Compound microbial fermentation inoculant, fermented feed and preparation method of compound microbial fermentation inoculant

Abstract

The preparation method of the fermented feed comprises the following steps: treating bagasse with an acetic acid solution to obtain a to-be-fermented solution, uniformly mixing the to-be-fermented solution, a nitrogen source, a carbon source and the compound microbial fermentation inoculant, and fermenting to obtain the fermented feed, the nitrogen source comprises corn flour, wheat bran and soybean meal; the compound microbial fermentation agent comprises aspergillus aculeatus, pichia pastoris and bacillus amyloliquefaciens. Compared with the prior art, the bagasse is crushed and then fermented with the soybean meal and the wheat to obtain the compound fermentation product, the compound fermentation product, the corn flour and the auxiliary materials are mixed and granulated to obtain the fermented feed, and the fermented feed is low in beta-glucan content, soybean agglutinin content and phytic acid content and good in feed conversion efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of feed preparation, and in particular to a composite microbial fermentation agent, fermented feed and a preparation method thereof. Background Art

[0002] Guangxi has a large market demand for pork, so the scale of pig farming and feed demand is large. Different stages of pig age require feed with different nutrients, and the fattening stage consumes the most feed. Currently, the pig fattening feed on the market is mainly "corn-wheat-soybean meal" type feed, but the feed conversion rate of "corn-wheat-soybean meal" type feed is low, and the defecation volume is small. It needs to drink more water or the stool will be dry. The reasons may be as follows:

[0003] First, wheat contains more acidified phenolic substances such as ferulic acid, p-coumaric acid, syringic acid, p-hydroxybenzoic acid and vanillic acid, as well as non-acidified anti-nutritional factors such as pentosan, arabinoxylan and β-glucan. These ingredients have high viscosity or irritate the gastrointestinal mucosa during metabolism, stimulate intestinal motility, affect intestinal microflora, and cause gastrointestinal indigestion, poor gastrointestinal absorption and digestion of feed;

[0004] Second, soybean meal contains a variety of anti-nutritional factors such as urease, soybean agglutinin, phytic acid and trypsin inhibitor, which affect the intestinal digestion and absorption of protein and nutrients in poultry and livestock. Although the feed consumption is large, the gastrointestinal digestion and absorption are poor, resulting in reduced bowel movements.

[0005] Bagasse contains nutrients such as fiber, lignin, protein, starch and soluble sugar, and can be used as one of the raw materials for preparing poultry and livestock feed. However, due to its rough texture, if it is not handled properly or added in excessive amounts, it will result in a hard texture and poor palatability as a feed, causing pigs to eat less or no feed, resulting in feed waste and weight loss. Summary of the invention

[0006] The object of the present invention is to provide a composite microbial fermentation agent, which is intended to reduce the anti-nutritional factors of wheat and soybeans and degrade a part of cellulose, hemicellulose and lignin in sugarcane bagasse.

[0007] The present invention also aims to provide a method for preparing a fermented feed, aiming to improve the fermentation efficiency and effect of the composite fermentation bacteria, increase the metabolizable sugars in the fermented feed, and improve the palatability of the fermented feed.

[0008] The present invention also aims to provide a fermented feed, aiming to improve the feed conversion efficiency of traditional fattening pig feed.

[0009] To achieve the above object, the present invention provides a method for preparing a fermented feed, and the preparation method is as follows:

[0010] Treating bagasse crushed with acetic acid solution to obtain a solution to be fermented, mixing the solution to be fermented with a nitrogen source, a bacterial agent growth promoter and a composite microbial fermentation agent to obtain a composite fermentation product, mixing the composite fermentation product, corn flour and auxiliary materials according to a preset ratio, granulating and drying to obtain a fermented feed;

[0011] The nitrogen source includes wheat and soybean meal;

[0012] The composite microbial fermentation agent is composed of Aspergillus aculeatus, Pichia pastoris and Bacillus amyloliquefaciens;

[0013] The auxiliary materials include sodium alginate, sodium chloride, calcium dihydrogen phosphate and gelatin.

