Vinasse fermented feed for aquaculture and application thereof

Abstract

The invention discloses a vinasse fermented feed for aquaculture and application thereof, and belongs to the technical field of feed processing. The vinasse fermented feed for aquaculture comprises the following components in percentage by mass: 89-90% of shelled brine shrimps and 10-11% of fermented vinasse, the crude protein content of the fermented vinasse is 5.86%-7.12%, the crude fat content of the fermented vinasse is 0.36%-0.74%, the crude fiber content of the fermented vinasse is 2.68%-4.33%, and the total amino acid content of the fermented vinasse is 5.89%-6.39%. The preparation method of the fermented vinasse comprises the following steps: sieving original vinasse, removing rice hulls, crushing, inoculating compound bacteria into the treated vinasse, and carrying out closed fermentation to obtain the fermented vinasse. When the vinasse fermented feed for aquaculture is used as a daily ration for fish culture for feeding, the oxidation resistance of fishes can be effectively improved, and the microecological health of intestinal tracts can be promoted.

Description

Technical Field

[0001] The invention belongs to the technical field of feed processing, relates to deep processing of distiller's grains as a protein source for aquatic feed, and specifically relates to a distiller's grains fermented feed for aquaculture, and a preparation method and application thereof. Background Art

[0002] Fishmeal has high digestible protein content, amino acid content, unsaturated fatty acid content and good palatability, and does not contain anti-nutritional factors. It is the main component of aquatic feed. The rapid expansion of my country's aquatic industry has driven the market demand for fishmeal, which in turn has led to an imbalance in the relationship between feed and fishing, which is not conducive to the development of fisheries. my country has a large demand for fishmeal, but its output is small and it is heavily dependent on imports. The huge gap in fishmeal has seriously restricted the development of the aquatic industry. Protein is the most important and expensive nutrient in animal feed. Therefore, increasing the diversity of protein sources in aquatic feed is one of the main problems facing the aquatic industry.

[0003] Some studies have found that it is feasible to use plant protein to replace fish meal. For example, hybrid tilapia was fed with soybean meal and different levels of methionine. It was found that with the increase of methionine content, the specific growth rate, feed conversion rate and protein retention efficiency of hybrid tilapia were significantly improved; some studies have also found that adding up to 30% corn distiller's grains to hybrid tilapia feed has no negative impact on its growth and feed efficiency. However, these plant proteins have low essential amino acid content, high anti-nutritional factors (ANF), high crude fiber content, poor palatability, and competition for food, feed, and fuel. When the level of distiller's grains replacing fish meal reaches a medium-high level of 12% or 16%, it will have a negative impact on the growth performance of aquatic products. Therefore, it is necessary to find a new source of feed protein with high protein, high availability, low anti-nutritional factor content and good palatability.

[0004] Wine lees are the main by-product of the brewing industry. They are solid residues formed by the cooking, saccharification, fermentation, and distillation of grains such as sorghum, rice, wheat, and corn under the action of fermentation agents such as koji and saccharifying enzymes. my country's liquor industry is well developed, and the annual output of wine lees is high. The crude protein content of wine lees is between 268-337g / kg, the crude fat content is between 35-128g / kg, and the ash content is between 28-98g / kg. Wine lees have a high content of usable ingredients, and have the advantages of high output, low price, and few anti-nutritional factors. They can be used as a high-quality source of feed protein.

