Compound feed for raising plateau live pigs and preparation method of compound feed

Abstract

The invention discloses a compound feed for raising plateau live pigs and a preparation method thereof, and relates to the technical field of feed processing. The compound feed for raising the plateau live pigs is prepared from manganese-selenium compound modified charcoal, soybean polysaccharide polylysine-based supported nanoparticles, aspergillus oryzae, soybean meal powder, corn flour, wheat bran, mountain flour, calcium hydrophosphate, table salt and multivitamins. Manganese-selenium composite modified charcoal, soybean polysaccharide polylysine-based supported nanoparticles and aspergillus oryzae are subjected to co-fermentation culture to form a uniform, stable, loose and porous three-dimensional network fermentation substrate composite system, so that the damage of gastric acid to components is reduced, the targeted release of intestinal tracts is realized, and the bioavailability is improved. The composite functional additive which is high in nutrition, easy to absorb, anti-oxidation, anti-anemia, anti-ultraviolet radiation and the like is obtained, and the adverse effects of low temperature, oxygen deficit and ultraviolet factors on animal growth and feed oxidative rancidity are effectively reduced.

Description

Technical Field

[0001] This invention belongs to the field of feed processing technology, specifically referring to a compound feed for raising high-altitude pigs and its preparation method. Background Technology

[0002] The abundant forest resources and natural grasslands of the plateau region provide a high-quality free-range environment for pigs, and the livestock industry provides a stable source of income for plateau farmers and herdsmen. Plateau pigs are rich in trace elements and high-quality protein, and their low-fat characteristics meet the needs of modern healthy diets, playing a positive role in improving anemia and cardiovascular diseases. However, with the continuous increase in feed raw material costs and feed prices, the pig farming industry faces significant challenges. Therefore, improving the feed utilization rate of fattening pigs is the core path to improving the economic benefits of breeding and promoting the sustainable development of animal husbandry.

[0003] The existing technology currently has the following main problems:

[0004] The unique geographical environment of the plateau, with its low temperature and lack of oxygen, affects the nutrient absorption of pigs, resulting in slow growth. At the same time, strong ultraviolet radiation accelerates the oxidation and rancidity of nutrients in feed, reducing feed quality and also having an adverse effect on the growth of pigs. Summary of the Invention

[0005] In view of the above situation and to overcome the defects of the prior art, the present invention proposes a compound feed for high-yield pigs, comprising the following components in parts by weight: 3-5 parts of manganese-selenium modified biochar, 3-6 parts of soybean polysaccharide polylysine-supported nanoparticles, 1-3 parts of Aspergillus oryzae, 40-50 parts of soybean meal, 80-120 parts of corn flour, 50-60 parts of wheat bran, 8-10 parts of limestone powder, 20-30 parts of dicalcium phosphate, 5-10 parts of salt, and 3-5 parts of compound vitamins.

[0006] The manganese-selenium composite modified biochar comprises the following components in parts by weight: 30-40 parts corn straw powder, 10-30 parts manganese chloride tetrahydrate, 0.1-0.3 parts sodium selenite, and 1-3 parts ascorbic acid.

[0007] The preparation method of the manganese-selenium composite modified biochar specifically includes the following steps:

[0008] (1) Dissolve manganese chloride tetrahydrate in 50 mL of deionized water, then add 3.0-4.0 g of washed corn stalk powder, stir for 30-40 min, and dry the resulting slurry in an oven at 60-80℃ for 1-2 h. Then transfer it to a crucible and place it in a tube furnace under nitrogen protection. Pyrolyze it at 500-600℃ for 1-2 h. After cooling, grind the product and pass it through a 60-80 mesh sieve. The organic matter in the corn stalk powder is carbonized under anaerobic conditions to form a porous biochar framework. At the same time, manganese oxide nanoparticles are loaded on the surface and pores of the biochar, increasing the specific surface area and active sites of the biochar. The porous structure of the biochar provides adsorption, protection and slow release functions. The biochar itself is black and has excellent ultraviolet absorption capacity. The tiny carbon particles The granules can effectively block and absorb ultraviolet rays, preventing them from directly irradiating sensitive nutrients in the feed and reducing oxidative rancidity. Biochar can also serve as an attachment point and proliferation carrier for beneficial microorganisms such as lactic acid bacteria and bifidobacteria, optimizing the intestinal flora structure, adsorbing nutrients, and prolonging their residence time in the intestine, thereby improving the absorption and utilization of nutrients in the feed. This strongly promotes the growth of high-yield pigs in extreme environments. Furthermore, through the action of slow-release manganese ions, it ensures that high-yield pigs can still synthesize sufficient manganese superoxide dismutase in hypoxic and low-temperature environments, enhancing the antioxidant capacity of the matrix and alleviating oxidative damage. Manganese is also an activator of various digestive enzymes. Sufficient manganese nutrition helps maintain normal digestive function and improve the absorption efficiency of nutrients, resulting in manganese-doped biochar.

[0009] (2) Dissolve sodium selenite in 500 mL of deionized water to obtain a sodium selenite solution for later use. Add the manganese-doped biochar described in step (1) to the sodium selenite solution, and then place it on a magnetic stirrer. Stir at 50-60℃ for 8-12 h at a stirring speed of 600-800 rpm. Then add 0.1-0.3 g of ascorbic acid and continue stirring for 1-2 h. Centrifuge at 8000-12000 rpm for 10-15 min. Collect the solid product and wash it with deionized water until no white precipitate is detected in the supernatant using silver nitrate solution. Finally, dry the product in an oven at 60-80℃ to constant weight. This process The reduced elemental selenium was deposited in situ on manganese-doped biochar. Manganese and selenium constructed a synergistic antioxidant system of manganese superoxide dismutase and glutathione peroxidase, which effectively reduced oxidative damage, maintained the integrity of intestinal mucosal cells, and improved the nutrient absorption area and efficiency. This improved nutrient absorption under low temperature and hypoxia conditions, helped improve the energy conversion efficiency of feed, and was beneficial to the growth performance of high-yield pigs. At the same time, it also reduced the inhibition of hematopoietic stem cells by oxidative damage, improved the anemia symptoms of high-yield pigs, promoted hematopoiesis and oxygen transport, and thus reduced the adverse effects of hypoxia and loss of appetite on growth performance, resulting in manganese-selenium composite modified biochar.