[0014] Preferably, in the above technical solution, in the step of treating the bagasse crushed with acetic acid solution to obtain the solution to be fermented, the method for obtaining the solution to be fermented is specifically to mix the bagasse crushed with 50-55% acetic acid solution in a ratio of 1-2:10-15, and react at a pressure of 0.05-0.1mPa and a temperature of 70-100°C for 1-3h to obtain the solution to be fermented.

[0015] Preferably, in the above technical solution, the raw materials of the composite microbial fermentation agent are Aspergillus aculeatus, Pichia pastoris and Bacillus amyloliquefaciens in a weight ratio of 2-3:1-2:1-2.

[0016] Preferably, in the above technical solution, in the step of mixing the solution to be fermented with the nitrogen source, the bacterial agent growth promoter and the composite microbial fermentation bacterial agent to obtain the composite fermentation product, specifically:

[0017] The bacterial agent growth promoter and the composite microbial fermentation bacterial agent are dissolved in the solution to be fermented, mixed, and then a nitrogen source is added to obtain a low-moisture fermentation product, and the composite fermentation product is obtained by fermentation under preset fermentation conditions; wherein the mass ratio of the solution to be fermented: the nitrogen source: the bacterial agent growth promoter is 2:4-6:0.5-1, and the added amount of the composite microbial fermentation bacterial agent accounts for 0.1-0.5% of the nitrogen source.

[0018] Preferably, in the above technical solution, the preset fermentation conditions are as follows: fermentation temperature is 25-30°C, pH value is 5.0-6.5, oxygen flow rate is 0.25-1L / min, and stirring interval time is set to 60-360min.

[0019] Preferably, in the above technical solution, the bacterial agent growth promoter includes inorganic salts and growth factors, the inorganic salts are magnesium sulfate, zinc sulfate, calcium hydrogen phosphate, and calcium chloride, and the growth factors are glycerol, vitamin A, vitamin B6, niacin and betaine.

[0020] Preferably, in the above technical solution, every 1000g of bacterial agent growth promoter includes: 152-190g magnesium sulfate, 155-180g zinc sulfate, 500-600g calcium hydrogen phosphate, 80-98g calcium chloride, 10-20g glycerol, 1-5g vitamin A, 1-5g vitamin B6, 0.5-1g niacin and 0.5-1g betaine.

[0021] Preferably, in the above technical solution, in the step of mixing the composite fermentation product, corn flour and auxiliary materials according to a preset ratio, by mass percentage, the composite fermentation product is 20%-35%, the corn flour is 55%-65%, and the auxiliary materials are 10-20%.

[0022] A fermented feed prepared by the method for preparing fermented feed as described above, wherein the phytic acid content of the fermented feed is 0.15-0.18 mg / mL, the soybean lectin content of the fermented feed is less than 0.03 mg / mL, and the β-glucan content of the fermented feed is less than 10 mg / mL.

[0023] A composite microbial fermentation agent as described above, wherein the components of the composite microbial fermentation agent are made of Aspergillus aculeatus, Pichia pastoris and Bacillus amyloliquefaciens in a weight ratio of 2-3:1-2:1-2.

[0024] Compared with the prior art, the method of the present invention has the following beneficial technical effects:

[0025] (1) Acetic acid solution has the best effect on destroying the molecular functional groups and intermolecular chemical bonds of lignin, cellulose, and hemicellulose in sugarcane bagasse at 80-90℃. The intermolecular connections are weakened and the structure is relatively loose, which is more conducive to the bacterial and enzymatic hydrolysis of the composite microbial fermentation agent to obtain fermented sugarcane bagasse with a moderate crude fiber content.

[0026] (2) Aspergillus aculeatus, Pichia pastoris and Bacillus amyloliquefaciens rapidly multiply and secrete enzyme systems under suitable temperature and oxygen conditions, and perform bacterial and enzymatic hydrolysis of bagasse, wheat and soybean meal, thereby increasing the metabolizable sugars in the composite fermentation product.

