Solid-state fermentation process of mixed grains and mixed meal and feed thereof

Abstract

The application provides a kind of coarse grain, coarse solid fermentation process of bran and feed thereof, and belongs to the technical field of fermentation engineering.The technical scheme first grinds the raw material through a sieve, mixes uniformly according to the proportion, adds magnesium and iron trace elements to prepare a fermentation substrate after water supplementing and humidifying to 48%-52% and adding red sugar water activation;Strain is expanded to seed liquid in liquid tank;After spraying and mixing at a ratio of 5%-8%, the material layer is laid to a thickness of 30-50 cm for fermentation;Temperature is controlled in sections within 72 hours, and the pile is turned over at regular intervals;The environmental humidity is maintained at 90%-100%;After fermentation, the finished product is obtained by low-temperature hot air drying.The application converts polysaccharides that are difficult to absorb in coarse grains into small-molecule organic acids and monosaccharides, improving the absorption efficiency of livestock and poultry;At the same time, microorganisms can degrade various anti-nutritional toxins in the bran, reduce the content of free gossypol and isothiocyanate, remove the feeding restrictions of raw materials, improve the overall nutritional value, and improve the palatability of feed.The application not only makes full use of low-cost agricultural and sideline resources, but also solves the three defects of poor palatability, toxicity and low digestibility of raw materials.

Description

Technical Field

[0001] This invention relates to the field of fermentation engineering technology, specifically to a solid-state fermentation process for miscellaneous grains and oilseed meals and its feed. Background Technology

[0002] Coarse grains refer to various cereals and legumes other than the two staple grains, rice and wheat. These include millet, oats, buckwheat, sorghum, red beans, and mung beans, which are consumed daily by humans and are rich in dietary fiber and various trace elements. They are often eaten in combination with refined rice and flour. There are also feed grains specifically for livestock, such as aged corn, broken rice, lower-grade sorghum, and bran, which primarily provide carbohydrate energy for livestock. Feed grains are of lower quality and not suitable for long-term human consumption. Oilseed meals are primarily used as feed ingredients and are byproducts of oilseed processing rarely consumed by humans. The residue remaining after oil extraction from various oil crops is collectively called oilseed meal. This includes residues from single or less common oilseeds, or mixtures of residues, except for soybean meal. Common examples include cottonseed meal after cottonseed oil extraction, rapeseed meal, peanut meal, sunflower meal, and palm kernel meal, which can supplement the crude protein of farmed animals.

[0003] Currently, miscellaneous grains are mainly used for food consumption and feed processing. Domestic feed companies routinely adjust their formulas by adding imported feed barley and feed wheat flour to stabilize the price fluctuations of staple grain raw materials. Drought-resistant miscellaneous grains grown on some marginal lands are also supplied to the livestock industry, taking into account both the diversification of grains and the feed-saving needs of livestock. At present, the core application of miscellaneous oilseed meals is concentrated in feed protein substitution. With the full implementation of the Ministry of Agriculture and Rural Affairs' policy to reduce soybean meal, various miscellaneous oilseed meals such as rapeseed meal, cottonseed meal, peanut meal, and sunflower meal are distributed to different livestock sectors according to their categories. 60% of rapeseed meal goes to aquatic feed, cottonseed meal is more suitable for ruminants such as cattle and sheep, peanut meal is mostly used in pig diets, and sunflower meal is suitable for both ruminants and poultry. Large-scale feed mills improve the utilization rate of miscellaneous oilseed meals through amino acid balanced formulas and fermentation, extrusion, and detoxification processes.

