Piglet weaning transition feed prepared from soybean meal through compound fermentation of lactic acid bacteria and saccharomycetes and preparation method thereof

Abstract

The present invention relates to the technical field of feeds and particularly relates to a piglet weaning transition feed containing lactic acid bacteria and saccharomycetes compound fermented soybean meal and a preparation method thereof, and the piglet weaning transition feed comprises the following components in parts by weight: 15-20 parts of compound fermented soybean meal, 45-50 parts of corn, 10-15 parts of wheat, 5-7 parts of fish meal, 3-5 parts of whey powder, 3-4 parts of vegetable oil, 1-2 parts of an amino acid supplement and 2-3 parts of a mineral premix, 1-2 parts of a vitamin premix and 1.5-2 parts of a calcium-phosphorus supplement; wherein the compound fermented soybean meal is prepared by performing compound fermentation on soybean meal through lactic acid bacteria and saccharomycetes, and a complementary and symbiotic microbial ecological system is formed by carefully selecting and optimizing the combination proportion of three lactic acid bacteria and two saccharomycetes, so that the fermentation efficiency and stability are improved, and the functionality of a fermentation product is enhanced. Different strains complement each other in the aspects of carbohydrate metabolism, pH tolerance and functional characteristics, and nutrition competition is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of feeds, specifically to a weaning transition feed for piglets fermented by lactic acid bacteria and yeast in a compound manner and a preparation method thereof, which is particularly suitable for feeding piglets aged 7 - 60 days, can effectively relieve the weaning stress reaction of piglets, reduce the incidence of diarrhea, improve the feed digestion and utilization rate, and promote the healthy growth of piglets. Background Art

[0002] Weaning is an important stress period in the growth process of piglets, mainly manifested as stress reactions caused by comprehensive factors such as environmental changes, feed conversion, and mother - piglet separation, often resulting in problems such as decreased feed intake, growth stagnation, diarrhea, and decreased immune function. Research shows that designing a reasonable weaning transition feed is of great significance for relieving weaning stress and ensuring the growth and development of piglets.

[0003] Soybean meal is a commonly used high - quality plant protein source in pig feeds, but it contains anti - nutritional factors such as trypsin inhibitors and soybean globulins, which have a negative impact on the digestive system of weaned piglets in particular. Treating soybean meal through biological fermentation technology can reduce the content of anti - nutritional factors, improve the protein utilization rate, and improve the nutritional value of soybean meal.

[0004] At present, the preparation methods of fermented soybean meal mainly include single - strain fermentation and simple mixed fermentation. US Patent US20160015055A1 discloses a "preparation method of fermented soybean meal", which uses single - strain fermentation of Lactobacillus or Bacillus for soybean meal. Although it can reduce the content of anti - nutritional factors to a certain extent, the degree of protein degradation is limited, the content of functional components is low, and it cannot fully meet the special physiological needs of weaned piglets. Japanese Patent JP2010512162A discloses a "fermented feed for livestock production using lactic acid bacteria and yeast and a preparation method thereof", which mixes Lactobacillus and Saccharomyces for fermentation, but this method only simply mixes the strains for simultaneous fermentation, does not consider the synergistic complementarity of the growth characteristics of different microorganisms, has low fermentation efficiency, and the product quality is unstable. Chinese Patent CN111903835A discloses a "preparation method of a fermented protein feed and a fermented protein feed", mainly through solid - state aerobic fermentation to obtain a fermented material, and does not conduct formula optimization for the special needs of weaned piglets.

[0005] The main problems existing in the prior art include: (1) Single - strain or simple mixed fermentation cannot fully exert the synergistic complementarity effect of microorganisms; (2) The fermentation process control is not precise, and the product quality is unstable; (3) Formula optimization is not carried out for the special needs of the weaning period of piglets; (4) Lack of functional additives to enhance immune regulation and intestinal health functions; (5) No complete system solution is formed, and the application effect is limited.

[0006] Therefore, it is necessary to develop a new type of weaned piglet transitional feed with fermented soybean meal by lactic acid bacteria and yeast and its preparation method to solve the above technical problems. Summary of the Invention

[0007] The object of the present invention is to provide a weaned piglet transitional feed with fermented soybean meal by lactic acid bacteria and yeast and its preparation method. By optimizing the composite strains, innovating the fermentation process and scientifically designing the formula, the content of anti-nutritional factors in soybean meal is significantly reduced, the protein digestibility is improved, short-chain fatty acids and functional polypeptides are produced, an intestinal protection barrier for piglets is established, the weaning stress response is reduced, and the feed digestion and utilization rate and the growth performance of piglets are improved.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A weaned piglet transitional feed with fermented soybean meal by lactic acid bacteria and yeast, comprising the following components in parts by weight: 15-20 parts of composite fermented soybean meal, 45-50 parts of corn, 10-15 parts of wheat, 5-7 parts of fish meal, 3-5 parts of whey powder, 3-4 parts of vegetable oil, 1-2 parts of amino acid supplement, 2-3 parts of mineral premix, 1-2 parts of vitamin premix, 1.5-2 parts of calcium and phosphorus supplement; wherein, the composite fermented soybean meal is prepared by fermenting soybean meal with lactic acid bacteria and yeast.

[0010] Preferably, the lactic acid bacteria in the composite fermented soybean meal include lactic acid bacteria of the genus Lactobacillus and lactic acid bacteria of the genus Pediococcus; the yeast includes Hansenula anomala and Saccharomyces cerevisiae.

[0011] More preferably, the lactic acid bacteria include: Lactobacillus casei, Lactobacillus plantarum and Pediococcus acidilactici, and the lactic acid bacteria are mixed in the ratio of Lactobacillus casei:Lactobacillus plantarum:Pediococcus acidilactici = 3:2:1; the yeast includes: Hansenula anomala and Saccharomyces cerevisiae, and the yeast are mixed in the ratio of Hansenula anomala:Saccharomyces cerevisiae = 2:1; the ratio of lactic acid bacteria to yeast is 2:1.

[0012] The compound fermented soybean meal of the present invention has the following characteristics: protein digestibility ≥ 80%; anti-nutritional factor reduction rate ≥ 85%; short-chain fatty acid content 2.5 - 3.0%; functional polypeptide content 3.0 - 3.5%; active lactic acid bacteria content ≥ 5×10 8 CFU / g; active yeast content ≥ 1×10 7 CFU / g.

[0013] The present invention also provides a method for preparing the above-mentioned weaning transition feed for piglets, comprising the following steps:

[0014] (1) Strain activation and cultivation: Inoculate lactic acid bacteria into MRS medium and culture at 36 - 38°C for 18 - 24 hours to make the bacterial concentration reach ≥ 5×10 9 CFU / mL; inoculate yeast into YPD medium and culture at 28 - 30°C for 20 - 24 hours to make the bacterial concentration reach ≥ 2×10 8 CFU / mL;

[0015] (2) Soybean meal pretreatment: Crush the soybean meal to 60 - 80 mesh, adjust the water content to 48 - 52%, perform high-pressure steaming at 121 ± 2°C for 18 - 22 minutes, cool to 38 - 42°C, and adjust the pH to 6.0 - 6.5;

[0016] (3) First-stage solid-state fermentation: Inoculate the cultured yeast into the pretreated soybean meal at 1.0 - 1.5% of the soybean meal weight and ferment at 28 ± 1°C for 22 - 26 hours, controlling the relative humidity at 75 - 80%;

[0017] (4) Enzyme preparation addition: After the end of the first-stage fermentation, add an enzyme preparation complex with a total addition amount of 0.4 - 0.8% of the soybean meal weight, adjust the pH to 5.8 - 6.2, and the temperature to 37 - 40°C;

[0018] (5) Second-stage compound fermentation: Inoculate the cultured lactic acid bacteria mixture into the fermented material added with the enzyme preparation at 2.0 - 2.5% of the soybean meal weight and ferment at 37 ± 1°C for 45 - 50 hours, controlling the relative humidity at 75 - 80%;

[0019] (6) Functional substance stabilization: Add 0.5 - 0.8 parts by weight of calcium carbonate and 1.0 - 1.5 parts by weight of microcrystalline cellulose, and adjust the pH to 4.8 - 5.2;

[0020] (7) Drying treatment: Hot air dry the fermented material at 60 - 65°C until the water content ≤ 12%;

[0021] (8) Functional additive mixing: Add 1.0 - 2.0 parts by weight of spirulina extract and 0.3 - 0.5 parts by weight of kelp extract;

[0022] (9) Feed formula mixing: Mix the prepared compound fermented soybean meal with other feed raw materials evenly according to the formula ratio to prepare the weaned piglet transition feed.

[0023] Preferably, in the first-stage solid-state fermentation described in step (3), control the thickness of the fermented material layer to be 2 - 3 cm, turn it over every 12 ± 1 hour, and the determination conditions for the fermentation end point are: the pH drops to 5.0 - 5.3, the number of yeast cells ≥ 5×10 7 CFU / g, and the degree of protein hydrolysis reaches 20 - 25%.

[0024] Preferably, the enzyme preparation complex described in step (4) includes:

[0025] Acidic protease 0.15 - 0.25 parts by weight, with an activity of 40,000 - 50,000 U / g;

[0026] Neutral protease 0.10 - 0.20 parts by weight, with an activity of 35,000 - 45,000 U / g;

[0027] β-glucanase 0.05 - 0.15 parts by weight, with an activity of 20,000 - 30,000 U / g;

[0028] Pectinase 0.05 - 0.10 parts by weight, with an activity of 8,000 - 12,000 U / g;

[0029] Xylanase 0.05 - 0.10 parts by weight, with an activity of 15,000 - 25,000 U / g.

