A large-mouth bass black soldier fly oil feed and a preparation method thereof

Abstract

This invention relates to the field of aquatic feed technology, specifically to a largemouth bass and black soldier fly oil feed and its preparation method, which is made by mixing basic components, oil source components, additives and functional components. The basic components include the following ingredients in parts by weight: 30-40% fish meal, 3-8% soybean meal, 15-25% chicken meal, 3-8% corn gluten meal, 10-15% cottonseed protein, 4-10% wheat flour and 2-6% cassava starch. The oil source components include the following ingredients in parts by weight: 1-2% soybean oil, 2-5% black soldier fly larvae oil and 1-3% Schizochytrium oil. The functional components include the following ingredients in parts by weight: 0.5-1.5% premix, 0.5-1.0% choline chloride, 0.05-0.2% vitamin C, 0.1-1.0% DL-methionine and 0.05-0.2% ethoxyquin. The fish oil-free compound oil feed of the present invention can not only replace fish oil, but also supplement n-3 LC-UFA through Schizochytrium oil, which can improve the problem of insufficient deposition of unsaturated fatty acids in muscle and deterioration of muscle fiber structure caused by the use of black soldier fly larvae oil alone, thus improving both economic benefits and meat quality.

Description

Technical Field

[0001] This invention relates to the field of aquatic feed technology, specifically to an oil feed for largemouth bass and black soldier fly larvae and its preparation method. Background Technology

[0002] Lipids, as an important component of fish nutrition, provide energy and essential nutrients, and are a crucial component of aquatic feed. Fish oil is considered one of the highest quality fats in aquatic feed and a major source of n-3 polyunsaturated fatty acids (PUFAs) for farmed fish. However, due to its fluctuating yield and price, as well as its unsustainability, it has long been considered a bottleneck restricting the development of aquaculture, prompting efforts to find inexpensive and sustainable lipid sources. Currently, most studies have identified oil sources that can serve as substitutes for fish oil in aquatic feed, typically including plant-based oils (soybean oil, microalgae oil, etc.) and animal-based oils (lard, insect oil, etc.). Among these, insect oil, as a highly sustainable animal oil, should not be overlooked, possessing advantages such as low cost, a balanced fatty acid composition, and wide availability, and is considered to have considerable application value in replacing fish oil in feed. Black soldier flies are resource-rich insects that can efficiently convert organic waste into abundant protein and fat, and have advantages such as sustainable production, low feeding costs, and low water and land utilization rates. Black soldier fly larvae oil (BSFLO), an important product of black soldier fly resources, has been studied in various aquatic animals and has the potential to replace fish oil in aquatic feeds, considering its fatty acid composition and price. However, studies have shown that BSFLO in feed, after replacing higher levels of fish oil, is generally detrimental to the growth, feed utilization, and muscle quality of farmed fish. This may be attributed to the lack of n-3 LC-PUFAs in BSFLO, whose content is much lower than that in fish oil. n-3 LC-PUFAs participate in many biological processes and play an important role in aquatic animal growth, metabolism, immunity, disease resistance, and muscle quality. Microalgae resources, rich in protein, fat (rich in n-3 LC-PUFAs), vitamins, and pigments, have attracted much attention and application in the development of novel aquatic feed resources. Schizochytrium is renowned for its high DHA content, reaching 55%-75% (approximately 49% DHA) on dry matter. In farmed fish, it promotes growth, regulates lipid metabolism and muscle fiber development, and improves muscle quality. Despite encouraging results, using this algal oil to completely replace fish oil and supplement high levels of n-3 LC-PUFA in fish oil-free diets is not economically feasible. Therefore, the use of multiple cost-effective lipid sources has been envisioned to avoid the potential negative effects of a single component and maximize the contribution of each component to the nutritional balance of aquatic feeds. Thus, DHA-rich Schizochytrium oil can be used in addition to BSFLO-rich feeds to mitigate the adverse effects of using BSFLO alone, improving the palatability of fish and making fish oil substitution economically feasible.

