Compound feed additive for improving salt and alkali tolerance of grass carps and application of compound feed additive

Abstract

The invention discloses a compound feed additive for improving salt and alkali tolerance of grass carps and application, and belongs to the field of aquaculture feed. The compound feed additive provided by the invention comprises cholesterol, arachidonic acid (ARA), betaine, taurine, vitamin E, vitamin C, organic selenium, organic zinc, fructooligosaccharide and lecithin which are compounded according to a specific proportion. Experimental results of feeding the grass carp in a high-salinity and high-alkalinity water body show that the growth performance of the grass carp added with the compound feed additive provided by the invention is obviously improved, the compound feed additive has obvious advantages in the aspects of osmotic regulation, nitrogen metabolism, oxidation resistance, immunity and the like, and the active ingredients have an obvious synergistic effect. The invention provides a new feed additive formula for improving the salt and alkali tolerance of the freshwater fish, lays a foundation for developing the freshwater fish breeding industry in salt and alkali water, and has huge industrial application potential and popularization value.

Description

Technical Field

[0001] This invention relates to the field of aquaculture feed, and in particular to a compound feed additive for improving the salt and alkali tolerance of grass carp and its application. Background Technology

[0002] In recent years, the problem of freshwater and soil salinization has become increasingly serious, and the global rise in freshwater salinity has adversely affected ecosystems and aquaculture organisms. Currently, large areas of saline-alkali land and water exist, and these land resources have been abandoned for a long time, severely restricting the development of agriculture and aquaculture. Saline-alkali water is characterized by high pH, ​​high carbonate content, high ionic strength, and complex ionic composition, significantly affecting the osmotic balance and metabolism of freshwater fish (such as grass carp). Although freshwater farmed fish such as grass carp have a certain tolerance to low-salinity environments, their growth is significantly inhibited in carbonate-rich, highly alkaline waters, resulting in strong physiological stress responses, manifested as elevated blood ammonia and urea levels, ion imbalance, and exacerbated oxidative stress.

[0003] In recent years, with the continuous and in-depth research on the impact of saline-alkali water characteristics on aquatic animals, various suitable saline-alkali tolerant aquaculture species have been developed. However, compared with the rapid development of saline-alkali tolerant aquaculture species, the development of special feeds suitable for saline-alkali water aquaculture and for improving the saline-alkali tolerance of aquatic animals is still in its initial stage, and there are many problems that urgently need to be solved.

[0004] Currently, research on feed additives to improve the salt tolerance of aquatic animals is mainly limited to a few shrimp species, such as Chinese patents CN120266982A, CN118901908A, and CN118000311A. Research on improving the salt tolerance of freshwater fish has not yet been reported. This lack of systematic research hinders the ability to meet the growing demand for high-quality, specialized feeds from the saline-alkali aquaculture industry, becoming a bottleneck restricting the further development and expansion of the aquaculture industry.

[0005] Therefore, there is an urgent need to develop nutritional intervention methods for grass carp to improve their survival rate and growth performance in saline-alkali water. Summary of the Invention

[0006] The purpose of this invention is to provide a compound feed additive and its application to improve the salt and alkali tolerance of grass carp, thereby solving the problems existing in the prior art. The compound feed additive of this invention significantly improves the growth performance of grass carp in high salinity and alkalinity water, and significantly improves the grass carp's osmotic regulation, nitrogen metabolism, antioxidant and immune stress responses. It provides a new feed additive formula for improving the salt and alkali tolerance of freshwater fish, lays the foundation for the development of freshwater fish farming in saline-alkali water, and has great potential for industrial application and promotion value.

[0007] To achieve the above objectives, the present invention provides the following solution:

[0008] The present invention provides a composition comprising, by weight: 3-4 parts cholesterol, 15-20 parts arachidonic acid, 5-8 parts lecithin, 5-10 parts betaine, 6-8 parts taurine, 3-5 parts fructooligosaccharide, 0.2-0.3 parts vitamin E and 0.3-0.5 parts vitamin C.