[0027] (3) The anti-nutritional factors such as β-glucan, phytic acid, and soybean lectin in fermented feed are reduced, reducing their irritation to the gastrointestinal tract. At the same time, the raw materials increase the fermented sugarcane bagasse to increase gastrointestinal motility, improve gastrointestinal digestion and absorption of feed nutrients, and improve feed conversion rate. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Example 1

[0030] A method for preparing a fermented feed, the preparation method is as follows:

[0031] (1) Preparation of solution to be fermented:

[0032] The bagasse was crushed to obtain bagasse crumbs, 10 kg of the bagasse crumbs and 150 L of 50% acetic acid solution were placed in a fermentation tank, the temperature was raised to 90° C. under a pressure of 0.1 mPa, and the reaction was carried out at a constant temperature and pressure for 2 hours to obtain a solution to be fermented.

[0033] (2) Preparation of composite fermentation products:

[0034] Aspergillus aculeatus, Pichia pastoris and Bacillus amyloliquefaciens are prepared in advance in a mass ratio of 3:2:1 to prepare a composite microbial fermentation agent, the pH value of the fermented product is adjusted to 6, 24 kg of a microbial agent growth promoter and 1.6 kg of a composite microbial fermentation agent are dissolved in the fermented product, 200 kg of wheat flour and 120 kg of soybean meal are added and mixed, the fermentation temperature is set to 30°C, the oxygen flow rate is 0.5 L / min, the mixture is automatically stirred every 2 hours, and the composite fermentation product is obtained by continuous fermentation for 3 days; wherein the mass ratio of the fermented product: the nitrogen source: the microbial agent promoter is 2:4:0.3, the addition amount of the composite microbial fermentation agent accounts for 0.5% of the mass of the nitrogen source, and each 1000 g of the microbial agent in the microbial agent growth promoter contains 190 g of magnesium sulfate, 180 g of zinc sulfate, 500 g of calcium hydrogen phosphate, 98 g of calcium chloride, 20 g of glycerol, 5 g of vitamin A, 5 g of vitamin B6, 1 g of nicotinic acid and 1 g of betaine.

[0035] (3) Fermented feed preparation:

[0036] Take 35% of the above-mentioned composite fermentation product, 55% corn flour, and 10% auxiliary material mixture, transfer it to a feed pellet equipment for granulation, dry it with hot air at 60-80°C, and bag it to obtain fermented feed; wherein the auxiliary material consists of 5 parts of sodium alginate, 0.5 parts of sodium chloride, 1.5 parts of calcium dihydrogen phosphate and 3 parts of gelatin.

[0037] Example 2

[0038] A method for preparing a fermented feed, the preparation method is as follows:

[0039] (1) Preparation of solution to be fermented:

[0040] The bagasse was crushed to obtain bagasse crumbs, 20 kg of the bagasse crumbs and 100 L of 50% acetic acid solution were placed in a fermentation tank, the temperature was raised to 80° C. under a pressure of 0.1 mPa, and the reaction was carried out at a constant temperature and pressure for 3 hours to obtain a solution to be fermented.

[0041] (2) Preparation of composite fermentation products:

[0042] Aspergillus aculeatus, Pichia pastoris and Bacillus amyloliquefaciens are prepared in a mass ratio of 3:1:1 to prepare a composite microbial fermentation agent, the pH value of the fermented product is adjusted to 6, 12 kg of a microbial agent growth promoter and 0.48 kg of the composite microbial fermentation agent are dissolved in the fermented product, 100 kg of wheat flour and 60 kg of soybean meal are added and mixed, the fermentation temperature is set to 30°C, the oxygen flow rate is 0.8 L / min, the mixture is automatically stirred every 2 hours, and the composite fermentation product is obtained by continuous fermentation for 3 days; wherein the mass ratio of the fermented product: the nitrogen source: the microbial agent promoter is 3:4:0.3, the addition amount of the composite microbial fermentation agent accounts for 0.1% of the mass of the nitrogen source, and each 1000 g of the microbial agent in the microbial agent growth promoter contains 190 g of magnesium sulfate, 180 g of zinc sulfate, 500 g of calcium hydrogen phosphate, 98 g of calcium chloride, 20 g of glycerol, 5 g of vitamin A, 5 g of vitamin B6, 1 g of nicotinic acid and 1 g of betaine.

[0043] (3) Fermented feed preparation:

[0044] Take 30% of the above-mentioned composite fermentation product, 55% corn flour, and 15% auxiliary material mixture, transfer it to a feed pellet equipment for granulation, dry it with hot air at 60-80°C, and bag it to obtain fermented feed; wherein the auxiliary material consists of 5 parts of sodium alginate, 0.5 parts of sodium chloride, 1.5 parts of calcium dihydrogen phosphate and 3 parts of gelatin.