[0005] The existing methods of using distiller's grains in animal husbandry feed are direct feeding of fresh distiller's grains and direct feeding of dry distiller's grains. Direct feeding is one of the most commonly used methods of distiller's grains feed. Fresh distiller's grains have a strong aroma, are rich in protein, active factors, starch, cellulose and trace elements, and have a high amino acid content and a full range of types, which can be well absorbed and utilized by animals. Untreated distiller's grains are highly acidic, high in water and sugar content, and are easy to deteriorate. Eating a large amount of them will damage the health of the animal body, and may also cause malnutrition and low immunity in the animal. This utilization method has great limitations and is only suitable for animals with high fiber ratio requirements and low feeding nutritional requirements, such as ruminants such as cattle and sheep; it can also be partially added to other animal feeds to reduce feed costs. Due to the high moisture content of fresh distiller's grains, it cannot be transported over long distances and is not conducive to storage. In order to solve these problems and enable distiller's grains to be used industrially on a large scale, they need to be dried. This method solves the problem that direct feeding of distiller's grains is prone to spoilage and difficult to transport over long distances, but drying requires a large drying area and drying equipment, which not only consumes a lot of energy and increases feed costs, but also leads to a certain degree of nutrient loss. At the same time, dry distiller's grains are easily affected by moisture, which leads to an increase in mold content. At present, mycotoxins such as fumonisin, zearalenone (F-2 toxin), ochratoxin, T-2 toxin and aflatoxin have been detected in dry distiller's grains. At the same time, distiller's grains are rich in bioactive substances such as organic acids, phenolic acids, flavonoids and alkaloids, which have antioxidant, anti-inflammatory and antibacterial effects, and play an important regulatory role in promoting the growth and development of animals. However, the existing feed method cannot fully utilize these effective ingredients. Therefore, distiller's grains processing also requires a new, environmentally friendly, refined and high-value processing method that fully utilizes its effective ingredients. Summary of the invention

[0006] The technical problem to be solved by the present invention is that when plant protein replaces fish and other animal protein powder for aquaculture, the essential amino acid content is low, the anti-nutritional factors are high, the crude fiber content is high, the palatability is poor, and there is also the problem of competition between food, feed and fuel; and the existing distiller's grains feed is not suitable for aquaculture due to the defects of its processing method. The present invention aims to provide a new way for distiller's grains to be used as aquatic feed and to develop nutritious and low-cost fish feed, which is crucial for more accurate use of alternative ingredients in future feed matrices.

[0007] The technical solution adopted by the present invention to solve its technical problem is:

[0008] In a first aspect, the present invention provides a fermented distiller's grains feed for aquaculture, the composition of which is 89-90% by mass of shelled brine shrimp and 10-11% by mass of fermented distiller's grains;

[0009] The crude protein content of the fermented wine lees is 5.86% to 7.12%, the crude fat content is 0.36% to 0.74%, the crude fiber content is 2.68% to 4.33%, and the total amino acid content is 5.89% to 6.39%.

[0010] In the above-mentioned fermented liquor lees feed for aquaculture, the preparation method of the fermented liquor lees is: the original liquor lees are sieved to remove rice husks and then crushed, and composite bacteria are inoculated into the treated liquor lees for closed fermentation to obtain fermented liquor lees.

[0011] Furthermore, the above-mentioned original distiller's grains are solid distiller's grains from liquor brewing, and the raw material thereof is sorghum, with a moisture content of 61.72% to 62.38%, a crude protein content of 5.56% to 5.72%, a crude fat content of 0.29% to 0.32%, a crude fiber content of 3.92% to 4.15%, and a total amino acid content of 5.25% to 5.59%.

[0012] Furthermore, the sieving is performed using a 60-mesh screen, and the crushing is performed using a high-speed crusher to crush the sieved original wine lees to a particle size of ≤0.5 mm.

[0013] Furthermore, the composite bacteria is a mixture of Candida utilis solution, Bacillus subtilis solution and Lactobacillus casei solution in equal mass ratios.

[0014] Furthermore, the number of viable cells in the above-mentioned Candida utilis liquid is ≥ 1×10 8 cfu / g, the number of viable bacteria in Bacillus subtilis liquid ≥ 1×10 8 cfu / g, the number of viable bacteria in Lactobacillus casei culture solution ≥ 1×10 8 cfu / g.

[0015] Furthermore, the inoculation amount of the above-mentioned composite bacteria is 8% to 12% of the mass of the original lees.