[0003] Largemouth bass is a freshwater carnivorous fish widely farmed in China due to its rich nutrition, delicious meat, and characteristics such as temperature adaptability, short growth cycle, and disease resistance. Annual farming volume exceeds 700,000 tons, earning it the title of "fifth largest freshwater fish." With the scale of farming increasing year by year, research into its nutritional and feed requirements is becoming increasingly urgent. Previous studies have found that excessive BSFLO substitution of fish oil in the diet negatively impacts the growth performance and muscle quality of largemouth bass, reducing farming efficiency, even though BSFLO feed is more cost-effective. Therefore, improving the application effect of BSFLO feed on largemouth bass and promoting the green and healthy development of aquaculture are urgent issues that need to be addressed. This is also a hot topic of continuous research and attention for aquatic animal nutritionists. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned shortcomings by providing a black soldier fly oil feed for largemouth bass and its preparation method. This method incorporates green and sustainable black soldier fly larvae oil and Schizochytridium oil as fish oil substitutes into the feed, and utilizes Schizochytridium oil to balance the fatty acid composition of the black soldier fly larvae oil feed, thereby improving the cultured quality of largemouth bass. This largemouth bass feed not only uses readily available raw materials and has a simple preparation method, but also contains complete and rationally balanced nutrients, is environmentally friendly, and can meet the normal growth needs of largemouth bass, possessing high practical value and promising application prospects.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A type of oil feed for black soldier fly larvae and largemouth bass is made from a mixture of basic components, oil source components, additives and functional components;

[0007] The basic components include the following ingredients in parts by weight: 30-40% fish meal, 3-8% soybean meal, 15-25% chicken meal, 3-8% corn gluten meal, 10-15% cottonseed protein, 4-10% wheat flour and 2-6% tapioca starch.

[0008] The oil source components include the following components in parts by weight: 1-2% soybean oil, 2-5% black soldier fly larvae oil and 1-3% Schizochytrium oil;

[0009] The functional components include the following ingredients in parts by weight: 0.5-1.5% premix, 0.5-1.0% choline chloride, 0.05-0.2% vitamin C, 0.1-1.0% DL-methionine and 0.05-0.2% ethoxyquin.

[0010] Preferably, the additive is 0-2% bentonite and 0.4-1.0% calcium dihydrogen phosphate.

[0011] Preferably, the premix is ​​composed of compound vitamins, mixed minerals, and zeolite powder mixed in a weight ratio of 1:1:198.

[0012] Preferably, the complex vitamin is a composition of vitamin A, vitamin D3, dl-α-tocopherol acetate, sodium menadione bisulfite, thiamine nitrate, riboflavin, pyridoxine hydrochloride, cyanocobalamin, nicotinamide, L-ascorbic acid-2-phosphate, D-calcium pantothenate, and inositol; the weight ratio of each component in the complex vitamin is: vitamin A: vitamin D3: dl-α-tocopherol acetate: sodium menadione bisulfite: thiamine nitrate: riboflavin: pyridoxine hydrochloride: cyanocobalamin: nicotinamide: L-ascorbic acid-2-phosphate: D-calcium pantothenate: inositol = 1:0.1:48:3.33:8:16:6.67:0.033:33.33:100:34.67:33.33.

[0013] Preferably, the mixed minerals comprise copper sulfate, ferrous sulfate, manganese sulfate, zinc sulfate, calcium iodate, sodium selenite, cobalt chloride, and magnesium sulfate; the weight ratio of each component in the mixed minerals is: copper sulfate: ferrous sulfate: manganese sulfate: zinc sulfate: calcium iodate: sodium selenite: cobalt chloride: magnesium sulfate = 12:230:30:60:6:1:3:15.

[0014] A method for preparing a black soldier fly oil feed for largemouth bass according to any one of the above methods includes the following steps:

[0015] S1. The fish meal, soybean meal, chicken meal, corn gluten meal, cottonseed gluten, flour, tapioca starch, bentonite, calcium dihydrogen phosphate, premix, choline chloride, vitamin C, DL-methionine, and ethoxyquin are pulverized and sieved separately.

[0016] S2, mix the raw materials obtained in step S1 step by step according to the weight percentage from small to large, to ensure the uniformity of the mixing of each raw material and the balanced nutrient ratio of the mixture, and obtain a uniformly mixed dry mixture.

