Freshwater fish low-carbon feed added with fermented bamboo powder and application of freshwater fish low-carbon feed

Abstract

The invention discloses a low-carbon freshwater fish feed added with fermented bamboo powder and application of the low-carbon freshwater fish feed, and belongs to the technical field of aquatic animal feeds. The low-carbon freshwater fish feed capable of reducing the fat rate of fish bodies and / or reducing nitrogen and phosphorus emission is prepared from the fermented bamboo powder, and the content of vitamins, enzymes and growth factors in the feed can be increased by adding the fermented bamboo powder, so that the freshwater fish bodies have good anti-pathogenic activity; the absorption and utilization of the freshwater fish on nutritional ingredients and fiber-rich ingredients in the feed are improved, so that the aim of reducing the emission of nitrogen and phosphorus is fulfilled; meanwhile, the fermented bamboo powder is used for partially replacing soybean meal in the freshwater fish feed, so that the dosage of feed raw materials such as the soybean meal is reduced, the intestinal health of the freshwater fish is improved, the muscle quality of the freshwater fish is improved, the earthy smell in muscles is reduced, the body type of the freshwater fish is also improved, and the fat content in abdominal muscles is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of aquatic animal feed, and in particular relates to a low-carbon feed for freshwater fish added with fermented bamboo powder and application thereof. Background Art

[0002] With the rapid development of the aquaculture industry, the reduction of feed raw materials and the increase in feed costs have become key factors restricting its green and sustainable development. On the one hand, high-energy grains (such as corn, soybeans, etc.) are mainly supplied to humans as food. On the other hand, aquatic feed raw materials are easily affected by price fluctuations in the international market and supply chains. In addition, protein sources in conventional feeds are prone to environmental pollution problems caused by nitrogen and phosphorus emissions from aquaculture waters. Traditional feed protein sources represented by soybean meal contain anti-nutritional factors such as trypsin inhibitors, which can easily lead to damaged intestinal barrier function and reduced digestive enzyme activity in fish, thereby affecting the metabolic efficiency of nitrogen and phosphorus in the feed and exacerbating the eutrophication of aquaculture waters.

[0003] In view of this, it is necessary to develop new freshwater fish feed to solve the technical problem that conventional feed easily leads to fat accumulation and nitrogen and phosphorus emissions in the liver of freshwater fish. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a low-carbon feed for freshwater fish added with fermented bamboo powder and application thereof.

[0005] To achieve the above objectives, the present invention provides the following technical solutions:

[0006] The present invention provides an application of fermented bamboo powder in preparing a low-carbon feed for freshwater fish capable of reducing the body fat rate of fish and / or reducing nitrogen and phosphorus emissions.

[0007] Furthermore, the preparation method of the fermented bamboo powder is as follows: the bamboo powder is inoculated with composite bacteria and fermented for 15-20 days under the conditions of a temperature of 25°C-35°C, a water content of 50%-60% and a pH value of 6.5-7.5;

[0008] The composite bacteria consists of bacillus, yeast, lactic acid bacteria and white rot fungi in a dosage ratio of 50:20:15:15.

[0009] In the present invention, bamboo, a renewable natural resource with a fast growth rate and huge yield, is used as a raw material for freshwater fish feed, which not only improves resource utilization but also reduces the overall cost of freshwater fish feed. Studies have shown that bamboo powder is rich in insoluble dietary fiber, glycosides, and polysaccharides, which are beneficial for regulating animals' immunity and antioxidant capacity. Bamboo stem shells contain various bioactive substances, which can lower cholesterol levels by absorbing cholesterol from the body and promote the proliferation of lactic acid bacteria, thereby improving the fermentation performance of substrates. However, bamboo powder contains a certain amount of lignin, which is not easily decomposed and absorbed by animals, which limits its application in aquatic feed. The present invention opens up the complex network of lignocellulose through microbial fermentation, which can increase the content of vitamins, enzymes, and growth factors in the feed, imparting good anti-pathogenic activity to freshwater fish, and improving the absorption and utilization of nutrients and fiber-rich components in the feed by freshwater fish, thereby achieving the goal of reducing nitrogen and phosphorus emissions. Fermented bamboo powder itself has a low fat content, directly reducing the fish's total fat intake. Furthermore, the antioxidants in bamboo powder, such as flavonoids and phenolic acids, are bioactive after fermentation, having the dual effects of downregulating the expression of lipase genes and enhancing the activity of lipases. The unsaturated fatty acids (such as linoleic acid and linolenic acid) produced during fermentation replace saturated fatty acids, reducing body fat deposition. Simultaneously, the organic acids (lactic acid and acetic acid) produced promote lipid oxidation and decomposition in the liver, reducing triglyceride synthesis.