[0016] Furthermore, the inoculation amount is 10% of the original stillage mass.

[0017] Furthermore, the fermentation temperature is 26-34° C., and the fermentation time is 4-6 days.

[0018] Furthermore, the fermentation temperature was 34°C and the fermentation time was 6 days.

[0019] In a second aspect, the present invention provides an application of the above-mentioned fermented distiller's grains feed for aquaculture: the above-mentioned fermented distiller's grains feed for aquaculture is used as a fish farming diet and fed to enhance the antioxidant capacity of the fish and promote the health of its intestinal microecology.

[0020] Furthermore, the fish is zebrafish, and the feeding amount of the above-mentioned diet is 4.0% to 7.0% of the body weight of the zebrafish.

[0021] The beneficial effects of the present invention are as follows: the traditional method of processing distiller's grains not only has low resource utilization, but also has high processing costs and serious environmental pollution, and the active ingredients contained in the distiller's grains cannot be fully utilized. Based on an in-depth analysis of the nutritional composition of matrices such as solid distiller's grains from liquor brewing, and the evaluation and improvement of feedability, the present invention uses 16S rRNA gene high-throughput sequencing and metagenomic technology to deeply study the effects of feeding fermented distiller's grains on aquatic species, and improves the nutrient value of distiller's grains through secondary deep fermentation to improve its availability. Ultimately, it provides technical support for promoting the resource utilization of liquor distiller's grains and the green development of brewing enterprises, and provides new perspectives for optimizing feed formulas in the aquatic industry and improving the production efficiency of commercial fish.

[0022] The present invention performs secondary deep processing on distiller's grains and uses them as a protein source for aquatic feed. The nutrient content of distiller's grains fermented with composite bacteria at 26-34°C is significantly increased compared with unfermented distiller's grains, which is more conducive to the feed utilization of solid distiller's grains from liquor brewing. When the fermented distiller's grains prepared by the method of the present invention replace animal protein / fish meal at a level of 10%, the structure of zebrafish intestinal microbial community can be significantly improved, the number of probiotics can be increased, the abundance of pathogenic bacteria can be reduced, and the antioxidant capacity and disease resistance of zebrafish can be improved; intestinal microorganisms can positively affect the health of zebrafish by increasing the abundance of pathways involved in energy metabolism, antioxidant and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 To investigate the contents of SOD, GSH, T-AOC, ALS and AST in the intestine and muscle of zebrafish fed with fermented diets made from distiller's grains for aquaculture;

[0024] Figure 2 Species composition of zebrafish intestinal microorganisms at the phylum level (a) and genus level (b);

[0025] Figure 3 Abundance statistics of zebrafish intestinal microorganisms at the KEGG primary (a) and KEGG secondary (b) metabolic levels. DETAILED DESCRIPTION

[0026] The technical solution of the present invention can be specifically implemented in the following manner.

[0027] 1. Analysis of lees components

[0028] Compared with traditional plant proteins such as soybean meal, sorghum distiller's grains have lower anti-nutritional factor content and there is no "feed-grain competition". Solid distiller's grains from liquor brewing have the advantages of high usable components, high yield, low price, and few anti-nutritional factors, and can be used as a high-quality source of feed protein. Nutrients such as amino acids, vitamins and proteins contained in distiller's grains can meet the nutrient requirements of common commercial fish.

[0029] 2. Distillers grains fermented feed for aquaculture

[0030] 1. Preparation of fermented lees

[0031] The strain used in this example is commercial strain powder purchased from the China Industrial Microbiology Collection Center. The purchased Bacillus subtilis, Candida utilis and Lactobacillus casei were prepared into a bacterial solution, and then the bacterial solutions of equal mass were mixed to prepare a composite bacteria for standby use. Among them: the number of viable bacteria in the Bacillus subtilis bacterial solution is ≥ 1×10 8 cfu / g, the number of viable cells in the Candida utilis solution ≥ 1×10 8 cfu / g, the number of viable bacteria in Lactobacillus casei culture solution ≥ 1×10 8 cfu / g.

