Feed additive for reducing fatty liver of micropterus salmoides and preparation method of feed additive

Abstract

The invention relates to a feed additive for reducing the fatty liver of micropterus salmoides and a preparation method of the feed additive, and belongs to the technical field of feed additives. The invention provides a preparation method of a feed additive, which comprises the following steps: mixing a purple perilla seed fermentation product, a turmeric fermentation product, sodium alginate and deionized water, and carrying out ultrasonic treatment and freeze drying to obtain the feed additive. Through organic compounding of various components, nutritional supplement is provided for the liver, and the protection effect on the liver is enhanced, so that the occurrence risk of fatty liver of micropterus salmoides is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of feed additives and relates to a feed additive for reducing fatty liver of California sea bass and a preparation method thereof. Background Art

[0002] As an important freshwater farmed fish, California bass is favored by farmers because of its fast growth rate and delicious meat. With the development of aquaculture, high-density farming of California bass has gradually become popular. However, in a high-density farming environment, fish are easily affected by a variety of stress factors, leading to health problems, among which fatty liver is one of the most common metabolic diseases. Fatty liver not only affects the growth and survival rate of California bass, but also reduces its meat quality, thereby affecting its market value. At present, California bass farming generally uses high-protein, high-energy feed to promote rapid growth. This formula often ignores the balance of nutrients. Overnutrition or nutritional imbalance leads to metabolic disorders, which easily cause fat to deposit in the liver, thereby causing fatty liver problems. Summary of the invention

[0003] The purpose of the present invention is to provide a feed additive for reducing fatty liver of California sea bass and a preparation method thereof. The present invention provides nutritional supplements for the liver and enhances the protective effect on the liver through the organic compounding of multiple components, thereby reducing the risk of fatty liver in California sea bass.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A method for preparing a feed additive for reducing fatty liver of California sea bass, the method for preparing the feed additive comprising:

[0006] The perilla seed fermentation product, the turmeric fermentation product, the sodium alginate and the deionized water are mixed, ultrasonicated and freeze-dried to obtain the feed additive.

[0007] Furthermore, the mass ratio of the perilla seed fermentation product, the turmeric fermentation product, the sodium alginate and the deionized water is 1.5-2.5:1.1-2:0.9-1.7:5-7.

[0008] Furthermore, the ultrasonic parameters are: ultrasonic frequency of 40-60kHz, ultrasonic power of 450-550W, and ultrasonic time of 25-35min; the freeze-drying is pre-freezing at -50°C for 1-2h, and then drying at a vacuum degree of 7-9Pa for 32-40h.

[0009] Furthermore, the preparation method of the perilla seed fermentation product is:

[0010] Bacillus subtilis is inoculated into the perilla seed extract at a ratio of 0.08-0.12:1 g / mL, fermented at 28-32°C for 45-51 hours, the pH is adjusted to 6.8-7.2, stirred every 4 hours during the fermentation process, and the stirring speed is 50-60 rmp. After the fermentation is completed, pre-frozen at -40°C for 3-4 hours, and dried at a vacuum degree of 9-11 Pa for 20-28 hours to obtain a perilla seed fermentation product.

[0011] Furthermore, the effective bacterial content of the Bacillus subtilis is 0.6-1×10 7 CFU / g; the perilla seed extract is obtained by mixing perilla seed extract, garlic extract, nutritional supplement and deionized water in a mass ratio of 2-3:1-2:0.3-0.5:8-10, and stirring at a speed of 100-120rmp for 20-40min.

[0012] Furthermore, the preparation method of the turmeric fermentation product is:

[0013] The Bacillus subtilis was inoculated into the turmeric extract at a ratio of 0.13-0.17:1 g / mL, and the mixture was fermented at 31-33°C for 40-44 hours, and the pH was adjusted to 7.1-7.3. During the fermentation process, the mixture was stirred every 3 hours at a stirring speed of 30-50 rpm. After the fermentation was completed, the mixture was pre-frozen at -40°C for 3-4 hours, and dried at a vacuum degree of 9-11 Pa for 30-32 hours to obtain a turmeric fermentation product.

[0014] Furthermore, the effective bacterial content of the Bacillus subtilis is 0.8-1.2×10 7 CFU / g; the turmeric extract is obtained by mixing turmeric extract, oligofructose, hawthorn acid, nutritional supplements and deionized water in a mass ratio of 3.5-4.5:1.2-2.8:0.8-1.2:0.52-0.6:10-12, and stirring at a speed of 70-90rmp for 20-30min.