[0010] The present invention also provides a low-carbon feed for freshwater fish added with fermented bamboo powder, wherein the fermented bamboo powder is used to replace soybean meal in the basic feed for freshwater fish at a mass replacement rate of 40-50%.

[0011] Furthermore, fermented bamboo powder was used to replace soybean meal in the basic feed of freshwater fish at a mass replacement rate of 45%.

[0012] Furthermore, the low-carbon feed for freshwater fish added with fermented bamboo powder includes the following raw materials in percentage by mass: 2.0% fish meal, 6.0% soybean meal, 5.0% fermented bamboo powder, 14.0% second-grade flour, 30.0% rapeseed meal, 20.0% wheat bran, 15.0% rice bran, 2.0% yeast powder, 1.0% monocalcium phosphate, 4.0% mineral elements and 1.0% vitamins.

[0013] Furthermore, the low-carbon feed for freshwater fish added with fermented bamboo powder also includes a microbial preparation.

[0014] Furthermore, the mass content of the microbial preparation in the low-carbon feed for freshwater fish added with fermented bamboo powder is 0.1-0.2%.

[0015] Furthermore, the microbial preparation is selected from lactic acid bacteria, yeast, Clostridium butyricum and Bacillus subtilis.

[0016] Furthermore, the usage ratio of the lactic acid bacteria, yeast, Clostridium butyricum and Bacillus subtilis is 50:25:15:10.

[0017] The present invention also provides a method for preparing the low-carbon feed for freshwater fish with added fermented bamboo powder as described in the above technical solution, wherein the raw materials are weighed according to the mass ratio and mixed evenly to obtain the low-carbon feed for freshwater fish with added fermented bamboo powder.

[0018] Compared with the prior art, the present invention has the following advantages and technical effects:

[0019] The present invention partially replaces soybean meal with fermented bamboo powder, thereby reducing the amount of feed raw materials such as soybean meal, improving the intestinal health of freshwater fish, improving the muscle quality of freshwater fish, reducing the earthy smell in the muscle, improving the body shape of freshwater fish, and reducing the fat content in the abdominal muscles. This provides a theoretical basis for alleviating the shortage of soybean meal supply and reducing body fat and nitrogen and phosphorus emissions of freshwater fish. DETAILED DESCRIPTION

[0020] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0021] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with specific embodiments.

[0022] The embodiment of the present invention provides an application of fermented bamboo powder in preparing a low-carbon feed for freshwater fish that reduces the fat rate of fish and / or reduces nitrogen and phosphorus emissions.

[0023] In a preferred embodiment, the fermented bamboo powder is obtained by inoculating bamboo powder with a composite bacteria and fermenting it for 15-20 days at a temperature of 25-35°C, a moisture content of 50%-60%, and a pH of 6.5-7.5. The composite bacteria are composed of Bacillus, yeast, lactic acid bacteria, and white rot fungi in a ratio of 50:20:15:15 (based on the number of microorganisms). The inoculum amount of the composite bacteria is 1.0-1.5% of the mass of the bamboo powder. Bamboo powder contains a certain amount of lignin, which hinders its effective utilization. The present invention, through microbial fermentation, opens up the complex lignocellulose network, thereby increasing the content of vitamins, enzymes, and growth factors in the feed, imparting good anti-pathogenic activity to freshwater fish, and improving the absorption and utilization of nutrients and fiber-rich components in the feed by freshwater fish.

[0024] The present invention also provides a low-carbon feed for freshwater fish added with fermented bamboo powder, wherein the fermented bamboo powder is used to replace soybean meal in the basic feed for freshwater fish at a mass replacement rate of 40-50%.

[0025] In a further preferred embodiment, fermented bamboo powder replaces soybean meal in the base feed for freshwater fish at a 45% mass replacement rate. This partial replacement of soybean meal with fermented bamboo powder reduces the amount of feed ingredients such as soybean meal, while also improving the intestinal health of freshwater fish, enhancing muscle quality, reducing earthy odor, improving body shape, and reducing fat content in abdominal muscles.