[0017] S3. Add soybean oil, black soldier fly larvae oil and schistocytic chytrid oil to the dry mixture obtained in S2, mix thoroughly, and then add 30-50% pure water by weight of the total mixture and stir to obtain a wet mixture.

[0018] S4. The wet mixture is processed into pellets with a particle size of 3.5~4.5 mm using a pellet mill, and then dried at 55~65℃ to obtain the finished feed product.

[0019] Preferably, the pelleted feed product is stored at -15 to -25°C.

[0020] The beneficial effects of this invention are:

[0021] This invention utilizes black soldier fly larvae oil and Schizochytridium oil in a specific ratio to completely replace fish oil in the feed of largemouth bass. This feed is nutritionally comprehensive and rich, mitigating the adverse effects of black soldier fly larvae oil on largemouth bass, increasing the deposition of polyunsaturated fatty acids in the muscle, promoting muscle fiber growth and development, and improving muscle quality. Furthermore, this feed is environmentally friendly and highly sustainable, helping to reduce the demand for fish oil in feed. This invention will provide theoretical guidance for the healthy aquaculture of largemouth bass and the development of environmentally friendly feeds.

[0022] This invention incorporates green and sustainable black soldier fly larvae oil and Schizochytridium oil as fish oil substitutes into feed, and utilizes Schizochytridium oil to balance the fatty acid composition of the black soldier fly larvae oil feed, thereby improving the cultured quality of largemouth bass. This largemouth bass feed not only uses readily available raw materials and has a simple preparation method, but also boasts complete and well-balanced nutrients, is environmentally friendly, and can meet the normal growth needs of largemouth bass, demonstrating high practical value and promising application prospects. Attached Figure Description

[0023] Figure 1 This diagram illustrates the effects of various feeds from this invention on the histological structure, muscle fiber area, diameter, and density of largemouth bass muscle cross-sections. Figure 1 A represents the H&E staining diagram (200 X) of a muscle cross-section. Figure 1 B represents the area, diameter, and density of muscle fibers, respectively;

[0024] Figure 2 This invention describes the effects of various feeds on the muscle growth and development of largemouth bass and the expression of myocyte growth regulator gene. Detailed Implementation

[0025] Basic components:

[0026] Fish meal (30-40%): A high-quality source of animal protein.

[0027] Soybean meal (3-8%): A plant-based protein source.

[0028] Chicken meal (15-25%): A high-value source of animal protein.

[0029] Corn gluten meal (3-8%): A source of plant-based protein and binding agents.

[0030] Cottonseed protein (10-15%): A plant-based protein source.

[0031] Flour (4-10%) & tapioca starch (2-6%): as a binder and a source of energy (carbohydrates).

[0032] Oil source components (designed to completely replace traditional fish oil and address the imbalance of fatty acids (especially n-3 LC-PUFAs):

[0033] Soybean oil (1-2%): Provides basic energy and unsaturated fatty acids.

[0034] Black soldier fly larvae oil (2-5%): A primary alternative oil source, serving as a sustainable insect oil.

[0035] Schizochytic chytridii oil (1-3%): A key functional supplemental oil source, providing n-3 long-chain polyunsaturated fatty acids (such as DHA) to compensate for the deficiencies of black soldier fly oil, together achieving fish oil substitution and muscle quality improvement.

[0036] Additives (providing essential minerals to feed and improving processing characteristics and physical properties):

[0037] Calcium dihydrogen phosphate (0.4~1.0%): Provides essential minerals such as calcium and phosphorus.

[0038] Bentonite (0-2%): Used as a binder and anti-caking agent to improve the stability of feed pellets.

[0039] Functional components (providing essential vitamins and trace minerals, and performing specific physiological, metabolic, or preservative functions):

[0040] Premix (0.5~1.5%): Contains vitamin and mineral premix to comprehensively supplement trace elements and vitamins.

[0041] Choline chloride (0.5~1.0%): A member of the B vitamins, involved in fat metabolism and nerve conduction.

[0042] Vitamin C (0.05~0.2%): An important antioxidant and vitamin that enhances the immunity and stress resistance of fish.