[0030] Preferably, in the second-stage compound fermentation described in step (5), the ventilation volume in the first 24 hours is 0.3 - 0.5 m 3 / h·kg of material, and the ventilation volume in the next 24 hours is 0.1 - 0.2 m 3 / h·kg of material; the determination conditions for the fermentation end point are: the pH drops to 4.0 - 4.5, the total number of lactic acid bacteria ≥ 1×10 9 CFU / g, the content of short-chain fatty acids ≥ 2.5%, the content of functional polypeptides ≥ 3.0%, and the activity of trypsin inhibitor is reduced by ≥ 85%.

[0031] Preferably, the drying treatment described in step (7) adopts a hierarchical drying strategy:

[0032] The first stage: 60 - 65 °C, 1.5 - 2.0 hours, reduce the moisture content to 25 - 30%;

[0033] The second stage: 50 - 55 °C, 1.0 - 1.5 hours, reduce the moisture content to 12 - 15%;

[0034] Cooling stage: 25 - 30 °C, 0.5 hour, to cool the product temperature to room temperature.

[0035] Use of the described weaning transition feed for piglets in the preparation of weaning transition feed for piglets, wherein the weaning transition feed for piglets is used for feeding piglets during the age of 7 - 60 days, including:

[0036] Pre - weaning preparation stage at 7 - 21 days of age: The initial daily feeding amount is 10 - 20 g / head, and the feeding amount is increased by 10 g / head every 3 days;

[0037] Early weaning transition stage at 22 - 35 days of age: Feed in small amounts and multiple meals, 4 - 6 times a day. The daily feeding amount gradually increases from 30 - 40 g / head to 150 - 200 g / head;

[0038] Post - weaning growth stage at 36 - 60 days of age: The daily feeding amount gradually increases from 200 - 300 g / head to 300 - 500 g / head, and gradually transitions from 4 - time feeding to 3 - time feeding.

[0039] The beneficial effects of the present invention include:

[0040] (1) Innovative composite strain system: By carefully selecting and optimizing the combination ratio of 3 lactic acid bacteria and 2 yeasts, a complementary and symbiotic microbial ecosystem is formed, improving fermentation efficiency and stability, and enhancing the functionality of fermentation products. Different strains complement each other in carbohydrate metabolism, pH tolerance, and functional characteristics, reducing nutrient competition and improving the robustness of the system.

[0041] (2) Innovation in two - stage fermentation process: Adopt the innovative fermentation strategy of "yeast first - lactic acid bacteria relay", which solves the contradiction that the growth conditions of lactic acid bacteria and yeasts are not completely compatible. In the first stage, yeast fermentation degrades complex carbohydrates, creating conditions for the subsequent growth of lactic acid bacteria; in the second stage, lactic acid bacteria and yeasts form a dynamic balance ecosystem, significantly improving fermentation efficiency and product quality.

[0042] (3) Innovation in enzymatic hydrolysis - assisted fermentation: Add a specific combination of enzyme preparations during the fermentation process to form a synergistic effect with microorganisms, significantly increasing the degree of protein hydrolysis and reducing the content of anti - nutritional factors. The enzyme systems produced by microorganisms and exogenous enzymes form a "broad pH range" hydrolysis system in different pH ranges, improving the overall hydrolysis efficiency.

[0043] (4) Synergistic innovation of functional polypeptides and short - chain fatty acids: By precisely controlling the fermentation conditions, bioactive substances with specific functions are produced directionally, including ACE - inhibitory peptides, antioxidant peptides, immunomodulatory peptides, and short - chain fatty acids, improving their bioaccessibility and stability.

[0044] (5) Multi-level nutrition and functional synergy: The various components in the feed formula form a multi-level nutrition and functional synergy system, including digestive system synergy mechanism, intestinal health synergy mechanism and immune regulation synergy mechanism, which fully meet the special nutritional needs of weaned piglets.

[0045] (6) Significant application effects: Compared with the prior art, the feed of the present invention can increase the feed intake of piglets by 15-20%, increase daily weight gain by 10-15%, reduce feed-to-meat ratio by 8-12%, reduce diarrhea rate by 60-70%, increase the number of beneficial intestinal bacteria by 3-5 times, increase immunoglobulin levels by 20-25%, and improve comprehensive economic benefits by 10-15%. DETAILED DESCRIPTION

[0046] The present invention is further described in detail below in conjunction with specific examples. It should be understood by those skilled in the art that these examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention.

[0047] The detailed information of the main raw materials used in the present invention is as follows:

[0048] 1. Bacteria

[0049] Lactobacillus casei CGMCC1.62: viable count ≥ 5.0 × 10 10 CFU / g;

[0050] Lactobacillus plantarum LP02: viable count ≥ 1.0 × 10 11 CFU / g;

[0051] Pediococcus acidilactici PA03: viable count ≥ 3.0 × 10 10 CFU / g;

[0052] Hansenula anomala CGMCC2.881: viable count ≥ 2.0 × 10 9 CFU / g;

[0053] Saccharomyces cerevisiae SC17-1: viable count ≥ 3.0 × 10 9 CFU / g;

[0054] 2. Enzyme preparations

[0055] Acid protease: activity 45,000U / g, EC number 3.4.23.18;

[0056] Neutral protease: activity 40,000U / g, EC number 3.4.24.28;

[0057] β-glucanase: Activity 25,000 U / g, EC number 3.2.1.6;

[0058] Pectinase: Activity 10,000 U / g, EC number 3.2.1.15;

[0059] Xylanase: Activity 20,000 U / g, EC number 3.2.1.8;

[0060] 3. Functional additives

[0061] In a preferred embodiment of the present invention, the spirulina extract is prepared by the following method: First, high-quality dried Arthrospira platensis powder is selected as the raw material, containing ≥65% protein, ≤8% moisture, ≤1.2% chlorophyll a, and ≥18% phycocyaninogen content, and the particle size is controlled at 80 - 100 mesh. The dried algal powder is pretreated in an environment with a temperature of 20 - 25°C and a relative humidity of ≤45% for 24 hours to ensure uniform distribution of moisture.

[0062] The pretreated algal powder is subjected to supercritical CO2 extraction, which is a key process step of the present invention. Specifically, the treated algal powder is loaded into the extraction tank, and the filling coefficient is controlled at 0.65 - 0.70 to ensure sufficient contact between CO2 and the material. The extraction process adopts a three-stage temperature-pressure combination: The first stage is carried out at 35 - 40°C and 15 - 18 MPa for 2.0 - 2.5 hours to mainly remove fat-soluble pigments and some lipids; the second stage is carried out at 45 - 50°C and 25 - 28 MPa for 1.5 - 2.0 hours to mainly extract medium-polar bioactive substances; the third stage is carried out at 55 - 60°C and 30 - 35 MPa for 1.0 - 1.5 hours to further extract residual active substances. The CO2 flow rate is controlled at 25 - 30 kg / h·kg of algal powder to ensure the extraction efficiency. To further improve the extraction rate of specific active substances, 5 - 8% and 8 - 10% of cosolvents (ethanol:water = 95:5) are added in the second and third stages respectively to promote the extraction of specific polar substances.

[0063] The algal powder after supercritical CO2 treatment is removed of residual solvent by low-temperature rotary evaporation, with the temperature controlled at 45±2 °C, the vacuum degree at -0.08 MPa, and the time at 30 - 40 minutes. Subsequently, hydrophilic active substances are extracted. The specific method is as follows: The treated algal powder is mixed with 0.1M phosphate buffer (pH 7.0 - 7.2) at a ratio of 1:10, and stirred and extracted at 28 - 30 °C for 2.5 - 3.0 hours, with the stirring speed at 150 - 180 rpm. The extract is centrifuged at 5000g for 20 minutes to collect the supernatant. The supernatant is subjected to ammonium sulfate fractional precipitation (first adding ammonium sulfate to 30% saturation, standing for 2 hours to separate impurities; then adding ammonium sulfate to 60% saturation, standing for 4 hours to collect the precipitate of the target component). The collected precipitate is dialyzed (cut-off molecular weight 6 - 8 kDa) to remove salts, and then made into powder by spray drying technology (inlet temperature 140 - 150 °C, outlet temperature 70 - 75 °C, feeding rate 15 - 18 mL / min).

[0064] The protein content of the final product is ≥60% detected by HPLC, the phycocyanin content is ≥15% determined by spectrophotometry, and it also contains a certain amount of superoxide dismutase (SOD) activity (≥1500 U / g) and polyunsaturated fatty acids (≥5%). The finished product is packaged in light-proof, moisture-proof and nitrogen-filled packaging, sealed in an aluminum foil composite bag, with a shelf life of 12 months at room temperature and 24 months in refrigeration (2 - 8 °C).

[0065] The Laminaria japonica extract used in the present invention is preferably prepared by the following enzymatic extraction method: Select fresh Laminaria japonica from the coasts of Shandong or Zhejiang in China, with a growth period of 3 - 4 years. After harvesting, it is immediately washed and the attachments are removed. After cutting into sections, it is blanched in steam at 70 - 80 °C for 3 - 5 minutes to inactivate endogenous enzymes, and then dried at 60±2 °C until the water content ≤12%. The dried Laminaria japonica is ground to a particle size of 60 - 80 mesh and reserved for use.

