Feed for improving antioxidant enzyme activity of oncorhynchus masu young fish and preparation method thereof

Abstract

The present application belongs to the technical field of compound feed for marine fish, and particularly relates to a feed for improving the antioxidant enzyme activity of juvenile Hexagrammos otakii and a preparation method thereof. The feed for improving the antioxidant enzyme activity of juvenile Hexagrammos otakii is prepared from the following raw materials in mass percentage: 95% to 96.5% of basic ingredients, 1% of compound vitamins, 1% of compound mineral salts, and 1.5% to 3% of an antioxidant enzyme activity composition, and the sum of the mass percentages of the raw materials is 100%; the antioxidant enzyme activity composition is composed of vitamin C and beta-carotene, and the mass ratio of vitamin C to beta-carotene is 1 to 3: 1 to 3. The feed for improving the antioxidant enzyme activity of juvenile Hexagrammos otakii obtained by the present application not only can provide sufficient natural antioxidant components to enhance the antioxidant defense mechanism of the juvenile fish, but also can effectively solve the problems of slow growth, low feed utilization rate, and water pollution of juvenile Hexagrammos otakii caused by insufficient antioxidant activity.

Description

Technical Field

[0001] This invention belongs to the field of formulated feed technology for marine fish, specifically relating to a feed that improves the antioxidant enzyme activity of juvenile rockfish and its preparation method. Background Technology

[0002] The rockfish (Hexagrammus oysterii), an important economic fish species, is a nearshore, cold-water benthic fish that primarily inhabits the continental shelf and rocky reef areas surrounding islands. With the development of aquaculture, in-depth research has been conducted on the nutritional requirements and feed formulations of the rockfish. The protein, fat, and carbohydrate requirements of rockfish vary at different growth stages, providing a scientific basis for its artificial breeding. Furthermore, adding specific components such as astaxanthin to the feed can significantly improve the growth performance, body color, and antioxidant capacity of the rockfish. Meanwhile, research on feed substitutes, such as chicken intestine meal, has also made progress, offering possibilities for diversifying the rockfish diet.

[0003] In recent years, with the promotion of high-density intensive aquaculture, while the Hexagrammos oysterfish farming industry has achieved some success in feed research and development, significant deficiencies remain in terms of antioxidant capacity. Specifically, firstly, the lack of antioxidant components in Hexagrammos oysterfish feed directly weakens its oxidative stability. This not only makes the feed itself prone to oxidation and spoilage, reducing its palatability, but also results in a large amount of uneaten feed remaining in the water, further exacerbating water pollution and posing a serious threat to the aquaculture environment. Secondly, insufficient antioxidant capacity severely hinders the effective resistance of Hexagrammos oysterfish to external environmental stress and free radicals generated by internal metabolism. This deficiency not only directly leads to a slowdown in the growth rate of Hexagrammos oysterfish but also indirectly damages their overall health by intensifying intracellular oxidative stress, posing a potential threat to the sustainable development of the aquaculture industry. Furthermore, insufficient antioxidant capacity also accelerates the degradation process of unsaturated fatty acids in feed and fish. The degradation of unsaturated fatty acids not only affects the nutritional value of oysterfish, but also generates harmful substances that are detrimental to consumer health, thereby reducing the market competitiveness of oysterfish. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a feed for improving the antioxidant enzyme activity of juvenile Hexagrammos oysterfish and its preparation method. This invention prepares the feed by combining basic ingredients, compound vitamins, compound mineral salts, and an antioxidant enzyme-active composition consisting of vitamin C and β-carotene. The feed obtained by this invention not only provides sufficient natural antioxidants to enhance the juvenile fish's antioxidant defense mechanisms but also effectively solves the problems of slow growth, low feed utilization, and water pollution caused by insufficient antioxidant capacity in juvenile Hexagrammos oysterfish.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: The first objective of this invention is to provide a feed for improving the antioxidant enzyme activity of juvenile rockfish, which is made from the following raw materials in the following mass percentages: 95%~96.5% basic ingredients, 1% compound vitamins, 1% compound mineral salts and 1.5%~3% antioxidant enzyme active composition, and the sum of the mass percentages of each raw material is 100%; the antioxidant enzyme active composition is composed of vitamin C and β-carotene.