[0010] Preferably, in step (1), the amount of manganese chloride tetrahydrate added is 1.0-3.0g. At high temperature, manganese chloride tetrahydrate is converted into manganese oxide, which can slowly release manganese ions in the intestine of high-altitude pigs, providing a safe and long-lasting manganese supplement, avoiding the problems of acute toxicity and excessive bioavailability of directly using manganese salts.

[0011] Preferably, in step (2), the amount of sodium selenite added is 10-30 mg. The introduction of selenium not only promotes the synthesis of glutathione peroxidase, but also helps maintain normal thyroid function. Thyroid hormones have a promoting effect on the absorption and utilization of iron.

[0012] This invention also provides a method for preparing a compound feed for feeding high-altitude pigs, specifically including the following steps:

[0013] S1. Add quercetin to a 1 mL centrifuge tube, then add 0.5-0.8 mL of dimethyl sulfoxide solvent. Vortex and heat to 35°C to completely dissolve it. Adjust the volume to 1 mL using a pH 5.5 buffer solution to obtain a quercetin solution for later use. Prepare a 0.5 mmol / L ferrous gluconate solution by directly using a pH 5.5 buffer solution with 0.45-0.50 g of ferrous gluconate. Dilute both the quercetin and ferrous gluconate solutions to 1 mmol / L, with each dilution volume being 10 mL. Maintain the pH of the quercetin dilution at 5.5. Slowly add 3 mL of the ferrous gluconate dilution to 6 mL of the quercetin dilution solution, and vortex to mix. Heat and stir the reaction system at 40-50°C and 100-200 rpm for 1-2 hours. Dialyze the system using a dialysis bag with a molecular weight cutoff of 100-500 Da. After 24-48 hours, the solution in the dialysis bag is collected and freeze-dried. After being chelated by quercetin, the reactivity of iron ions is encapsulated and stabilized, no longer catalyzing the Fenton reaction to produce hydroxyl radicals. This avoids the adverse effects of traditional iron supplements on feed oxidative rancidity, forming organic iron with higher absorption rate. It effectively improves anemia symptoms in high-altitude environments, reduces hypoxia in pig tissues, and thus improves oxygen supply and function of the intestinal mucosa. At the same time, quercetin protects cell membranes and DNA from oxidative damage, and iron helps the body efficiently remove peroxides such as hydrogen peroxide. Together, they construct a comprehensive antioxidant defense network from prevention to elimination, effectively resisting oxidative stress, thereby protecting intestinal cells, improving nutrient absorption efficiency, and forming a strong antioxidant protective layer at the feed level to directly resist the damage of ultraviolet radiation, ensuring the nutritional quality of the feed, and obtaining quercetin@ferrous gluconate supramolecular freeze-dried powder.

[0014] S2. Add 0.2-0.8g of soybean polysaccharide to 50-60mL of deionized water, stir magnetically for 1-2 hours, and adjust the pH to 7.0 to obtain a soybean polysaccharide solution for later use. Dissolve polylysine in 40-50mL of PBS buffer, and then slowly add the polylysine solution dropwise to the soybean polysaccharide solution. Stir magnetically for 1-2 hours, and adjust the pH to 7.0. Centrifuge at 3000-4000rpm for 10-15min, and then separate and purify using a Millipore ultrafiltration tube with a molecular weight cutoff of 100kDa to obtain a soybean polysaccharide-based polylysine nanoparticle suspension for later use. Dissolve the quercetin@ferrous gluconate supramolecular lyophilized powder obtained in step S1 in PBS buffer at pH 7.5-8.5, and sonicate at 50-80W. Slowly add the obtained quercetin@ferrous gluconate solution to soybean polysaccharide solution under magnetic stirring and in the dark. After the polysaccharide-based polylysine nanoparticles were added dropwise to the suspension, the mixture was stirred for 1-2 hours in the dark. The mixture was then separated and purified again using a Millipore ultrafiltration tube with a molecular weight cutoff of 100 kDa. The suspension in the ultrafiltration tube was collected, and 0.3-0.5 g of mannitol was added. The mixture was pre-frozen at -80℃ for 2-3 hours and then freeze-dried. Polylysine and soybean polysaccharides formed nanoparticles through electrostatic interaction, providing a water-soluble and protective shell for the hydrophobic quercetin@ferrous gluconate supramolecular freeze-dried powder. The nanoparticles significantly increased the specific surface area, improved dispersibility and mucosal cell contact in the gastrointestinal tract of high-yield pigs, enhanced the absorption efficiency of quercetin and iron, improved blood oxygen-carrying capacity, effectively improved intestinal oxygen supply and mucosal health, improved nutrient absorption efficiency in high-yield pigs, and improved growth performance, resulting in soybean polysaccharide polylysine-based supported nanoparticles.

[0015] S3. Inoculate 1.0-3.0g of Aspergillus oryzae cells onto potato dextrose agar slant medium and incubate at 28-30℃ for 3-5 days. Add 10-20mL of sterile physiological saline containing 0.05% Tween-80 to the activated slant. Gently scrape the surface of the mycelial growth with a sterile L-shaped glass rod to wash off the spores. Then filter through a sterile filter containing defatted cotton, remove the mycelial fragments, add 2-3 sterile glass beads to the filtrate, and vortex for 5-10 minutes to ensure sufficient spore dispersion. Count the spores under a microscope using a hemocytometer, and dilute with sterile physiological saline containing 0.05% Tween-80 to a bacterial concentration of 2×10⁻⁶. 8 Spore count / mL: Aspergillus oryzae improves feed digestibility by producing proteases and amylases through fermentation, reduces the oxygen consumption required to digest the food itself, and can also produce a large number of exogenous enzymes such as proteases, amylases, and cellulases to pre-digest macromolecular nutrients in feed, generating more easily absorbed small peptides, amino acids and oligosaccharides, improving digestive performance, and better improving growth performance, thus obtaining Aspergillus oryzae spore suspension;