[0009] The present invention also provides an application of the above-described composition in the preparation of compound feed additives.

[0010] Furthermore, the compound feed additive is a compound feed additive that improves the salt and alkali tolerance of freshwater fish.

[0011] Furthermore, the freshwater fish in question is grass carp.

[0012] The present invention also provides a compound feed additive, with the above-mentioned composition as the main component.

[0013] Furthermore, it also includes organic selenium and organic zinc.

[0014] The present invention also provides an application of the above-mentioned compound feed additive in the preparation of fish feed.

[0015] Furthermore, the fish feed is designed to improve the salt and alkali tolerance of freshwater fish.

[0016] The present invention also provides a fish feed to improve the salt and alkali tolerance of freshwater fish, comprising the above-mentioned compound feed additive.

[0017] Furthermore, the compound feed additive is present in the fish feed at a mass fraction of 3.8%-5.7%.

[0018] The present invention also provides the application of the above-described composition, the above-described compound feed additive, and the above-described fish feed in improving the salt and alkali tolerance of freshwater fish.

[0019] The present invention discloses the following technical effects:

[0020] The compound feed additive provided by this invention comprises cholesterol, arachidonic acid (ARA), betaine, taurine, vitamin E, vitamin C, organic selenium, organic zinc, fructooligosaccharides, and lecithin, compounded in specific proportions. Feeding experiments in high-salinity and alkaline water bodies showed that grass carp fed with the compound feed additive provided by this invention exhibited significantly improved growth performance and demonstrated marked advantages in osmotic regulation, nitrogen metabolism, antioxidant activity, and immunity. The active ingredients showed significant synergistic effects. This invention provides a novel feed additive formulation for improving the salinity and alkalinity tolerance of freshwater fish, laying the foundation for developing freshwater fish farming in saline-alkali waters, and possesses enormous industrial application potential and promotional value. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a statistical chart of nitrogen metabolism indicators in fish; K1 is the control group; K2 is the composite group.

[0023] Figure 2 The graph shows the statistical values ​​of sodium (a), potassium (b), chloride (c), and calcium (d) ions in fish serum; K1 is the control group; K2 is the composite group.

[0024] Figure 3 Na for fish gill tissue + / K + - ATPase activity statistics; where K1 is the control group; K2 is the compound group;

[0025] Figure 4 This is a statistical graph of CAT enzyme activity in fish; K1 is the control group; K2 is the compound group.

[0026] Figure 5 This is a statistical graph of SOD enzyme activity in fish; K1 is the control group; K2 is the compound group.

[0027] Figure 6 This is a statistical chart of MDA content in fish; where K1 is the control group and K2 is the compound group.

[0028] Figure 7 This is a statistical chart of total protein concentration in fish serum; where K1 is the control group and K2 is the composite group.

[0029] Figure 8This is a statistical graph of GSH-Px enzyme activity in fish; K1 is the control group; K2 is the compound group.

[0030] Figure 9 These are microscopic images of fish gill tissue; K1 is the control group; K2 is the composite group; GF represents gill filaments; GL represents gill lobes.

[0031] Figure 10 The image shows a microscopic observation of fish liver tissue; K1 represents the control group; K2 represents the composite group; BC represents bile canaliculi, CV represents the central vein, HS represents the hepatic sinusoids, and LC represents stem cells. Detailed Implementation

[0032] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0033] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0034] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0035] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0036] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0037] This invention provides a compound feed additive to significantly improve the tolerance of freshwater fish such as grass carp in saline-alkali aquaculture water. The compound feed additive includes a certain proportion of compounded functional components such as cholesterol, arachidonic acid (ARA), betaine, taurine, vitamin E, vitamin C, organic selenium, organic zinc, fructooligosaccharides, and lecithin. Adding this compound feed additive to the basic feed exerts multiple synergistic effects. This invention specifically targets grass carp, a typical freshwater fish species that is tolerant to saline-alkali conditions but susceptible to high alkalinity, and has designed a combination of cholesterol and ARA, as well as vacuum oil coating formulations, to enhance the fish's osmotic regulation and antioxidant capacity.