[0026] In a preferred embodiment, the low-carbon feed for freshwater fish with added fermented bamboo powder comprises the following raw materials in percentage by mass: 2.0% fish meal, 6.0% soybean meal, 5.0% fermented bamboo powder, 14.0% second-grade flour, 30.0% rapeseed meal, 20.0% wheat bran, 15.0% rice bran, 2.0% yeast powder, 1.0% monocalcium phosphate, 4.0% mineral elements and 1.0% vitamins.

[0027] In a preferred embodiment, the mineral elements include the following components per kilogram of feed: 500 mg of sodium chloride, 8200 mg of magnesium sulfate, 12500 mg of sodium dihydrogen phosphate, 16000 mg of potassium dihydrogen phosphate, 7500 mg of calcium hydrogen phosphate, 2250 mg of ferrous sulfate, 1750 mg of calcium lactate, 50 mg of manganese sulfate and 15 mg of copper sulfate.

[0028] In a preferred embodiment, the vitamins include the following components per kilogram of feed: vitamin E 100 mg, vitamin A 10 mg, vitamin D 3500 mg, vitamin B1 20 mg, vitamin B2 20 mg, vitamin B6 20 mg, vitamin B 12 0.02mg, D-calcium pantothenate 50mg, folic acid 5mg and D-biotin 3000mg.

[0029] In a preferred embodiment, the low-carbon feed for freshwater fish containing fermented bamboo powder further comprises a microbial preparation, wherein the mass content of the microbial preparation in the low-carbon feed for freshwater fish containing fermented bamboo powder is 0.1-0.2%. The addition of the microbial preparation in the present invention is beneficial to improving the feed conversion ratio.

[0030] In a preferred embodiment, the microbial preparation is selected from lactic acid bacteria, yeast, Clostridium butyricum and Bacillus subtilis; the usage ratio of the lactic acid bacteria, yeast, Clostridium butyricum and Bacillus subtilis (based on the number of microorganisms) is 50:25:15:10.

[0031] The present invention also provides a method for preparing the low-carbon feed for freshwater fish with added fermented bamboo powder as described in the above technical solution, wherein the raw materials are weighed according to the mass ratio and mixed evenly to obtain the low-carbon feed for freshwater fish with added fermented bamboo powder.

[0032] Unless otherwise specified, the raw materials in the examples of the present invention were purchased from commercial sources.

[0033] The feeds in the following examples and comparative examples were all processed by the feed base of the South China Sea Fisheries Research Institute.

[0034] Example 1

[0035] A low-carbon feed for freshwater fish supplemented with fermented bamboo powder is composed of the following raw materials in percentage by mass: 2.0% fish meal, 6.0% soybean meal, 5.0% fermented bamboo powder, 14.0% second-grade flour, 30.0% rapeseed meal, 20.0% wheat bran, 15.0% rice bran, 2.0% yeast powder, 1.0% calcium dihydrogen phosphate, 4.0% mineral elements, and 1.0% vitamins. The fermented bamboo powder is obtained by inoculating bamboo powder with composite bacteria and fermenting it for 15 days at a temperature of 30°C, a moisture content of 55%, and a pH of 6.5. The composite bacteria are composed of Bacillus, yeast, lactic acid bacteria, and white rot fungi in a ratio of 50:20:15:15 (in terms of the number of microorganisms). The inoculation amount of the composite bacteria is 1.0% of the mass of the bamboo powder. The mineral elements are composed of the following components per kilogram of feed: 500mg sodium chloride, 820mg magnesium sulfate, and 100mg iodine. 0mg, sodium dihydrogen phosphate 12500mg, potassium dihydrogen phosphate 16000mg, calcium hydrogen phosphate 7500mg, ferrous sulfate 2250mg, calcium lactate 1750mg, manganese sulfate 50mg and copper sulfate 15mg; per kilogram of feed, vitamins are composed of the following components: vitamin E 100mg, vitamin A 10mg, vitamin D 3500mg, vitamin B1 20mg, vitamin B2 20mg, vitamin B6 20mg, vitamin B 12 0.02 mg of calcium phosphate, 50 mg of D-pantothenate calcium, 5 mg of folic acid, and 3000 mg of D-biotin were weighed according to the mass ratio and mixed evenly to obtain a low-carbon feed for freshwater fish containing fermented bamboo powder.

[0036] Comparative Example 1

[0037] A freshwater fish feed is composed of the following raw materials in percentage by mass: 2.0% fish meal, 11.0% soybean meal, 14.0% wheat flour, 30.0% rapeseed meal, 20.0% wheat bran, 15.0% rice bran, 2.0% yeast powder, 1.0% calcium dihydrogen phosphate, 4.0% mineral elements, and 1.0% vitamins. The composition of the mineral elements and vitamins is the same as in Example 1. The raw materials are weighed according to their mass ratio and mixed evenly to obtain the freshwater fish feed.