[0004] When coarse grains are fed directly, their high crude fiber content makes them difficult for endogenous enzymes in the digestive tract of livestock and poultry to break down, resulting in low energy and nutrient absorption efficiency. Furthermore, anti-nutritional factors such as phytic acid and tannins can hinder the absorption of calcium, phosphorus, and trace elements, and inhibit protease activity, reducing overall feed utilization. Some aged or inferior coarse grains have poor palatability, leading to decreased feed intake. Long-term single-feeding can result in slow growth and dull coats. Excessive use can also dilute dietary protein levels, failing to meet the rapid growth needs of livestock and poultry. The defects of untreated oilseed meals are even more pronounced. Cottonseed meal contains free gossypol, which is sensitive to young poultry; excessive feeding can damage reproductive organs and affect growth and reproduction. Rapeseed meal contains isothiocyanates that decompose to produce toxic substances that damage thyroid function. Peanut meal is highly susceptible to aflatoxin contamination, posing a food safety risk. Most oilseed meals have an unbalanced amino acid profile, lacking lysine, leading to protein waste when used alone. Additionally, oilseed meals are high in crude fiber and lignin, resulting in a much lower digestibility and absorption rate than soybean meal. Direct addition can only be done in small amounts and cannot replace expensive soybean meal on a large scale. The raw materials of miscellaneous grains and oilseed meals do not contain beneficial live bacteria. Untreated feed cannot regulate the balance of intestinal flora when it enters the intestines, resulting in weak digestive function, frequent diarrhea and intestinal diseases, large nitrogen and phosphorus emissions in feces, heavy ammonia in the pens, and pollution of the breeding environment. The raw materials themselves are not palatable, resulting in low appetite and limited breeding production performance. They are also prone to moisture absorption and mold during storage, with a short shelf life, posing feeding safety risks. All of these factors increase the feed conversion ratio, increase breeding costs, and make it difficult to achieve low-cost and efficient utilization of miscellaneous grains and oilseed meals. Summary of the Invention

[0005] This invention aims to address the technical deficiencies of existing technologies by providing a solid-state fermentation process for miscellaneous grains and oilseed meals and their feed, thereby solving the technical problems of low digestibility and poor palatability of raw materials such as miscellaneous grains and oilseed meals as feed, which can easily cause intestinal and metabolic diseases in animals.

[0006] To achieve the above technical objectives, the present invention adopts the following technical solution: A solid-state fermentation process for miscellaneous grains and oilseed meals includes the following steps: 1) Grind the miscellaneous grains and meals separately to 20-40 mesh, sieve to remove large particles and impurities, and mix them evenly according to the following weight ratios: rapeseed meal 20%, peanut meal 20%, cottonseed meal 10%, wheat bran 10%, rice husk powder 10%, miscellaneous grain powder 20%, and rice bran 10%. Adjust the humidity to 48%-52% by spraying water, and add 0.1%-0.3% Mg. 2+ Fe 2+ Trace elements are used to obtain fermentation substrates; 2) Inoculate the freeze-dried bacterial powder into sterile brown sugar water, let it stand for 12-16 hours to activate, and test the bacterial concentration; if it is ≥10... 8 CFU / mL is ready for use; inoculate the bacterial culture into the liquid seed tank at a 5% inoculation rate and incubate at 32℃ for 18-24 hours to obtain the seed culture for production; 3) Spray the seed liquid obtained in step 2) onto the fermentation substrate at a rate of 5% to 8% of the total mass of the substrate in step 1), stirring while spraying; then spread the material evenly into the fermentation bed, controlling the thickness of the material layer to be 30 to 50 cm. 4) During the 0-24 hour period, maintain the ambient temperature at 28-32℃; during the 24-48 hour period, maintain the ambient temperature at 28-32℃, and turn the material pile once every 8-12 hours to control the material temperature below 40℃; during the 48-72 hour period, do not turn the material pile, and control the material temperature at 32-35℃ by adjusting the ambient temperature; during the 0-72 hour period, maintain the relative humidity of the fermentation environment at 90%-100%. 5) After fermentation, break up and spread out the material, and dry it with hot air at ≤60℃ (temperature ≤60℃) to reduce the moisture content of the finished product to below 12%.

[0007] Preferably, the mixed grain powder in step 1) contains the following ingredients by weight percentage: 13% oats, 13% millet, 24% yellow millet, 35% quinoa, and 15% soybeans.

[0008] Preferably, in step 1), the fermentation substrate further contains 0.2%~0.3% salt and 0.1%~0.2% Mn. 2+ And 0.1%~0.2% Zn 2+ .

[0009] Preferably, in step 1), the fermentation substrate also contains cellulase, protease and phytase.

[0010] As preferred options, the potencies of cellulase, protease, and phytase are as follows: cellulase 200~350U / g, protease 300~500U / g, and phytase 500~700U / g.

[0011] Preferably, the temperature of the sterile brown sugar water in step 2) is 36~38℃, and the mass concentration of brown sugar is 3%~4%.

[0012] Preferably, the freeze-dried bacterial powder in step 2) contains lactic acid bacteria, Bacillus, yeast, Clostridium butyricum, and Aspergillus oryzae, with a live bacteria ratio of 2:1:1:0.4:0.5.