[0006] The mass ratio of vitamin C to β-carotene is 1~3:1~3; wherein, if the mass percentage of the antioxidant enzyme activity composition is lower than this range, the antioxidant enzyme activity of the feed for improving the antioxidant enzyme activity of juvenile Hexagrammos oysterfish will decrease, and conversely, if it is higher than this range, the cost will increase and the effect of improving the antioxidant enzyme activity of juvenile Hexagrammos oysterfish will no longer be significant.

[0007] Preferably, the basic ingredients consist of the following raw materials in the following mass percentages: 41%~43% fish meal, 30%~32% soybean meal, 16% casein, 4% fish oil, 2% flour and 1% corn starch, with the sum of the mass percentages of each raw material being 100%.

[0008] Preferably, the compound vitamins include the following ingredients: VA, VE, VD3, VK3, VB1, VB2, VB6, VB12, niacin, VC, calcium pantothenate, folic acid, and inositol.

[0009] Preferably, the ratio of VA, VE, VD3, VK3, VB1, VB2, VB6, VB12, niacin, VC, calcium pantothenate, folic acid and inositol is 6500 IU: 50 mg: 2500 IU: 5 mg: 20 mg: 20 mg: 25 mg: 0.05 mg: 50 mg: 100 mg: 80 mg: 6 mg: 80 mg.

[0010] Preferably, the composite mineral salt comprises the following raw materials: MgSO4·7H2O, FeSO4·7H2O, NaCl, ZnSO4·7H2O, MnSO4·4H2O, CuSO4·5H2O, CoCl2·6H2O, and KI.

[0011] Preferably, the mass ratio of MgSO4·7H2O, FeSO4·7H2O, NaCl, ZnSO4·7H2O, MnSO4·4H2O, CuSO4·5H2O, CoCl2·6H2O and KI is 5782:1000:3000:150:50.3:15:1.2:1.5.

[0012] A second objective of this invention is to provide a method for preparing the above-mentioned feed for improving the antioxidant enzyme activity of juvenile rockfish, comprising the following steps: The basic ingredients, compound vitamins, compound mineral salts and antioxidant enzyme active composition are pulverized and mixed to obtain a mixed powder. After conditioning and maturation, the mixed powder is extruded, granulated, and dried to obtain feed that improves the antioxidant enzyme activity of juvenile rockfish.

[0013] Preferably, the basic ingredients, compound vitamins, compound mineral salts and antioxidant enzyme active composition are pulverized and passed through a 60-mesh sieve.

[0014] Preferably, the temperature for the modulation and ripening treatment is 90℃~100℃.

[0015] Preferably, the extrusion granulation conditions are extrusion at 4MPa to 5MPa.

[0016] Preferably, the moisture content of the feed for improving the antioxidant enzyme activity of juvenile rockfish is less than 10%.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention provides a feed for improving the antioxidant enzyme activity of juvenile Hexagrammos oysterfish. The feed is made from the following raw materials in the indicated weight percentages: 95%–96.5% basic ingredients, 1% compound vitamins, 1% compound mineral salts, and 1.5%–3% antioxidant enzyme activity composition, with the sum of the weight percentages of each raw material being 100%. The antioxidant enzyme activity composition consists of vitamin C and β-carotene, with a weight ratio of vitamin C to β-carotene of 1–3:1–3. The feed obtained by this invention not only provides sufficient natural antioxidants to enhance the antioxidant defense mechanism of the juveniles but also effectively solves the problems of slow growth, low feed utilization, and water pollution caused by insufficient antioxidant capacity in juvenile Hexagrammos oysterfish.

[0018] 2. In the feed antioxidant enzyme activity composition for improving the antioxidant enzyme activity of juvenile Hexagrammos oysterfish of this invention, vitamin C exhibits outstanding performance in enhancing the activity of antioxidant enzymes against superoxide anion (ASA), hydroxyl radical (AHR), and superoxide dismutase (SOD). By effectively reducing malondialdehyde (MDA) content, it significantly improves the antioxidant capacity of muscle, thereby mitigating damage caused by oxidative stress. Furthermore, vitamin C can also activate the Nrf2 signaling pathway, regulating the gene expression of antioxidant enzymes and related proteins, particularly SOD expression, further enhancing the antioxidant defense system of juvenile Hexagrammos oysterfish. This mechanism not only directly enhances the antioxidant enzyme activity of SOD but also promotes the efficient operation of the entire antioxidant network, providing juvenile fish with more robust antioxidant protection.