[0038] The raw material compositions of the feeds in Example 1 and Comparative Example 1 are shown in Table 1.

[0039] Table 1

[0040] raw material Mass content (%) Mass content (%) fishmeal 2.0 2.0 soybean meal 11.0 6.0 Fermented bamboo powder 0 5.0 Second powder 14.0 14.0 rapeseed meal 30.0 30.0 wheat bran 20.0 20.0 rice bran 15.0 15.0 yeast powder 2.0 2.0 Calcium dihydrogen phosphate 1.0 1.0 Mineral elements 4.0 4.0 vitamins 1.0 1.0

[0041] Breeding experiment:

[0042] 1. Experimental fish

[0043] The experimental grass carp were provided by an aquaculture company in Baiyun District, Guangzhou City. They weighed about 50 to 60 g and were required to be healthy and lively with basically the same size.

[0044] 2. Experimental Methods

[0045] 2.1 Experimental fish grouping and feeding

[0046] The test site is the breeding base of the Pearl River Fisheries Research Institute. The experimental grass carp was first soaked and disinfected with a KMnO4 solution with a mass concentration of 0.1% for 1 hour, and then temporarily raised for 5 days. Subsequently, 300 healthy and disease-free grass carp weighing about 50g were selected and randomly divided into two groups: a control group and an experimental group, with three replicates in each group and 50 fish in each replicate. Before the experiment began, they were temporarily raised for 7 days and acclimated with experimental feeds respectively. The main test period was 56 days. The control group was fed with the feed in comparative example 1, and the experimental group was fed with the feed in embodiment 1. The experimental fish were raised in cylindrical plastic barrels indoors (the volume of the plastic barrel was 2.75m 3 , the effective water volume is 2.00m 3 To prevent the experimental fish from jumping out, the plastic bucket was covered with mesh. During the experiment, the water temperature was maintained at 22-30°C, and artificial oxygen was provided 24 hours a day. Feeding was strictly carried out according to the "four fixed" principles of timing, quantity, quality, and location. Feed was administered three times daily at 08:00, 12:00, and 17:00, with a daily feed intake of 2% of body weight. Fish were weighed and feed intake adjusted every two weeks. Fish health was observed daily, and water temperature, feed intake, and fish mortality were recorded. Leftover feed and feces were removed weekly, and one-third of the water supply was replaced with aerated tap water.

[0047] 2.2 Sample collection and processing

[0048] After the experiment, the grass carp were weighed one by one, and the daily weight gain (DWG), specific growth rate (sGR), survival rate and feed conversion coefficient were calculated using the following formula:

[0049] Average daily weight gain (g / d) = (average final weight - average initial weight) / number of experimental days;

[0050] Specific growth rate (% / d) = 100% × (ln (average final body weight) - ln (average initial body weight)) / number of days of feeding;

[0051] Survival rate (%) = last digit / first digit × 100%;

[0052] Feed coefficient = total feed amount fed / total weight gain.

[0053] Six grass carp were randomly sampled from each group. Muscle samples were taken from both sides of the fish, from the head to the anus. To prevent urine contamination, each fish was urinated before sampling. The internal organs were removed, the skin was peeled, and the meat was finally minced and mixed evenly, and stored at -20°C until further use.

[0054] 2.3 Routine nutrient composition determination

[0055] The determination of moisture, crude protein, crude fat, crude ash and cellulose shall be in accordance with GB5009.3-2003, GB5009.5-2003, GB5009.6-2003, GB5009.4-2003 and GB / T5009.10-2003 respectively.

[0056] 2.4 Determination of free amino acids

[0057] The contents of 16 free amino acids were determined using high-performance liquid chromatography (HPLC) using an American HPLC instrument and a PIOC.TAG amino acid analysis column. The temperature was 38°C, the detection wavelength was 254 nm, and the flow rate was 1 mL / min. Due to insufficient sample volume, tryptophan and cystine were not determined.

[0058] 2.5 Data Processing

[0059] Data were processed using STATISTICA 6.0 for Windows and Excel. Results are presented as mean ± standard error. Means within the index were compared using the least significant difference (LSD) method at the 95% confidence level (P < 0.05) or the 99% confidence level (P < 0.01).