[0032] After removing the rice husk from the original lees through a 60-mesh sieve, the lees were crushed into uniform fine powder (particle size ≤ 0.5 mm) using a high-speed grinder and stored in a sealed bag for later use; 100 g of the treated lees were placed in a 250 ml conical flask and inoculated with 10 g of composite bacteria; the conical flask was sealed and placed in a constant temperature incubator for culture and fermentation, and fermented lees were obtained after the fermentation was completed. The fermentation temperature was set at 26°C (TA), 28°C (TB), 30°C (TC), 32°C (TD), and 34°C (TE), and the fermentation time was four days; a control group (UG) was set up without fermentation; and three parallel experiments were set up for each group of experiments.

[0033] 2. Analysis of nutrients in fermented distiller's grains

[0034] The components of the fermented lees obtained above were tested, and the basic nutrient content in the lees is shown in Table 1, and the content of different amino acids in the lees is shown in Table 2. The amino acid content was determined according to the GB / T 18246-2019 method; the crude protein content was determined according to the GB / T6432-2018 method; the ash content was determined according to the GB / T6438-2007 method; the crude fat content was determined according to the hydrochloric acid hydrolysis method and the GB / T6433-2006 method; the moisture content was determined according to the GB / T6435-2006 method; and the starch content was determined according to the enzymatic colorimetric method.

[0035] Table 1 Basic nutrient content in distiller's grains

[0036]

[0037] As shown in Table 1, the crude protein content of the TB group and the TE group was significantly higher than that of the unfermented group (P<0.05). The protein content in the TE group was the highest, which was 22.20% higher than that in the UG group. The crude fat content of the TB, TC, and TD groups was significantly higher than that in the UG group (P<0.05). Compared with the UG group, the crude fiber content in each fermentation group was significantly reduced. The TD group had the lowest crude fiber content, which was 27.15% lower than that in the UG group. The total amino acid content in the lees increased significantly after fermentation, and the TE group had the highest amino acid content, which was 21.71% higher than that in the UG group.

[0038] Table 2 Content of different amino acids in distiller's grains

[0039] As shown in Table 2, the contents of amino acids such as leucine, glutamic acid, aspartic acid, and histidine in the lees were significantly increased after fermentation under the conditions of composite bacteria. Compared with the UG group, the histidine content of the TE group increased by 36.36%, the lysine content increased by 33.33%, the valine content increased by 32.14, and the essential amino acid methionine content increased by 28.57%. Leucine had the highest content in the TB group, which increased by 23.61% compared with the UG group, and the TE group increased by 16.67% compared with the UG group.

[0040] In summary, adding composite bacteria to ferment increases the content of crude protein and various amino acids in the lees, and the fermentation effect is best at 34° C. Therefore, this example uses fermented lees obtained by fermentation at 34° C. for subsequent experiments.

[0041] 3. Application of distiller's grains fermented feed for aquaculture

[0042] 1. Experimental subjects

[0043] Adult wild-type zebrafish (AB, 34 months old) were purchased from the China Zebrafish Resource Center (Wuhan), with an initial body weight of 0.4±0.05g and a body length of 3.0±0.5cm. Before the experiment, the zebrafish were placed in a 65L glass fish tank for 7 days to ensure that the natural mortality rate was less than 5%. The air stone was connected to the blower to introduce air into the water to ensure that the dissolved oxygen in the water was close to saturation. Brine shrimp were fed at 8:00 and 16:00 every day until they were obviously full, and feces and food residues were cleaned up in time. During the experiment, the temperature of the zebrafish was kept within the range of 26±2℃, the pH was kept within the range of 7.4±0.4, and the photoperiod was 12h / 12h (light and dark).

