.
[0036] Figure 2 The effect of red algae polysaccharides on hydrogen peroxide-induced oxidative damage in Caco-2 cells.
[0037] Figure 3 The effect of chlorella polysaccharide on hydrogen peroxide-induced oxidative damage in Caco-2 cells.
[0038] Figure 4 The effect of chlorella polysaccharide on serum antioxidant indexes of largemouth bass.
[0039] Figure 5 The effect of chlorella polysaccharides on antioxidant indicators in the foregut of largemouth bass.
[0040] Figure 6 The effect of green algae polysaccharides on foregut gene expression in largemouth bass.
[0041] Figure 7 The effect of green algae polysaccharides on the foregut epithelial cell barrier of largemouth bass. DETAILED DESCRIPTION
[0042] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.
[0043] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.
[0044] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.
[0045] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.
[0046] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.
[0047] Example 1
[0048] (1) Wash and soak the seaweed with clean water, then dry and grind into powder, and pass through a 60-mesh sieve to obtain seaweed powder.
[0049] (2) Soak the seaweed powder in ultrapure water at a ratio of 1 (g) to 30 (mL) of seaweed powder and ultrapure water, and perform ultrasonic treatment at a power of 400 W for 1 h. After ultrasonic treatment, place the mixture in a 95° C. hot water bath for 4 h, centrifuge at a speed of 5000 rpm for 10 min, and collect the supernatant.
[0050] (3) Add three times the volume of 95% anhydrous ethanol to the supernatant to precipitate, let it stand at 4°C for 12 hours, centrifuge it at 5000 rpm for 10 minutes, and take the precipitate. Dissolve the precipitate in 95°C hot water, add three times the volume of 95% anhydrous ethanol to precipitate, let it stand at 4°C for 12 hours, centrifuge it at 5000 rpm / min for 10 minutes, take the precipitate, and freeze-dry it in a vacuum freeze dryer at a freezing temperature of -60°C and a vacuum degree of 1 Pa to obtain seaweed polysaccharides.
[0051] The above method is adopted to extract seaweed polysaccharides from Ulva, Porphyra and Laminaria japonica to obtain green algae polysaccharide, red algae polysaccharide and brown algae polysaccharide respectively.
[0052] Caco-2 cells were incubated with different concentrations of green algae polysaccharide, red algae polysaccharide and brown algae polysaccharide for 24 hours.
[0053] A hydrogen peroxide-induced Caco-2 cell oxidative damage model was established: Caco-2 cells incubated with seaweed polysaccharides were treated with hydrogen peroxide for 4 hours, where the treatment concentration of hydrogen peroxide was 2500 μM. The viability of Caco-2 cells was observed.
[0054] like Figure 1-3 As shown, green algae polysaccharide, red algae polysaccharide and brown algae polysaccharide all have the effect of resisting hydrogen peroxide oxidation stress, among which green algae polysaccharide has the best antioxidant stress ability.
[0055] Example 2
[0056] The commercial feed was commercial feed No. 2 for largemouth bass purchased from Foshan Shunde Fenghua Feed Industry Co., Ltd. The commercial feed did not contain seaweed polysaccharide.
[0057] 0% (SP0), 0.08% (SP1), 0.14% (SP2), 0.20% (SP3), 0.26% (SP4), and 0.32% (SP5) of the chlorella polysaccharide obtained in Example 1 were taken as the mass of the commercial feed, dissolved in 20% of the water of the feed mass, heated at 95°C to dissolve, and added to the commercial feed in small amounts and multiple times after complete dissolution, stirring continuously and mixing thoroughly until the base feed was evenly coated with the chlorella polysaccharide liquid, and dried at 55°C to obtain six groups of largemouth bass feeds containing additives with different concentration gradients.
[0058] Effect verification:
[0059] The experiment selected 540 healthy largemouth bass of uniform size and divided them into 18 tanks with 30 fish in each tank. The 18 tanks were divided into 6 groups with 3 replicates in each group. The fish were fed with full food for 2 weeks. After 2 weeks, 250mM hydrogen peroxide was injected into the base of the pectoral fins. Samples were collected 24 hours later to determine the effects of feed additives on the growth performance, serum biochemical indicators, intestinal antioxidant indicators, etc. of largemouth bass.