[0015] Furthermore, the nutritional supplement is obtained by mixing choline, inositol, vitamin C, vitamin E and deionized water in a mass ratio of 0.4-0.6:0.25-0.35:0.18-0.22:0.05-0.15:9-11, stirring at a speed of 60-80 rpm for 25-35 minutes, standing for 1 hour, and filtering with a filter membrane with a pore size of 0.22 μm.

[0016] Furthermore, the feed additive prepared by the preparation method is added to California bass feed in an amount of 1.5-2.5% of the total mass of the feed.

[0017] Beneficial effects of the present invention:

[0018] (1) The present invention utilizes perilla seed extract, garlic extract, nutritional supplements and deionized water to prepare a perilla seed extract, wherein the perilla seed extract contains unsaturated fatty acids and flavonoid compounds, which can effectively regulate fat metabolism, reduce liver oxidative damage, and reduce the risk of fatty liver; the garlic extract has antibacterial and antiviral effects, synergizes with the antioxidant effect of the perilla extract, further reduces the oxidative stress of the liver, and enhances the immunity of California sea bass; the perilla seed extract can be fermented to decompose the macromolecular substances therein into small molecular substances that are easier to absorb, thereby improving the utilization rate of the perilla seed extract by California sea bass.

[0019] (2) The present invention utilizes turmeric extract, oligofructose, hawthorn acid, nutritional supplements and deionized water to prepare a turmeric extract, wherein the turmeric extract is rich in curcumin, has strong antioxidant, anti-inflammatory and anti-fibrosis effects, can improve the inflammatory state of the liver, prevent liver fibrosis, and reduce the risk of fatty liver; oligofructose, as a prebiotic, can effectively promote the growth of beneficial bacteria in the intestines of California sea bass, maintain the balance of intestinal microecology, and good intestinal health is conducive to the absorption and metabolism of nutrients, thereby indirectly reducing the burden on the liver; hawthorn acid has antioxidant and lipid-regulating effects, and can synergistically enhance the protection of the liver with the turmeric extract.

[0020] (3) The present invention utilizes choline, inositol, vitamin C, vitamin E and deionized water to compound and obtain a nutritional supplement, wherein choline helps maintain the normal metabolic function of the liver, participates in the transport and metabolism of fat, and prevents fat from accumulating in the liver; inositol can promote cell metabolism and is beneficial to the health of liver cells; vitamin C and vitamin E have powerful antioxidant effects and protect liver cells from oxidative damage; and the nutritional supplement is added to the perilla seed extract and the turmeric extract to provide additional active ingredients, thereby enhancing the nutritional supplement and protective effects on the liver.

[0021] (4) The present invention also adds sodium alginate to the feed additive, which helps to improve the stability and dispersibility of the additive, ensure the uniform intake and full absorption of the California sea bass, thereby improving the utilization rate of the additive and synergistically reducing the risk of fatty liver in California sea bass. DETAILED DESCRIPTION

[0022] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in combination with the embodiments.

[0023] The sodium alginate in all the embodiments and comparative examples of the present invention is purchased directly from the market, and is purchased from Hebei Chuangzhiyuan Biotechnology Co., Ltd.; Bacillus subtilis is purchased directly from the market, and is purchased from Jinan Huiteng Chemical Co., Ltd.; Perilla seed extract is purchased directly from the market, and is purchased from Shanghai Zhongfeng Biotechnology Co., Ltd.; garlic extract is purchased directly from the market, and is purchased from Shanghai Zhongfeng Biotechnology Co., Ltd.; turmeric extract is purchased directly from the market, and is purchased from Shanghai Zhongfeng Biotechnology Co., Ltd.; oligofructose is purchased directly from the market, and is purchased from Lanzhou Waters Biotechnology Co., Ltd.; hawthorn acid is purchased directly from the market, and is purchased from Lanzhou Waters Biotechnology Co., Ltd.

[0024] Example 1

[0025] A method for preparing a feed additive for reducing fatty liver in California sea bass. The method for preparing the feed additive in this embodiment is as follows:

[0026] The perilla seed fermentation product, the turmeric fermentation product, the sodium alginate and the deionized water are mixed, ultrasonicated and freeze-dried to obtain the feed additive.