[0043] DL-Methionine (0.1~1.0%): An essential amino acid supplement that optimizes the amino acid balance in feed.

[0044] Ethoxyquin (0.05~0.2%): An antioxidant that prevents the oxidation and rancidity of fats in feed.

[0045] Raw material source:

[0046] Fishmeal, imported from Peru, with a crude protein content of 70.2% (dry matter basis); black soldier fly larvae oil sourced from Xi'an Bruputing Biotechnology Co., Ltd., and Schizochytrium oil sourced from Xiamen Huisheng Biotechnology Co., Ltd.

[0047] Premixed feed contains multivitamins and mixed minerals (per kilogram of feed):

[0048] Vitamin A: 0.75 mg; Vitamin D3: 0.075 mg; dl-α-tocopheryl acetate: 36 mg; Sodium menadione bisulfite: 2.5 mg; Thiamine nitrate: 6 mg; Riboflavin: 12 mg; Pyridoxine hydrochloride: 5 mg; Cyanocobalamin: 0.025 mg; Nicotinamide: 25 mg; L-Ascorbic acid-2-phosphate: 75 mg; Calcium D-pantothenate: 26 mg; Inositol: 25 mg; Copper sulfate: 6 mg; Ferrous sulfate: 115 mg; Manganese sulfate: 15 mg; Zinc sulfate: 30 mg; Calcium iodate: 3 mg; Sodium selenite: 0.5 mg; Cobalt chloride: 1.5 mg; Magnesium sulfate: 7.5 mg; Carrier zeolite powder: 9541 mg.

[0049] Example 1

[0050] The raw materials of the black soldier fly oil feed 1 for largemouth bass, by weight percentage, include: fish meal: 35%, soybean meal: 5%, chicken meal: 20.1%, corn gluten meal: 5%, cottonseed protein: 12%, soybean oil: 1.8%, black soldier fly larvae oil: 3.9%, Schizochytridium oil: 1.1%, wheat flour: 7%, cassava starch: 4%, bentonite: 2%, calcium dihydrogen phosphate: 1%, premix: 1%, choline chloride: 0.6%, vitamin C: 0.1%, DL-methionine: 0.3%, and ethoxyquin: 0.1%. This is the experimental black soldier fly oil + Schizochytridium oil group 1, denoted as BS1 (i.e., the feed group of this invention).

[0051] S1. The fish meal, soybean meal, chicken meal, corn gluten meal, cottonseed gluten, flour, tapioca starch, bentonite, calcium dihydrogen phosphate, premix, choline chloride, vitamin C, DL-methionine, and ethoxyquin are pulverized and sieved separately.

[0052] S2, mix the raw materials obtained in step S1 step by step according to the weight percentage from small to large to obtain dry mixture;

[0053] S3. Add soybean oil, black soldier fly larvae oil and schistocytic chytrid oil to the dry mixture obtained in S2, mix thoroughly, and then add 30-50% pure water by weight of the total mixture and stir to obtain a wet mixture.

[0054] S4. The wet mixture is processed into pellets with a particle size of 3.5~4.5 mm using a pellet mill, and then dried at 55~65℃ to obtain the finished feed product.

[0055] Example 2

[0056] The raw materials for the largemouth bass black soldier fly oil feed 1, by weight percentage, include: fish meal: 30%, soybean meal: 8%, chicken meal: 25%, corn gluten meal: 8%, cottonseed protein: 10%, soybean oil: 1%, black soldier fly larvae oil: 2%, Schizochytridium oil: 3%, wheat flour: 4%, cassava starch: 6%, bentonite: 0%, calcium dihydrogen phosphate: 0.4%, premix: 0.5%, choline chloride: 1.0%, vitamin C: 0.05%, DL-methionine: 1.0%, and ethoxyquin: 0.05%, denoted as BS2.

[0057] S1. The fish meal, soybean meal, chicken meal, corn gluten meal, cottonseed gluten, flour, tapioca starch, bentonite, calcium dihydrogen phosphate, premix, choline chloride, vitamin C, DL-methionine, and ethoxyquin are pulverized and sieved separately.