[0060] 1. Effects of anti-stress feed additives on the growth performance of largemouth bass
[0061] The average initial body weight, average final body weight and body length of each group of largemouth bass after 2 weeks of culture were calculated, and the weight gain rate was calculated as follows: weight gain rate (%) = 100 × (final body weight (g) - initial body weight (g)) / initial body weight (g), specific growth rate (% / day) = 100 × (Ln final body weight (g) - Ln initial body weight (g)) / culture days (day), feed coefficient was calculated as follows: feed coefficient = total feed intake / (final body weight - initial body weight), and fatness was calculated as follows: fatness (g / cm 3 )=100×(final body weight (g) / final body length (cm) 3 ), and calculate the survival rate, survival rate (%) = 100 × (final number of fish tails) / (initial number of fish tails); after dissecting each group of largemouth bass, weigh the weight of viscera and liver, calculate the liver-body ratio of each group of largemouth bass, liver-body ratio (%) = 100 × liver weight (g) / final body weight (g), calculate the viscera-body ratio, viscera-body ratio (%) = 100 × viscera weight (g) / final body weight (g). The experimental results are shown in Table 1.
[0062] Table 1 Growth performance
[0063]
[0064] SP0, SP1, SP2, SP3, SP4, and SP5 represent the groups with 0%, 0.08%, 0.14%, 0.20%, 0.26%, and 0.32% seaweed polysaccharide added to feed, respectively.
[0065] As shown in Table 1, adding the anti-stress feed additive for largemouth bass of the present invention to the feed of largemouth bass for 2 weeks slightly improves the growth performance of largemouth bass and reduces the feed coefficient, wherein the addition of 0.08% (SP1) has the best effect.
[0066] 2. Effects of anti-stress feed additives on serum biochemical parameters of largemouth bass
[0067] Serum of largemouth bass after 2 weeks of culture was taken, and serum biochemical indicators including total protein (TP), albumin (ALB), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were measured using commercial kits (Nanjing Jiancheng Bioengineering Institute). Immunoglobulin M (IgM), endotoxin (LPS), interleukin-6 (IL-6), interleukin-8 (IL-8), and interleukin-1β (IL-1β) were measured using Elisa kits (Shanghai Enzyme-Linked Biotechnology Co., Ltd.). The experimental results are shown in Table 2.
[0068] Commercial kit (Nanjing Jiancheng Bioengineering Institute): total protein (TP) (A045-4-2), albumin (ALB) (A028-2-1), alanine aminotransferase (ALT) (C009-2-1), aspartate aminotransferase (AST) (C010-2-1).
[0069] Elisa kit (Shanghai ELISA Biotechnology Co., Ltd.): Immunoglobulin M (IgM) (ml025819), lipopolysaccharide (LPS) (ml035471), interleukin 6 (IL-6) (ml0257510), interleukin 8 (IL-8) (ml025752), and interleukin 1-β (IL-1β) (ml025799).
[0070] Table 2 Serum enzyme activities
[0071]
[0072] As can be seen from Table 2, the anti-stress feed additive for largemouth bass of the present invention is added to the feed of largemouth bass, which significantly reduces the activity of aspartate aminotransferase, alanine aminotransferase and the content of endotoxin in the serum of largemouth bass, wherein the addition amounts of 0.08% (SP1), 0.14% (SP2) and 0.20% (SP3) also significantly increase the serum albumin content.
[0073] 3. Effects of anti-stress feed supplementation on foregut enzyme activity in largemouth bass
[0074] The foregut of the largemouth bass cultured for 2 weeks was taken and the foregut enzyme activity indexes were measured using a commercial kit (Nanjing Jiancheng Bioengineering Research Institute), including acid phosphatase (ACP), alkaline phosphatase (AKP), lysozyme (LZM), myeloperoxidase (MPO), amylase, trypsin, and lipase. Immunoglobulin M (IgM) and endotoxin (LPS) were measured using an Elisa kit (Shanghai Enzyme Biotechnology Co., Ltd.). The experimental results are shown in Table 3.
[0075] Commercial kit (Nanjing Jiancheng Bioengineering Institute): acid phosphatase (ACP) (A060-2-1), alkaline phosphatase (AKP) (A059-2-2), lysozyme (LZM) (A050-1-1), myeloperoxidase (MPO) (A044-1-1), amylase (C016-1-2), trypsin (A080-2-2), lipase (A054-2-1).
[0076] Elisa kit (Shanghai ELISA Biotechnology Co., Ltd.): immunoglobulin M (IgM) (ml025819), endotoxin (LPS) (ml035471).
[0077] Table 3 Foregut enzyme activities
[0078]
[0079] As shown in Table 3, the anti-stress feed additive for largemouth bass provided by the present invention is added to the feed of largemouth bass, which increases the acid phosphatase and alkaline phosphatase activities in the foregut of largemouth bass, and reduces the myeloperoxidase activity and endotoxin content. Among them, the addition amounts of 0.08% (SP1) and 0.14% (SP2) have the best effect.