[0013] Preferably, the Bacillus species include Bacillus subtilis, Bacillus licheniformis, Bacillus pumilus, and Bacillus orientalis.

[0014] Preferably, the freeze-dried bacterial powder also contains Saccharomyces cerevisiae, Lactobacillus acidophilus, and Pediococcus pentosaceus, wherein the ratio of the number of live bacteria of lactic acid bacteria to those of Saccharomyces cerevisiae, Lactobacillus acidophilus, and Pediococcus pentosaceus is 2:0.5:0.5:0.2.

[0015] Based on the above technical solutions, the present invention further provides a feed containing a product prepared by any of the above solid-state fermentation processes.

[0016] In the above technical solution, this invention first pre-treats the raw materials. Crushing and sieving refines the particle size, removes coarse impurities, and increases the specific surface area of ​​the materials. This facilitates uniform adhesion and penetration growth of the microorganisms, improving fermentation efficiency and avoiding problems such as insufficient fermentation and uneven product quality caused by large particles. Based on this, a blend of various grains and oilseed meals is added to compensate for the nutritional deficiencies of different raw materials, balance the carbon-nitrogen ratio of the substrate, enrich the nutrient system of the fermentation substrate, and provide sufficient and comprehensive nutritional support for microbial growth and metabolism. Simultaneously, precise control of material humidity adapts to the microbial growth environment of solid-state fermentation, ensuring microbial activity. The addition of trace elements such as magnesium and iron acts as activators for microbial enzymes, promoting microbial proliferation and metabolism, effectively improving fermentation results and laying the foundation for subsequent full-process fermentation.

[0017] In step 2), most of the strains in the freeze-dried bacterial powder are in a dormant state. Sterile brown sugar water provides the carbon source, and after standing for 12-16 hours, dormancy is broken, allowing lactic acid bacteria, Bacillus, yeast, Clostridium butyricum, and Aspergillus oryzae to regain their physiological activity. Simultaneously, a strictly controlled sterile environment is maintained to avoid contamination by other microorganisms. After activation, the concentration of live bacteria in the bacterial solution reaches the standard, ensuring bacterial viability. Based on this, a 5% inoculum is transferred to a liquid seed tank for constant-temperature expansion, significantly increasing the total number of live bacteria to meet the subsequent inoculation requirements of large quantities of solid substrate. A fixed culture condition of 32℃ and 18-24 hours is maintained to adapt to the synergistic growth of the compound bacterial strains, ensuring the synchronous growth of various Bacillus species such as Bacillus subtilis and lichens with lactic acid bacteria and fungi, and maintaining the set live bacteria ratio. The liquid seed solution is evenly dispersed, allowing it to adhere evenly to the substrate of miscellaneous grains and meals during subsequent spraying and mixing, thus avoiding insufficient local bacterial count. The microbial community is pre-adapted to the liquid nutrient environment, enabling it to quickly colonize and reproduce after being introduced into solid materials, shortening the solid fermentation start-up cycle, improving the degradation efficiency of substrate protein and fiber, and enhancing the ability to inhibit miscellaneous bacteria in the early stage of fermentation.

[0018] In step 3), spray the seed liquid at a ratio of 5% to 8% and simultaneously stir to ensure the live bacteria liquid adheres evenly to the surface of the grain and meal substrate particles. This prevents excessively high local bacterial concentrations or blank areas lacking inoculum, laying the foundation for subsequent simultaneous fermentation and preventing uneven fermentation rates and significant differences in the degree of decomposition. Construct a suitable fermentation bed environment: Spread the material into a 30-50cm thick fermentation bed. This thickness provides stable heat retention and moisture control, maintaining the necessary humidity and temperature for fermentation while allowing adequate ventilation space for subsequent turning and temperature control. This avoids insufficient insulation due to a thin bed or excessive heat buildup due to oxygen deficiency, meeting the requirements of 72-hour segmented temperature-controlled fermentation. Standardize the initial fermentation state of the material: Stirring and mixing breaks up material clumps, allowing the substrate moisture, trace elements, and inoculum to fully integrate. A uniformly spread material bed facilitates even distribution of temperature, humidity, and oxygen during fermentation, reducing localized anaerobic conditions, dry spots, wet clumps, and other fermentation defects, thus improving the overall fermentation conversion rate.