[0019] Beta-carotene can rapidly quench singlet oxygen free radicals and significantly reduce lipid peroxidation, thereby protecting cell membranes and intracellular proteins from oxidative damage. Simultaneously, beta-carotene enhances the body's ability to scavenge free radicals by participating in gene regulation, promoting the synthesis of antioxidant enzymes such as superoxide dismutase and glutathione peroxidase.

[0020] Vitamin C and β-carotene work synergistically in feeds that improve the activity of antioxidant enzymes in juvenile Hexagrammos oysters. Vitamin C promotes the expression of antioxidant enzymes by activating the Nrf2 signaling pathway, while β-carotene directly participates in the synthesis of antioxidant enzymes. Together, they enhance the activity of antioxidant enzymes, thus more effectively resisting oxidative stress.

[0021] 3. The feed provided by this invention, which improves the antioxidant enzyme activity of juvenile Hexagrammos oysterfish, can also meet the nutritional needs for the growth of juvenile Hexagrammos oysterfish. The fishmeal, soybean meal, and casein in the basic ingredients contain a variety of essential amino acids for fish, which can improve the protein quality of the feed and thus improve the muscle quality of the fish. Vitamins B and D can promote the growth and development of Hexagrammos oysterfish and improve its productivity. The compound mineral salts can also increase the level of antioxidants in the fish and reduce the damage of free radicals to the fish. Attached Figure Description

[0022] Figure 1 This is a picture of the finished product of the feed for improving the antioxidant enzyme activity of juvenile rockfish prepared in Example 1 of the present invention. Detailed Implementation

[0023] The technical solution of the present invention will be clearly and completely described below with reference to the data in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] It should be noted that the technical terms used in this invention are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of this invention. Unless otherwise specified, all raw materials, reagents, instruments and equipment used in the following embodiments of this invention can be purchased on the market or prepared by existing methods.

[0025] Traditional feeds often lack sufficient natural antioxidants, which directly affects the antioxidant defense capabilities of rockfish (Hexagrammos oxtalii), making it difficult for them to effectively cope with oxidative stress in the aquaculture environment. This leads to a series of problems, including stunted growth, low feed utilization efficiency, and increased pollution of the aquaculture water. These problems not only affect the profitability of rockfish farming but also pose a potential threat to its market competitiveness and consumer health and safety.

[0026] To address these technical deficiencies, this invention provides a feed for improving the antioxidant enzyme activity of juvenile Hexagrammos oysterfish. The feed is made from the following raw materials in the indicated mass percentages: 95%–96.5% basic ingredients, 1% compound vitamins, 1% compound mineral salts, and 1.5%–3% antioxidant enzyme activity composition, with the sum of the mass percentages of all raw materials being 100%. The antioxidant enzyme activity composition consists of vitamin C and β-carotene, and the mass ratio of vitamin C to β-carotene is 1–3:1–3.

[0027] An antioxidant enzyme-active composition was obtained by combining vitamin C and β-carotene. Vitamin C enhances the activity of ASA, AHR, and SOD, reduces MDA content, strengthens muscle antioxidant capacity, and regulates enzyme expression through Nrf2 signaling. β-carotene efficiently quenches free radicals, reduces lipid peroxidation, protects cells from oxidative damage, and improves meat coloring. Simultaneously, β-carotene promotes antioxidant enzyme synthesis and enhances free radical scavenging ability. The feed obtained in this invention, which improves the antioxidant enzyme activity of juvenile Hexagrammos oysterfish, not only provides sufficient natural antioxidants to enhance the juvenile fish's antioxidant defense mechanisms but also effectively solves the problems of slow growth, low feed utilization, and water pollution caused by insufficient antioxidant capacity in juvenile Hexagrammos oysterfish.

[0028] The technical solution of the present invention will be further explained and illustrated below with examples, as detailed below: Example 1 A method for preparing feed to improve the antioxidant enzyme activity of juvenile rockfish (Hexagrammos oysterii) includes the following steps: S1. An antioxidant enzyme-active composition was obtained by using vitamin C at a mass percentage of 1% and β-carotene at a mass percentage of 1%.