[0080] 4. Effects of anti-stress feed additives on antioxidant indexes in serum and foregut of largemouth bass
[0081] The serum and foregut of the largemouth bass cultured for 2 weeks were collected and the antioxidant indexes, including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and malondialdehyde (MDA), were determined using a commercial kit (Nanjing Jiancheng Bioengineering Institute). Figure 4 (serum), Figure 5 (foregut).
[0082] Commercial kit (Nanjing Jiancheng Bioengineering Institute): superoxide dismutase (SOD) (A001-3-2), glutathione peroxidase (GSH-Px) (A005-1-2), catalase (CAT) (A007-1-1), malondialdehyde (MDA) (A003-1-2).
[0083] Depend on Figure 4 , Figure 5 It can be seen that the anti-stress feed additive of the present invention is added to the feed of largemouth bass, which not only improves the superoxide dismutase, glutathione peroxidase and catalase activities in the serum and foregut of largemouth bass, but also reduces the malondialdehyde content generated by lipid peroxidation. Among them, the addition amounts of 0.08% (SP1) and 0.14% (SP2) have the best effect.
[0084] 5. Effects of anti-stress feed additives on foregut gene expression in largemouth bass
[0085] The foregut of largemouth bass cultured for 2 weeks was taken and gene expression was determined by qPCR technology. The primers were synthesized by Shanghai Sangon Biotechnology Co., Ltd., the reverse transcription kit was from the Evo M-MLV reverse transcription premix kit (AG11728) of Hunan Aikerui Biotechnology Co., Ltd., and the SYBR Green fluorescent dye was from Nanjing Novozyme Biotechnology Co., Ltd. The experimental results are shown in Figure 6 .
[0086] Primers:
[0087] β-actin:
[0088] F:5′-AAAGGGAAATCGTGCGTGAC-3′;
[0089] R:5′-AAGGAAGGCTGGAAGAGGG-3′;
[0090] paint:
[0091] F:5′-TGGTGTTCACGGATGAGATGG-3′;
[0092] R:5′-GGAGAAGCGGACAGCAATAGG-3′;
[0093] sod:
[0094] F:5′-CCACCAGAGGTCTCACAGCA-3′;
[0095] R:5′-CCACTGAACCGAAGAAGGACT-3′;
[0096] gsh-px:
[0097] F:5′-ATGGCTCTCATGACTGATCCAAA-3′;
[0098] R:5′-GACCAACCAGGAACTTCTCAAA-3′;
[0099] with-1:
[0100] F:5′-ATCGGAGCAGATTAAGGC-3′;
[0101] R:5′-TTGTACTGTGGCAGGGTG-3′;
[0102] nrf-2:
[0103] F:5′-GCGAACTGGACTCACTGAAGGA-3′;
[0104] R:5′-AGGAAGATGCTGCCGTCTGTT-3′;
[0105] keap-1:
[0106] F:5′-AGGACTCCACTCATCACAACACA-3′;
[0107] R:5′-TCAGCAGTATTCCAGCGGTTCT-3′;
[0108] occludin:
[0109] F:5′-AGCGTCTTTAAAAGCGGGGTC-3′;
[0110] R:5′-TTGGAGCAGTTAACCCGACA-3′;
[0111] person-1:
[0112] F:5′-CCCCAACAAAAACAGAGCGG-3′;
[0113] R:5′-GCTGCGAAGACCACGAAATC-3′;
[0114] claudin-1:
[0115] F:5′-CCAGGGAAGGGGAGCAATG-3′;
[0116] R:5′-GCTCTTTGAACCAGTGCGAC-3′;
[0117] Figure-6:
[0118] F:5′-CGCGCAATTTGCCGATGATA-3′;
[0119] R:5′-CGTTGTTGCTGGTTGCATGA-3′;
[0120] Figure-8:
[0121] F:5′-GAGGGTACATGTCTGGGGGA-3′;
[0122] R:5′-CCTTGAAGGTTTGTTCTTCATCGT-3′;
[0123] il-10:
[0124] F:5′-CGGCACAGAAATCCCAGAGC-3′;
[0125] R:5′-CAGCAGGCTCACAAAATAAACATCT-3′;
[0126] tnf-α:
[0127] F:5′-CTTCGTCTACAGCCAGGCATCG-3′;
[0128] R:5′-TTTGCCACACCGACCTCACC-3′;
[0129] NF-κB:
[0130] F:5′-AGAAGACGACTCGGGGATGA-3′;
[0131] R: 5′-GCTTCTGCAGGTTCTGGTCT-3′.