[0019] During fermentation, temperature is controlled in stages and the material is turned regularly to precisely regulate the temperature. In the early stage, a stable and suitable temperature for microbial proliferation is maintained. In the middle stage, turning the material dissipates heat to prevent excessive temperature from inhibiting microbial activity. In the later stage, the material is left to stand still to maintain a stable fermentation temperature, ensuring continuous microbial metabolism. A high-humidity environment is maintained throughout to lock in moisture and prevent the substrate from drying out, ensuring the necessary water environment for normal microbial growth and reproduction. Aeration and fermentation rhythm are managed in stages and with differentiation. From 0-48 hours, regular turning replenishes oxygen to meet the needs of aerobic fermentation. From 48-72 hours, the material is left to stand still to reduce aeration, stabilizing the later stages of conversion, balancing the fermentation process, and improving substrate decomposition and fermentation product accumulation.

[0020] After fermentation is complete, the material is broken up and spread out to remove any fermentation clumps, increasing the surface area exposed to heat and facilitating rapid drying. Low-temperature hot air drying at temperatures below 60℃ is used to avoid damaging the active bacteria, enzymes, and nutrients generated during fermentation. The moisture content of the finished product is reduced to below 12%, inhibiting the growth of unwanted bacteria, extending the shelf life of the finished product, and facilitating storage and transportation.

[0021] This invention provides a solid-state fermentation process for coarse grains and their byproducts, and the resulting feed. Coarse grains are inherently high in fiber and anti-nutritional factors, while coarse meals generally contain harmful substances such as gossypol, sinigrin, and phytic acid, resulting in low digestibility when directly fed. The solid-state fermentation process of this invention relies on the growth and metabolism of microorganisms on a solid substrate, eliminating the need for large amounts of liquid, thus lowering processing costs and making it compatible with conventional feed mill equipment. During fermentation, the microorganisms decompose coarse fiber and convert the difficult-to-absorb polysaccharides in the coarse grains into small-molecule organic acids and monosaccharides, improving the absorption efficiency of energy sources by livestock and poultry. Simultaneously, the microorganisms degrade various anti-nutritional toxins in the coarse meals, reducing the content of free gossypol and isothiocyanates, removing feeding restrictions, significantly increasing the proportion of coarse meals that can be added, and reducing the use of expensive soybean meal. Fermentation also generates a large amount of microbial protein, amino acids, vitamins, and active probiotics, compensating for the deficiencies in protein in coarse grains and the imbalance of amino acids in coarse meals, improving the overall nutritional value of the feed. Organic acids can improve feed palatability, stimulate livestock and poultry feeding, reduce ammonia emissions from feces, and alleviate odor pollution in farms.

[0022] The solid-state fermentation process of this invention allows for controllable moisture content throughout. After fermentation, the drying energy consumption is far lower than that of liquid fermentation. The finished product is less prone to mold growth during storage. The fermented mixed grains and meals do not require complex purification and can be directly mixed into compound feed. It is suitable for various animal feeds such as pigs, poultry, aquatic animals, and ruminants. It not only fully utilizes low-cost agricultural by-products such as mixed grains and meals, but also solves the three major defects of raw materials: poor palatability, toxicity, and low digestibility. This meets the industry demand for feed cost reduction and replacement of imported protein raw materials. Attached Figure Description

[0023] Figure 1 These are the performance testing indicators for each embodiment and comparative example in the specific implementation of this invention. Detailed Implementation

[0024] The specific embodiments of the present invention will be described in detail below. To avoid excessive and unnecessary detail, well-known structures or functions will not be described in detail in the following embodiments. The approximate language used in the following embodiments is for quantitative purposes, indicating that a certain degree of variation in quantity is permissible without changing the basic function. Unless otherwise defined, the technical and scientific terms used in the following embodiments have the same meaning as commonly understood by those skilled in the art to which this invention pertains.

[0025] Example 1 A solid-state fermentation process for miscellaneous grains and oilseed meals includes the following steps: I. Detailed Preparations Beforehand Raw material pretreatment Grind the mixed grains and meal separately to 20-40 mesh, sieve to remove large particles and impurities, and mix them evenly according to the target formula (20% rapeseed meal, 20% peanut meal, 10% cottonseed meal, 10% wheat bran, 10% rice husk powder, 20% mixed grain powder, and 10% rice bran). Test the initial moisture content and adjust it precisely to 48%-52% by spraying water to replenish moisture, while adding 0.1%-0.3% Mg. 2 +, Fe 2 Trace elements provide the nutrients needed for microbial growth.