[0027] The mass ratio of the perilla seed fermentation product, the turmeric fermentation product, the sodium alginate and the deionized water in this embodiment is 1.5:1.1:0.9:5.

[0028] The ultrasonic parameters of this embodiment are: ultrasonic frequency of 40kHz, ultrasonic power of 450W, and ultrasonic time of 25min; the freeze-drying of this embodiment is to pre-freeze at -50°C for 1h, and then dry at 7Pa vacuum for 32h.

[0029] The preparation method of the perilla seed fermentation product of this embodiment is:

[0030] Bacillus subtilis was inoculated into the perilla seed extract at a ratio of 0.08:1 g / mL, fermented at 28°C for 45 hours, the pH was adjusted to 6.8, stirred every 4 hours during the fermentation process, and the stirring speed was 50 rpm. After the fermentation was completed, it was pre-frozen at -40°C for 3 hours and dried at a vacuum degree of 9 Pa for 20 hours to obtain the perilla seed fermentation product.

[0031] The effective bacterial content of Bacillus subtilis in this example is 0.6×10 7 CFU / g; the perilla seed extract of this embodiment is obtained by mixing perilla seed extract, garlic extract, nutritional supplements and deionized water in a mass ratio of 2:1:0.3:8 and stirring at a speed of 100 rpm for 20 min.

[0032] The preparation method of the turmeric fermentation product of this embodiment is:

[0033] Bacillus subtilis was inoculated into turmeric extract at a ratio of 0.13:1 g / mL, fermented at 31°C for 40 h, the pH was adjusted to 7.1, stirred every 3 h during the fermentation process at a stirring speed of 30 rpm, and after the fermentation was completed, pre-frozen at -40°C for 3 h and dried at a vacuum degree of 9 Pa for 30 h to obtain a turmeric fermentation product.

[0034] The effective bacterial content of Bacillus subtilis in this example is 0.8×10 7 CFU / g; the turmeric extract of this embodiment is obtained by mixing turmeric extract, oligofructose, hawthorn acid, nutritional supplements and deionized water in a mass ratio of 3.5:1.2:0.8:0.52:10 and stirring at a speed of 70rmp for 20min.

[0035] The nutritional supplement of this embodiment is obtained by mixing choline, inositol, vitamin C, vitamin E and deionized water in a mass ratio of 0.4-:0.25:0.18:0.05:9, stirring at a speed of 60 rpm for 25 minutes, standing for 1 hour, and filtering with a filter membrane with a pore size of 0.22 μm.

[0036] The feed additive prepared by the preparation method of this embodiment is added to the California sea bass feed in an amount of 1.5% of the total mass of the feed.

[0037] Example 2

[0038] A method for preparing a feed additive for reducing fatty liver in California sea bass. The method for preparing the feed additive in this embodiment is as follows:

[0039] The perilla seed fermentation product, the turmeric fermentation product, the sodium alginate and the deionized water are mixed, ultrasonicated and freeze-dried to obtain the feed additive.

[0040] The mass ratio of the perilla seed fermentation product, the turmeric fermentation product, the sodium alginate and the deionized water in this embodiment is 2.5:2:1.7:7.

[0041] The ultrasonic parameters of this embodiment are: ultrasonic frequency of 60kHz, ultrasonic power of 550W, and ultrasonic time of 35min; the freeze-drying of this embodiment is to pre-freeze at -50°C for 2h, and then dry at a vacuum degree of 9Pa for 40h.

[0042] The preparation method of the perilla seed fermentation product of this embodiment is:

[0043] Bacillus subtilis was inoculated into the perilla seed extract at a ratio of 0.12:1 g / mL, fermented at 32°C for 51 hours, the pH was adjusted to 7.2, stirred every 4 hours during the fermentation process, and the stirring speed was 60 rpm. After the fermentation was completed, it was pre-frozen at -40°C for 4 hours and dried at a vacuum degree of 11 Pa for 28 hours to obtain the perilla seed fermentation product.

[0044] The effective bacterial content of Bacillus subtilis in this example is 1×10 7 CFU / g; the perilla seed extract of this embodiment is obtained by mixing perilla seed extract, garlic extract, nutritional supplements and deionized water in a mass ratio of 3:2:0.5:10 and stirring at a speed of 120rmp for 40min.