[0016] S4. Mix soybean meal powder and manganese-selenium composite modified biochar evenly, add deionized water to adjust the moisture content to 50-55%, autoclave at 121℃ for 20-30 minutes, cool, and obtain the fermentation medium for later use. Inoculate the Aspergillus oryzae spore suspension obtained in step S3 into the fermentation medium, wherein the inoculation amount of Aspergillus oryzae spore suspension is based on 5-10% of the fermentation medium volume. Perform shallow-tray solid-state fermentation at 28-30℃ and 70-80% humidity for 48-72 hours, stirring 1-2 times during the process. 6-12 hours before the end of fermentation, evenly sprinkle the soybean polysaccharide polylysine-supported nanoparticles obtained in step S2 into the medium, stir evenly, and continue culturing. After fermentation, dry at low temperature at 50-60℃, pulverize and sieve. The manganese-selenium composite modified biochar and soybean polysaccharide polylysine-supported nanoparticles are then fermented. Particles, Aspergillus oryzae spores, and soybean meal powder combine with each other through physical adsorption, intermolecular forces, and even hyphal entanglement to form a uniform, stable, loose, and porous three-dimensional network fermentation substrate composite system. The enzymes secreted by microorganisms and the pre-digested nutrients produced are also present in this network. This feed additive integrates multiple functions such as digestive enhancement, anti-oxidation, anti-anemia, and anti-ultraviolet radiation, which significantly improves the digestive performance of pigs, enhances their growth performance, and effectively reduces the adverse effects of low temperature, hypoxia, and ultraviolet radiation on feed and animal growth. The resulting compound functional additive is ready for use. Finally, the compound functional additive is mixed evenly with corn flour, wheat bran, limestone powder, dicalcium phosphate, salt, and compound vitamins. The compound vitamins are pig compound vitamins produced by Shanghai Fulante Animal Health Co., Ltd., to obtain a compound feed for high-altitude pigs.

[0017] Preferably, in step S1, the amount of quercetin added is 3.02-3.22 mg. Quercetin can increase the expression of iron transport proteins in intestinal cells, promote the absorption and transport of iron into the body, improve iron deficiency anemia from the root cause, and improve the blood's oxygen-carrying capacity and nutrient transport capacity.

[0018] Preferably, in step S2, the amount of polylysine added is 160-200 mg. As a natural cationic antimicrobial peptide, polylysine directly inhibits the growth of mold and putrefactive bacteria in high-altitude feed, preventing feed spoilage.

[0019] The beneficial effects achieved by this invention are as follows:

[0020] This invention utilizes manganese-selenium composite modified biochar, soybean polysaccharide polylysine-supported nanoparticles, and Aspergillus oryzae for co-fermentation. The components are interconnected through physical adsorption, intermolecular forces, and hyphal entanglement, forming a uniform, stable, loose, and porous three-dimensional network fermentation matrix composite system. This not only reduces the damage of gastric acid to the components and achieves targeted release into the intestine, but also provides an environment for the activation, growth, and enzyme production of Aspergillus oryzae spores. The result is a multifunctional additive with high nutritional value, easy absorption, antioxidant properties, anti-anemia effects, and UV radiation resistance. This significantly improves the digestive performance of high-yield pigs and effectively reduces the adverse effects of low temperature, hypoxia, and UV radiation on animal growth and feed oxidative rancidity. The manganese-selenium composite modified... In this biochar process, manganese oxide nanoparticles are first loaded onto the surface and pores of the biochar. Then, elemental selenium generated from reduction is deposited in situ onto the manganese-doped biochar. The manganese and selenium construct a synergistic antioxidant system of manganese superoxide dismutase and glutathione peroxidase, effectively reducing oxidative damage, maintaining the integrity of intestinal mucosal cells, and increasing nutrient absorption area and efficiency. This improves nutrient absorption under low temperature and hypoxic conditions, promoting the growth of high-altitude pigs. Simultaneously, it reduces the inhibition of hematopoietic stem cells by oxidative damage, improves anemia symptoms in high-altitude pigs, and promotes hematopoiesis and oxygen transport, thereby reducing the adverse effects of hypoxia and loss of appetite on growth performance. Furthermore, the biochar exhibits excellent ultraviolet absorption... The biochar has excellent absorption capacity, effectively blocking and absorbing ultraviolet rays, reducing feed oxidative rancidity. It also serves as an attachment point and proliferation carrier for beneficial microorganisms, optimizing the intestinal flora structure, adsorbing nutrients, and prolonging their residence time in the intestines, thereby improving nutrient absorption and utilization. This also helps improve the growth performance of high-altitude pigs in extreme environments. In the soybean polysaccharide polylysine-supported nanoparticles, polylysine and soybean polysaccharide form nanoparticles through electrostatic interaction, providing a water-soluble and protective shell for the quercetin@ferrous gluconate supramolecular freeze-dried powder. The nanoparticles significantly increase the specific surface area, improving dispersibility in the gastrointestinal tract of high-altitude pigs and their contact with mucosal cells, thus significantly enhancing... This study improved the absorption efficiency of quercetin and iron, correcting hypoxic-iron-deficiency anemia in a highly bioavailable organic form, enhancing blood oxygen-carrying capacity, effectively improving intestinal oxygen supply and mucosal health, increasing nutrient absorption efficiency in high-yield pigs, and improving growth performance. Quercetin and ferrous gluconate together constructed a comprehensive antioxidant defense network, effectively resisting oxidative stress, protecting the integrity of intestinal cells, and improving nutrient absorption efficiency. At the same time, the biopolysaccharides and polylysine on the surface of the nanoparticles provided the first physical antioxidant barrier for vitamins, fats, and other nutrients in the feed, while quercetin@ferrous gluconate served as the second antioxidant protective layer, effectively resisting the damage of ultraviolet radiation and reducing oxidative rancidity of the feed.This invention relates to a compound feed for high-altitude pigs, made from manganese-selenium modified biochar, soybean polysaccharide polylysine-supported nanoparticles, Aspergillus oryzae, soybean meal, corn flour, wheat bran, limestone powder, dicalcium phosphate, salt, and compound vitamins. This feed improves symptoms of oxidative stress and anemia caused by the high-altitude environment, promotes nutrient absorption efficiency, and effectively reduces the adverse effects of low temperature, hypoxia, and ultraviolet radiation on animal growth and feed oxidative rancidity. Attached Figure Description

[0021] Figure 1 The graph shows the hemoglobin concentration results of Examples 1-4 and Comparative Examples 1-3 of this invention;

[0022] Figure 2 These are growth performance results for Examples 1-4 and Comparative Examples 1-3 of the present invention;

[0023] Figure 3 The graphs show the peroxide value results of Examples 1-4 and Comparative Examples 1-3 of the present invention. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those familiar to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to this invention. The preferred embodiments and materials described herein are for illustrative purposes only and do not limit the scope of this application.