[0132] Depend on Figure 6 It can be seen that the anti-stress feed additive prepared by the present invention is added to the feed of largemouth bass, and the addition amount of 0.08% (SP1) and 0.14% (SP2) can increase the expression of largemouth bass foregut antioxidant related genes CAT, SOD, GSH-PX, NRF2, HO-1, reduce the expression of Keap1 gene; increase the expression of tight junction protein genes occludin, claudin-1, ZO-1; reduce the expression of pro-inflammatory factors IL-6 and TNF-α, and increase the expression of anti-inflammatory factor IL-10. It shows that the above feed additive has the effects of improving antioxidant capacity, relieving inflammation, protecting intestinal barrier, etc. on largemouth bass.
[0133] 6. Effects of anti-stress feed supplementation on the intestinal barrier of largemouth bass
[0134] The foregut of the largemouth bass cultured for 2 weeks was taken and photographed by transmission electron microscope (Wuhan Bolfu Biotechnology Co., Ltd.), with a magnification of 10,000 times and an operating voltage of 80 kV. Figure 7 .
[0135] Depend on Figure 7 It can be seen that the anti-stress feed additive for largemouth bass of the present invention is added to largemouth bass feed, and the addition amount of 0.08% (SP1) can significantly strengthen the tight junctions between intestinal epithelial cells (white arrows), and the intestinal microvilli (red bidirectional arrows) are also more complete.
[0136] The above results indicate that adding 0.08% to 0.14% seaweed polysaccharides as feed additives can improve the growth performance, antioxidant capacity and immunity of largemouth bass, and has a certain protective effect on the intestinal barrier.
[0137] The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.
Claims
1. Application of seaweed polysaccharides in the preparation of feed additives for largemouth bass to resist intestinal stress.
2. The method for applying seaweed polysaccharide in largemouth bass breeding is characterized by: When feeding the feed, 0.08% to 0.14% of the total weight of the feed is added to the feed.
3. The method for applying seaweed polysaccharide in largemouth bass breeding according to claim 2, characterized in that: The seaweed polysaccharide is brown algae polysaccharide, red algae polysaccharide or green algae polysaccharide.
4. The method for applying seaweed polysaccharide in largemouth bass breeding according to claim 2, characterized in that: The seaweed polysaccharide is green algae polysaccharide.
5. A feed additive for largemouth bass to resist intestinal stress, characterized in that: Composed of seaweed polysaccharides.
6. The feed additive for resisting intestinal stress of largemouth bass according to claim 5, characterized in that: The seaweed polysaccharide is extracted by the following method: (1) grinding dried seaweed into powder to obtain seaweed powder; (2) soaking the seaweed powder in water, ultrasonically treating it, bathing it in hot water, and centrifuging it to obtain the supernatant. (3) adding ethanol to the supernatant to precipitate, allowing it to stand, and then centrifuging to obtain the precipitate; (4) dissolving the precipitate in hot water, repeating step (3), and then freeze-drying to obtain the seaweed polysaccharide.
7. The feed additive for resisting intestinal stress of largemouth bass according to claim 6, characterized in that: The seaweed powder described in the step (1) is passed through a 60-mesh sieve; the water described in the step (2) is ultrapure water, and the mass volume ratio of seaweed powder to ultrapure water is 1g:30mL; the ultrasonic treatment is performed at a power of 400W for 1 hour; the hot water bath is performed at a temperature of 95°C for 4 hours; the centrifugation condition is performed at a speed of 5000rpm for 10 minutes; the ethanol concentration described in the step (3) is 95%, and the volume of ethanol is 3 times the volume of the supernatant; the standing condition is performed at a temperature of 4°C for 12 hours, and the centrifugation condition is performed at a speed of 5000rpm for 10 minutes; the hot water in the step (4) is 95°C, and the freeze-drying is performed at a freezing temperature of -60°C and a vacuum degree of 1Pa for 24 hours.
8. A feed for largemouth bass to resist intestinal stress, including a basic feed, characterized in that: It also includes seaweed polysaccharide, and the added amount of the seaweed polysaccharide is 0.08% to 0.14% of the mass of the basic feed.
9. The anti-intestinal stress feed for largemouth bass according to claim 8, characterized in that: The seaweed polysaccharide is brown algae polysaccharide, red algae polysaccharide or green algae polysaccharide.
10. The method for preparing the anti-intestinal stress feed for largemouth bass according to claim 8 or 9, characterized in that: The seaweed polysaccharide is dissolved in water to obtain a seaweed polysaccharide liquid, which is then poured into the basic feed in small amounts and multiple times, with continuous stirring, until the basic feed is evenly coated with the seaweed polysaccharide liquid; and then the feed mixed with the seaweed polysaccharide is dried.