[0044] 2. Specific experimental methods

[0045] Shelled brine shrimp was used as the basic feed for zebrafish, and 0% (control group), 10% (D10), 20% (D20), and 30% (D30) of fermented distiller's grains were added respectively to prepare four experimental feeds, which were stored in a refrigerator at minus 20 degrees Celsius for future use.

[0046] 360 domesticated zebrafish were randomly assigned to 12 5L fish tanks, 30 fish in each tank. The fish were fed a diet of 4.0% to 7.0% of their body weight, and the feeding was adjusted according to the number of fish. Feces, food residues and dead fish were removed immediately, and 2 / 3 of the water in the tank was replaced with dechlorinated tap water every two days to maintain stable water quality.

[0047] The experimental period was 21 days, and all fish were fasted for 24 hours before sampling. Eight fish were randomly selected from each fish tank, euthanized with frozen water, and samples were collected in a sterilized operating tray. The entire intestine was aseptically removed from the abdominal cavity, and the intestinal contents were gently scraped with tweezers and placed in a cryopreservation tube for later use. The zebrafish back muscles and the intestines without contents were also taken for biochemical index detection. After all samples were collected, they were stored in a -80℃ refrigerator.

[0048] 3. Result detection

[0049] Biochemical indicators including ALT, AST, SOD, GSH, and T-AOC were detected in the intestine and muscle of zebrafish. All indicators were detected using detection kits (Nanjing Jiancheng Bioengineering Institute, Jiangsu, China). For the analysis of intestinal microbiota composition, total DNA of intestinal samples was extracted using a commercial kit. Universal primers 515F (5'-GTGYCAGCMGCCGCGGTA-3') and 907R (5'-CCGTCAATTCMTTTRAGT-3') were used to amplify the V4-V5 hypervariable region of the microbial 16S rRNA gene. The PCR amplification conditions were 94℃ pre-denaturation for 3min, followed by 30 cycles of conventional amplification (94℃ denaturation for 40s, 56℃ annealing for 60s, and 72℃ extension for 60s), and finally 72℃ extension for 10min.

[0050] The PCR amplification products were sequenced using the Illumina Miseq sequencing platform to identify the microbial composition and relative abundance in the community. High-quality sequences were obtained after primer removal, shearing, quality filtering, and chimera removal. QIIME 1.9.0 software was used to perform OTUs (Operational Taxonomic Units) denovo division according to 97% sequence similarity, calculate the α-diversity index and weighted / unweighted UniFrac distance matrix, and perform PCoA sorting analysis. Species annotation was performed using the Ribosomal Database Project classifier method (Wang et al., 2007), and the prokaryotic reference database was greengenes gg_13_8 (http: / / qiime.org / home_static / dataFiles.html).

[0051] 3.1 Changes in biochemical indices and antioxidant activity in zebrafish

[0052] Effects of feeding aquaculture distiller's grains fermented feed on intestinal and muscle biochemical parameters of zebrafish Figure 1 Data are shown as standard deviation ± mean (n = 3), columns with different letters indicate values ​​with significant differences (P < 0.05), Figure 1 It can be seen that:

[0053] (1) Compared with the D0 group, the activities of SOD and GSH in the intestine of zebrafish in the D10 group increased, while those in the D20 and D30 groups decreased;

[0054] (2) The intestinal T-AOC activity of zebrafish fed with fermented diets made from distiller's grains for aquaculture decreased, and the T-AOC content of the D10 group was significantly higher than that of the other groups (P<0.05);

[0055] (3) The activities of ALT and AST in zebrafish muscle were significantly higher than those in the intestine. Compared with the D0 group, the activities of ALT and AST in the intestine increased with the increase of the content of fermented feed from distiller's grains for aquaculture in the fish feed. However, there were no significant differences in the activities of SOD, GSH, T-AOC, ALT and AST in the muscle (P>0.05).