[0026] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods; unless otherwise specified, the experimental materials used in the following embodiments are all purchased from commercial channels.

[0027] The reagents used in the examples were sourced from the following sources:

[0028] Aspergillus oryzae brand Tanmo quality inspection, product number BHCC102358.

[0029] Example 1

[0030] This embodiment proposes a compound feed for raising high-yield pigs, comprising the following components in parts by weight: 5 parts manganese-selenium modified biochar, 6 parts soybean polysaccharide polylysine-supported nanoparticles, 3 parts Aspergillus oryzae, 50 parts soybean meal, 120 parts corn flour, 60 parts wheat bran, 10 parts limestone powder, 30 parts dicalcium phosphate, 10 parts salt, and 5 parts compound vitamins.

[0031] Manganese-selenium composite modified biochar comprises the following components in parts by weight: 40 parts corn straw powder, 30 parts manganese chloride tetrahydrate, 0.3 parts sodium selenite, and 3 parts ascorbic acid.

[0032] The preparation method of manganese-selenium composite modified biochar specifically includes the following steps:

[0033] (1) Manganese chloride tetrahydrate was dissolved in 50 mL of deionized water. The amount of manganese chloride tetrahydrate added was 3.0 g. At high temperature, manganese chloride tetrahydrate was converted into manganese oxide, which can slowly release manganese ions in the intestine of high-altitude pigs, providing a safe and long-lasting manganese supplement, avoiding the problems of acute toxicity and excessive bioavailability of direct use of manganese salt. Then, 4.0 g of washed corn stalk powder was added and stirred for 40 min. The resulting slurry was first dried in an oven at 80 °C for 2 h, and then transferred to a crucible and placed in a tube furnace under nitrogen protection. It was pyrolyzed at 600 °C for 2 h. After cooling, the product was ground and passed through an 80-mesh sieve. The organic matter in the corn stalk powder was carbonized under anaerobic conditions to form a porous biochar framework. At the same time, manganese oxide nanoparticles were loaded on the surface and pores of the biochar, increasing the specific surface area and active sites of the biochar. The porous structure of the biochar provided adsorption, Biochar offers protection and slow-release properties. Its black color and excellent UV absorption capabilities, combined with tiny carbon particles, effectively block and absorb ultraviolet rays, preventing direct exposure to sensitive nutrients in feed and reducing oxidative rancidity. Biochar also serves as an attachment point and growth carrier for beneficial microorganisms such as lactic acid bacteria and bifidobacteria, optimizing intestinal flora structure, adsorbing nutrients, and prolonging their residence time in the intestines. This enhances the absorption and utilization of nutrients in feed, significantly promoting the growth of high-yield pigs in extreme environments. Furthermore, through the slow-release of manganese ions, it ensures that high-yield pigs can still synthesize sufficient manganese superoxide dismutase under hypoxic and low-temperature conditions, enhancing the matrix's antioxidant capacity and mitigating oxidative damage. Manganese is also an activator of various digestive enzymes; sufficient manganese nutrition helps maintain normal digestive function and improves nutrient absorption efficiency, resulting in manganese-doped biochar.

[0034] (2) Dissolve sodium selenite in 500 mL of deionized water. The amount of sodium selenite added is 30 mg. The introduction of selenium not only promotes the synthesis of glutathione peroxidase, but also helps maintain normal thyroid function. Thyroid hormones promote the absorption and utilization of iron. Sodium selenite solution is obtained and set aside. Add the manganese-doped biochar described in step (1) to the sodium selenite solution, and then place it on a magnetic stirrer. Stir at 60°C for 12 h at a stirring speed of 800 rpm. Then add 0.3 g of ascorbic acid and continue stirring for 2 h. Centrifuge at 12000 rpm for 15 min. Collect the solid product and wash it with deionized water until no white precipitate is detected in the supernatant by silver nitrate solution. Finally, the product was dried to constant weight in an 80℃ oven. This process deposits the reduced elemental selenium in situ onto manganese-doped biochar. Manganese and selenium construct a synergistic antioxidant system of manganese superoxide dismutase and glutathione peroxidase, which effectively reduces oxidative damage, maintains the integrity of intestinal mucosal cells, and improves the nutrient absorption area and efficiency. This improves nutrient absorption under low temperature and hypoxia conditions, helps improve the energy conversion efficiency of feed, and is beneficial to the growth performance of high-yield pigs. At the same time, it also reduces the inhibition of hematopoietic stem cells by oxidative damage, improves the anemia symptoms of high-yield pigs, promotes hematopoiesis and oxygen transport, and thus reduces the adverse effects of hypoxia and loss of appetite on growth performance, resulting in manganese-selenium composite modified biochar.

[0035] This embodiment provides a method for preparing a compound feed for feeding high-altitude pigs, specifically including the following steps:

[0036] S1. Add quercetin to a 1mL centrifuge tube. The amount of quercetin added is 3.22mg. Quercetin can increase the expression of iron transport proteins in intestinal cells, promote iron absorption and transport into the body, fundamentally improve iron deficiency anemia, and improve the blood's oxygen-carrying capacity and nutrient transport capacity. Then add 0.8mL of dimethyl sulfoxide solvent, vortex and heat to 35℃ to completely dissolve it. Use a pH 5.5 buffer solution to make up to 1mL to obtain a quercetin solution for later use. Then add 0. 50g of ferrous gluconate was directly prepared into a 0.5mmol / L ferrous gluconate solution using a pH 5.5 buffer solution. Then, the quercetin solution and ferrous gluconate solution were diluted to 1mmol / L, with each dilution volume being 10mL. The pH of the quercetin dilution was controlled at 5.5. 3mL of the ferrous gluconate dilution was slowly added to 6mL of the quercetin dilution, and the mixture was shaken to mix thoroughly. The reaction system was then incubated at 50℃ and 200rpm. The mixture was heated and stirred for 2 hours, then dialyzed for 48 hours using a dialysis bag with a molecular weight cutoff of 500 Da. The solution in the dialysis bag was collected and freeze-dried. After being chelated by quercetin, the reactivity of iron ions was encapsulated and stabilized, no longer catalyzing the Fenton reaction to produce hydroxyl radicals. This avoided the adverse effects of traditional iron supplements on feed oxidative rancidity, forming organic iron with higher absorption rate. This effectively improved anemia symptoms in high-altitude environments, reduced hypoxia in pig tissues, and improved oxygen supply and function of the intestinal mucosa. At the same time, quercetin protected cell membranes and DNA from oxidative damage, and iron helped the body efficiently remove peroxides such as hydrogen peroxide. Together, they constructed a comprehensive antioxidant defense network from prevention to removal, effectively resisting oxidative stress, thus protecting intestinal cells, improving nutrient absorption efficiency, and forming a strong antioxidant protective layer at the feed level to directly resist the damage of ultraviolet radiation, ensuring the nutritional quality of the feed. The resulting product was quercetin@ferrous gluconate supramolecular freeze-dried powder.

[0037] S2. Add 0.8g of soybean polysaccharide to 60mL of deionized water, stir magnetically for 2 hours, and adjust the pH to 7.0 to obtain a soybean polysaccharide solution for later use. Dissolve 200mg of polylysine in 40mL of PBS buffer. Polylysine, as a natural cationic antimicrobial peptide, directly inhibits the growth of mold and putrefactive bacteria in high-altitude feed, preventing feed spoilage. Slowly add the polylysine solution dropwise to the soybean polysaccharide solution, stir magnetically for 2 hours, and adjust the pH to 7.0. Centrifuge at 4000rpm for 15min, then separate and purify using a Millipore ultrafiltration tube with a molecular weight cutoff of 100kDa to obtain a soybean polysaccharide-based polylysine nanoparticle suspension for later use. Dissolve the quercetin@ferrous gluconate supramolecular lyophilized powder obtained in step S1 in PBS buffer at pH 8.5, and use 80W ultrasonic assistance to obtain quercetin@gluconate supramolecular lyophilized powder. The acid solution was slowly added to the suspension of soybean polysaccharide-based polylysine nanoparticles under magnetic stirring and in the dark. After the addition was completed, stirring was continued for 2 hours in the dark. The suspension was then separated and purified again using a Millipore ultrafiltration tube with a molecular weight cutoff of 100 kDa. The suspension in the ultrafiltration tube was collected, and 0.5 g of mannitol was added. The suspension was pre-frozen at -80℃ for 3 hours and then freeze-dried. Polylysine and soybean polysaccharide formed nanoparticles through electrostatic interaction, providing a water-soluble and protective shell for the hydrophobic quercetin@ferrous gluconate supramolecular freeze-dried powder. The nanoparticles greatly increased the specific surface area, improved the dispersibility and mucosal cell contact in the gastrointestinal tract of high-yield pigs, enhanced the absorption efficiency of quercetin and iron, improved the blood oxygen carrying capacity, effectively improved intestinal oxygen supply and mucosal health, improved the nutrient absorption efficiency of high-yield pigs, and improved growth performance, thus obtaining soybean polysaccharide polylysine-based supported nanoparticles.

[0038] S3. Inoculate 3.0g of Aspergillus oryzae cells onto potato dextrose agar slant and incubate at 30℃ for 5 days. Add 20mL of sterile physiological saline containing 0.05% Tween-80 to the activated slant. Gently scrape the surface of the mycelial growth with a sterile L-shaped glass rod to wash away the spores. Then filter through a sterile filter containing defatted cotton, remove the mycelial fragments, add 3 sterile glass beads to the filtrate, and vortex for 10 minutes to ensure sufficient spore dispersion. Count the spores under a microscope using a hemocytometer, and dilute with sterile physiological saline containing 0.05% Tween-80 to a bacterial concentration of 2×10⁻⁶. 8 Spore count / mL: Aspergillus oryzae improves feed digestibility by producing proteases and amylases through fermentation, reduces the oxygen consumption required to digest the food itself, and can also produce a large number of exogenous enzymes such as proteases, amylases, and cellulases to pre-digest macromolecular nutrients in feed, generating more easily absorbed small peptides, amino acids and oligosaccharides, improving digestive performance, and better improving growth performance, thus obtaining Aspergillus oryzae spore suspension;

[0039] S4. Mix soybean meal powder and manganese-selenium composite modified biochar evenly, add deionized water to adjust the moisture content to 55%, autoclave at 121℃ for 30 minutes, cool, and obtain fermentation medium for later use. Inoculate the Aspergillus oryzae spore suspension obtained in step S3 into the fermentation medium, wherein the inoculation amount of Aspergillus oryzae spore suspension is based on 10% of the fermentation medium volume. Perform shallow-tray solid-state fermentation at 30℃ and 80% humidity for 72 hours, stirring twice during the process. 12 hours before the end of fermentation, evenly sprinkle the soybean polysaccharide polylysine-supported nanoparticles obtained in step S2 into the medium, stir evenly, and continue culturing. After fermentation, dry at 60℃, pulverize and sieve. The mixture of manganese-selenium composite modified biochar, soybean polysaccharide polylysine-supported nanoparticles, Aspergillus oryzae spores, and soybean meal powder is then fermented. Through physical adsorption, intermolecular forces, and even mycelial entanglement, a uniform, stable, loose, and porous three-dimensional network fermentation substrate composite system is formed. The enzymes secreted by microorganisms and the pre-digested nutrients produced are also present in this network. This feed additive integrates multiple functions such as digestive enhancement, anti-oxidation, anti-anemia, and anti-ultraviolet radiation, which significantly improves the digestive performance of pigs, enhances their growth performance, and effectively reduces the adverse effects of low temperature, hypoxia, and ultraviolet radiation on feed and animal growth. The resulting compound functional additive is ready for use. Finally, the compound functional additive is mixed evenly with corn flour, wheat bran, limestone powder, dicalcium phosphate, salt, and compound vitamins. The compound vitamins are pig compound vitamins produced by Shanghai Fulante Animal Health Co., Ltd., to obtain a compound feed for high-altitude pigs.