[0026] Stepwise propagation of bacterial strains Primary activation: Inoculate the freeze-dried bacterial powder into sterile brown sugar water (3% concentration) at 37℃, allow to stand for 12-16 hours for activation, and test the bacterial concentration to be ≥10. 8 CFU / mL; Secondary expansion culture: Inoculate the activated bacterial solution into the liquid seed tank at an inoculation rate of 5%, and incubate at a constant temperature of 32℃ for 18-24 hours to obtain a well-mixed seed solution for production, ensuring that the live bacteria ratio of lactic acid bacteria, Bacillus, yeast, Clostridium butyricum, and Aspergillus oryzae is 2:1:1:0.4:0.5.

[0027] II. Precise Control of Fermentation Process Inoculation fabric Spray the seed liquid evenly into the mixed raw materials at a ratio of 5% to 8% of the total mass of the materials, stirring constantly while spraying to ensure that the materials and the bacterial liquid are in complete contact without any dead corners. Then spread the materials evenly into the fermentation bed, controlling the thickness of the material layer to 30 to 50 cm. If it is too thick, it will easily accumulate heat and cause overheating; if it is too thin, it will not retain enough heat and fermentation will be incomplete.

[0028] Phased temperature control Fermentation 0~24 hours: Maintain an ambient temperature of 30℃ to allow the microorganisms to quickly colonize and multiply, and the material temperature will naturally rise to about 35℃; Fermentation time 24~48 hours: The peak temperature of the material is likely to exceed 50℃. It is necessary to turn the pile every 12 hours and strictly control the temperature of the material below 40℃ to avoid high temperature causing the inactivation of the inoculum and the deterioration of the material. Fermentation for 48-72 hours: Maintain the material temperature at 32-35℃ to allow microorganisms to fully metabolize and degrade anti-nutritional factors. During this stage, frequent turning of the pile is not necessary to ensure a micro-aerobic environment.

[0029] Environmental control The relative humidity in the fermentation workshop should be maintained at 90%~100%. People should avoid entering and leaving the workshop unless necessary to reduce the introduction of bacteria by personnel. If cement / metal fermentation tanks are used, breathable non-woven fabric should be laid on the inner wall of the tank to prevent condensation from accumulating and causing localized high moisture content and spoilage of the materials.

[0030] III. Post-processing and Finished Product Quality Inspection Discharge drying Immediately after fermentation, the material is broken up and spread out, and then dried with low-temperature hot air (temperature ≤60℃) to reduce the moisture content of the finished product to below 12%, thus avoiding high temperature damage to the active probiotics and small peptides in the material.

[0031] Indicator Testing Qualified fermented products must meet the following requirements: total acid content ≥3.4%, lactic acid content ≥3.2%, free gossypol degradation rate ≥80% and glucosinolate degradation rate ≥35% in the meal, crude protein content increased by more than 8% compared with the raw materials, no mold or putrid odor, and after passing the test, they should be sealed in packaging and stored in a cool and dry place.

[0032] The performance and feeding effect of this embodiment will be examined through experimental methods.

[0033] I. Pre-experimental preparation Instrument and Consumable Calibration Beforehand, preheat and zero-point calibrate the core equipment such as the Kjeldahl nitrogen analyzer, UV spectrophotometer, and HPLC. Prepare the corresponding standards and reagents. Autoclave all glassware at 121°C for 20 minutes and dry them for later use to avoid contamination by other microorganisms that could affect the viable cell count results.

[0034] Sample grouping settings The fermentation products were set up as 3 parallel experimental groups, and an unfermented raw mixed grain and meal raw material was set up as a blank control group. 500g of each sample was taken and divided into 2 parts after being reduced by quartering. One part was used for fresh sample index detection, and the other part was sealed and stored at 4℃ for retesting.

[0035] II. Sensory and Physicochemical Indicators Sensory quantitative assessment A five-person evaluation panel was formed to score the fermentation products based on four dimensions: color (20 points), odor (40 points), texture (20 points), and impurities (20 points). A total score of ≥80 points was considered a qualified fermentation product, thus avoiding judgment based solely on subjective experience.

[0036] Crude protein determination Accurately weigh 0.5g of the dried and pulverized sample, add catalyst and concentrated sulfuric acid, digest at 420℃ for 2 hours until the solution is clear, cool and complete the distillation titration on a Kjeldahl nitrogen analyzer. Perform 3 parallel samples for each sample, and control the relative deviation to ≤0.5%. Finally, calculate the crude protein enhancement rate after converting to dry basis.