[0038] Example 1

[0039] The grass carp feed formula in this embodiment, by mass fraction, is as follows: 36.6% fish meal, 15% soybean meal, 15.6% wheat bran, 2.5% fish oil, 2.5% soybean oil, 4% premix, 10% brewer's yeast, 10% compound amino acids, and 3.8% feed additives.

[0040] The feed additive formula is as follows: cholesterol 0.30%, ARA 1.50%, lecithin 0.50%, betaine 0.50%, taurine 0.60%, fructooligosaccharide 0.30%, vitamin E 0.02%, vitamin C 0.03%, and trace element agent 0.05%; each kg of feed contains 0.35 mg of organic selenium (calculated as selenium element Se) and 65 mg of organic zinc (calculated as zinc element Zn), with the remainder supplemented with starch.

[0041] Each kilogram of premix contains: VA 165000IU, VB1 85mg, VK3 45mg, VB2 85mg, VB6 85mg, VD3 35000IU, choline chloride 22000mg, nicotinic acid (nicotinamide) 440mg, calcium pantothenate 260mg, sodium chloride 4%, iodine 30mg, calcium 9%, manganese 460mg, copper 110mg, magnesium 6200mg, iron 1800mg, total phosphorus 3%, and moisture 10%.

[0042] The above feed was prepared using a post-oil spraying process at a pressure of 0.12 MPa for 8 minutes. The resulting product had a lipid peroxidation value of ≤5 meq / kg, which allowed cholesterol and ARA to be stably encapsulated and attached to the particle surface.

[0043] Example 2

[0044] The grass carp feed formula in this embodiment, by mass fraction, is as follows: 36.6% fish meal, 15% soybean meal, 13.7% wheat bran, 2.5% fish oil, 2.5% soybean oil, 4% premix, 10% brewer's yeast, 10% compound amino acids, and 5.7% feed additives.

[0045] The feed additive formula is as follows: cholesterol 0.40%, ARA 2.00%, lecithin 0.80%, betaine 1.00%, taurine 0.80%, fructooligosaccharide 0.50%, vitamin E 0.03%, vitamin C 0.05%, and trace element agent 0.12%; each kg of feed contains 0.40 mg of organic selenium (calculated as selenium element Se) and 110 mg of organic zinc (calculated as zinc element Zn), with the remainder supplemented with starch.

[0046] Each kilogram of premix contains: VA 165000 IU, VB1 85 mg, VK3 45 mg, VB2 85 mg, VB6 85 mg, VD3 35000 IU, choline chloride 22000 mg, nicotinic acid (nicotinamide) 440 mg, calcium pantothenate 260 mg, sodium chloride 4%, iodine 30 mg, calcium 9%, manganese 460 mg, copper 110 mg, magnesium 6200 mg, iron 1800 mg, total phosphorus 3%, and moisture 10%.

[0047] The above feed was prepared using a post-oil spraying process at a pressure of 0.08 MPa for 6 minutes. The resulting product had a lipid peroxidation value of ≤5 meq / kg, which allowed cholesterol and ARA to be stably encapsulated and attached to the particle surface.

[0048] Comparative Example 1

[0049] The grass carp feed formula in this comparative example, by mass fraction, is: 38.6% fish meal, 16% soybean meal, 16.4% wheat bran, 2.5% fish oil, 2.5% soybean oil, 4% premix, 10% brewer's yeast, and 10% compound amino acids.

[0050] Comparative Example 2

[0051] The grass carp feed formula in this comparative example, by mass fraction, is: 38.6% fish meal, 15% soybean meal, 16.4% wheat bran, 2.5% fish oil, 2.5% soybean oil, 4% premix, 10% brewer's yeast, 10% compound amino acids, and 1% cholesterol.

[0052] Comparative Example 3

[0053] The grass carp feed formula in this comparative example, by mass fraction, is: fish meal 36.6%, soybean meal 15%, wheat bran 13.7%, fish oil 2.5%, soybean oil 2.5%, premix 4%, brewer's yeast 10%, compound amino acids 10%, and ARA 3.0%.