[0058] S2, mix the raw materials obtained in step S1 step by step according to the weight percentage from small to large to obtain dry mixture;

[0059] S3. Add soybean oil, black soldier fly larvae oil and schistocytic chytrid oil to the dry mixture obtained in S2, mix thoroughly, and then add 30-50% pure water by weight of the total mixture and stir to obtain a wet mixture.

[0060] S4. The wet mixture is processed into pellets with a particle size of 3.5~4.5 mm using a pellet mill, and then dried at 55~65℃ to obtain the finished feed product.

[0061] Example 3

[0062] The raw materials for the largemouth bass black soldier fly oil feed 1, by weight percentage, include: fish meal: 40%, soybean meal: 3%, chicken meal: 15%, corn gluten meal: 3%, cottonseed protein: 15%, soybean oil: 2%, black soldier fly larvae oil: 5%, Schizochytridium oil: 1%, wheat flour: 10%, cassava starch: 2%, bentonite: 1%, calcium dihydrogen phosphate: 0.5%, premix: 1.5%, choline chloride: 0.5%, vitamin C: 0.2%, DL-methionine: 0.1%, and ethoxyquin: 0.2%, denoted as BS3.

[0063] S1. The fish meal, soybean meal, chicken meal, corn gluten meal, cottonseed gluten, flour, tapioca starch, bentonite, calcium dihydrogen phosphate, premix, choline chloride, vitamin C, DL-methionine, and ethoxyquin are pulverized and sieved separately.

[0064] S2, mix the raw materials obtained in step S1 step by step according to the weight percentage from small to large to obtain dry mixture;

[0065] S3. Add soybean oil, black soldier fly larvae oil and schistocytic chytrid oil to the dry mixture obtained in S2, mix thoroughly, and then add 30-50% pure water by weight of the total mixture and stir to obtain a wet mixture.

[0066] S4. The wet mixture is processed into pellets with a particle size of 3.5~4.5 mm using a pellet mill, and then dried at 55~65℃ to obtain the finished feed product.

[0067] Comparative Example 1 (Fish Oil Group)

[0068] The only difference from Example 1 is that 5% fish oil completely replaces black soldier fly larvae oil and Schizochytridium oil; the remaining components, their amounts, and preparation steps are the same as in Example 1.

[0069] Comparative Example 2 (single black soldier fly larvae oil group)

[0070] The only difference from Example 1 is that 5% black soldier fly larvae oil was used, and no Schizochytrium oil was used; the remaining components, their amounts, and preparation steps are the same as in Example 1.

[0071] Test Implementation Examples

[0072] Three types of feed prepared in Example 1, Comparative Example 1, and Comparative Example 2 were selected to investigate their effects on the growth performance, muscle nutrient composition, and muscle growth of largemouth bass, in order to evaluate the feasibility of applying the black soldier fly oil diet of the present invention to largemouth bass.

[0073] Table 1. Raw material and fatty acid composition of various feeds

[0074]

[0075] The largemouth bass used in the experiment and the experimental site were both from the Ankang Aquatic Experiment and Demonstration Station of Northwest A&F University (Ankang, Shaanxi). Healthy experimental fish were first acclimatized for two weeks in a recirculating aquaculture system (RAS) consisting of nine 130 L cylindrical culture tanks, water treatment equipment, and oxygenation equipment. They were fed commercial feed with a crude protein level ≥48% and a crude fat level ≥10% daily at 08:00 and 18:00. After acclimatization, 180 largemouth bass (6.93±0.02 g) were randomly divided into three groups with three replicates per group and placed in nine cylindrical culture tanks, with 20 fish per tank. During the 60-day rearing period, the fish were hand-fed until they appeared to be satiated (twice daily, at 8:00 and 18:00). Uneaten feed was collected from the bottom of the cages, dried at 60℃, and weighed to accurately determine the actual feed intake. Settled feces were siphoned off daily. Water temperature: 24.0 ~ 27.0℃, pH: 7.0 ~ 8.0, NH4+ +-N content is less than 0.2 mg / L, NO2--N is less than 0.005 mg / L, and dissolved oxygen is greater than 8 mg / L.