[0045] Example 3

[0046] A method for preparing a fermented feed, the preparation method is as follows:

[0047] (1) Preparation of solution to be fermented:

[0048] The bagasse was crushed to obtain bagasse crumbs, 20 kg of the bagasse crumbs and 150 L of 55% acetic acid solution were placed in a fermentation tank, the temperature was raised to 90° C. under a pressure of 0.1 mPa, and the reaction was carried out at a constant temperature and pressure for 3 hours to obtain a solution to be fermented.

[0049] (2) Preparation of composite fermentation products:

[0050] Aspergillus aculeatus, Pichia pastoris and Bacillus amyloliquefaciens are prepared in a mass ratio of 2:1:1 to prepare a composite microbial fermentation agent, the pH value of the fermented product is adjusted to 5.0, 8.5 kg of a microbial agent growth promoter and 1.7 kg of a composite microbial fermentation agent are dissolved in the fermented product, 212.5 kg of wheat flour and 127.5 kg of soybean meal are added and mixed, the fermentation temperature is set to 28°C, the oxygen flow rate is 1 L / min, the mixture is automatically stirred every 2 hours, and the composite fermentation product is obtained by continuous fermentation for 3 days; wherein the mass ratio of the fermented product: the nitrogen source: the microbial agent promoter is 2:4:0.1, the addition amount of the composite microbial fermentation agent accounts for 0.5% of the mass of the nitrogen source, and each 1000 g of the microbial agent in the microbial agent growth promoter contains 190 g of magnesium sulfate, 180 g of zinc sulfate, 500 g of calcium hydrogen phosphate, 98 g of calcium chloride, 20 g of glycerol, 5 g of vitamin A, 5 g of vitamin B6, 1 g of nicotinic acid and 1 g of betaine.

[0051] (3) Fermented feed preparation:

[0052] Take 20% of the above-mentioned composite fermentation product, 65% corn flour, and 15% auxiliary materials, transfer them to a feed pellet equipment for granulation, dry them with hot air at 60-80°C, and bag them to obtain fermented feed; wherein the auxiliary materials are composed of 5 parts of sodium alginate, 0.5 parts of sodium chloride, 1.5 parts of calcium dihydrogen phosphate and 3 parts of gelatin.

[0053] Example 4

[0054] A method for preparing a fermented feed, the preparation method is as follows:

[0055] (1) Preparation of solution to be fermented:

[0056] The bagasse was crushed to obtain bagasse crumbs, 20 kg of the bagasse crumbs and 100 L of 50% acetic acid solution were placed in a fermentation tank, the temperature was raised to 80° C. under a pressure of 0.1 mPa, and the reaction was carried out at a constant temperature and pressure for 2 hours to obtain a solution to be fermented.

[0057] (2) Preparation of composite fermentation products:

[0058] Aspergillus aculeatus, Pichia pastoris and Bacillus amyloliquefaciens are prepared in advance in a mass ratio of 2:1:1 to prepare a composite microbial fermentation agent, the pH value of the fermented product is adjusted to 6.5, 18kg of a microbial agent growth promoter and 1.08kg of a composite microbial fermentation agent are dissolved in the fermented product, 180kg of wheat flour and 180kg of soybean meal are added and mixed, the fermentation temperature is set to 25°C, the oxygen flow rate is 0.5L / min, the mixture is automatically stirred every 3h, and the composite fermentation product is obtained by continuous fermentation for 3 days; wherein the mass ratio of the fermented product: the nitrogen source: the microbial agent promoter is 3:6:0.3, the addition amount of the composite microbial fermentation agent accounts for 0.3% of the mass of the nitrogen source, and each 1000g of the microbial agent in the microbial agent growth promoter contains 190g of magnesium sulfate, 180g of zinc sulfate, 500g of calcium hydrogen phosphate, 98g of calcium chloride, 20g of glycerol, 5g of vitamin A, 5g of vitamin B6, 1g of nicotinic acid and 1g of betaine.