[0037] Moisture and pH retesting Moisture content was determined using the 105℃ constant weight method. The constant weight was defined as the weight difference between two drying cycles ≤ 0.002g. For pH testing, fresh samples were extracted at a material-to-water ratio of 1:10 for 30 minutes, with stirring every 10 minutes. The supernatant was taken and the pH was read using a calibrated pH meter to ensure that the data error was ≤ 0.1.

[0038] III. Core Functional Indicators Quantitative detection of anti-nutritional factors Free gossypol: The sample was extracted with 70% acetone solution for 1 hour, filtered, and then measured at 435 nm wavelength using a UV spectrophotometer. The content was calculated by substituting the sample into the standard curve, and the free gossypol removal rate was finally obtained. Glucosides: High performance liquid chromatography was used. After purification by ion exchange column, glucosinolates were detected by the instrument and quantified by external standard method. The degradation rate of glucosinolates was calculated.

[0039] Precise counting of active substances Small peptide content: The sample was extracted with 15% trichloroacetic acid solution at a material-to-water ratio of 1:20. After centrifugation, the supernatant was taken and the acid-soluble protein content was determined by the Folin-Ciocalteu method. The proportion of small peptides in the total protein was calculated. Probiotic viable count: Fresh samples were serially diluted 10-fold, and three suitable dilutions were selected. The samples were then spread onto the corresponding selective culture media for lactic acid bacteria, Bacillus, and yeast, respectively. After incubation at 37°C for 48 hours, the counts were performed, and the total number of viable bacteria per gram of sample was calculated.

[0040] IV. Safety and Feeding Validation Health and safety indicator testing Aflatoxin B1 was detected using an ELISA kit, and volatile basic nitrogen was determined using a semi-micro nitrogen determination method to ensure that the product was free from spoilage and toxins exceeding the standard, and met the feed hygiene standards.

[0041] Animal feeding trial control Eighteen healthy weaned piglets of similar weight were randomly divided into three groups, with six replicates in each group. The pre-trial period was seven days, and the formal trial period was 28 days. During this period, the piglets had free access to feed and water, and their daily feed intake was recorded. After the trial, the piglets were weighed to calculate the average daily weight gain and feed conversion ratio. At the same time, fecal samples were collected to determine the apparent digestibility of crude protein. Finally, the actual feed performance of the fermentation products was verified.

[0042] V. Experimental Results Sensory and conventional physicochemical results The fermentation product is uniformly light yellowish-brown with a rich, sweet and sour fermented aroma and no musty or off-odors. The dry-basis crude protein content increased from the initial 36.2% to 42.1%, an increase of 16.3%, and the final moisture content stabilized at 11.2%, with a pH value of 4.7, meeting the basic requirements for high-quality fermented feed.

[0043] Core functional indicator results The total number of live probiotics in the product reached 2.3 × 10⁻⁶. 9 CFU / g, the proportion of small peptides in total protein increased from 8.7% before fermentation to 32.5%; in terms of anti-nutritional factors, the degradation rate of free gossypol reached 82.7%, and the degradation rate of isothiocyanate reached 71.2%, which are far below the feed safety limit standards.

[0044] Feeding application results In a 28-day feeding trial of weaned piglets, the experimental group with 15% of this fermentation product showed an average daily weight gain of 12.4% higher than the control group, a feed conversion ratio of 8.1% lower, an apparent digestibility of crude protein of 9.6% higher, and a diarrhea rate of 3.7% lower than 11.3%. At the same time, the activity of glutathione peroxidase in muscle was significantly increased, and the antioxidant capacity was significantly better than that of the ordinary diet group.

[0045] Example 2 Based on the technical solution of Example 1, the following conditions are further specified: the mixed grain powder in step 1) contains the following components by weight percentage: oats 13%, millet 13%, yellow millet 24%, quinoa 35%, and soybeans 15%. In step 1), the fermentation substrate also contains 0.2%~0.3% salt and 0.1%~0.2% manganese. 2+ And 0.1%~0.2% Zn 2+ In step 1), the fermentation substrate also contains cellulase, protease, and phytase, with potencies of 200-350 U / g for cellulase, 300-500 U / g for protease, and 500-700 U / g for phytase. In step 2), the freeze-dried bacterial powder contains lactic acid bacteria, Bacillus, yeast, Clostridium butyricum, Aspergillus oryzae, Saccharomyces cerevisiae, Lactobacillus acidophilus, and Pediococcus pentosaceus, with a live bacteria ratio of 2:1:1:0.4:0.5:0.5:0.5:0.2. The Bacillus includes Bacillus subtilis, Bacillus licheniformis, Bacillus pumilus, and Bacillus orientalis.