[0056] The immune health of aquatic animals can be affected by plant protein, so it is important to check the health of zebrafish after feeding fermented feed with distiller's grains for aquaculture. SOD, GSH, and T-AOC are important indicators for evaluating the antioxidant capacity of individuals. The present invention found that compared with the D0 group, the antioxidant enzymes (SOD, GSH) in the intestines of zebrafish fed with a low level of fermented feed with distiller's grains for aquaculture were improved.

[0057] GSH is a scavenger of hydroxyl radicals and singlet oxygen, which minimizes the damage of free radicals to tissues and organs in a short time and protects animals from oxidative damage. In the present invention, the GSH activity of the D10 group is higher than that of the D0 group, while the GSH activity of the experimental group with a higher replacement level decreases. This shows that feeding a low level of fermented feed with distiller's grains for aquaculture improves the detoxification ability of zebrafish, and a high replacement level of fermented feed with distiller's grains for aquaculture increases free radicals in the body and consumes GSH in the body.

[0058] The level of total antioxidant capacity (T-AOC) can directly reflect the compensatory capacity of the enzymatic and non-enzymatic systems in response to external stimuli, and the metabolic state of free radicals can also reflect the strength of the body's overall antioxidant capacity. With the increase in the replacement level of fermented feed with distiller's grains for aquaculture, the content of T-AOC in the intestine gradually decreases, but the content of T-AOC in the muscle is not affected. This is because high levels of fermented feed with distiller's grains for aquaculture increase the burden on the intestine, which in turn causes damage to the antioxidant system in the intestine.

[0059] SOD is a cytoplasmic enzyme that protects the body from damage by removing peroxides. In this experiment, the SOD activity of the D10 group was higher than that of the D0 group. This shows that feeding fermented distillers grains feed for aquaculture can improve the antioxidant capacity of zebrafish and reduce oxidative damage by inducing an increase in SOD to neutralize the damage of oxidative stress. ALT and AST play an important role in the amino acid metabolism of aquatic animals and are indicators for predicting liver function and overall nutritional status. When liver cells are damaged, ALT and AST will be transferred to the blood. The study found that there was no significant difference in the activity of ALT and AST in the intestine of zebrafish in the D10 group compared with the D0 group, which shows that feeding fermented distillers grains feed for aquaculture will not affect the metabolic function of the liver and kidneys of zebrafish.

[0060] 3.2 Analysis of zebrafish intestinal microbial composition

[0061] The intestine is an important place for fish digestion, immune protection, hormone secretion, and regulation of water and mineral balance, and plays a key role in ensuring the health of fish. Intestinal flora participates in the process of biological nutrient harvesting, energy regulation, intestinal barrier and inflammation prevention. Therefore, maintaining a normal intestinal microbial community structure is crucial to the normal growth and development of fish.

[0062] A total of 61 phyla were detected at the phylum level, including four archaeal phyla and 57 bacterial phyla. Proteobacteria, Fusobacteria, Firmicutes, Actinobacteria, Bacteroidetes, Planctomycetes, Cyanobacteria, Tenericutes, and Nitrospirae were the dominant bacterial phyla in the zebrafish intestine. Figure 2 (a). Feeding aquaculture distiller's grains fermented feed reduced the relative abundance of Planctomycetes in the intestine of zebrafish and increased the relative abundance of Firmicutes, Cyanobacteria and Bacteroidetes. Compared with the D0 group, the Proteobacteria in the D10 and D30 groups decreased by 38.01% and 7.38%, respectively, while the D20 group increased by 23.96%. Fusobacteria increased by 133.25 and 37.62% in the D10 and D30 groups, respectively, but decreased by 94.82% in the D20 group. At the genus level, feeding aquaculture distiller's grains fermented feed increased the relative abundance of Lactococcus and Pseudomonas, Vagococcus, and Serratia. Compared with the control group, the relative abundance of Cetobacterium in the D10 and D30 groups increased significantly, and the abundance in the D20 group decreased. The relative abundance of Rhodobacter decreased in the D10 group and increased in the D20 and D30 groups.