[0059] (3) Fermented feed preparation:

[0060] Take 25% of the above-mentioned composite fermentation product, 55% corn flour, and 20% auxiliary materials, transfer them to a feed pellet equipment for granulation, dry them with hot air at 60-80°C, and bag them to obtain fermented feed; wherein the auxiliary materials are composed of 5 parts of sodium alginate, 0.5 parts of sodium chloride, 1.5 parts of calcium dihydrogen phosphate and 3 parts of gelatin.

[0061] Comparative Example 1

[0062] A feed for fattening, wherein the preparation method of the feed is as follows:

[0063] 55% corn flour, 20% wheat flour, 16% soybean meal powder, and 10% auxiliary materials are mixed to obtain pig feed, wherein the auxiliary materials consist of 5 parts of sodium alginate, 0.5 parts of sodium chloride, 1.5 parts of monocalcium phosphate, and 3 parts of gelatin.

[0064] Comparative Example 2

[0065] The method is basically the same as Example 1, except that the preparation steps of step (1) and step (2) are as follows:

[0066] (1) Preparation of solution to be fermented:

[0067] The sugarcane bagasse is crushed to obtain sugarcane bagasse crumbs, 1 kg of the sugarcane bagasse crumbs and 15 L of water are placed in a fermentation tank, the temperature is raised to 90° C. under a pressure of 0.1 mPa, and the reaction is carried out at a constant temperature and pressure for 2 hours to obtain a solution to be fermented.

[0068] (2) Preparation of composite fermentation products:

[0069] Aspergillus aculeatus, Pichia pastoris and Bacillus amyloliquefaciens were prepared in a mass ratio of 3:2:2 to prepare a composite microbial fermentation agent. 2.4 kg of a bacterial agent growth promoter and 0.16 kg of the composite microbial fermentation agent were dissolved in water. 20 kg of wheat flour and 12 kg of soybean meal were added and mixed. The fermentation temperature was set at 30°C. The fermentation was continued for 3 days to obtain a composite fermentation product.

[0070] Comparative Example 3

[0071] The method is basically the same as Example 1, except that the method for preparing the composite fermented product is different. The steps for preparing the composite fermented product are as follows:

[0072] Aspergillus aculeatus and Bacillus amyloliquefaciens were taken in a mass proportion of 3:2 to prepare a composite microbial fermentation agent, 2.4 kg of agent growth promoter and 0.16 kg of composite microbial fermentation agent were dissolved in the solution to be fermented, and then 20 kg of wheat flour and 12 kg of soybean meal were added and mixed, the fermentation temperature was set to 30°C, the oxygen flow rate was 0.5 L / min, the mixture was automatically stirred every 2 hours, and the composite fermentation product was obtained after continuous fermentation for 3 days.

[0073] Comparative Example 4

[0074] The method is basically the same as Example 1, except that the preparation steps of step (2) are as follows:

[0075] (2) Preparation of composite fermentation products:

[0076] Saccharomyces cerevisiae, Pichia pastoris and Bacillus amyloliquefaciens were taken in a mass proportion of 3:2:2 to prepare a composite microbial fermentation agent, 2.4 kg of agent growth promoter and 0.16 kg of composite microbial fermentation agent were dissolved in the fermented solution, and then 20 kg of wheat flour and 12 kg of soybean meal were added and mixed, the fermentation temperature was set at 30°C, the oxygen flow rate was 0.5 L / min, the mixture was automatically stirred every 2 hours, and the composite fermentation product was obtained after continuous fermentation for 3 days.

[0077] Comparative Example 5

[0078] The method is basically the same as Example 1, except that the preparation steps of step (2) are as follows:

[0079] (2) Preparation of composite fermentation products:

[0080] Aspergillus niger, Pichia pastoris and Bacillus amyloliquefaciens were prepared in a mass proportion of 3:2:2 to prepare a composite microbial fermentation agent. 2.4 kg of a bacterial agent growth promoter and 0.16 kg of the composite microbial fermentation agent were dissolved in the solution to be fermented. Then 20 kg of wheat flour and 12 kg of soybean meal were added and mixed. The fermentation temperature was set at 30 °C and the oxygen flow rate was 0.5 L / min. The mixture was automatically stirred every 2 hours and fermented continuously for 3 days to obtain a composite fermentation product.