[0046] The performance indicators of the product in this example were tested using the same method as in Example 1, and the results are as follows: the dry basis crude protein increase rate reached 18.9%, small peptides accounted for 35.2% of the total protein, the free gossypol degradation rate reached 83.6%, the isothiocyanate degradation rate reached 77.3%, the average daily weight gain increase rate was 12.2%, and the piglet diarrhea rate was 2.4%.

[0047] Comparative Example 1 A solid-state fermentation process for miscellaneous grains and oilseed meals includes the following steps: One loopful of *Bacillus natto* colonies is picked from an agar slant and transferred to a 250ml Erlenmeyer flask containing 100ml of glucose-beef extract peptone liquid medium. The flask is then placed on a shaker at 37℃ and 160r / min for 12h (6-24h is acceptable). The bacterial culture is centrifuged to remove the supernatant, and the bacterial cells are collected. The collected bacterial cells are washed with sterile physiological saline and centrifuged again. This washing and centrifugation process is repeated three times to obtain washed and centrifuged bacterial cells. The washed and centrifuged bacterial cells are resuspended in sterile physiological saline at a volume ratio of 1g:200mL to obtain a bacterial content of 10%. 12 The bacterial solution was prepared by mixing the bacterial solution with sterilized sodium alginate solution at a volume ratio of 1:2 and stirring thoroughly. The mixture was then injected into cooled CaCl2 solution at a volume ratio of 1:8, and allowed to solidify for 60 minutes. After solidification, the mixture was washed three times with sterile physiological saline to obtain microcapsule bacterial agent. The concentration of the sodium alginate solution was 10% (w / v), and the concentration of the calcium chloride solution was 10% (w / v). The amount of microencapsulated bacterial agent added was 0.1% of the weight of oilseed cake, and the amount of water added was 20% of the total weight of oilseed cake and water. The microencapsulated bacterial agent, oilseed cake and water were mixed evenly and allowed to ferment at room temperature for 24 hours (solid-state fermentation) to obtain the fermentation product. The oilseed cake was dehulled and cold-pressed rapeseed meal. After fermentation, the fermentation product was dried at 50°C to maintain the moisture content of the dried product at 10%.

[0048] The performance indicators of the product in this example were tested using the same method as in Example 1, and the results are as follows: the dry basis crude protein increase rate reached 11.4%, the proportion of small peptides in the total protein was 22.1%, the free gossypol degradation rate reached 56.3%, the isothiocyanate degradation rate reached 38.0%, the average daily weight gain increase rate was 8.8%, and the piglet diarrhea rate was 7.6%.

[0049] Comparative Example 2 A solid-state fermentation process for miscellaneous grains and meals includes the following steps: Adding 5% microecological preparation, 8% corn flour, 8% wheat bran, 5% brown sugar, and 35% water to the raw materials soybean meal, cottonseed meal, and rapeseed meal, and stirring evenly to obtain a mixture, wherein the sum of the mass percentages of each material in the mixture is 100%; using a compound bacterial solution of *Lactobacillus plantarum*, yeast, and *Bifidobacterium*: *Lactobacillus plantarum* ≥ 1 × 10⁻⁶ 8 CFU / mL, yeast ≥0.2×10⁻⁶ 8 cfu / mL, Bifidobacteria ≥1×10 8CFU / mL; The bacterial culture was mixed into the mixture, and then the material was evenly spread into the fermentation bed. The fermentation conditions were: fermentation temperature 30-36℃, seed culture addition amount 5.08×10⁻⁶. 6 cfu / g, material-to-water ratio 1:0.5-0.7, fermentation time 4-6 days.

[0050] The performance indicators of the product in this example were tested using the same method as in Example 1, and the results are as follows: the dry basis crude protein increase rate reached 10.1%, small peptides accounted for 26.5% of the total protein, the free gossypol degradation rate reached 61.1%, the isothiocyanate degradation rate reached 40.2%, the average daily weight gain increase rate was 9.5%, and the piglet diarrhea rate was 4.9%.