[0029] S2. Weigh out the following ingredients according to their mass percentages: fish meal (43%), soybean meal (30%), casein (16%), fish oil (4%), flour (2%), corn starch (1%), complex vitamins (1%), complex mineral salts (1%), and antioxidant enzyme active composition (2%). Crush the weighed materials, pass them through a 60-mesh sieve (approximately 0.225 mm), and mix them to obtain a mixed powder. The complex vitamins consist of: VA 6500 IU, VE 50 mg, VD3 2500 IU, VK3 5 mg, VB1 20 mg, VB2 20 mg, VB6 25 mg, VB12 0.05 mg, niacin 50 mg, VC 100 mg, calcium pantothenate 80 mg, folic acid 6 mg, and inositol 80 mg. The complex mineral salts consist of: MgSO4·7H2O 5782 mg, FeSO4·7H2O... It consists of 1000mg of NaCl, 3000mg of ZnSO4·7H2O, 150mg of MnSO4·4H2O, 50.3mg of CuSO4·5H2O, 15mg of CoCl2·6H2O, 1.2mg of KI, and 1.5mg of KI.

[0030] S3. The mixed powder is fed into a rotating feeder and steam-conditioned at 90°C. Then, it is extruded into granules using a twin-screw extruder at 4.5 MPa. After extrusion, the granules are dried at 70°C for 12 hours to obtain feed that improves the antioxidant enzyme activity of juvenile Hexagrammos otakii. Figure 1 As shown.

[0031] The feed that improves the antioxidant enzyme activity of juvenile rockfish has a crude protein content of 47.57% and a crude fat content of 12.24%.

[0032] Example 2 A method for preparing feed to improve the antioxidant enzyme activity of juvenile rockfish (Hexagrammos oysterii) includes the following steps: S1. An antioxidant enzyme-active composition was obtained by comprising vitamin C at a mass percentage of 1.5% and β-carotene at a mass percentage of 1.5%.

[0033] S2. Weigh out the following ingredients according to their mass percentages: fish meal (41%), soybean meal (31%), casein (16%), fish oil (4%), flour (2%), corn starch (1%), complex vitamins (1%), complex mineral salts (1%), and antioxidant enzyme active composition (3%). Crush the weighed materials, pass them through a 60-mesh sieve (approximately 0.225 mm), and mix them to obtain a mixed powder. The complex vitamins consist of: VA 6500 IU, VE 50 mg, VD3 2500 IU, VK3 5 mg, VB1 20 mg, VB2 20 mg, VB6 25 mg, VB12 0.05 mg, niacin 50 mg, VC 100 mg, calcium pantothenate 80 mg, folic acid 6 mg, and inositol 80 mg. The complex mineral salts consist of: MgSO4·7H2O 5782 mg, FeSO4·7H2O... It consists of 1000mg of NaCl, 3000mg of ZnSO4·7H2O, 150mg of MnSO4·4H2O, 50.3mg of CuSO4·5H2O, 15mg of CoCl2·6H2O, 1.2mg of KI, and 1.5mg of KI.

[0034] S3. The mixed powder is fed into a rolling feeder and steam-conditioned at 92°C. Then, it is extruded into granules by a twin-screw extruder under a pressure of 4MPa. After extrusion, the granules are dried at 70°C for 12 hours to obtain feed that improves the antioxidant enzyme activity of juvenile rockfish.

[0035] The feed that improves the antioxidant enzyme activity of juvenile rockfish has a crude protein content of 47.98% and a crude fat content of 12.34%.

[0036] Example 3 A method for preparing feed to improve the antioxidant enzyme activity of juvenile rockfish (Hexagrammos oysterii) includes the following steps: S1. Weigh out vitamin C and β-carotene according to the ratio of vitamin C to 0.5% by mass and β-carotene to 1% by mass to obtain an antioxidant enzyme active composition.

[0037] S2. Weigh out the following ingredients according to their mass percentages: fish meal (42%), soybean meal (31.5%), casein (16%), fish oil (4%), flour (2%), corn starch (1%), complex vitamins (1%), complex mineral salts (1%), and antioxidant enzyme active composition (1.5%). Crush the weighed materials, pass them through a 60-mesh sieve (approximately 0.225 mm), and mix them to obtain a mixed powder. The complex vitamins consist of: VA 6500 IU, VE 50 mg, VD3 2500 IU, VK3 5 mg, VB1 20 mg, VB2 20 mg, VB6 25 mg, VB12 0.05 mg, niacin 50 mg, VC 100 mg, calcium pantothenate 80 mg, folic acid 6 mg, and inositol 80 mg. The complex mineral salts consist of: MgSO4·7H2O 5782 mg, FeSO4·7H2O... It consists of 1000mg of NaCl, 3000mg of ZnSO4·7H2O, 150mg of MnSO4·4H2O, 50.3mg of CuSO4·5H2O, 15mg of CoCl2·6H2O, 1.2mg of KI, and 1.5mg of KI.