[0045] The preparation method of the turmeric fermentation product of this embodiment is:

[0046] Bacillus subtilis was inoculated into turmeric extract at a ratio of 0.17:1 g / mL, fermented at 33°C for 44 hours, the pH was adjusted to 7.3, stirred every 3 hours during the fermentation process, and the stirring speed was 50 rpm. After the fermentation was completed, it was pre-frozen at -40°C for 4 hours and dried at a vacuum degree of 11 Pa for 32 hours to obtain a turmeric fermentation product.

[0047] The effective bacterial content of Bacillus subtilis in this example is 1.2×10 7 CFU / g; the turmeric extract of this embodiment is obtained by mixing turmeric extract, oligofructose, hawthorn acid, nutritional supplements and deionized water in a mass ratio of 4.5:2.8:1.2:0.6:12 and stirring at a speed of 90rmp for 30min.

[0048] The nutritional supplement of this embodiment is obtained by mixing choline, inositol, vitamin C, vitamin E and deionized water in a mass ratio of 0.6:0.35:0.22:0.15:11, stirring at 80 rpm for 35 minutes, standing for 1 hour, and filtering with a filter membrane with a pore size of 0.22 μm.

[0049] The feed additive prepared by the preparation method of this embodiment is added to the California bass feed in an amount of 2.5% of the total mass of the feed.

[0050] Example 3

[0051] A method for preparing a feed additive for reducing fatty liver in California sea bass. The method for preparing the feed additive in this embodiment is as follows:

[0052] The perilla seed fermentation product, the turmeric fermentation product, the sodium alginate and the deionized water are mixed, ultrasonicated and freeze-dried to obtain the feed additive.

[0053] The mass ratio of the perilla seed fermentation product, the turmeric fermentation product, the sodium alginate and the deionized water in this embodiment is 2:1.55:1.3:6.

[0054] The ultrasonic parameters of this embodiment are: ultrasonic frequency of 50kHz, ultrasonic power of 500W, and ultrasonic time of 30min; the freeze-drying of this embodiment is to pre-freeze at -50°C for 1.5h, and then dry at 8Pa vacuum for 36h.

[0055] The preparation method of the perilla seed fermentation product of this embodiment is:

[0056] Bacillus subtilis was inoculated into the perilla seed extract at a ratio of 0.1:1 g / mL, fermented at 30°C for 48 hours, the pH was adjusted to 7, stirred every 4 hours during the fermentation process, and the stirring speed was 55 rpm. After the fermentation was completed, it was pre-frozen at -40°C for 3.5 hours and dried at a vacuum degree of 10 Pa for 24 hours to obtain the perilla seed fermentation product.

[0057] The effective bacterial content of Bacillus subtilis in this example is 0.8×10 7 CFU / g; the perilla seed extract of this embodiment is obtained by mixing perilla seed extract, garlic extract, nutritional supplements and deionized water in a mass ratio of 2.5:1.5:0.4:9 and stirring at a speed of 110rmp for 30min.

[0058] The preparation method of the turmeric fermentation product of this embodiment is:

[0059] Bacillus subtilis was inoculated into turmeric extract at a ratio of 0.15:1 g / mL, fermented at 32°C for 42 hours, the pH was adjusted to 7.2, stirred every 3 hours during the fermentation process, and the stirring speed was 40 rpm. After the fermentation was completed, it was pre-frozen at -40°C for 3.5 hours and dried at a vacuum degree of 10 Pa for 31 hours to obtain a turmeric fermentation product.

[0060] The effective bacterial content of Bacillus subtilis in this example is 1×10 7 CFU / g; the turmeric extract of this embodiment is obtained by mixing turmeric extract, oligofructose, hawthorn acid, nutritional supplements and deionized water in a mass ratio of 4:2:1:0.56:11 and stirring at a speed of 80rmp for 25min.

[0061] The nutritional supplement of this embodiment is obtained by mixing choline, inositol, vitamin C, vitamin E and deionized water in a mass ratio of 0.5:0.3:0.2:0.1:10, stirring at 70 rpm for 30 minutes, standing for 1 hour, and filtering with a filter membrane with a pore size of 0.22 μm.

[0062] The feed additive prepared by the preparation method of this embodiment is added to the California sea bass feed in an amount of 2% of the total mass of the feed.