[0066] The enzymatic extraction process first undergoes pretreatment: The Laminaria japonica powder is mixed with 0.1N hydrochloric acid solution at a ratio of 1:15 (w / v), soaked at room temperature for 30 - 40 minutes for acid swelling, with the pH controlled at 2.0 - 2.5. Subsequently, the pH is adjusted to 5.0 - 5.5, and a composite enzyme system is added for enzymatic hydrolysis. The composite enzyme system includes alginate lyase (EC 4.2.2.3), cellulase (EC 3.2.1.4) and xylanase (EC 3.2.1.8), with the activity units being 20,000 U / g, 15,000 U / g and 10,000 U / g respectively, and the addition amounts being 0.2%, 0.15% and 0.1% of the substrate weight respectively. The enzymatic hydrolysis conditions are: temperature 45 - 50 °C, pH 5.0 - 5.5, time 4 - 6 hours, and stirring is carried out every 30 minutes during this period to ensure full contact between the enzyme and the substrate.

[0067] After the enzymatic hydrolysis is completed, the mixture is heated at 90 - 95 °C for 15 - 20 minutes to inactivate the enzyme, cooled to room temperature, and centrifuged at 4000 g for 30 minutes to separate the supernatant. The pH of the supernatant is adjusted to 7.0 - 7.5, activated carbon (0.5 - 1.0%) is added for decolorization, and it is stirred at 60 - 65 °C for 30 - 40 minutes, followed by centrifugation for separation. The treated liquid is concentrated to 1 / 5 - 1 / 4 of the original volume using ultrafiltration technology (using an ultrafiltration membrane with a molecular weight cut-off of 10 kDa), then 3 volumes of 95% ethanol are added for precipitation, and it is left standing at 4 °C for 8 - 12 hours. The precipitate is collected, washed 2 - 3 times with 80% ethanol, and finally washed once with absolute ethanol.

[0068] After the precipitate is vacuum dried at 40 - 45 °C for 10 - 12 hours, it is ground into powder, an appropriate amount of maltodextrin (10 - 15%) is added as a carrier, and it is prepared into kelp extract through secondary drying (35 - 40 °C, 6 - 8 hours). The content of fucoidan in the final product is determined by high performance liquid chromatography to be ≥25%, the content of alginic acid is ≥35%, and it also contains various trace elements (such as iodine, zinc, selenium, etc.) and antioxidant active substances. The finished product is stored in a light-proof and sealed container, and stored in an environment with a temperature of 15 - 25 °C and a relative humidity of ≤60%, and the shelf life is 18 months.

[0069] In another embodiment of the present invention, the above-mentioned kelp extract can also be further separated and purified by ion exchange chromatography (using a DEAE - cellulose column) to obtain a high - purity product with a higher content of fucoidan (≥35%), which is particularly suitable for application scenarios with higher requirements for immunomodulatory functions.

[0070] It should be understood that the above - mentioned preparation method can be appropriately adjusted according to specific process conditions and equipment conditions, as long as the content of functional components that meet the requirements of the present invention can be obtained, that is, a spirulina extract with a protein content of ≥60% and a phycocyanin content of ≥15%, and a kelp extract with a fucoidan content of ≥25% and an alginic acid content of ≥35%, all of which fall within the protection scope of the present invention.

[0071] 4. Main feed raw materials

[0072] Soybean meal: Protein content ≥46%, particle size 60 - 80 mesh;

[0073] Corn: Provided by Beidahuang Agricultural Reclamation Group Co., Ltd., protein content 8.7%, particle size 90 mesh;

[0074] Wheat: Provided by COFCO Corporation, protein content 11.8%, particle size 85 mesh;

[0075] Fish meal: Origin Peru, protein content 65%;

[0076] Whey powder: Protein content 12%, lactose content 72%;

[0077] Standard Operating Procedure for Strain Activation

[0078] Activation of Lactic Acid Bacteria

[0079] 1. Thaw the strain stored at -80°C at room temperature, with the thawing temperature controlled at 20 - 25°C and the thawing time not exceeding 3 minutes;

[0080] 2. Inoculate the thawed strain into 15 mL of MRS liquid medium (inoculation amount 1 - 2%), and incubate statically at 37 ± 1°C for 12 - 16 hours;

[0081] 3. Activity detection: Measure the pH value (should drop to 4.0 - 4.5) and cell density (OD600 should reach 1.0 - 1.5)

[0082] Activation of Yeast

[0083] 1. Thaw the strain stored at -80°C at room temperature, with the thawing temperature controlled at 20 - 25°C and the thawing time not exceeding 3 minutes;

[0084] 2. Inoculate the thawed strain into 15 mL of YPD liquid medium (inoculation amount 1 - 2%), and incubate with shaking (150 - 180 rpm) at 28 ± 1°C for 16 - 20 hours;

[0085] 3. Activity detection: Measure the cell density (OD600 should reach 2.0 - 3.0) and conduct morphological examination under the microscope;

[0086] Standard Operating Procedure for Seed Culture

[0087] Seed Culture of Lactic Acid Bacteria

[0088] 1. Inoculate the activated bacterial liquid into 250 mL of modified MRS medium (inoculation amount 3 - 5%), composition (g / L): glucose 20 - 25, yeast extract 8 - 10, peptone 12 - 15, sodium acetate 3 - 5, ammonium citrate 2 - 3, dipotassium hydrogen phosphate 1.5 - 2.0, magnesium sulfate 0.2 - 0.3, manganese sulfate 0.02 - 0.05, Tween - 80 1.0 - 1.5 mL, pH 6.2 - 6.5;

[0089] 2. Culture conditions: Incubate statically at 37 ± 1°C for 18 - 24 hours;

[0090] 3. Target bacterial concentration: ≥5×10 9 CFU / mL;

[0091] 4. Quality control: The pH should drop to 3.8 - 4.3, the morphological examination of the bacterial cells under the microscope is normal, and the contamination rate < 0.1%;

[0092] Seed Culture of Yeast

[0093] 1. Inoculate the activated bacterial liquid into 250 mL of modified YPD medium (inoculation amount 3 - 5%), composition (g / L): glucose 25 - 30, yeast extract 10 - 15, peptone 18 - 22, dipotassium hydrogen phosphate 2.0 - 2.5, magnesium sulfate 0.5 - 0.8, pH 5.5 - 6.0;

[0094] 2. Culture conditions: Shake - culture at 28 ± 1°C (150 - 180 rpm) for 20 - 24 hours;

[0095] 3. Target bacterial concentration: ≥2×10 8 CFU / mL;

[0096] 4. Quality control: Under the microscope, check that the bacterial morphology is normal, without pseudohyphae, and the contamination rate <0.1%.

[0097] The superiority of the compound - fermented soybean meal weaning transition feed for piglets by lactic acid bacteria and yeast in this invention in alleviating weaning stress and promoting the growth and development of piglets is mainly based on the following synergistic mechanisms:

[0098] 1. The interaction mechanism of the two - phase fermentation strains

[0099] The two - stage compound fermentation process adopted in this invention realizes the best synergistic effect between lactic acid bacteria and yeast. From the perspective of microbial physiological ecology, this synergy is mainly reflected in the following aspects:

[0100] First of all, during the fermentation process of yeast in the first stage, Hansenula anomala has a strong extracellular hydrolase system, especially α - galactosidase, α - amylase and protease, which can initially degrade complex carbohydrates and macromolecular proteins in soybean meal into simpler compounds. Saccharomyces cerevisiae, through its strong fermentation ability, converts simple sugars into organic acids, alcohols and aromatic substances, and at the same time produces a variety of B - group vitamins (especially pantothenic acid, biotin and nicotinamide) and amino acids. These metabolites provide an ideal nutritional environment for the growth of subsequent lactic acid bacteria.

[0101] Secondly, during the co-fermentation of lactic acid bacteria and yeast in the second stage, Lactobacillus casei, Lactobacillus plantarum, and Pediococcus acidilactici each play to their strengths, forming complementary ecological niches. L. casei mainly utilizes glucose and galactose to produce L(+)-lactic acid; L. plantarum has a broader spectrum of carbohydrate utilization ability and can produce various organic acids; P. acidilactici preferentially utilizes pentose sugars to produce DL-lactic acid and antibacterial peptides. The lactic acid and other organic acids produced by the three lactic acid bacteria gradually lower the environmental pH, creating an environment that is unfavorable to harmful bacteria but has less impact on yeast because yeast has strong acid tolerance. At the same time, certain extracellular polysaccharides produced by lactic acid bacteria can stimulate the metabolic activity of yeast.

[0102] This staged design solves problems such as the competition for carbon sources between lactic acid bacteria and yeast, differences in pH tolerance, and mismatches in growth rates in direct mixed culture, enabling the complex bacterial system to exert the maximum synergistic effect. Microbiomics research shows that this synergistic effect leads to the production of specific secondary metabolites, including a unique short-chain fatty acid profile, a bioactive polypeptide profile, and an aromatic substance combination, which are difficult to obtain through single-strain or simple mixed fermentation.

[0103] 2. Enzyme system synergistic effect and anti-nutritional factor degradation mechanism

[0104] The multiple enzyme preparations added during the fermentation process of the present invention and the endogenous enzymes produced by microorganisms form a multiple enzyme system synergistic effect network. From the perspective of molecular enzymology, this synergistic effect is mainly reflected in the following aspects:

[0105] First, acid protease and neutral protease complement each other under different pH conditions, forming a "broad pH range" proteolytic system. Acid protease has the highest activity in the range of pH 3.0 - 5.5 and preferentially cleaves the peptide bonds between hydrophobic amino acid residues in proteins; neutral protease has the highest activity in the range of pH 5.5 - 8.0 and preferentially cleaves the peptide bonds near basic or charged amino acid residues. This complementary effect ensures that the proteolytic activity remains at a high level throughout the dynamic change of the fermentation pH.