[0038] S3. The mixed powder is fed into a rolling feeder and steam-conditioned at 100°C. Then, it is extruded into granular material through a twin-screw extruder under a pressure of 5MPa. After extrusion, the granular material is dried at 70°C for 12 hours to obtain feed that improves the antioxidant enzyme activity of juvenile rockfish.

[0039] The feed that improves the antioxidant enzyme activity of juvenile rockfish has a crude protein content of 47.01% and a crude fat content of 12.56%.

[0040] Example 4 A method for preparing feed to improve the antioxidant enzyme activity of juvenile rockfish (Hexagrammos oysterii) includes the following steps: S1. Weigh out vitamin C and β-carotene according to the ratio of vitamin C to 0.5% by mass and β-carotene to 1.5% by mass to obtain an antioxidant enzyme active composition.

[0041] S2. Weigh out the following ingredients according to their mass percentages: fish meal (42%), soybean meal (31%), casein (16%), fish oil (4%), flour (2%), corn starch (1%), complex vitamins (1%), complex mineral salts (1%), and antioxidant enzyme active composition (2%). Crush the weighed materials, pass them through a 60-mesh sieve (approximately 0.225 mm), and mix them to obtain a mixed powder. The complex vitamins consist of: VA 6500 IU, VE 50 mg, VD3 2500 IU, VK3 5 mg, VB1 20 mg, VB2 20 mg, VB6 25 mg, VB12 0.05 mg, niacin 50 mg, VC 100 mg, calcium pantothenate 80 mg, folic acid 6 mg, and inositol 80 mg. The complex mineral salts consist of: MgSO4·7H2O 5782 mg, FeSO4·7H2O... It consists of 1000mg of NaCl, 3000mg of ZnSO4·7H2O, 150mg of MnSO4·4H2O, 50.3mg of CuSO4·5H2O, 15mg of CoCl2·6H2O, 1.2mg of KI, and 1.5mg of KI.

[0042] S3. The mixed powder is fed into a rolling feeder and steam-conditioned at 100°C. Then, it is extruded into granular material through a twin-screw extruder under a pressure of 5MPa. After extrusion, the granular material is dried at 70°C for 12 hours to obtain feed that improves the antioxidant enzyme activity of juvenile rockfish.

[0043] Example 5 A method for preparing feed to improve the antioxidant enzyme activity of juvenile rockfish (Hexagrammos oysterii) includes the following steps: S1. Weigh out vitamin C and β-carotene according to the ratio of vitamin C to 1.5% by mass and β-carotene to 0.5% by mass to obtain an antioxidant enzyme active composition.

[0044] S2. Weigh out the following ingredients according to their mass percentages: fish meal (42%), soybean meal (31%), casein (16%), fish oil (4%), flour (2%), corn starch (1%), complex vitamins (1%), complex mineral salts (1%), and antioxidant enzyme active composition (2%). Grind the weighed materials to 0.225 mm and mix them to obtain a mixed powder. The complex vitamins consist of: VA 6500 IU, VE 50 mg, VD3 2500 IU, VK3 5 mg, VB1 20 mg, VB2 20 mg, VB6 25 mg, VB12 0.05 mg, niacin 50 mg, VC 100 mg, calcium pantothenate 80 mg, folic acid 6 mg, and inositol 80 mg. The complex mineral salts consist of: MgSO4·7H2O 5782 mg, FeSO4·7H2O 1000 mg, and NaCl... It consists of 3000mg, ZnSO4·7H2O 150mg, MnSO4·4H2O 50.3mg, CuSO4·5H2O 15mg, CoCl2·6H2O 1.2mg and KI 1.5mg.

[0045] S3. The mixed powder is fed into a rolling feeder and steam-conditioned at 100°C. Then, it is extruded into granular material through a twin-screw extruder under a pressure of 5MPa. After extrusion, the granular material is dried at 70°C for 12 hours to obtain feed that improves the antioxidant enzyme activity of juvenile rockfish.