[0076] After the feeding trial, samples were collected from each experimental group after a 24-hour fast. The fish in each tank were then anesthetized with 50 mg / L MS-222 solution. The weight, body length, and total number of fish in each cage were recorded, and the growth rate and survival rate of the largemouth bass were calculated. Then, the weight of individual largemouth bass was weighed and the body length was measured to calculate condition factor. The liver, visceral mass, and mesenteric fat of the largemouth bass were separated and weighed to calculate the liver-to-body ratio, visceral-to-body ratio, and intestinal-to-fat ratio. In addition, a portion of the whole fish was collected to determine the approximate nutritional composition of the whole fish. Muscle tissue samples were collected, and the fatty acid composition of the muscle, HE sections, and expression of genes related to muscle growth and development were analyzed. Statistical analysis of all data was performed using SPSS 23.0 software, and data are expressed as mean ± standard deviation (mean ± SD). Normality and homogeneity of variance were tested using the Shapiro-Wilk test and Levene's test, respectively. One-way ANOVA or non-parametric Kruskal-Wallis analysis was used to analyze differences in data among groups, followed by Duncan's test for multiple comparisons. A p-value < 0.05 was considered statistically significant.

[0077] Table 2. Effects of various feeds on growth performance, feed efficiency, and morphological parameters of largemouth bass.

[0078]

[0079] Note: Data in the table are mean ± standard deviation (n=3); in the same row of data, those without the same lowercase letter label are considered to be significantly different (P < 0.05).

[0080] Table 3. Effects of different feeds on the whole fish and muscle composition (wet weight) of yellow catfish.

[0081]

[0082] Note: Data in the table are mean ± standard deviation (n=3); in the same row of data, those without the same lowercase letter label are considered to be significantly different (P < 0.05).

[0083] Table 4. Effects of different diets on the fatty acid composition of largemouth bass muscle (wet weight)

[0084]

[0085] Note: Data in the table are mean ± standard deviation (n=3); in the same row of data, those without the same lowercase letter label are considered to be significantly different (P < 0.05).

[0086] Depend on Figure 1 Histological examination of the muscle tissue revealed that, compared to Comparative Example 1, the diet of Comparative Example 2 significantly increased the area of ​​largemouth bass muscle fibers and significantly decreased their fiber density (P < 0.05). Although no significant differences were observed in the area and density of largemouth bass muscle fibers fed the diet of the Examples compared to Comparative Example 1 and Comparative Example 2 (P > 0.05), the addition of Schizochyptella oil to the black soldier fly larvae oil diet of the Examples could, to some extent, reduce the diameter and area of ​​largemouth bass muscle fibers and increase their fiber density. Figure 2 The results of gene expression analysis for muscle growth and development showed that, compared with Comparative Example 1, the diet of Comparative Example 2 significantly reduced the mRNA expression level of the muscle growth regulator myod-1 in largemouth bass (P < 0.05), while the diet of the Example 1 could upregulate the mRNA expression of this gene to some extent. Compared with Comparative Example 2, both Comparative Example 1 and the diet of the Example 1 significantly reduced the mRNA expression level of the syndecan-4 gene, which induces cell hypertrophy, in muscle (P < 0.05). This indicates that adding Schizochytridium oil to the black soldier fly oil diet of the Example 1 can, to some extent, improve the reduction in muscle fiber density in largemouth bass caused by black soldier fly larvae oil. Studies have shown that muscle fiber density is closely related to muscle texture quality; higher muscle fiber density generally results in higher muscle firmness and better palatability.

[0087] The growth indicators of Example 1, such as final average weight, weight gain rate, specific growth rate, and feed conversion ratio, were not significantly different from those of Comparative Examples 1 and 2, indicating that the feed of the present invention did not affect the normal growth of largemouth bass.

[0088] The DHA (C22:6n-3) content in the muscles of Example 1 group was significantly higher than that of Comparative Example 2, and the muscle fiber density was significantly improved.

[0089] The muscle glycogen content in Example 1 was significantly higher than that in Comparative Example 2, indicating that the compound fat is beneficial to improving muscle energy reserves and quality.