[0106] Second, β-glucanase, pectinase, and xylanase form a complex polysaccharide degradation system that synergistically degrades the cell wall structure of soybean meal. β-glucanase cleaves β-1,3 and β-1,4 glycosidic bonds, pectinase hydrolyzes α-1,4-glycuronic acid bonds, and xylanase cleaves β-1,4-xylose bonds. This multi-enzyme synergistic effect can quickly destroy the integrity of the plant cell wall, release the embedded proteins and other nutrients, and significantly improve the subsequent hydrolysis efficiency.

[0107] Third, the endogenous enzymes of microorganisms and the exogenously added enzymes complement each other in terms of specific substrate recognition and cleavage patterns. For example, the exoprotease (EC 3.4.11.x) produced by yeast sequentially cleaves single amino acids from the N-terminus of proteins, while the endoprotease (EC 3.4.21.x) produced by lactic acid bacteria cleaves at specific internal sites in proteins to generate polypeptide fragments. The exogenously added protease further hydrolyzes these polypeptide fragments to produce more small peptides and free amino acids.

[0108] Through the synergistic action of this multiple enzyme system, the main antinutritional factors in soybean meal are efficiently degraded. The active center regions of trypsin inhibitors (Kunitz type and Bowman - Birk type) are specifically cleaved, resulting in conformational changes and loss of inhibitory activity; the glycosylation sites of lectins are modified by glycosidases, reducing their specific binding ability to carbohydrates; phytic acid is hydrolyzed by phytase produced during fermentation, releasing phosphorus and inositol; oligosaccharides (stachyose, raffinose, and stachyritol) are hydrolyzed into monosaccharides by α - galactosidase and β - fructosidase.

[0109] 3. Formation and Regulation Mechanisms of Functional Bioactive Substances

[0110] The fermentation products of the present invention contain abundant short - chain fatty acids and functional polypeptides. The formation and regulation mechanisms of these bioactive substances are as follows:

[0111] Short - chain fatty acids are mainly produced through the metabolism of lactic acid bacteria and yeast, and their composition and content are precisely regulated by fermentation conditions. During the first - stage yeast fermentation, acetic acid, propionic acid, and a small amount of butyric acid are mainly produced; during the second - stage co - fermentation of lactic acid bacteria and yeast, lactic acid bacteria ferment to produce a large amount of lactic acid, and part of the lactic acid is converted into propionic acid and butyric acid under microaerobic conditions. By controlling the oxygen supply in the later stage of fermentation, the composition ratio of short - chain fatty acids can be adjusted to optimize their biological effects.

[0112] Functional polypeptides are mainly formed through the controlled hydrolysis of proteins, and their types and content are precisely regulated by the type, activity, and action time of proteases. In the present invention, by optimizing the protease combination and hydrolysis conditions, specific polypeptides with ACE inhibitory activity, antioxidant activity, and immunomodulatory activity are produced directionally. For example, specific sequence polypeptides (such as LPYPR, IAVPGEVA, and VVPP) produced by hydrolyzing 7S globulin and 11S globulin in soybean protein have significant ACE inhibitory activity; polypeptides containing multiple hydrophobic amino acids (such as LLPHH) have strong antioxidant activity; while polypeptides containing regions rich in glutamine - lysine have immunomodulatory activity.

[0113] The regulatory mechanisms of these functional bioactive substances on the intestinal health and immune function of piglets mainly include:

[0114] (1) Short-chain fatty acids promote intestinal health through multiple pathways: ① Butyric acid, as the preferred energy substrate for intestinal epithelial cells, promotes the proliferation and differentiation of intestinal epithelial cells; ② Lactic acid and acetic acid inhibit the growth of harmful bacteria by reducing the intestinal pH value; ③ Propionic acid and butyric acid regulate intestinal inflammatory responses and mucus secretion through the G protein-coupled receptor (GPR41 / GPR43) signaling pathway; ④ Butyric acid regulates gene expression by inhibiting the activity of histone deacetylase (HDAC), enhancing the expression of proteins related to intestinal barrier function (such as zonula occludens protein ZO-1, claudin-1, and occludin).

[0115] (2) Functional polypeptides regulate immune function at multiple levels: ① Specific small peptides are efficiently absorbed through peptide transporter (PepT1), reducing the burden on the digestive system; ② Polypeptides containing hydrophobic amino acids (such as leucine and valine) activate macrophages and dendritic cells, enhancing innate immunity; ③ Polypeptides containing glutamine provide an energy substrate for immune cells, promoting the production of secretory IgA; ④ Certain polypeptides with specific sequences maintain intestinal immune homeostasis by regulating the balance of T cell subsets.

[0116] 4. Synergistic mechanism of algal extracts and fermentation products

[0117] The Spirulina extract and Laminaria extract added in the present invention form a multi-level synergistic action system with the fermentation product. This synergistic action is mainly reflected in the following aspects:

[0118] Phycocyanin (C-phycocyanin and allophycocyanin) in the Spirulina extract has significant antioxidant activity, which can neutralize free radicals and reduce the damage of oxidative stress to intestinal epithelial cells. Research shows that phycocyanin enhances the intracellular redox balance system by activating the Nrf2 signaling pathway and upregulating the expression of antioxidant enzymes (such as SOD, GSH-Px, and CAT). This antioxidant effect complements the antioxidant polypeptides in the fermentation product, jointly improving the antioxidant capacity of the body.

[0119] Fucoidan in the Laminaria extract is a sulfated polysaccharide with unique immunomodulatory functions. Fucoidan binds to pattern recognition receptors (such as Toll-like receptor TLR4 and Dectin-1) on the surface of macrophages, dendritic cells, and NK cells, activating immune cells and promoting the secretion of cytokines (such as IL-12 and IFN-γ), enhancing cellular and humoral immune responses. At the same time, fucoidan can also regulate the composition of the intestinal flora, promoting the growth of beneficial bacteria (such as lactic acid bacteria and bifidobacteria) and inhibiting the reproduction of harmful bacteria. This effect synergizes with the short-chain fatty acids in the fermentation product.

[0120] In addition, the micronutrients (such as polyunsaturated fatty acids, minerals, vitamins) in the algal extract and the B vitamins, amino acids, and small molecule peptides in the fermentation products act synergistically to meet the special nutritional requirements of piglets during the weaning period and promote intestinal development and the maturation of immune organs.

[0121] Through the above multiple synergistic mechanisms, the weaning transition feed for piglets of the present invention can effectively alleviate the weaning stress response, maintain intestinal health, enhance immune function, improve feed utilization efficiency, and ultimately promote the healthy growth and development of piglets.

[0122] Example 1

[0123] This example provides a weaning transition feed for piglets with a compound fermented soybean meal of lactic acid bacteria and yeast, and its component ratio is as follows (by weight): 15 parts of compound fermented soybean meal, 50 parts of corn, 10 parts of wheat, 7 parts of fish meal, 3 parts of whey powder, 3 parts of vegetable oil, 1 part of amino acid supplement, 2 parts of mineral premix, 1 part of vitamin premix, and 1.5 parts of calcium and phosphorus supplement.

[0124] Among them, the preparation method of the compound fermented soybean meal includes the following steps:

[0125] (1) Strain activation and cultivation: Lactobacillus casei CGMCC1.62, Lactobacillus plantarum LP02, and Pediococcus acidilactici PA03 are taken out from the seed bank stored at -80°C, thawed at room temperature for 3 minutes, and then inoculated into 15 mL of MRS liquid medium respectively, and statically cultured at 37°C for 12 hours. After activation, the three lactic acid bacteria are respectively inoculated into 250 mL of MRS medium, with an inoculation amount of 3%, and statically cultured at 37°C for 20 hours to make the bacterial concentration reach 6×10 9 CFU / mL. Hansenula anomala CGMCC2.881 and Saccharomyces cerevisiae SC17-1 are taken out from the seed bank stored at -80°C, thawed at room temperature for 3 minutes, and then inoculated into 15 mL of YPD liquid medium respectively, and cultured with shaking (150 rpm) at 28°C for 16 hours. After activation, the two yeasts are respectively inoculated into 250 mL of YPD medium, with an inoculation amount of 3%, and cultured with shaking (150 rpm) at 28°C for 22 hours to make the bacterial concentration reach 2.5×10 8 CFU / mL.

[0126] (2) Soybean meal pretreatment: Select non-GMO soybean meal with a protein content of 46%, crush it using a pulverizer with a 60-mesh sieve, and the sieve passing rate reaches 95%. Mix the crushed soybean meal with water at a weight ratio of 1:1 to make the final moisture content reach 50%. After thorough mixing, perform high-pressure steaming at 121°C for 20 minutes. After steaming, use a cooling conveyor belt to cool the soybean meal to 40°C, and adjust the pH to 6.2 with a 2% citric acid solution.

[0127] (3) First-stage solid-state fermentation: Mix Hansenula anomala and Saccharomyces cerevisiae in a ratio of 2:1, inoculate them into the pretreated soybean meal at 1.0% of the soybean meal weight, and evenly spray them using a sprayer with a spray pressure of 0.2 MPa. After inoculation, use a horizontal mixer to mix evenly for 6 minutes at a rotation speed of 18 rpm, and then load the material into a fermentation tray, controlling the material layer thickness to be 2.5 cm. Place the loaded material in a fermentation chamber with a controlled temperature of 28°C and a relative humidity of 78% for fermentation for 24 hours, turning it over every 12 hours for 4 minutes each time. At the end of fermentation, the pH drops to 5.2, the yeast count reaches 5.5×10 7 CFU / g, and the degree of protein hydrolysis reaches 22%.