[0040] Example 2

[0041] This embodiment proposes a compound feed for raising high-yield pigs, comprising the following components in parts by weight: 3 parts manganese-selenium modified biochar, 3 parts soybean polysaccharide polylysine-supported nanoparticles, 1 part Aspergillus oryzae, 40 parts soybean meal, 80 parts corn flour, 50 parts wheat bran, 8 parts limestone powder, 20 parts dicalcium phosphate, 5 parts salt, and 3 parts compound vitamins.

[0042] Manganese-selenium composite modified biochar comprises the following components in parts by weight: 30 parts corn straw powder, 10 parts manganese chloride tetrahydrate, 0.1 parts sodium selenite, and 1 part ascorbic acid.

[0043] The preparation method of manganese-selenium composite modified biochar specifically includes the following steps:

[0044] (1) Manganese chloride tetrahydrate was dissolved in 50 mL of deionized water. The amount of manganese chloride tetrahydrate added was 1.0 g. At high temperature, manganese chloride tetrahydrate was converted into manganese oxide, which can slowly release manganese ions in the intestine of high-altitude pigs, providing a safe and long-lasting manganese supplement, avoiding the problems of acute toxicity and excessive bioavailability of direct use of manganese salt. Then, 3.0 g of washed corn stalk powder was added and stirred for 30 min. The resulting slurry was first dried in an oven at 60 °C for 1 h, and then transferred to a crucible and placed in a tube furnace under nitrogen protection. It was pyrolyzed at 500 °C for 1 h. After cooling, the product was ground and passed through a 60-mesh sieve. The organic matter in the corn stalk powder was carbonized under anaerobic conditions to form a porous biochar framework. At the same time, manganese oxide nanoparticles were loaded on the surface and pores of the biochar, increasing the specific surface area and active sites of the biochar. The porous structure of the biochar provided adsorption, Biochar offers protection and slow-release properties. Its black color and excellent UV absorption capabilities, combined with tiny carbon particles, effectively block and absorb ultraviolet rays, preventing direct exposure to sensitive nutrients in feed and reducing oxidative rancidity. Biochar also serves as an attachment point and growth carrier for beneficial microorganisms such as lactic acid bacteria and bifidobacteria, optimizing intestinal flora structure, adsorbing nutrients, and prolonging their residence time in the intestines. This enhances the absorption and utilization of nutrients in feed, significantly promoting the growth of high-yield pigs in extreme environments. Furthermore, through the slow-release of manganese ions, it ensures that high-yield pigs can still synthesize sufficient manganese superoxide dismutase under hypoxic and low-temperature conditions, enhancing the matrix's antioxidant capacity and mitigating oxidative damage. Manganese is also an activator of various digestive enzymes; sufficient manganese nutrition helps maintain normal digestive function and improves nutrient absorption efficiency, resulting in manganese-doped biochar.

[0045] (2) Dissolve sodium selenite in 500 mL of deionized water. The amount of sodium selenite added is 10 mg. The introduction of selenium not only promotes the synthesis of glutathione peroxidase, but also helps maintain normal thyroid function. Thyroid hormones promote the absorption and utilization of iron. Sodium selenite solution is obtained and set aside. Add the manganese-doped biochar described in step (1) to the sodium selenite solution, and then place it on a magnetic stirrer. Stir at 50°C for 8 h at a stirring speed of 600 rpm. Then add 0.1 g of ascorbic acid and continue stirring for 1 h. Centrifuge at 8000 rpm for 10 min. Collect the solid product and wash it with deionized water until no white precipitate is detected in the supernatant by silver nitrate solution. Finally, the product was dried to constant weight in a 60℃ oven. This process deposits the reduced elemental selenium in situ onto manganese-doped biochar. Manganese and selenium construct a synergistic antioxidant system of manganese superoxide dismutase and glutathione peroxidase, which effectively reduces oxidative damage, maintains the integrity of intestinal mucosal cells, and increases the nutrient absorption area and efficiency. This improves nutrient absorption under low temperature and hypoxic conditions, helps improve the energy conversion efficiency of feed, and is beneficial to the growth performance of high-yield pigs. At the same time, it also reduces the inhibition of hematopoietic stem cells by oxidative damage, improves anemia symptoms in high-yield pigs, promotes hematopoiesis and oxygen transport, and thus reduces the adverse effects of hypoxia and loss of appetite on growth performance, resulting in manganese-selenium composite modified biochar.

[0046] This embodiment provides a method for preparing a compound feed for feeding high-altitude pigs, specifically including the following steps:

[0047] S1. Add quercetin to a 1mL centrifuge tube. The amount of quercetin added is 3.02mg. Quercetin can increase the expression of iron transport proteins in intestinal cells, promote iron absorption and transport into the body, fundamentally improve iron deficiency anemia, and improve the blood's oxygen-carrying capacity and nutrient transport capacity. Then add 0.5mL of dimethyl sulfoxide solvent, vortex and heat to 35℃ to completely dissolve it. Use a pH 5.5 buffer solution to make up to 1mL to obtain a quercetin solution for later use. Then add 0. 45g of ferrous gluconate was directly prepared into a 0.5mmol / L ferrous gluconate solution using a pH 5.5 buffer solution. Then, the quercetin solution and ferrous gluconate solution were diluted to 1mmol / L, with each dilution volume being 10mL. The pH of the quercetin dilution was controlled at 5.5. 3mL of the ferrous gluconate dilution was slowly added to 6mL of the quercetin dilution, and the mixture was shaken to mix thoroughly. The reaction system was then incubated at 40℃ and 100rpm. After hot stirring for 1 hour, the solution was dialyzed for 24 hours using a dialysis bag with a molecular weight cutoff of 100 Da. The solution in the dialysis bag was collected and freeze-dried. After being chelated by quercetin, the reactivity of iron ions was encapsulated and stabilized, no longer catalyzing the Fenton reaction to produce hydroxyl radicals. This avoided the adverse effects of traditional iron supplements on feed oxidative rancidity, forming organic iron with higher absorption rate. This effectively improved anemia symptoms in high-altitude environments and reduced hypoxia in pig tissues, thereby improving oxygen supply and function of the intestinal mucosa. At the same time, quercetin protected cell membranes and DNA from oxidative damage, and iron helped the body efficiently remove peroxides such as hydrogen peroxide. Together, they constructed a comprehensive antioxidant defense network from prevention to removal, effectively resisting oxidative stress, thereby protecting intestinal cells, improving nutrient absorption efficiency, and forming a strong antioxidant protective layer at the feed level to directly resist the damage of ultraviolet radiation, ensuring the nutritional quality of the feed. The resulting product is quercetin@ferrous gluconate supramolecular freeze-dried powder.