[0063] The abundance of Proteobacteria in the D10 group decreased by 38%, and the abundance of Firmicutes increased by 28%, indicating that appropriate fermented feed with distiller's grains for aquaculture can improve the disease resistance of zebrafish and improve the intestinal barrier function. Cetobacterium uses polysaccharides and proteins as substrates and produces short-chain fatty acids for host absorption and utilization, which is considered to be beneficial bacteria in fish. The increase in the abundance of Cetobacterium in the D10 group indicates that fermented feed with distiller's grains for aquaculture can promote the digestion and absorption of protein and polysaccharides by zebrafish. Fusobacteria has a positive effect on fish health by participating in the metabolic process of vitamins and butyrate. Fusobacterium can produce butyrate, which is beneficial to the host and is considered to be a probiotic. The significant enrichment of these two bacteria in the D10 group also indicates that feeding fermented feed with distiller's grains for aquaculture is beneficial to zebrafish.

[0064] In summary, feeding 10% fermented distillers grains feed for aquaculture promoted the abundance of probiotics in the intestine of zebrafish, which is beneficial to the health of zebrafish.

[0065] 3.3 Analysis of zebrafish intestinal microbial metabolism

[0066] Considering that changes in the structure of intestinal microbial communities can affect intestinal function, PICRUSt2 was used to predict microbial metabolic functions based on the 16S rRNA gene annotated by the Kyoto Encyclopedia of Genes and Genomes (KEGG). In the intestinal content samples, a total of six metabolic pathways at the KEGG1 level and 47 metabolic pathways at the KEGG2 level were predicted. There were four metabolic groups at the KEGG1 level that showed significant differences between different treatments, including Environmental Information Processing, Genetic Information Processing, Metabolism, and Organic Systems. Among them, metabolism was the most abundant group, accounting for 70.75-73.69%. Compared with the D0 group, the relative abundance of metabolic pathways in the D10 group was significantly reduced, the relative abundance of organic systems and environmental information metabolism was significantly increased, and the metabolic abundance in the D20 group was significantly increased.

[0067] PICRUST analysis showed that in the secondary metabolism of the KEGG database, the addition of fermented distillers grains for aquaculture to the diet significantly changed the metabolic pathway pattern of zebrafish intestinal microorganisms, such as Figure 3 (a) As shown. Cofactors and vitamins, carbohydrate metabolism and amino acid metabolism are the main metabolic pathways. The relative abundance of metabolic pathways such as Immune disease, Carbohydrate metabolism, and Immune system increased significantly in the D10 group, and there was no significant difference between the D20 and D30 groups and the D0 group. Energy metabolism, Metabolism of cofactors and vitamins, Nucleotide metabolism, Folding, sorting and degradation increased significantly in D10, decreased significantly in D20, and had no significant difference in D30. Infectious disease: viral, Neurodegenerative disease, and Amino acid metabolism decreased significantly in the D0 group, and there was no significant change in the D20 and D30 groups. This shows that adding fermented feed from distiller's grains for aquaculture to the diet can significantly affect the function of zebrafish intestinal microorganisms.

[0068] To further determine the effect of the replacement level of fermented distillers grains feed for aquaculture on the metabolic function of zebrafish intestinal microorganisms, the KEGG tertiary metabolism of the intestinal microbial community was established, such as Figure 3(b) The results showed that the metabolic functions of the intestinal microbial community of zebrafish changed significantly after feeding with fermented feed of distiller's grains for aquaculture. The abundance of metabolic functions such as Phosphotransferase system (PTS), Sulfur relay system, Galactose metabolism, Inositol phosphate metabolism, One carbon pool by folate, and Thiamine metabolism increased significantly in the D10 group, decreased significantly in the D20 group, and had no significant changes in the D30 group.