[0128] (4) Enzyme preparation addition: After the first-stage fermentation ends, add an enzyme preparation complex, including 0.2 parts by weight of acidic protease (activity 45,000 U / g), 0.15 parts by weight of neutral protease (activity 40,000 U / g), 0.1 parts by weight of β-glucanase (activity 25,000 U / g), 0.08 parts by weight of pectinase (activity 10,000 U / g), and 0.07 parts by weight of xylanase (activity 20,000 U / g). Dissolve the enzyme mixture in water at 4% of the material weight, and evenly spray it using an atomizing spray system with a pressure of 0.18 MPa, and then mix for 6 minutes to ensure uniform distribution. After adding the enzyme, adjust the material pH to 6.0 and the temperature to 38°C.

[0129] (5) Second-stage compound fermentation: Mix Lactobacillus casei, Lactobacillus plantarum, and Pediococcus acidilactici in a ratio of 3:2:1, inoculate them into the fermented material with added enzyme preparation at 2.0% of the soybean meal weight, and evenly spray them using a low-pressure atomizing spray system (pressure 0.12 MPa). After inoculation, mix for 6 minutes to ensure uniform distribution. Place the inoculated material in a fermentation chamber with a controlled temperature of 37°C and a relative humidity of 77% for fermentation for 48 hours. The ventilation volume in the first 24 hours is 0.4 m 3 / h·kg of material, and the ventilation volume in the next 24 hours is 0.15 m 3 / h·kg of the material, turn it over every 12 hours in the first 24 hours and turn it over slightly every 24 hours in the next 24 hours. At the end of fermentation, the pH drops to 4.2, the total number of lactic acid bacteria reaches 1.2×10 9 CFU / g, the content of short-chain fatty acids reaches 2.7%, the content of functional polypeptides reaches 3.2%, and the activity of trypsin inhibitor decreases by 87%.

[0130] (6) Stabilization of functional substances: Add 0.6 parts by weight of food-grade calcium carbonate and 1.2 parts by weight of microcrystalline cellulose, gently mix for 12 minutes, and adjust the pH to 5.0 to avoid loss of active substances caused by excessive stirring.

[0131] (7) Drying treatment: Adopt a hierarchical drying strategy. In the first stage, dry at 62°C for 1.8 hours to reduce the moisture content to 28%; in the second stage, dry at 52°C for 1.2 hours to reduce the moisture content to 13%; finally, cool at 28°C for 0.5 hours to reduce the product temperature to room temperature. At the end of drying, the moisture content is 11%, the water activity is 0.62, the viable count of lactic acid bacteria is 6×10 8 CFU / g, and the viable count of yeast is 1.5×10 7 CFU / g.

[0132] (8) Mixing of functional additives: Add 1.5 parts by weight of spirulina extract (protein content 60%, phycocyanin 15%) and 0.4 parts by weight of kelp extract (fucoidan content 25%, alginic acid 35%). Put the additives and the dried fermented soybean meal into a V-type mixer with a rotation speed of 18 rpm and mix for 18 minutes.

[0133] (9) Feed formula mixing: Mix the prepared compound fermented soybean meal with other feed raw materials evenly according to the formula ratio. The specific feed raw materials include: corn (protein content 8.7%, particle size 90 mesh), wheat (protein content 11.8%, particle size 85 mesh), fish meal (protein content 65%, imported Peruvian fish meal), whey powder (protein content 12%, lactose content 72%), a mixture of soybean oil and palm oil (ratio 2:1, peroxide value 0.2 meq / kg), amino acid supplement (including lysine hydrochloride 98.5%, methionine 99.0%, threonine 98.5%, tryptophan 98.0%, ratio 5:3:3:1), mineral premix (containing copper sulfate, zinc sulfate, manganese sulfate, potassium iodide, sodium selenite, etc., prepared according to the NRC 2012 standard), vitamin premix (containing vitamins A, D3, E, K, B vitamins, etc., prepared according to the NRC 2012 standard) and calcium and phosphorus supplement (calcium hydrogen phosphate 65% and limestone powder 35%). Use a horizontal double spiral ribbon mixer to mix at a rotation speed of 15 rpm for 16 minutes, and the filling coefficient is 0.45.

[0134] Example 2

[0135] This example provides a weaning transition feed for piglets with fermented soybean meal by compound fermentation of lactic acid bacteria and yeast. Its component ratio is as follows (by weight): 18 parts of compound fermented soybean meal, 48 parts of corn, 12 parts of wheat, 6 parts of fish meal, 4 parts of whey powder, 3.5 parts of vegetable oil, 1.5 parts of amino acid supplement, 2.5 parts of mineral premix, 1.5 parts of vitamin premix, and 2 parts of calcium and phosphorus supplement.

[0136] Among them, the preparation method of the compound fermented soybean meal includes the following steps:

[0137] (1) Strain activation and cultivation: Similar to Example 1, but the cultivation time of lactic acid bacteria is 22 hours to make the bacterial concentration reach 7×10 9 CFU / mL; the cultivation time of yeast is 24 hours to make the bacterial concentration reach 3×10 8 CFU / mL.

[0138] (2) Pretreatment of soybean meal: Select non-genetically modified soybean meal with a protein content of 47%, crush it with a pulverizer with a 70-mesh sieve, and the sieve-through rate reaches 97%. Mix the crushed soybean meal with water at a weight ratio of 1:0.9 to make the final moisture content reach 48%, and perform high-pressure steaming at 121°C for 19 minutes. After steaming, cool it to 39°C and adjust the pH to 6.5 with 3% sodium bicarbonate solution.

[0139] (3) First-stage solid-state fermentation: Mix Hansenula anomala and Saccharomyces cerevisiae in a ratio of 2:1 and inoculate them into the pretreated soybean meal at 1.2% of the weight of the soybean meal. After inoculation, control the thickness of the material layer to be 2.2 cm, and ferment at 29°C and a relative humidity of 75% for 25 hours, turning it over every 12 hours. At the end of fermentation, the pH drops to 5.0, the number of yeast reaches 6×10 7 CFU / g, and the degree of protein hydrolysis reaches 24%.

[0140] (4) Enzyme preparation addition: Add an enzyme preparation complex, including 0.22 parts by weight of acidic protease (activity 48,000 U / g), 0.18 parts by weight of neutral protease (activity 42,000 U / g), 0.12 parts by weight of β-glucanase (activity 28,000 U / g), 0.09 parts by weight of pectinase (activity 11,000 U / g), and 0.09 parts by weight of xylanase (activity 22,000 U / g). After adding the enzyme, adjust the pH of the material to 6.2 and the temperature to 39°C.

[0141] (5) Second-stage compound fermentation: Mix the three lactic acid bacteria in a ratio of 3:2:1 and inoculate them into the fermented material added with enzyme preparation at 2.2% of the weight of soybean meal. Ferment at 37 °C and relative humidity of 76% for 50 hours. The ventilation volume in the first 24 hours is 0.45 m 3 / h·kg of material, and the ventilation volume in the next 24 hours is 0.12 m 3 / h·kg of material. At the end of fermentation, the pH drops to 4.1, the total number of lactic acid bacteria reaches 1.5×10 9 CFU / g, the content of short-chain fatty acids reaches 2.8%, the content of functional polypeptides reaches 3.3%, and the activity of trypsin inhibitor is reduced by 89%.

[0142] (6) Stabilization of functional substances: Add 0.7 parts by weight of food-grade calcium carbonate and 1.3 parts by weight of microcrystalline cellulose, gently mix for 13 minutes, and adjust the pH to 5.1.

[0143] (7) Drying treatment: In the first stage, dry at 63 °C for 1.7 hours to reduce the moisture content to 27%; in the second stage, dry at 53 °C for 1.3 hours to reduce the moisture content to 12%; in the cooling stage, cool at 27 °C for 0.5 hours. At the end of drying, the moisture content is 10.5%.

[0144] (8) Mixing of functional additives: Add 1.8 parts by weight of spirulina extract and 0.45 parts by weight of kelp extract.

[0145] (9) Mixing of feed formula: Mix the prepared compound fermented soybean meal with other feed raw materials evenly according to the formula ratio. Among them, the amino acid supplement includes 98.5% lysine hydrochloride, 99.0% methionine, 98.5% threonine, 98.0% tryptophan, and the ratio is 6:3:2:1; the vegetable oil is a mixture of soybean oil and palm oil, and the ratio is 3:1.

[0146] Example 3

[0147] This example provides a weaning transition feed for piglets with compound fermented soybean meal of lactic acid bacteria and yeast, and its component ratio is as follows (in parts by weight): 20 parts of compound fermented soybean meal, 45 parts of corn, 15 parts of wheat, 5 parts of fish meal, 5 parts of whey powder, 4 parts of vegetable oil, 2 parts of amino acid supplement, 3 parts of mineral premix, 2 parts of vitamin premix, and 2 parts of calcium and phosphorus supplement.

[0148] Among them, the preparation method of the compound fermented soybean meal includes the following steps:

[0149] (1) Strain activation and cultivation: The cultivation time of lactic acid bacteria is 24 hours to make the bacterial concentration reach 8×10 9 CFU / mL; the cultivation time of yeast is 20 hours to make the bacterial concentration reach 2×10 8CFU / mL.

[0150] (2) Soybean meal pretreatment: Select non-genetically modified soybean meal with a protein content of 48%, crush it using a crusher with an 80-mesh sieve, and the sieve passing rate reaches 98%. Mix the crushed soybean meal with water at a weight ratio of 1:1.2 to make the final moisture content reach 52%, and perform high-pressure steaming at 121°C for 22 minutes. After steaming, cool it to 38°C and adjust the pH to 6.0 with a 2.5% citric acid solution.