[0046] Comparative Example 1 A method for preparing a formulated feed for juvenile rockfish (Hexagrammos davidii) includes the following steps: First, fish meal, soybean meal, casein, fish oil, flour, corn starch, multivitamins, and multimineral salts were weighed out according to the following mass percentages: 43% fish meal, 32% soybean meal, 16% casein, 4% fish oil, 2% flour, 1% corn starch, 1% multivitamins, and 1% multimineral salts. The weighed materials were then pulverized, passed through a 60-mesh sieve (approximately 0.225 mm), and mixed to obtain a mixed powder. The multivitamins consisted of 6500 IU of vitamin A, 50 mg of vitamin E, 2500 IU of vitamin D3, 5 mg of vitamin K3, 20 mg of vitamin B1, 20 mg of vitamin B2, 25 mg of vitamin B6, 0.05 mg of vitamin B12, 50 mg of niacin, 100 mg of vitamin C, 80 mg of calcium pantothenate, 6 mg of folic acid, and 80 mg of inositol. The multimineral salts consisted of 5782 mg of MgSO4·7H2O, 1000 mg of FeSO4·7H2O, and NaCl. It consists of 3000mg, 150mg ZnSO4·7H2O, 50.3mg MnSO4·4H2O, 15mg CuSO4·5H2O, 1.2mg CoCl2·6H2O and 1.5mg KI.

[0047] S3. The mixed powder is loaded into a rotating feeder and steam-conditioned at 90°C. Then, it is extruded into granules by a twin-screw extruder under a pressure of 4.5 MPa. After extrusion, the granules are dried at 70°C for 12 hours to obtain a formulated feed for juvenile rockfish (Hexagrammos octopus).

[0048] The crude protein content of the formulated feed for juvenile rockfish is 47.21%, and the crude fat content is 12.41%.

[0049] The following examples use the feeds prepared in Examples 1-3 that improve the antioxidant enzyme activity of juvenile Hexagrammos oysterfish and the formulated feed for juvenile Hexagrammos oysterfish prepared in Comparative Example 1 as examples. These feeds were then used to feed juvenile Hexagrammos oysterfish and the results were studied. Application method: The feeds for improving the antioxidant enzyme activity of juvenile Hexagrammos oysterfish prepared in Examples 1 to 3 of the present invention, and the formulated feed for juvenile Hexagrammos oysterfish prepared in Comparative Example 1, were used to conduct an indoor culture experiment on juvenile Hexagrammos oysterfish for 8 weeks. After disinfection, juvenile Hexagrammos oysters were placed in a temporary cement pond measuring 4.0m×6.0m×2.0m for 14 days to acclimate them to the aquaculture environment. After fasting for 24 hours, 360 juvenile Hexagrammos oysters from the same batch, with an individual weight of 30.00g±0.16g and a body length of 15.00±0.28cm, were randomly selected and divided into 4 groups, with 3 parallel experiments in each group and 30 experimental fish in each group. The juvenile Hexagrammos oysters were loaded into cylindrical net cages with a diameter of 0.9m and a height of 1.2m and placed in the same aquaculture pond in the factory-style aquaculture workshop for flow-through culture.

[0050] The differences in growth and liver antioxidant indicators of juvenile Hexagrammos otakii prepared in Examples 1-3 and the formulated feed for juvenile Hexagrammos otakii prepared in Comparative Example 1 were detected.

[0051] Test method: .

[0052] .

[0053] .

[0054] .

[0055] In the formula: Mo and Mt represent the initial and final body weights (g) of each fish, respectively; t represents the experimental time (d); F represents the amount of food consumed during the experimental period (g); and L represents the fish length (cm) at the end of the experiment.

[0056] Liver antioxidant indicators: Liver samples were retrieved, and after thawing, the tissue samples were accurately weighed. Nine volumes of physiological saline were added at a mass:volume (m / v) ratio of 1:9, and the mixture was homogenized. The homogenate was then centrifuged at 4°C and 2500 rpm for 10 min, and the supernatant was collected for further analysis. The measurement process was controlled and completed within 24 hours. Liver antioxidant capacity indicators were all detected using commercial kits: the CAT test kit (A007-1-1) - ammonium molybdate method and the SOD test kit (A001-1-1) - hydroxylamine method.