[0069] The physiological effects of the gut microbiota on fish are driven by the interaction between the metabolism of the gut microbiota and the metabolism of the host. The present invention shows that the metabolic pathways in the gut flora of zebrafish are significantly changed after feeding aquaculture distiller's grains fermented feed. The relative abundance of phosphotransferase system (PTS), one carbon pool by folate and vitamin B6metabolism increased significantly in the D10 group. The physiological effects of the gut microbiota on fish are mediated by the interaction between the metabolic activities of the gut microbiota and the host metabolism. PTS plays an important role in catalyzing, transporting and phosphorylating various carbohydrates (including amino sugars, polyols and monosaccharides) to provide energy for the host. Dependence on one carbon pool by folate plays a key role in conferring antioxidant stress. In general, the addition of aquaculture distiller's grains fermented feed to the diet can enhance the intestinal health of zebrafish by regulating the intestinal flora. However, excessive amounts of fermented distiller's grains may have harmful effects.

[0070] In summary, the present invention limits the amount of fermented distiller's grains to replace animal protein (shelled brine shrimp) to 10% of the mass of the shelled brine shrimp; the feeding amount of the diet is 4.0% to 7.0% of the fish body weight. Feeding aquatic animals with fermented distiller's grains feed for aquaculture within the scope of the present invention can enhance the antioxidant capacity of fish and promote the health of intestinal microecology.

Claims

1. Aquaculture feed fermented with distiller's grains, characterized by: The composition thereof is 89-90% by mass of shelled brine shrimp and 10-11% by mass of fermented distiller's grains; The crude protein content of the fermented wine lees is 5.86% to 7.12%, the crude fat content is 0.36% to 0.74%, the crude fiber content is 2.68% to 4.33%, and the total amino acid content is 5.89% to 6.39%.

2. The fermented feed made from liquor lees for aquaculture according to claim 1, characterized in that: The method for preparing the fermented vinasse comprises the following steps: sieving the original vinasse to remove the rice husk and then crushing it, inoculating the treated vinasse with composite bacteria to perform closed fermentation, and obtaining the fermented vinasse.

3. The fermented feed made from liquor lees for aquaculture according to claim 2, characterized in that: The original distiller's grains are solid distiller's grains from liquor brewing, and the raw material thereof is sorghum, with a moisture content of 61.72-62.38%, a crude protein content of 5.56-5.72%, a crude fat content of 0.29-0.32%, a crude fiber content of 3.92-4.15%, and a total amino acid content of 5.25-5.59%.

4. The fermented feed made from liquor lees for aquaculture according to claim 2, characterized in that: The sieving is performed using a 60-mesh screen, and the crushing is performed using a high-speed crusher to crush the sieved original wine lees into a particle size of ≤0.5 mm.

5. The fermented feed made from liquor lees for aquaculture according to claim 2, characterized in that: The composite bacteria is a mixture of Candida utilis liquid, Bacillus subtilis liquid and Lactobacillus casei liquid in equal mass ratios.

6. The fermented feed made from liquor lees for aquaculture according to claim 5, characterized in that: The number of viable cells in the Candida utilis liquid is ≥ 1×10 8 cfu / g, the number of viable bacteria in Bacillus subtilis liquid ≥ 1×10 8 cfu / g, the number of viable bacteria in Lactobacillus casei culture solution ≥ 1×10 8 cfu / g.

7. The fermented feed made from liquor lees for aquaculture according to claim 2, characterized in that: The inoculation amount of the composite bacteria is 8% to 12% of the mass of the original lees.

8. The fermented feed made from liquor lees for aquaculture according to claim 1, characterized in that: The fermentation temperature is 26-34° C., and the fermentation time is 4-6 days.

9. Application of distiller's grains fermented feed for aquaculture, characterized by: The fermented distiller's grains feed for aquaculture according to any one of claims 1 to 8 is used as a fish farming diet and fed to enhance the fish's antioxidant capacity and promote the health of its intestinal microecology.

10. The use of distiller's grains fermented feed for aquaculture according to claim 9, characterized in that: The fish is zebrafish, and the feeding amount of the daily diet is 4.0% to 7.0% of the body weight of the zebrafish.

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