[0054] Experimental Example 1

[0055] 1. Experimental Methods

[0056] To verify the effectiveness of the feed additive of the present invention, the following experiments were conducted:

[0057] 1.1 Feeding method

[0058] Healthy grass carp fry (average weight 16g) were selected and randomly divided into two groups: a control group (fed grass carp feed as described in Comparative Example 1) and a compound group (fed grass carp feed as described in Example 2). The grass carp in each group were fed in a high-alkalinity (60mmol / L NaHCO3) water culture pond simulating inland saline-alkali aquaculture conditions.

[0059] The feeding experiment lasted for 8 weeks. All fish fry were fed with suspended pellet feed twice a day. The amount of feed was controlled within the palatability range, and the amount of uneaten feed was kept to less than 5% of the feed amount. During the experiment, water quality (temperature, pH, oxygen, alkalinity, etc.) was measured regularly and dissolved oxygen was ensured to be sufficient.

[0060] 1.2 Detection Method

[0061] Record the fish's weight every two weeks and calculate growth parameters such as weight gain rate and feed conversion ratio.

[0062] The sampling and testing indicators at the end of the test include:

[0063] (1) Serum urea nitrogen (BUN) and blood ammonia (NH3) levels were determined using an automated biochemical analyzer;

[0064] (2) Serum ions (Na+) were measured using an electrode analyzer. + K + Cl - HCO3 - (etc.) concentration;

[0065] (3) The Na+ of gill tissue was measured using the ELISA method. + / K + -ATPase (NKA) activity;

[0066] (4) Antioxidant enzyme activity (SOD, CAT, GSH-Px), peroxide level (MDA) and total protein concentration were detected using a kit method;

[0067] (5) Take gill and liver tissues from fish, perform H&E staining and histological observation of gill filament morphology and hepatocyte pathological changes.

[0068] 2. Experimental Results

[0069] The compound supplement group showed superior growth and physiological indicators compared to the control group under different alkaline conditions. For example, the weight gain rate of grass carp in the compound group was about 15% higher than that of the control, and the specific growth rate (SGR) was about 10% higher; serum urea nitrogen and blood ammonia concentrations were reduced by about 20%-30%, respectively; gill sodium... + / K +- ATPase activity increased by approximately 25%; SOD, CAT, and GSH-Px activities increased by over 30%, while MDA decreased by nearly 40%. These changes indicate that the compound-group grass carp exhibited a significant tolerance advantage and improved health under saline-alkali stress, further supporting the synergistic effect and unexpected technical benefits of the composition of this invention. Specific results are as follows:

[0070] 2.1 Growth performance

[0071] Growth performance includes: survival rate (SR), weight gain rate (WGR), specific growth rate (SGR), feed conversion ratio (FCR), liver index (HSI), and visceral index (VSI);

[0072] As shown in Table 1, the body weight gain rate and specific growth rate (SGR) of grass carp in the compound group were significantly higher than those in the control group, while the feed conversion ratio (FCR) was significantly lower, indicating that the additives had a synergistic effect in promoting growth.

[0073] Table 1. Results of Grass Carp Growth Performance Testing

[0074]

[0075]

[0076] 2.2 Nitrogen metabolism indicators

[0077] like Figure 1 As shown, the serum urea nitrogen and blood ammonia levels in the compound group were significantly lower than those in the control group, indicating that the feed effectively alleviated nitrogen metabolism stress.

[0078] 2.3 Ion steady state

[0079] like Figure 2 As shown, the Na+ in the serum of the compound group fish after feeding... + K + Cl - The plasma concentration is closer to the freshwater control level. For example... Figure 3 As shown, gill tissue analysis revealed that the compound group Na + / K + - ATPase activity is significantly upregulated, which helps maintain the body's ion balance and osmotic pressure.