[0090] The above results confirm that the fish oil-free compound oil feed of the present invention can not only replace fish oil, but also supplement n-3 LC-UFA through Schizochytrium oil, thereby improving the problem of insufficient deposition of unsaturated fatty acids in muscle and deterioration of muscle fiber structure caused by the use of black soldier fly larvae oil alone, achieving the dual goals of economic benefits and meat quality improvement.

[0091] The specific embodiments described herein are merely illustrative examples of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the scope defined by this invention.

Claims

1. An oil feed for black soldier fly larvae and largemouth bass, characterized in that, It is made from a mixture of basic components, oil-based components, additives, and functional components; The basic components include the following ingredients in parts by weight: 30-40% fish meal, 3-8% soybean meal, 15-25% chicken meal, 3-8% corn gluten meal, 10-15% cottonseed protein, 4-10% wheat flour and 2-6% tapioca starch. The oil source components include the following components in parts by weight: 1-2% soybean oil, 2-5% black soldier fly larvae oil and 1-3% Schizochytrium oil; The functional components include the following ingredients in parts by weight: 0.5-1.5% premix, 0.5-1.0% choline chloride, 0.05-0.2% vitamin C, 0.1-1.0% DL-methionine and 0.05-0.2% ethoxyquin.

2. The oil feed for largemouth bass and black soldier fly larvae according to claim 1, characterized in that, The additives are 0-2% bentonite and 0.4-1.0% calcium dihydrogen phosphate.

3. The oil feed for largemouth bass and black soldier fly larvae according to claim 1, characterized in that, The premix is ​​composed of compound vitamins, mixed minerals and zeolite powder in a weight ratio of 1:1:

198.

4. The oil feed for largemouth bass and black soldier fly larvae according to claim 3, characterized in that, The compound vitamin is a composition of vitamin A, vitamin D3, dl-α-tocopherol acetate, sodium menadione bisulfite, thiamine nitrate, riboflavin, pyridoxine hydrochloride, cyanocobalamin, nicotinamide, L-ascorbic acid-2-phosphate, D-calcium pantothenate, and inositol; the weight ratio of each component in the compound vitamin is: vitamin A: vitamin D3: dl-α-tocopherol acetate: sodium menadione bisulfite: thiamine nitrate: riboflavin: pyridoxine hydrochloride: cyanocobalamin: nicotinamide: L-ascorbic acid-2-phosphate: D-calcium pantothenate: inositol = 1:0.1: 48：3.33：8：16：6.67：0.033：33.33：100：34.67：33.33。 5. The oil feed for largemouth bass and black soldier fly larvae according to claim 4, and its preparation method, characterized in that, The mixed minerals comprise copper sulfate, ferrous sulfate, manganese sulfate, zinc sulfate, calcium iodate, sodium selenite, cobalt chloride, and magnesium sulfate; the weight ratio of each component in the mixed minerals is: copper sulfate: ferrous sulfate: manganese sulfate: zinc sulfate: calcium iodate: sodium selenite: cobalt chloride: magnesium sulfate = 12:230:30:60:6:1:3:

15.

6. A method for preparing a black soldier fly oil feed for largemouth bass according to any one of claims 1-5, characterized in that, Includes the following steps: S1. The fish meal, soybean meal, chicken meal, corn gluten meal, cottonseed gluten, flour, tapioca starch, bentonite, calcium dihydrogen phosphate, premix, choline chloride, vitamin C, DL-methionine, and ethoxyquin are pulverized and sieved separately. S2, mix the raw materials obtained in step S1 step by step according to the weight percentage from small to large to obtain dry mixture; S3, add soybean oil, black soldier fly larvae oil and schistocytic chytrid oil to the dry mixture obtained in S2, mix thoroughly, and then add 30-50% pure water by weight of the total mixture and stir to obtain a wet mixture. S4. The wet mixture is granulated into pellets with a particle size of 3.5~4.5 mm using a pellet mill, and then dried at 55~65℃ to obtain the finished feed product.

7. The method for preparing a black soldier fly oil feed for largemouth bass according to claim 6, characterized in that, The finished pelleted feed should be stored at -15 to -25°C.

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