[0081] Comparative Example 6

[0082] The method is basically the same as Example 1, except that the preparation steps of step (2) are as follows:

[0083] (2) Preparation of composite fermentation products:

[0084] Aspergillus aculeatus, Pichia pastoris and Bacillus amyloliquefaciens were prepared in a mass proportion of 2:1:3, 2.4 kg of bacterial agent growth promoter and 0.16 kg of composite microbial fermentation agent were dissolved in the fermented solution, and then 20 kg of wheat flour and 12 kg of soybean meal were added and mixed. The fermentation temperature was set at 30°C, the oxygen flow rate was 0.5 L / min, the mixture was automatically stirred every 2 hours, and the composite fermentation product was obtained after continuous fermentation for 3 days.

[0085] The nutrient weight, phytic acid, urease, soybean lectin, soybean trypsin inhibitor and β-glucan content of the feed obtained in Example 1, Example 2, Comparative Example 1, Comparative Example 2, Comparative Example 3, Comparative Example 4, Comparative Example 5 and Comparative Example 6 are shown in Table 1 below; wherein the soybean lectin and β-glucan detection kits were purchased from Shenzhen Ruiqing Bioinformation Technology Co., Ltd., the phytic acid content kit was purchased from Shanghai Lianzu Biotechnology Co., Ltd., and the urease activity was sent to a testing agency for detection.

[0086] Table 1 Nutritional weight and composition of other substances in Examples 1-2 and Comparative Examples 1-2

[0087] Test items Example 1 Example 2 Comparative Example 1 Comparative Example 2 Crude protein (g) 935.8 930.6 752.4 806.1 Crude fat (g) 46.3 48.1 37.8 43.8 Crude ash(g) 125.8 123.5 134.6 132.4 Phytic acid (mg / mL) 0.15 0.18 0.98 0.53 Urease activity 0.21 0.23 0.82 0.35 Soybean lectin (mg / mL) 0.02 0.03 0.34 0.27 β-Glucan (mg / mL) 4.3 4.6 37.4 14.6

[0088] Table 2 Nutritional weight and composition of other substances in Comparative Examples 3-6

[0089] Test items Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Crude protein (g) 853.8 896.3 912.7 921.4 Crude fat (g) 41.8 45.5 43.7 46.8 Crude ash(g) 132.6 128.3 136.4 131.5 Phytic acid (mg / mL) 0.61 0.73 0.67 0.28 Urease activity 0.83 0.69 0.59 0.32 Soybean lectin (mg / mL) 0.28 0.16 0.03 0.08 β-Glucan (mg / mL) 24.9 18.3 17.9 8.7

[0090] 50kg fattening pigs were fed 2kg of each group of feed for 10 consecutive days. The daily feed intake and daily weight gain of the fattening pigs were recorded. The average daily feed intake and average daily weight gain of the pigs were calculated after 10 days, and the feed conversion rate was calculated using the average daily feed intake and average daily weight gain. The formula for feed conversion rate is: feed daily weight gain rate = average daily feed intake / average daily weight gain; among which, the body weight was uniformly weighed at 8:00-9:00 in the morning of the experiment on the same day, and the feed was fed after weighing. The feeding times were 9:30, 12:00, 15:00, and 18:00, respectively. When feeding, the leftover feed from the last feeding was taken out and weighed to calculate the feed intake.

[0091] Table 3 Daily feed intake, daily weight gain and feed conversion rate of pigs in each group

[0092] Grouping Daily feed intake (g / d) Daily weight gain (g / d) Feed conversion ratio (F / G) Example 1 1660 958 1.73 Example 2 1690 953 1.77 Comparative Example 1 1340 636 2.11 Comparative Example 2 1640 875 1.87 Comparative Example 3 1470 760 1.93 Comparative Example 4 1440 789 1.83 Comparative Example 5 1580 874 1.81 Comparative Example 6 1650 921 1.79

[0093] The present invention can be implemented in various ways and is not limited to the embodiments described. A person skilled in the art can understand that the present invention can be implemented in other specific ways without changing the technical concept or essential features of the present invention. Therefore, it should be understood that the embodiments described above are exemplary and are not intended to limit the present invention.