[0060] 3. Experimental Results

[0061] 3.1 Growth performance indicators

[0062] The effects of the feeds in Example 1 and Comparative Example 1 on the growth performance and feed conversion rate of grass carp are shown in Table 2.

[0063] Table 2 Growth performance of grass carp in each group

[0064] Control group (Comparative Example 1) Experimental group (Example 1) Initial weight (g) 51.54±0.55 51.10±0.45 Final weight (g) <![CDATA[60.49±0.71 a ]]> <![CDATA[63.03±1.85 b ]]> Daily weight gain (g / d) <![CDATA[0.213±0.0l4 a ]]> <![CDATA[0.224±0.0l6 b ]]> Specific growth rate (% / d) <![CDATA[0.381±0.030 a ]]> <![CDATA[0.497±0.028 b ]]> Survival rate (%) <![CDATA[86.67±1.15 a ]]> <![CDATA[92.00±3.46 b ]]> Feed coefficient <![CDATA[2.25±0.36 a ]]> <![CDATA[1.96±0.25 b ]]>

[0065] Note: The differences in the same group are significantly different (p<0.05). The experimental days were 56 days.

[0066] Table 1 shows that compared to the control group, the daily weight gain of grass carp in the experimental group increased by 5.16% and the specific growth rate increased by 30.45%. Statistical results indicate significant differences between the control and experimental groups. Adding fermented bamboo powder to the experimental group had a modest effect on feed conversion efficiency, as evidenced by a slight decrease in the feed conversion efficiency of the experimental group compared to the control group. Adding fermented bamboo powder also had a significant effect on the survival rate of grass carp.

[0067] 3.2 Comparison of main nutrients

[0068] The results of the determination of the nutritional components (water content, ash content, crude fat, and protein) of grass carp in the experimental and control groups are shown in Table 3.

[0069] Table 3 Nutritional components of grass carp muscle

[0070] name Moisture (%) Ash content (%) Crude protein (mg / g) Crude fat (mg / g) Experimental group <![CDATA[81.22±0.28 a ]]> 1.09±0.11 <![CDATA[19.53±0.48 b ]]> <![CDATA[1.58±0.15 b ]]> control group <![CDATA[78.83±0.48 b ]]> 1.09±0.31 <![CDATA[17.17±0.15 a ]]> <![CDATA[1.70±0.12 a ]]>

[0071] Note: Different lowercase letters in the same column indicate significant differences (P<0.05).

[0072] As can be seen from Table 3, the protein content of the experimental group increased and the fat content decreased, which meets people's demand for high protein and low fat.

[0073] 3.3 Amino acid analysis results

[0074] The amino acid contents of grass carp muscles in the experimental and control groups are shown in Table 4.

[0075] Table 4 Amino acid content of grass carp muscle in the experimental and control groups (fresh weight mg / 100g)

[0076] Amino acid types Experimental group control group Aspartic acid* 0.97±0.11 0.95±0.13 Glutamate* <![CDATA[25.03±6.35 a ]]> <![CDATA[13.10±4.28 b ]]> Serine <![CDATA[4.27±0.45 a ]]> <![CDATA[1.07±0.07 b ]]> Glycine* <![CDATA[21.90±1.65 a ]]> <![CDATA[19.87±1.73 b ]]> Threonine** <![CDATA[13.53±2.65 a ]]> <![CDATA[1.70±0.60 b ]]> Histidine 97.87±7.20 98.53±21.47 Arginine <![CDATA[23.47±1.98 a ]]> <![CDATA[13.27±1.49 b ]]> Alanine* <![CDATA[23.50±1.88 a ]]> <![CDATA[13.31±1.46 b ]]> Tyrosine <![CDATA[2.70±0.10 a ]]> <![CDATA[1.33±0.18 b ]]> Valine** <![CDATA[4.37±0.33 a ]]> <![CDATA[1.05±0.08 b ]]> Methionine** <![CDATA[1.57±0.19 a ]]> <![CDATA[0.95±0.13 b ]]> Phenylalanine** <![CDATA[1.97±0.17 a ]]> <![CDATA[1.02±0.05 b ]]> Isoleucine** <![CDATA[2.40±0.21 a ]]> <![CDATA[0.98±0.11 b ]]> Leucine** <![CDATA[5.03±0.42 a ]]> <![CDATA[1.00±0.15 b ]]> Lysine** <![CDATA[46.20±10.01 a ]]> <![CDATA[4.60±1.46 b ]]> Proline <![CDATA[27.10±5.98 a ]]> <![CDATA[15.93±5.33 b ]]> TAA (total amino acids) <![CDATA[301.88±33.13 a ]]> <![CDATA[188.66±44.54 b ]]> EAA (essential amino acids) <![CDATA[75.07±13.97 a ]]> <![CDATA[11.30±1.65 b ]]> NEAA (non-essential amino acids) 226.81±19.37 177.36±43.10 DTAA (umami amino acid) <![CDATA[97.48±9.56 a ]]> <![CDATA[60.50±7.10 b ]]> EAA / TAA% <![CDATA[24.87±2.14 a ]]> <![CDATA[5.99±0.87 b ]]> EAA / NEAA% <![CDATA[33.10±3.83 a ]]> <![CDATA[6.37±0.99 b ]]> DTAA / TAA% 32.29±0.67 32.07±3.95