[0080] 2.4 Antioxidant and Immunity

[0081] like Figure 4 , Figure 5 and Figure 8 As shown, the activities of antioxidant enzymes such as CAT, SOD, and GSH-Px in the fish of the compound group were significantly increased; Figure 6 As shown, the MDA content decreased significantly, indicating that oxidative stress damage was effectively suppressed.

[0082] like Figure 7 As shown, serum immune indicators (total protein concentration) also improved significantly, indicating that the additives enhanced the immune function of the fish.

[0083] 2.5 Organizational Form

[0084] like Figure 9 As shown, the gill tissue pathological sections revealed that the composite group had a more orderly distribution of gill filaments underwater, reduced blood cell retention, and reduced mucus cell proliferation.

[0085] like Figure 10 As shown, the degree of vacuolar degeneration in the liver tissue of grass carp in the compound feed group was also reduced compared with that in the control group, further confirming the protective effect of compound feed on tissue health.

[0086] Therefore, the combined application of the above-mentioned functional components demonstrates a significant synergistic effect in improving grass carp ion balance, nitrogen metabolism, and antioxidant capacity. In particular, compared with the control group without the added components, the grass carp in the compound group of this invention showed a clear advantage in saline-alkali water. This proves that the formula of this invention not only improves the production performance of farmed fish but also provides a practical technical solution for freshwater fish farming in saline-alkali water conditions, possessing significant industrial promotion value.

[0087] Based on the experimental results of this invention, it can be determined that: cholesterol is an important component of cell membranes, helping fish adapt to salinity changes by regulating membrane fluidity; arachidonic acid (ARA) is an ω-6 polyunsaturated fatty acid, and its metabolites, such as prostaglandins, can regulate cortisol synthesis and antioxidant responses in fish, thereby affecting stress tolerance. Betaine and taurine, as natural osmotic regulators, can act as organic osmolars within cells to maintain cell volume stability and improve fish's adaptability to salinity changes. Vitamins E and C, as well as trace elements such as organic selenium and zinc, are known antioxidants and immune boosters, capable of increasing the activity of antioxidant enzymes in fish, reducing oxidative damage, and enhancing stress resistance. In addition, fructooligosaccharides, as prebiotics, can regulate intestinal flora and promote digestion and absorption; lecithin provides phospholipid nutrition, which helps in the absorption of lipids and fat-soluble nutrients and cell repair. In summary, the combined application of the above functional components in grass carp feed can produce synergistic effects in improving ion homeostasis, nitrogen metabolism, and antioxidant capacity, thereby significantly improving the tolerance and growth performance of grass carp in saline-alkali water environments.

[0088] In summary, this invention, through a carefully designed compound nutrient formula and a special administration method, significantly improves the tolerance of freshwater fish such as grass carp in saline-alkali water environments, demonstrating novelty and industrial application potential.

[0089] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A composition, characterized in that, The composition, by weight, comprises: 3-4 parts cholesterol, 15-20 parts arachidonic acid, 5-8 parts lecithin, 5-10 parts betaine, 6-8 parts taurine, 3-5 parts fructooligosaccharides, 0.2-0.3 parts vitamin E, and 0.3-0.5 parts vitamin C.

2. The use of the composition as described in claim 1 in the preparation of a compound feed additive.

3. The application as described in claim 2, characterized in that, The compound feed additive is a compound feed additive that improves the salt and alkali tolerance of freshwater fish.

4. The application as described in claim 3, characterized in that, The freshwater fish in question is grass carp.

5. A compound feed additive, characterized in that, The composition according to claim 1 is the main component.

6. The compound feed additive as described in claim 5, characterized in that, It also includes organic selenium and organic zinc.

7. The application of a compound feed additive as described in claim 5 or 6 in the preparation of fish feed.

8. The application as described in claim 7, characterized in that, The fish feed described is designed to improve the salt and alkali tolerance of freshwater fish.

9. A fish feed for improving the salt and alkali tolerance of freshwater fish, characterized in that, Includes the compound feed additives described in claim 5 or 6.

10. The use of the composition of claim 1, the compound feed additive of claim 5 or 6, and the fish feed of claim 9 in improving the salt and alkali tolerance of freshwater fish.

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