[0048] S2. Add 0.2g of soybean polysaccharide to 50mL of deionized water, stir magnetically for 1h, and adjust the pH to 7.0 to obtain a soybean polysaccharide solution for later use. Then dissolve polylysine in 50mL of PBS buffer (160mg of polylysine is added). Polylysine, as a natural cationic antimicrobial peptide, directly inhibits the growth of mold and putrefactive bacteria in high-altitude feed, preventing feed spoilage. Then slowly add the polylysine solution dropwise to the soybean polysaccharide solution, stir magnetically for 1h, and adjust the pH to 7.0. Centrifuge at 3000rpm for 10min, and then separate and purify using a Millipore ultrafiltration tube with a molecular weight cutoff of 100kDa to obtain a soybean polysaccharide-based polylysine nanoparticle suspension for later use. Dissolve the quercetin@ferrous gluconate supramolecular lyophilized powder obtained in step S1 in PBS buffer at pH 7.5, and use 50W sonication to obtain quercetin@gluconate supramolecular lyophilized powder. The acid solution was slowly added to the suspension of soybean polysaccharide-based polylysine nanoparticles under magnetic stirring and in the dark. After the addition was completed, stirring was continued for 1 hour in the dark. The suspension was then separated and purified again using a Millipore ultrafiltration tube with a molecular weight cutoff of 100 kDa. The suspension in the ultrafiltration tube was collected, and 0.3 g of mannitol was added. The suspension was pre-frozen at -80℃ for 2 hours and then freeze-dried. Polylysine and soybean polysaccharide formed nanoparticles through electrostatic interaction, providing a water-soluble and protective shell for the hydrophobic quercetin@ferrous gluconate supramolecular freeze-dried powder. The nanoparticles greatly increased the specific surface area, improved the dispersibility and mucosal cell contact in the gastrointestinal tract of high-yield pigs, enhanced the absorption efficiency of quercetin and iron, improved the blood oxygen carrying capacity, effectively improved intestinal oxygen supply and mucosal health, improved the nutrient absorption efficiency of high-yield pigs, and improved growth performance, thus obtaining soybean polysaccharide polylysine-based supported nanoparticles.

[0049] S3. Inoculate 1.0 g of Aspergillus oryzae cells onto potato dextrose agar slant and incubate at 28°C for 3 days. Add 10 mL of sterile physiological saline containing 0.05% Tween-80 to the activated slant. Gently scrape the surface of the mycelial growth with a sterile L-shaped glass rod to wash away the spores. Then filter through a sterile filter containing absorbent cotton, remove the mycelial fragments, add 2 sterile glass beads to the filtrate, and vortex for 5 minutes to ensure sufficient spore dispersion. Count the spores under a microscope using a hemocytometer, and dilute with sterile physiological saline containing 0.05% Tween-80 to a bacterial concentration of 2 × 10⁻⁶. 8 Spore count / mL: Aspergillus oryzae improves feed digestibility by producing proteases and amylases through fermentation, reduces the oxygen consumption required to digest the food itself, and can also produce a large number of exogenous enzymes such as proteases, amylases, and cellulases to pre-digest macromolecular nutrients in feed, generating more easily absorbed small peptides, amino acids and oligosaccharides, improving digestive performance, and better improving growth performance, thus obtaining Aspergillus oryzae spore suspension;

[0050] S4. Mix soybean meal powder and manganese-selenium composite modified biochar evenly, add deionized water to adjust the moisture content to 50%, autoclave at 121℃ for 20 minutes, cool, and obtain fermentation medium for later use. Inoculate the Aspergillus oryzae spore suspension obtained in step S3 into the fermentation medium, wherein the inoculation amount of Aspergillus oryzae spore suspension is based on 5% of the fermentation medium volume. Perform shallow-tray solid-state fermentation at 28℃ and 70% humidity for 48 hours, stirring once during the process. Six hours before the end of fermentation, evenly sprinkle the soybean polysaccharide polylysine-supported nanoparticles obtained in step S2 into the medium, stir evenly, and continue culturing. After fermentation, dry at 50℃, pulverize and sieve. The manganese-selenium composite modified biochar, soybean polysaccharide polylysine-supported nanoparticles, Aspergillus oryzae spores, and soybean meal powder are then processed. Through physical adsorption, intermolecular forces, and even hyphal entanglement, a uniform, stable, loose, and porous three-dimensional network fermentation substrate composite system is formed. The enzymes secreted by microorganisms and the pre-digested nutrients produced are also present in this network. This feed additive integrates multiple functions such as digestive enhancement, anti-oxidation, anti-anemia, and anti-ultraviolet radiation, which significantly improves the digestive performance of pigs, enhances their growth performance, and effectively reduces the adverse effects of low temperature, hypoxia, and ultraviolet radiation on feed and animal growth. The resulting compound functional additive is ready for use. Finally, the compound functional additive is mixed evenly with corn flour, wheat bran, limestone powder, dicalcium phosphate, salt, and compound vitamins. The compound vitamins are pig compound vitamins produced by Shanghai Fulante Animal Health Co., Ltd., to obtain a compound feed for high-altitude pigs.

[0051] Example 3

[0052] This embodiment proposes a compound feed for raising high-yield pigs, comprising the following components in parts by weight: 4 parts manganese-selenium modified biochar, 4.5 parts soybean polysaccharide polylysine-supported nanoparticles, 2 parts Aspergillus oryzae, 45 parts soybean meal, 100 parts corn flour, 55 parts wheat bran, 9 parts limestone powder, 25 parts dicalcium phosphate, 7.5 parts salt, and 4 parts compound vitamins.