[0057] The test results are shown in Tables 1 and 2.

[0058] Table 1. Effects of the feeds prepared in Examples 1-3 to improve the antioxidant enzyme activity of juvenile Hexagrammos oysterfish and the formulated feed prepared in Comparative Example 1 on the growth of juvenile Hexagrammos oysterfish. Table 1 shows that the average weight gain, specific growth rate, and condition factor of Examples 1 to 3 were all increased compared with Comparative Example 1, while the feed conversion ratio decreased. Adding vitamin C and β-carotene to the feed can effectively improve the growth of juvenile rockfish and promote their development. Among them, Example 2 showed better overall results.

[0059] Table 2. Effects of the feeds prepared in Examples 1-3 to improve the antioxidant enzyme activity of juvenile Hexagrammos oysterfish and the formulated feed prepared in Comparative Example 1 on liver antioxidant indices. Note: Data in the table are mean ± standard error. Table 2 shows that the SOD and CAT activities of the feeds prepared in Examples 1-3 to improve the antioxidant enzyme activity of juvenile Hexagrammos oysterfish were all increased compared with Comparative Example 1. Adding vitamin C and β-carotene to the feed can effectively improve the antioxidant capacity of juvenile Hexagrammos oysterfish, and Example 2 showed better overall results.

[0060] It should be noted that when numerical ranges are involved in this invention, it should be understood that both endpoints of each numerical range, as well as any value between the two endpoints, can be selected. Since the steps and methods used are the same as in the embodiments, preferred embodiments are described here to avoid redundancy. Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this invention.

Claims

1. A feed for improving the antioxidant enzyme activity of juvenile Hexagrammos oysterfish, characterized in that, The feed for improving the antioxidant enzyme activity of juvenile rockfish is made from the following raw materials in the following weight percentages: 95%~96.5% basic ingredients, 1% compound vitamins, 1% compound mineral salts, and 1.5%~3% antioxidant enzyme activity composition, with the sum of the weight percentages of each raw material being 100%. The antioxidant enzyme-active composition consists of vitamin C and β-carotene; The mass ratio of vitamin C to β-carotene is 1~3:1~3.

2. The feed for improving the antioxidant enzyme activity of juvenile Hexagrammos oysterfish according to claim 1, characterized in that, The mass ratio of vitamin C to β-carotene is 1:

1.

3. The feed for improving the antioxidant enzyme activity of juvenile Hexagrammos oysterfish according to claim 1, characterized in that, The basic ingredients consist of the following raw materials by weight percentage: 41%~43% fish meal, 30%~32% soybean meal, 16% casein, 4% fish oil, 2% flour and 1% corn starch, with the sum of the weight percentages of each raw material being 100%.

4. The feed for improving the antioxidant enzyme activity of juvenile Hexagrammos oysterfish according to claim 1, characterized in that, The multivitamin contains the following ingredients: VA, VE, VD3, VK3, VB1, VB2, VB6, VB12, niacin, VC, calcium pantothenate, folic acid, and inositol.

5. The feed for improving the antioxidant enzyme activity of juvenile Hexagrammos oysterfish according to claim 1, characterized in that, The composite mineral salt comprises the following raw materials: MgSO4·7H2O, FeSO4·7H2O, NaCl, ZnSO4·7H2O, MnSO4·4H2O, CuSO4·5H2O, CoCl2·6H2O, and KI.

6. A feed for improving the antioxidant enzyme activity of juvenile Hexagrammos oysterfish according to any one of claims 1 to 5, characterized in that, Includes the following steps: The basic ingredients, compound vitamins, compound mineral salts and antioxidant enzyme active composition are pulverized and mixed to obtain a mixed powder. After conditioning and maturation, the mixed powder is extruded, granulated, and dried to obtain feed that improves the antioxidant enzyme activity of juvenile rockfish.

7. The method for preparing feed for improving the antioxidant enzyme activity of juvenile Hexagrammos oysterfish according to claim 6, characterized in that, The basic ingredients, compound vitamins, compound mineral salts, and antioxidant enzyme active composition were pulverized and passed through a 60-mesh sieve.

8. The method for preparing feed for improving the antioxidant enzyme activity of juvenile Hexagrammos oysterfish according to claim 6, characterized in that, The temperature for the conditioning and ripening process is 90℃~100℃.

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