[0051] The embodiments of the present invention have been described in detail above, but the content described is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the scope of the present invention should be included within the protection scope of the present invention.

Claims

1. A solid-state fermentation process for miscellaneous grains and oilseed meals, characterized in that, Includes the following steps: 1) Grind the miscellaneous grains and meals separately to 20-40 mesh, sieve to remove large particles and impurities, and mix them evenly according to the following weight ratios: rapeseed meal 20%, peanut meal 20%, cottonseed meal 10%, wheat bran 10%, rice husk powder 10%, miscellaneous grain powder 20%, and rice bran 10%. Adjust the humidity to 48%-52% by spraying water, and add 0.1%-0.3% Mg. 2+ Fe 2+ Trace elements are used to obtain fermentation substrates; 2) Inoculate the freeze-dried bacterial powder into sterile brown sugar water, let it stand for 12-16 hours to activate, and test the bacterial concentration; if it is ≥10... 8 CFU / mL is ready for use; inoculate the bacterial culture into the liquid seed tank at a 5% inoculation rate and incubate at 32℃ for 18-24 hours to obtain the seed culture for production; 3) Spray the seed liquid obtained in step 2) onto the fermentation substrate at a rate of 5% to 8% of the total mass of the substrate in step 1), stirring while spraying; then spread the material evenly into the fermentation bed, controlling the thickness of the material layer to be 30 to 50 cm. 4) During the 0-24 hour period, maintain the ambient temperature at 28-32℃; during the 24-48 hour period, maintain the ambient temperature at 28-32℃, and turn the material pile once every 8-12 hours to control the material temperature below 40℃; during the 48-72 hour period, do not turn the material pile, and control the material temperature at 32-35℃ by adjusting the ambient temperature; during the 0-72 hour period, maintain the relative humidity of the fermentation environment at 90%-100%. 5) After fermentation, break up and spread out the material, and dry it with hot air at ≤60℃ (temperature ≤60℃) to reduce the moisture content of the finished product to below 12%.

2. The solid-state fermentation process for miscellaneous grains and oilseed meals according to claim 1, characterized in that, The mixed grain powder mentioned in step 1) contains the following ingredients by weight percentage: oats 13%, millet 13%, yellow millet 24%, quinoa 35%, and soybeans 15%.

3. The solid-state fermentation process for miscellaneous grains and oilseed meals according to claim 1, characterized in that, In step 1), the fermentation substrate also contains 0.2%~0.3% salt and 0.1%~0.2% Mn. 2+ And 0.1%~0.2% Zn 2+ .

4. The solid-state fermentation process for miscellaneous grains and oilseed meals according to claim 1, characterized in that, In step 1), cellulase, protease and phytase are also added to the fermentation substrate.

5. The solid-state fermentation process for miscellaneous grains and oilseed meals according to claim 4, characterized in that, The potencies of cellulase, protease, and phytase are as follows: cellulase 200~350U / g, protease 300~500U / g, and phytase 500~700U / g.

6. The solid-state fermentation process for miscellaneous grains and oilseed meals according to claim 1, characterized in that, The temperature of the sterile brown sugar water in step 2) is 36~38℃, and the mass concentration of brown sugar is 3%~4%.

7. The solid-state fermentation process for miscellaneous grains and oilseed meals according to claim 1, characterized in that, The freeze-dried bacterial powder described in step 2) contains lactic acid bacteria, Bacillus, yeast, Clostridium butyricum, and Aspergillus oryzae, with a live bacteria ratio of 2:1:1:0.4:0.

5.

8. The solid-state fermentation process for miscellaneous grains and oilseed meals according to claim 7, characterized in that, The Bacillus species include Bacillus subtilis, Bacillus licheniformis, Bacillus pumilus, and Bacillus orientalis.

9. The solid-state fermentation process for miscellaneous grains and oilseed meals according to claim 7, characterized in that, The freeze-dried bacterial powder also contains Saccharomyces cerevisiae, Lactobacillus acidophilus, and Pediococcus pentosaceus, wherein the ratio of the number of live bacteria of lactic acid bacteria to Saccharomyces cerevisiae, Lactobacillus acidophilus, and Pediococcus pentosaceus is 2:0.5:0.5:0.

2.

10. A feed, characterized in that, The feed contains the product prepared by any one of the solid-state fermentation processes according to claims 1 to 9.

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