[0151] (3) First-stage solid-state fermentation: Mix Hansenula anomala and Saccharomyces cerevisiae in a ratio of 2:1 and inoculate them into the pretreated soybean meal at 1.5% of the soybean meal weight. After inoculation, control the material layer thickness to be 3 cm and ferment at 28°C and a relative humidity of 80% for 26 hours, turning it once every 12 hours. At the end of fermentation, the pH drops to 5.3, the number of yeast cells reaches 6.5×10 7 CFU / g, and the degree of protein hydrolysis reaches 25%.

[0152] (4) Enzyme preparation addition: Add an enzyme preparation complex, including 0.25 parts by weight of acidic protease (activity 50,000 U / g), 0.2 parts by weight of neutral protease (activity 45,000 U / g), 0.15 parts by weight of β-glucanase (activity 30,000 U / g), 0.1 parts by weight of pectinase (activity 12,000 U / g), and 0.1 parts by weight of xylanase (activity 25,000 U / g). After adding the enzymes, adjust the material pH to 5.8 and the temperature to 40°C.

[0153] (5) Second-stage compound fermentation: Mix three kinds of lactic acid bacteria in a ratio of 3:2:1 and inoculate them into the fermented material with added enzyme preparation at 2.5% of the soybean meal weight. Ferment at 37°C and a relative humidity of 80% for 45 hours. The ventilation volume in the first 24 hours is 0.5 m 3 / h·kg of material, and the ventilation volume in the next 24 hours is 0.1 m 3 / h·kg of material. At the end of fermentation, the pH drops to 4.0, the total number of lactic acid bacteria reaches 2×10 9 CFU / g, the content of short-chain fatty acids reaches 3.0%, the content of functional polypeptides reaches 3.5%, and the activity of trypsin inhibitor is reduced by 90%.

[0154] (6) Functional substance stabilization: Add 0.8 parts by weight of food-grade calcium carbonate and 1.5 parts by weight of microcrystalline cellulose, gently mix for 15 minutes, and adjust the pH to 4.8.

[0155] (7) Drying treatment: In the first stage, dry at 65°C for 2.0 hours to reduce the moisture content to 25%; in the second stage, dry at 55°C for 1.5 hours to reduce the moisture content to 10%; in the cooling stage, cool at 25°C for 0.5 hours.

[0156] (8) Mixing of functional additives: Add 2.0 parts by weight of spirulina extract and 0.5 parts by weight of kelp extract.

[0157] (9) Mixing of feed formula: Mix the prepared compound fermented soybean meal with other feed raw materials evenly according to the formula ratio. Among them, in addition to the conventional lysine, methionine, threonine, and tryptophan in the amino acid supplement, glutamine and arginine are also added; the proportion of organic trace elements (chelated zinc, chelated iron, etc.) is increased in the mineral premix.

[0158] Example 4

[0159] This example provides a weaning transition feed for piglets with compound fermented soybean meal of lactic acid bacteria and yeast, and its component ratio is as follows (by weight): 17 parts of compound fermented soybean meal, 47 parts of corn, 14 parts of wheat, 5.5 parts of fish meal, 4.5 parts of whey powder, 3.8 parts of vegetable oil, 1.8 parts of amino acid supplement, 2.8 parts of mineral premix, 1.8 parts of vitamin premix, and 1.8 parts of calcium and phosphorus supplement.

[0160] Among them, the preparation method of the compound fermented soybean meal is similar to that of Example 2, but after the second-stage compound fermentation, the following additional steps are added:

[0161] Before the stabilization of the functional substances, add 0.2 parts by weight of oligopeptide mixture (molecular weight <5000Da, peptide content 88%) and 0.3 parts by weight of glutamine peptide (glutamine content 32%), and mix well for 10 minutes to further enhance the functional characteristics of the product.

[0162] In addition, in the step of mixing functional additives, in addition to adding spirulina extract and kelp extract, 0.2 parts by weight of taurine (purity 99.5%) and 0.1 parts by weight of arginine (L-arginine, purity 99.0%) are also added.

[0163] Example 5

[0164] This example provides a weaning transition feed for piglets with compound fermented soybean meal of lactic acid bacteria and yeast, and its main difference from Example 1 lies in the method of preparing the compound fermented soybean meal. The specific changes are as follows:

[0165] (1) Strain combination: Lactobacillus acidophilus LA05 was added to the Lactobacillus combination. The four Lactobacillus strains were mixed in the ratio of L. casei : L. plantarum : P. acidilactici : L. acidophilus = 3:2:1:1; Kluyveromyces marxianus KM06 was added to the yeast. The three yeast strains were mixed in the ratio of H. anomala : S. cerevisiae : K. marxianus = 2:1:1.

[0166] (2) Fermentation process adjustment: A three-stage fermentation process was adopted, and a transition stage was added between the original two stages. That is, after the yeast fermentation for 24 hours in the first stage, L. acidophilus and K. marxianus were first added for 12 hours of adaptive fermentation, and then other Lactobacillus strains were added for the third-stage fermentation for 36 hours.

[0167] (3) Enhancement of functional additives: In the step of mixing functional additives, in addition to the basic algal extract, 0.3 parts by weight of β-glucan (purity 95%, derived from yeast cell wall) and 0.2 parts by weight of mannan oligosaccharide (purity 98%) were added.

[0168] Example 6

[0169] This example provides a weaned piglet transition feed with fermented soybean meal by Lactobacillus and yeast. Its component ratio is similar to that of Example 3, but the preparation method of the fermented soybean meal adopts a combined liquid and solid fermentation process. The specific changes are as follows:

[0170] (1) Liquid fermentation in the first stage: The pretreated soybean meal was mixed with water at a ratio of 1:3 to make a soybean meal suspension. After inoculating yeast, it was fermented at 30 °C, pH 5.5, with a stirring speed of 150 rpm for 18 hours.

[0171] (2) Solid-liquid separation: The solid part in the fermentation broth was separated using a centrifuge (3000 g, 15 minutes) to obtain a wet material with a moisture content of about 70%.

[0172] (3) Semi-solid fermentation in the second stage: The moisture of the wet material was adjusted to 60%, inoculated with Lactobacillus, and fermented at 36 °C for 36 hours.

[0173] (4) Subsequent treatment: Similar to Example 3, but drying was carried out by microwave-assisted hot air drying with a microwave power of 600 W, and the drying time was shortened by 30%.

[0174] Example 7: Weaned piglets were fed in stages with the product of Example

[0175] This embodiment details the specific application method of the weaned piglet transition feed described in claim 10 during the period of 7 - 60 days of age. 120 healthy piglets of Duroc×Landrace×Yorkshire three - way crossbred were selected for the experiment and randomly divided into an experimental group and a control group, with 60 piglets in each group, 6 piglets in each pen, and 10 replicates in each group. The experimental group was fed the weaned piglet transition feed prepared in Example 3, and the control group was fed the traditional feed of Comparative Example 3. According to the piglet age, the feeding process was divided into three stages:

[0176] 1. Pre - weaning preparation stage (7 - 21 days of age):

[0177] At 7 days of age of the piglets, a small amount of weaned transition feed was provided, with an initial feeding amount of 15 g / head / day, and the feed particle diameter was 1.0 mm. To guide the piglets to eat, it was fed twice a day at 8:30 am and 16:30 pm. A small amount of 10% whey solution was sprayed in the feeder before feeding to increase palatability. The feeding amount was increased by 10 g / head every 3 days, and reached 75 g / head / day at 21 days of age. At this stage, the piglets still took breast milk as the main source of nutrition, and the feed was mainly used to cultivate the eating habit and adapt to solid feed. The remaining feed in the feeder was cleaned daily and the actual feed intake was recorded. The average daily feed intake of the experimental group reached 62 ± 5 g / head, significantly higher than that of the control group (48 ± 6 g / head, P < 0.05).

[0178] 2. Initial post - weaning transition stage (22 - 35 days of age):

[0179] The piglets were weaned at 21 days of age. On the day of weaning, the feeding amount was reduced to 35 g / head and fed in 4 small meals at 8:00, 12:00, 16:00, and 20:00. The feed particle diameter was increased to 1.2 mm. From the 2nd to the 3rd day after weaning, it was gradually increased to 80 g / head / day, and then increased by 20 g / head every 2 days, reaching 180 g / head / day at 35 days of age. Special attention was paid to observing the defecation and mental state of the piglets, and the feeding amount was adjusted in time if any abnormality was found. The average daily feed intake of the experimental group was 125 ± 12 g / head (22 - 28 days of age) and 172 ± 15 g / head (29 - 35 days of age), 18% and 24% higher than that of the control group respectively; the diarrhea rate of the experimental group was 3.3%, significantly lower than that of the control group (12.5%, P < 0.01).

[0180] 3. Post - weaning growth stage (36 - 60 days of age):

[0181] From 36 to 45 days of age, the daily feed intake gradually increases from 200 g / head to 300 g / head, and it is fed 3 times a day (8:00, 14:00, 20:00); from 46 to 60 days of age, the daily feed intake gradually increases from 300 g / head to 500 g / head, and the 3 - time feeding is maintained. The diameter of the feed pellets is 1.5 mm. The body weight of the piglets is measured weekly, and the daily weight gain is calculated. The average daily weight gains of the experimental group at 36 - 45 days of age and 46 - 60 days of age are 320 ± 25 g / head and 385 ± 30 g / head respectively, which are 15.2% and 18.7% higher than those of the control group respectively; the feed - to - gain ratios are 1.36 and 1.42 respectively, which are 10.5% and 12.3% lower than those of the control group respectively.