[0063] Comparative Example 1

[0064] On the basis of Example 3, the perilla seed extract was not fermented, and other conditions remained the same as in Example 3.

[0065] Comparative Example 2

[0066] On the basis of Example 3, the garlic extract in the perilla seed extract was removed and replaced with an equal weight of nutritional supplements, and other conditions remained the same as in Example 3.

[0067] Comparative Example 3

[0068] On the basis of Example 3, the nutritional supplement in the perilla seed extract was removed and replaced with an equal weight of garlic extract, and other conditions remained the same as in Example 3.

[0069] Comparative Example 4

[0070] On the basis of Example 3, the turmeric extract was not fermented, and other conditions remained the same as in Example 3.

[0071] Comparative Example 5

[0072] On the basis of Example 3, the oligofructose in the turmeric extract was removed and replaced with an equal weight of nutritional supplements, and other conditions remained the same as in Example 3.

[0073] Comparative Example 6

[0074] On the basis of Example 3, the maslinic acid in the turmeric extract was removed and replaced with an equal weight of a nutritional supplement, and other conditions remained the same as in Example 3.

[0075] Comparative Example 7

[0076] On the basis of Example 3, choline in the nutritional supplement was removed and replaced with an equal weight of inositol, and other conditions remained the same as in Example 3.

[0077] Comparative Example 8

[0078] On the basis of Example 3, inositol was removed from the nutritional supplement and replaced with an equal weight of vitamin C, and other conditions remained the same as in Example 3.

[0079] Comparative Example 9

[0080] On the basis of Example 3, vitamin C in the nutritional supplement was removed and replaced with an equal weight of vitamin E, and other conditions remained the same as in Example 3.

[0081] Comparative Example 10

[0082] On the basis of Example 3, the vitamin E in the nutritional supplement was removed and replaced with an equal weight of choline, and other conditions remained the same as in Example 3.

[0083] Comparative Example 11

[0084] On the basis of Example 3, sodium alginate in the feed additive was removed, and other conditions remained the same as in Example 3.

[0085] The formula of the feed used in the experiment is: 50% fish meal, 11% chicken meal, 15% flour, 9% soybean protein, 4.2% squid paste, 6.5% soybean oil, 2% monocalcium phosphate, 2% feed additives obtained in the above embodiments or comparative examples, and 0.3% inorganic salt.

[0086] After disinfection, the same batch of purchased asymptomatic California bass fingerlings were acclimated for one week, stopped feeding for 24 hours, and randomly divided into 14 cube pools with a side length of 1.5m, numbered 1-14, and fed with feed prepared by the feed additives in Examples 1-3 and Comparative Examples 1-11, 20 tails per pool, with a specification of 4.9±0.1g / tail, one meal each morning and evening (8:00 and 18:00), and quantitatively fed feed per pool, the feed feeding amount accounted for about 3% of the fish body weight, and the feeding cycle was 60d. Natural light was maintained during the test, the water temperature was 27-30°C, the dissolved oxygen concentration was>6.0mg / L, the ammonia nitrogen concentration was<0.10mg / L, the nitrite concentration was<0.01mg / L, and the pH value was 7.6-7.9. After the test, the test fish was starved for 24 hours, the final weight was measured, and the liver was weighed and the fat content was measured. The test results were recorded as shown in Table 1.

[0087] Among them, weight gain rate = (final body weight - initial body weight) / initial body weight × 100%; liver fat content = liver fat weight / liver weight × 100%.

[0088] Table 1

[0089] Weight gain rate (%) Liver fat content (%) Example 1 370.84 21.05 Example 2 374.51 20.97 Example 3 378.92 20.83 Comparative Example 1 346.85 21.43 Comparative Example 2 362.59 21.24 Comparative Example 3 358.14 21.19 Comparative Example 4 352.77 21.41 Comparative Example 5 360.69 21.12 Comparative Example 6 365.52 21.10 Comparative Example 7 363.37 21.21 Comparative Example 8 366.48 21.09 Comparative Example 9 367.53 21.09 Comparative Example 10 368.66 21.07 Comparative Example 11 343.74 21.46

[0090] As can be seen from Table 1, the feed additives prepared in Examples 1-3 of the present invention can effectively increase the weight gain rate of California bass and reduce the crude fat content of the liver. Comparative Examples 1-11 arbitrarily or replace a certain component in the present invention, or modify the preparation process of this scheme, and the final weight gain rate and liver fat content are not as good as those of Examples 1-3, indicating that the present invention can promote the synergistic effect between the components through the compounding of various components and specific processing methods. The prepared feed additive can promote the growth and development of California bass while reducing the deposition of fat in the liver of California bass, protecting the normal metabolic function of liver lipids, thereby reducing the incidence of fatty liver in California bass.