Claims

1. A method for preparing fermented feed, characterized in that: The preparation method is as follows: Treating bagasse crushed with acetic acid solution to obtain a solution to be fermented, mixing the solution to be fermented with a nitrogen source, a bacterial agent growth promoter and a composite microbial fermentation agent to obtain a composite fermentation product, mixing the composite fermentation product, corn flour and auxiliary materials according to a preset ratio, granulating and drying to obtain a fermented feed; The nitrogen source includes wheat and soybean meal; The composite microbial fermentation agent is composed of Aspergillus aculeatus, Pichia pastoris and Bacillus amyloliquefaciens; The auxiliary materials include sodium alginate, sodium chloride, calcium dihydrogen phosphate and gelatin.

2. The method for preparing fermented feed according to claim 1, characterized in that: In the step of treating the bagasse crushed with acetic acid solution to obtain the solution to be fermented, the method for obtaining the solution to be fermented is specifically to mix the bagasse crushed with 50-55% acetic acid solution in a ratio of 1-2:10-15, and react at a pressure of 0.05-0.1 mPa and a temperature of 70-100° C. for 1-3 hours to obtain the solution to be fermented.

3. The method for preparing fermented feed according to claim 1, characterized in that: The raw materials of the composite microbial fermentation agent are calculated by weight ratio of Aspergillus aculeatus, Pichia pastoris and Bacillus amyloliquefaciens in an amount of 2-3:1-2:1-2.

4. The method for preparing fermented feed according to claim 1, characterized in that: In the step of mixing the solution to be fermented with the nitrogen source, the bacterial agent growth promoter and the composite microbial fermentation bacterial agent to obtain the composite fermentation product, the steps are as follows: The bacterial agent growth promoter and the composite microbial fermentation bacterial agent are dissolved in the solution to be fermented, mixed, and then the nitrogen source is added and mixed, and fermented for 3-4 days under preset fermentation conditions to obtain a composite fermentation product; wherein the mass ratio of the solution to be fermented: the nitrogen source: the bacterial agent growth promoter is 2-3:4-6:0.1-0.3, and the addition amount of the composite microbial fermentation bacterial agent accounts for 0.1-0.5% of the nitrogen source.

5. The method for preparing fermented feed according to claim 4, characterized in that: The preset fermentation conditions are as follows: fermentation temperature is 25-30°C, pH value is 5.0-6.5, oxygen flow rate is 0.25-1L / min, and stirring interval time is set to 60-360min.

6. The method for preparing fermented feed according to claim 4, characterized in that: The bacterial agent growth promoter comprises inorganic salts and growth factors, wherein the inorganic salts are magnesium sulfate, zinc sulfate, calcium hydrogen phosphate and calcium chloride, and the growth factors are glycerol, vitamin A, vitamin B6, niacin and betaine.

7. The method for preparing fermented feed according to claim 5, characterized in that: Every 1000g of bacterial agent growth promoter includes: 152-190g of magnesium sulfate, 155-180g of zinc sulfate, 500-600g of calcium hydrogen phosphate, 80-98g of calcium chloride, 10-20g of glycerol, 1-5g of vitamin A, 1-5g of vitamin B6, 0.5-1g of niacin and 0.5-1g of betaine.

8. The method for preparing fermented feed according to claim 1, characterized in that: In the step of mixing the composite fermented product, corn flour and auxiliary materials according to a preset ratio, the composite fermented product accounts for 20%-35%, the corn flour accounts for 55%-65%, and the auxiliary materials accounts for 10-20% by mass percentage.

9. A fermented feed prepared by the method for preparing a fermented feed according to any one of claims 1 to 8, characterized in that: The phytic acid content of the fermented feed is 0.15-0.18 mg / mL, the soybean lectin content of the fermented feed is lower than 0.05 mg / mL, and the beta-glucan content of the fermented feed is lower than 10 mg / mL.

10. A composite microbial fermentation agent as claimed in claim 1, 3 or 4, characterized in that: The components of the composite microbial fermentation agent are prepared from Aspergillus aculeatus, Pichia pastoris and Bacillus amyloliquefaciens in a weight ratio of 2-3:1-2:1-2.