[0182] 4. Transition strategy:

[0183] During the transition period of each stage (20 - 22 days of age, 34 - 36 days of age), the mixed feeding method is adopted, and the proportion of the feed in the new stage increases day by day (33%, 67%, 100%) to help the piglets make a smooth transition. At the same time, after 36 days of age, the transition from a small feeding trough to a standard feeding trough begins to reduce the stress response.

[0184] Example 8: Health status monitoring

[0185] On the basis of Example 7, the health status of the piglets in the experimental group and the control group was systematically monitored.

[0186] During the pre - weaning preparation stage (7 - 21 days of age), fecal samples of 10 piglets are collected every 3 days to measure the contents of lactic acid bacteria, bifidobacteria and Escherichia coli in the feces. The results show that the contents of lactic acid bacteria and bifidobacteria in the feces of the experimental group increase from 6.35 log CFU / g and 5.82 log CFU / g at 7 days of age to 7.85 log CFU / g and 7.12 log CFU / g at 21 days of age, and the increase amplitude is significantly higher than that of the control group; while the content of Escherichia coli decreases from 6.25 log CFU / g at 7 days of age to 5.65 log CFU / g at 21 days of age, and the decrease amplitude is significantly greater than that of the control group.

[0187] During the initial weaning transition stage (22 - 35 days of age), blood samples of 10 piglets are collected every week to measure the levels of IgG, IgA and the content of inflammatory factors in the serum. The results show that the levels of IgG and IgA in the serum of the piglets in the experimental group slightly decrease 3 days after weaning, but the amplitude is significantly smaller than that of the control group; they start to recover and rise after 7 days, and are 28% and 35% higher than those of the control group respectively at 35 days of age. At the same time, the increase amplitude of the serum inflammatory factors (TNF - α and IL - 6) of the piglets in the experimental group during the weaning stress period is 45% lower than that of the control group, and the recovery speed is 38% faster.

[0188] During the post - weaning growth stage (36 - 60 days of age), intestinal morphology was examined in 10 piglets every two weeks. The results showed that the intestinal villus height, crypt depth ratio, and goblet cell count in the experimental group of piglets were significantly better than those in the control group, indicating better intestinal development and stronger barrier function. By 60 days of age, the jejunal villus height in the experimental group of piglets was 25% higher than that in the control group, the crypt depth ratio was 15% lower, and the villus height / crypt depth ratio was 45% higher.

[0189] Comparative Example 1

[0190] This comparative example provides a weaning transition feed for piglets fermented with single - strain lactic acid bacteria soybean meal, with the same component ratio as in Example 1, but the compound - fermented soybean meal is replaced by single - strain lactic acid bacteria fermented soybean meal.

[0191] The preparation method of single - strain lactic acid bacteria fermented soybean meal is as follows:

[0192] (1) Strain culture: Only Lactobacillus casei was cultured, and the method was the same as in Example 1.

[0193] (2) Soybean meal pretreatment: The method was the same as in Example 1.

[0194] (3) Fermentation: The cultured L. casei was directly inoculated into the pretreated soybean meal at 2.0% of the soybean meal weight, and fermented at 37 °C and a relative humidity of 77% for 72 hours, with turning once every 24 hours.

[0195] (4) Drying treatment: The method was the same as in Example 1.

[0196] (5) Mixing of functional additives and feed formula mixing: The method was the same as in Example 1.

[0197] Comparative Example 2

[0198] This comparative example provides a weaning transition feed for piglets fermented with simply - mixed strains of lactic acid bacteria synchronous fermentation soybean meal, with the same component ratio as in Example 2, but the compound - fermented soybean meal is replaced by simply - mixed strains of lactic acid bacteria synchronous fermentation soybean meal.

[0199] The preparation method of simply - mixed strains of lactic acid bacteria synchronous fermentation soybean meal is as follows:

[0200] (1) Strain culture: Lactobacillus casei, Lactobacillus plantarum, Pediococcus acidilactici, Hanseniaspora anomala, and Saccharomyces cerevisiae were cultured separately, and the method was the same as in Example 2.

[0201] (2) Soybean meal pretreatment: The method was the same as in Example 2.

[0202] (3) Fermentation: All the cultured strains were inoculated into the pretreated soybean meal simultaneously at 3.0% of the weight of the soybean meal (2.0% lactic acid bacteria and 1.0% yeast), and fermented for 60 hours at 35°C and a relative humidity of 75%. It was turned over every 12 hours.

[0203] (4) Drying treatment: The method was the same as that in Example 2.

[0204] (5) Mixing of functional additives and feed formula mixing: The method was the same as that in Example 2.

[0205] Comparative Example 3

[0206] This comparative example provides a traditional weaned piglet transition feed without compound fermented soybean meal, and its component ratio is as follows (by weight): 20 parts of unfermented soybean meal, 47 parts of corn, 15 parts of wheat, 8 parts of fish meal, 3 parts of plasma protein, 4 parts of whey powder, 3.5 parts of vegetable oil, 2 parts of amino acid supplement, 2.5 parts of mineral premix, 2 parts of vitamin premix, 2 parts of calcium and phosphorus supplement, and 0.1 part of antibiotic growth promoter.

[0207] Experimental Example 1: Detection of feed physical and chemical indexes

[0208] The physical and chemical indexes of the feeds prepared in Examples 1-6 and Comparative Examples 1-3 were detected, and the results are shown in Table 1.

[0209] Table 1 Detection results of feed physical and chemical indexes

[0210]

[0211]

[0212] Experimental Example 2: Detection of compound fermented soybean meal characteristics

[0213] The characteristics of the fermented soybean meal used in Examples 1-6 and Comparative Examples 1-2 and the unfermented soybean meal used in Comparative Example 3 were detected, and the results are shown in Table 2.

[0214] Table 2 Detection results of fermented soybean meal characteristics

[0215]

[0216] Experimental Example 3: Evaluation of piglet growth performance

[0217] Healthy weaned piglets (Duroc×Landrace×Yorkshire three-way crossbreds) were selected, weaned at 21 days of age, with an average weight of 7.2±0.4 kg. They were randomly divided into 9 groups, with 36 piglets in each group, 6 piglets in each pen, and 6 replicates in each group. The experimental period was 35 days (21 - 56 days of age), and the piglets were fed the feeds prepared in Examples 1 - 6 and Comparative Examples 1 - 3, respectively. The average daily feed intake (ADFI), average daily gain (ADG), feed to gain ratio (F / G), and diarrhea rate of piglets in each group were recorded. The results are shown in Table 3.

[0218] Table 3 Results of the evaluation of growth performance of piglets

[0219]

[0220] Experimental Example 4: Evaluation of intestinal health indicators

[0221] After the experiment, 12 piglets were randomly selected from each group (2 piglets were selected from each replicate pen), and fecal samples were collected to measure indicators such as the composition of intestinal microflora and the content of short-chain fatty acids. The results are shown in Table 4.

[0222] Table 4 Results of the evaluation of intestinal health indicators

[0223]

[0224]

[0225] Experimental Example 5: Evaluation of immune function

[0226] After the experiment, 12 piglets were randomly selected from each group (2 piglets were selected from each replicate pen), and blood samples were collected to measure serum immunoglobulins, inflammatory factors, antioxidant indicators, etc. The results are shown in Table 5.

[0227] Table 5 Results of the evaluation of immune function

[0228]

[0229]

[0230] From the above experimental results, it can be seen that the weaning transition feed for piglets with the compound fermentation of soybean meal by lactic acid bacteria and yeast of the present invention is significantly superior to the control group in all indicators.

[0231] First, from the perspective of the characteristics of fermented soybean meal, the fermented soybean meal prepared by the two-stage composite fermentation process adopted in the present invention has a higher protein digestibility (82 - 86%) and anti-nutritional factor reduction rate (86 - 90%), which are significantly better than those of single lactic acid bacteria fermentation (Comparative Example 1, 65% and 70%) and simple mixed-strain synchronous fermentation (Comparative Example 2, 72% and 75%). In addition, the composite fermented soybean meal of the present invention contains higher concentrations of short-chain fatty acids (2.7 - 3.0%) and functional polypeptides (3.2 - 3.5%), and these bioactive substances play an important protective role in the intestinal health of piglets.

[0232] Secondly, from the perspective of the growth performance of piglets, the feed intake of the piglet group fed with the feed of the present invention increased (456 - 483 g / d vs 395 - 428 g / d), the daily weight gain increased (324 - 355 g / d vs 255 - 298 g / d), the feed-to-meat ratio improved (1.36 - 1.41 vs 1.44 - 1.55), and the diarrhea rate decreased significantly (3.2 - 4.2% vs 6.5 - 12.3%). Among them, Examples 3 and 6 had the best effects, which may be related to their higher addition amount of composite fermented soybean meal (20%) and more optimized fermentation process.

[0233] From the perspective of intestinal health indicators, the feed of the present invention significantly increased the number of beneficial bacteria (lactic acid bacteria and bifidobacteria) in the intestines of piglets, decreased the number of potential pathogenic bacteria (Escherichia coli), increased the content of short-chain fatty acids, and decreased the intestinal pH value. These changes are conducive to maintaining the balance of the intestinal flora, enhancing the intestinal barrier function, reducing intestinal inflammation, thereby reducing the incidence of diarrhea and improving the feed digestion and absorption efficiency.

[0234] From the perspective of immune function, the feed of the present invention increased the serum IgG and IgA levels of piglets, decreased the content of inflammatory factors (TNF-α and IL-6), and enhanced the activities of antioxidant enzymes (SOD and GSH-Px). This indicates that the feed of the present invention can enhance the immune function of piglet bodies, reduce the inflammatory response, improve the antioxidant capacity, and comprehensively enhance the resistance of piglets.