[0091] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any indirect modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a feed additive for reducing fatty liver of California sea bass, characterized in that: The preparation method of the feed additive is: The perilla seed fermentation product, the turmeric fermentation product, sodium alginate and deionized water are mixed, ultrasonicated and freeze-dried to obtain a feed additive.

2. The method for preparing a feed additive for reducing fatty liver of California sea bass according to claim 1, characterized in that: The mass ratio of the perilla seed fermentation product, the turmeric fermentation product, the sodium alginate and the deionized water is 1.5-2.5:1.1-2:0.9-1.7:5-7.

3. The method for preparing a feed additive for reducing fatty liver of California sea bass according to claim 1, characterized in that: The ultrasonic parameters are: ultrasonic frequency of 40-60kHz, ultrasonic power of 450-550W, and ultrasonic time of 25-35min; the freeze-drying is pre-freezing at -50°C for 1-2h, and then drying at a vacuum degree of 7-9Pa for 32-40h.

4. The method for preparing a feed additive for reducing fatty liver of California sea bass according to claim 1, characterized in that: The preparation method of the perilla seed fermentation product is as follows: Bacillus subtilis is inoculated into the perilla seed extract at a ratio of 0.08-0.12:1 g / mL, fermented at 28-32°C for 45-51 hours, the pH is adjusted to 6.8-7.2, stirred every 4 hours during the fermentation process, and the stirring speed is 50-60 rmp. After the fermentation is completed, pre-frozen at -40°C for 3-4 hours, and dried at a vacuum degree of 9-11 Pa for 20-28 hours to obtain a perilla seed fermentation product.

5. The method for preparing a feed additive for reducing fatty liver of California sea bass according to claim 4, characterized in that: The effective bacterial content of Bacillus subtilis is 0.6-1×10 7 CFU / g; the perilla seed extract is obtained by mixing perilla seed extract, garlic extract, nutritional supplement and deionized water in a mass ratio of 2-3:1-2:0.3-0.5:8-10, and stirring at a speed of 100-120rmp for 20-40min.

6. The method for preparing a feed additive for reducing fatty liver of California sea bass according to claim 1, characterized in that: The preparation method of the turmeric fermentation product is: The Bacillus subtilis was inoculated into the turmeric extract at a ratio of 0.13-0.17:1 g / mL, and the mixture was fermented at 31-33°C for 40-44 hours, and the pH was adjusted to 7.1-7.

3. During the fermentation process, the mixture was stirred every 3 hours at a stirring speed of 30-50 rpm. After the fermentation was completed, the mixture was pre-frozen at -40°C for 3-4 hours, and dried at a vacuum degree of 9-11 Pa for 30-32 hours to obtain a turmeric fermentation product.

7. The method for preparing a feed additive for reducing fatty liver of California sea bass according to claim 6, characterized in that: The effective bacterial content of Bacillus subtilis is 0.8-1.2×10 7 CFU / g; the turmeric extract is obtained by mixing turmeric extract, oligofructose, hawthorn acid, nutritional supplements and deionized water in a mass ratio of 3.5-4.5:1.2-2.8:0.8-1.2:0.52-0.6:10-12, and stirring at a speed of 70-90rmp for 20-30min.

8. The method for preparing a feed additive for reducing fatty liver of California sea bass according to claim 5 or 7, characterized in that: The nutritional supplement is prepared by mixing choline, inositol, vitamin C, vitamin E and deionized water in a mass ratio of 0.4-0.6:0.25-0.35:0.18-0.22:0.05-0.15:9-11, stirring at a speed of 60-80 rpm for 25-35 minutes, standing for 1 hour, and filtering with a filter membrane with a pore size of 0.22 μm.

9. A feed additive for reducing fatty liver of California sea bass prepared by the preparation method according to any one of claims 1 to 8, characterized in that: The feed additive prepared by the preparation method is added to California bass feed in an amount of 1.5-2.5% of the total mass of the feed.