[0077] Note: The difference between the lowercase letters in the same column is significant (0.01 <P<0.05)。

[0078] As shown in Table 4, the amino acids with high concentrations in both experimental fish groups were glycine, histidine, alanine, and arginine. Histidine was the highest, while glycine, arginine, and alanine were at lower levels. The essential amino acid content in the experimental group was significantly higher than that in the control group.

[0079] The flavor of fish is determined by the amount and composition of a class of amino acids called "umami-producing amino acids" in their muscle. These amino acids primarily consist of glutamic acid, aspartic acid, glycine, alanine, and arginine. The total amount of umami amino acids in the experimental group was significantly higher than in the control group. The glutamic acid content in the experimental group was also higher than in the control group, indicating that grass carp fed the low-carbon freshwater fish feed supplemented with fermented bamboo powder provided by the present invention have a more flavorful flavor.

[0080] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. Application of fermented bamboo powder in preparing low-carbon feed for freshwater fish that reduces fish body fat rate and / or reduces nitrogen and phosphorus emissions.

2. The use according to claim 1, characterized in that The preparation method of the fermented bamboo powder is as follows: the bamboo powder is inoculated with composite bacteria and fermented for 15-20 days under the conditions of a temperature of 25-35° C., a water content of 50%-60% and a pH value of 6.5-7.

5. The composite bacteria consists of bacillus, yeast, lactic acid bacteria and white rot fungi in a dosage ratio of 50:20:15:

15.

3. A low-carbon feed for freshwater fish with added fermented bamboo powder, characterized in that: Fermented bamboo powder is used to replace soybean meal in freshwater fish basic feed at a mass replacement rate of 40-50%.

4. The low-carbon feed for freshwater fish added with fermented bamboo powder according to claim 3, characterized in that: Fermented bamboo powder was used to replace soybean meal in the basic feed of freshwater fish at a mass replacement rate of 45%.

5. The low-carbon feed for freshwater fish added with fermented bamboo powder according to claim 3 or 4, characterized in that: The low-carbon feed for freshwater fish added with fermented bamboo powder comprises the following raw materials in percentage by mass: 2.0% of fish meal, 6.0% of soybean meal, 5.0% of fermented bamboo powder, 14.0% of second-grade flour, 30.0% of rapeseed meal, 20.0% of wheat bran, 15.0% of rice bran, 2.0% of yeast powder, 1.0% of monocalcium phosphate, 4.0% of mineral elements and 1.0% of vitamins.

6. The low-carbon feed for freshwater fish added with fermented bamboo powder according to claim 3, characterized in that: The low-carbon feed for freshwater fish added with fermented bamboo powder also includes a microbial preparation.

7. The low-carbon feed for freshwater fish added with fermented bamboo powder according to claim 6, characterized in that: The mass content of the microbial preparation in the low-carbon feed for freshwater fish added with fermented bamboo powder is 0.1-0.2%.

8. The low-carbon feed for freshwater fish added with fermented bamboo powder according to claim 6, characterized in that: The microbial preparation is selected from lactic acid bacteria, yeast, Clostridium butyricum and Bacillus subtilis.

9. The low-carbon feed for freshwater fish added with fermented bamboo powder according to claim 8, characterized in that: The usage ratio of the lactic acid bacteria, yeast, Clostridium butyricum and Bacillus subtilis is 50:25:15:

10.

10. A method for preparing a low-carbon feed for freshwater fish containing fermented bamboo powder according to any one of claims 1 to 9, characterized in that: The raw materials are weighed according to the mass ratio and mixed evenly to obtain the low-carbon feed for freshwater fish with added fermented bamboo powder.