[0235] The superiority of the present invention is mainly reflected in the following aspects:

[0236] 1. Innovative composite strain system: Three kinds of lactic acid bacteria and two kinds of yeasts are selected and combined in a specific ratio to form a complementary and symbiotic microbial ecosystem, which improves the fermentation efficiency and product functionality. Different strains complement each other in carbohydrate metabolism, pH tolerance, and functional characteristics, reducing nutrient competition and improving the system robustness.

[0237] 2. Innovation in two-stage fermentation process: An innovative fermentation strategy of "yeast first - lactic acid bacteria relay" is adopted to solve the contradiction that the growth conditions of lactic acid bacteria and yeast are not completely compatible. In the first stage, yeast ferments to degrade complex carbohydrates, creating conditions for the subsequent growth of lactic acid bacteria; in the second stage, lactic acid bacteria and yeast form a dynamic equilibrium ecosystem, improving fermentation efficiency and product quality.

[0238] 3. Innovation in enzymatic hydrolysis and co-fermentation: Specific combinations of enzyme preparations are added during the fermentation process to form a synergistic effect with microorganisms, significantly increasing the degree of protein hydrolysis and the degradation rate of anti-nutritional factors. The enzyme systems produced by microorganisms and exogenous enzymes form a "wide pH range" hydrolysis system at different pH intervals, improving the overall hydrolysis efficiency.

[0239] 4. Directed production of functional polypeptides and short-chain fatty acids: By precisely controlling the fermentation conditions, bioactive substances with specific functions are produced directionally, including ACE inhibitory peptides, antioxidant peptides, immunomodulatory peptides, and short-chain fatty acids, improving their bioaccessibility and stability.

[0240] 5. Multi-level nutrition and functional synergy: Each component in the feed formula forms a multi-level nutrition and functional synergy system, including a digestive system synergy mechanism, an intestinal health synergy mechanism, and an immunomodulatory synergy mechanism, comprehensively meeting the special nutritional needs of weaned piglets.

[0241] In summary, the weaned piglet transition feed with compound fermentation of lactic acid bacteria and yeast of the present invention has obvious technological innovation and application value, can effectively alleviate the weaning stress reaction of piglets, reduce the incidence of diarrhea, improve the growth performance and health level of piglets, and provides a new technical approach for the healthy breeding of piglets.

Claims

1. The weaning transition feed for piglets with fermented soybean meal by compound fermentation of lactic acid bacteria and yeast is characterized in that, The feed contains the following components in parts by weight: Compound fermented soybean meal 15 - 20 parts, Corn 45 - 50 parts, Wheat 10 - 15 parts, Fish meal 5 - 7 parts, Whey powder 3 - 5 parts, Vegetable oil 3 - 4 parts, Amino acid supplement 1 - 2 parts, Mineral premix 2 - 3 parts, Vitamin premix 1 - 2 parts, Calcium and phosphorus supplement 1.5 - 2 parts; Among them, the compound fermented soybean meal is prepared by compound fermentation of soybean meal with lactic acid bacteria and yeast.

2. The weaning transition feed for piglets according to claim 1, wherein The lactic acid bacteria in the compound fermented soybean meal include one or more of the following: lactic acid bacteria of the genus Lactobacillus and lactic acid bacteria of the genus Pediococcus; the yeast includes one or more of the following: Hansenula anomala and Saccharomyces cerevisiae.

3. The weaning transition feed for piglets according to claim 2, wherein The lactic acid bacteria include: Lactobacillus casei, Lactobacillus plantarum and Pediococcus acidilactici, and the lactic acid bacteria are mixed in the ratio of Lactobacillus casei:Lactobacillus plantarum:Pediococcus acidilactici = 3:2:1; the yeast includes: Hansenula anomala and Saccharomyces cerevisiae, and the yeast is mixed in the ratio of Hansenula anomala:Saccharomyces cerevisiae = 2:1; the ratio of lactic acid bacteria to yeast is 2:

1.

4. The weaning transition feed for piglets according to claim 1, characterized in that, The compound fermented soybean meal has the following characteristics: Protein digestibility ≥ 80%; Reduction rate of anti-nutritional factors ≥ 85%; Content of short-chain fatty acids is 2.5 - 3.0%; Content of functional polypeptides is 3.0 - 3.5%; The viable lactic acid bacteria content ≥ 5×10 8 CFU / g; The viable yeast content ≥ 1×10 7 CFU / g.

5. A method for preparing the weaning transition feed for piglets according to any one of claims 1-4, characterized in that, It includes the following steps: (1) Strain activation and cultivation: Inoculate lactic acid bacteria into MRS medium and culture at 36 - 38 °C for 18 - 24 hours to make the bacterial concentration reach ≥ 5×10 9 CFU / mL; Inoculate yeast into YPD medium and culture at 28 - 30 °C for 20 - 24 hours to make the bacterial concentration reach ≥ 2×10 8 CFU / mL; (2) Pretreatment of soybean meal: Crush the soybean meal to 60 - 80 mesh, adjust the water content to 48 - 52%, carry out high-pressure steaming at 121 ± 2 °C for 18 - 22 minutes, cool to 38 - 42 °C, and adjust the pH to 6.0 - 6.5; (3) First-stage solid-state fermentation: Inoculate the cultured yeast into the pretreated soybean meal at 1.0 - 1.5% of the weight of the soybean meal, ferment at 28 ± 1 °C for 22 - 26 hours, and control the relative humidity at 75 - 80%; (4) Addition of enzyme preparation: After the first-stage fermentation is completed, add an enzyme preparation complex, with a total addition amount of 0.4 - 0.8% of the weight of the soybean meal, adjust the pH to 5.8 - 6.2, and the temperature to 37 - 40 °C; (5) Second-stage compound fermentation: Inoculate the cultured lactic acid bacteria mixture into the fermented material added with the enzyme preparation at 2.0 - 2.5% of the weight of the soybean meal, ferment at 37 ± 1 °C for 45 - 50 hours, and control the relative humidity at 75 - 80%; (6) Stabilization of functional substances: Add 0.5 - 0.8 parts by weight of calcium carbonate and 1.0 - 1.5 parts by weight of microcrystalline cellulose, and adjust the pH to 4.8 - 5.2; (7) Drying treatment: Hot air dry the fermented material at 60 - 65 °C until the moisture content ≤ 12%; (8) Mixing of functional additives: Add 1.0 - 2.0 parts by weight of spirulina extract and 0.3 - 0.5 parts by weight of kelp extract; (9) Feed formula mixing: Mix the prepared compound fermented soybean meal with other feed raw materials evenly according to the ratio described in Claim 1 to make a weaning transition feed for piglets.

6. The method according to claim 5, wherein In the first-stage solid-state fermentation described in step (3), the thickness of the fermentation material layer is controlled to be 2 - 3 cm, and it is turned over every 12 ± 1 hour. The determination conditions for the fermentation end point are: the pH drops to 5.0 - 5.3, the number of yeast cells ≥ 5×10 7 CFU / g, and the degree of proteolysis reaches 20 - 25%.

7. The method according to claim 5, wherein The enzyme preparation complex described in step (4) includes: 0.15 - 0.25 parts by weight of acidic protease with an activity of 40,000 - 50,000 U / g; 0.10 - 0.20 parts by weight of neutral protease with an activity of 35,000 - 45,000 U / g; 0.05 - 0.15 parts by weight of β-glucanase with an activity of 20,000 - 30,000 U / g; 0.05 - 0.10 parts by weight of pectinase with an activity of 8,000 - 12,000 U / g; 0.05 - 0.10 parts by weight of xylanase with an activity of 15,000 - 25,000 U / g.

8. The method according to claim 5, wherein In the second-stage compound fermentation described in step (5), the ventilation volume in the first 24 hours is 0.3 - 0.5 m 3 / h·kg of material, and the ventilation volume in the subsequent 24 hours is 0.1 - 0.2 m 3 / h·kg of material; the determination conditions for the fermentation end point are: the pH drops to 4.0 - 4.5, the total number of lactic acid bacteria ≥ 1×10 9 CFU / g, the short-chain fatty acid content ≥ 2.5%, the functional polypeptide content ≥ 3.0%, and the trypsin inhibitor activity is reduced by ≥ 85%.

9. The method according to claim 5, characterized in that The drying treatment described in step (7) adopts a staged drying strategy: The first stage: 60 - 65 °C, 1.5 - 2.0 hours, reduce the moisture to 25 - 30%; The second stage: 50 - 55 °C, 1.0 - 1.5 hours, reduce the moisture to 12 - 15%; The cooling stage: 25 - 30 °C, 0.5 hours, reduce the product temperature to room temperature.

10. Use of the piglet weaning transition feed according to any one of claims 1-4 in the preparation of a piglet weaning transition feed, characterized in that, The weaning transition feed for piglets is used for feeding piglets during the period of 7 - 60 days old, and includes: The pre-weaning preparation stage at 7 - 21 days old: The initial daily feeding amount is 10 - 20 g / head, and the feeding amount is increased by 10 g / head every 3 days; The early weaning transition stage at 22 - 35 days old: Feed in 4 - 6 small meals at a time, and the daily feeding amount gradually increases from 30 - 40 g / head to 150 - 200 g / head; The post-weaning growth stage at 36 - 60 days old: The daily feeding amount gradually increases from 200 - 300 g / head to 300 - 500 g / head, and gradually transitions from 4 feedings to 3 feedings.

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