[0053] Manganese-selenium composite modified biochar comprises the following components in parts by weight: 35 parts corn straw powder, 20 parts manganese chloride tetrahydrate, 0.2 parts sodium selenite, and 2 parts ascorbic acid.

[0054] The preparation method of manganese-selenium composite modified biochar specifically includes the following steps:

[0055] (1) Manganese chloride tetrahydrate was dissolved in 50 mL of deionized water. The amount of manganese chloride tetrahydrate added was 2.0 g. At high temperature, manganese chloride tetrahydrate was converted into manganese oxide, which can slowly release manganese ions in the intestine of high-altitude pigs, providing a safe and long-lasting manganese supplement. This avoids the problems of acute toxicity and excessive bioavailability caused by direct use of manganese salts. Then, 3.5 g of washed corn stalk powder was added and stirred for 35 min. The resulting slurry was first dried in an oven at 70 °C for 1.5 h, and then transferred to a crucible and placed in a tube furnace under nitrogen protection. It was then pyrolyzed at 550 °C for 1.5 h. After cooling, the product was ground and passed through a 70-mesh sieve. The organic matter in the corn stalk powder was carbonized under anaerobic conditions to form a porous biochar framework. At the same time, manganese oxide nanoparticles were loaded on the surface and pores of the biochar, increasing the specific surface area and active sites of the biochar. The porous structure of the biochar provided absorption Biochar possesses attachment, protection, and slow-release functions. Its black color and excellent UV absorption capacity, along with its tiny carbon particles, effectively block and absorb ultraviolet rays, preventing direct exposure to sensitive nutrients in feed and reducing oxidative rancidity. Biochar also serves as an attachment point and proliferation carrier for beneficial microorganisms such as lactic acid bacteria and bifidobacteria, optimizing the intestinal flora structure, adsorbing nutrients, and prolonging their residence time in the intestines. This enhances the absorption and utilization of nutrients in feed, significantly promoting the growth of high-yield pigs in extreme environments. Furthermore, through the slow-release of manganese ions, it ensures that high-yield pigs can still synthesize sufficient manganese superoxide dismutase under hypoxic and low-temperature conditions, enhancing the matrix's antioxidant capacity and mitigating oxidative damage. Manganese is also an activator of various digestive enzymes; sufficient manganese nutrition helps maintain normal digestive function and improves nutrient absorption efficiency, resulting in manganese-doped biochar.

[0056] (2) Dissolve sodium selenite in 500 mL of deionized water. The amount of sodium selenite added is 20 mg. The introduction of selenium not only promotes the synthesis of glutathione peroxidase, but also helps maintain normal thyroid function. Thyroid hormones promote the absorption and utilization of iron. Sodium selenite solution is obtained and set aside. Add the manganese-doped biochar described in step (1) to the sodium selenite solution, and then place it on a magnetic stirrer. Stir at 55°C for 10 h at a stirring speed of 700 rpm. Then add 0.2 g of ascorbic acid and continue stirring for 1.5 h. Centrifuge at 10000 rpm for 12.5 min. Collect the solid product and wash it with deionized water until the supernatant is free of white residue when tested with silver nitrate solution. After precipitation, the product is dried to constant weight in a 70℃ oven. This process deposits the reduced elemental selenium in situ onto manganese-doped biochar. Manganese and selenium construct a synergistic antioxidant system of manganese superoxide dismutase and glutathione peroxidase, effectively reducing oxidative damage, maintaining the integrity of intestinal mucosal cells, and increasing the nutrient absorption area and efficiency. This improves nutrient absorption under low temperature and hypoxic conditions, helps improve the energy conversion efficiency of feed, and is beneficial to the growth performance of high-yield pigs. At the same time, it also reduces the inhibition of hematopoietic stem cells by oxidative damage, improves anemia symptoms in high-yield pigs, promotes hematopoiesis and oxygen transport, and thus reduces the adverse effects of hypoxia and loss of appetite on growth performance, resulting in manganese-selenium composite modified biochar.

[0057] This embodiment provides a method for preparing a compound feed for feeding high-altitude pigs, specifically including the following steps:

[0058] S1. Add quercetin to a 1mL centrifuge tube. The amount of quercetin added is 3.12mg. Quercetin can increase the expression of iron transport proteins in intestinal cells, promote iron absorption and transport into the body, fundamentally improve iron deficiency anemia, and improve blood oxygen-carrying capacity and nutrient transport capacity. Then add 0.65mL of dimethyl sulfoxide solvent, vortex and heat to 35℃ to completely dissolve it. Use pH 5.5 buffer solution to make up to 1mL to obtain a quercetin solution for later use. Then add 0... 0.47g of ferrous gluconate was directly prepared into a 0.5mmol / L ferrous gluconate solution using a pH 5.5 buffer solution. Then, the quercetin solution and ferrous gluconate solution were diluted to 1mmol / L, with each dilution volume being 10mL. The pH of the quercetin dilution was controlled at 5.5. 3mL of the ferrous gluconate dilution was slowly added to 6mL of the quercetin dilution, and the mixture was shaken to mix thoroughly. The reaction system was then incubated at 45℃ and 150rpm. After hot stirring for 1.5 hours, the solution was dialyzed for 36 hours using a dialysis bag with a molecular weight cutoff of 300 Da. The solution in the dialysis bag was collected and freeze-dried. After being chelated by quercetin, the reactivity of iron ions was encapsulated and stabilized, no longer catalyzing the Fenton reaction to produce hydroxyl radicals. This avoided the adverse effects of traditional iron supplements on feed oxidative rancidity, forming organic iron with higher absorption rate. This effectively improved anemia symptoms in high-altitude environments and reduced hypoxia in pig tissues, thereby improving oxygen supply and function of the intestinal mucosa. At the same time, quercetin protected cell membranes and DNA from oxidative damage, and iron helped the body efficiently remove peroxides such as hydrogen peroxide. Together, they constructed a comprehensive antioxidant defense network from prevention to removal, effectively resisting oxidative stress, thereby protecting intestinal cells, improving nutrient absorption efficiency, and forming a strong antioxidant protective layer at the feed level to directly resist the damage of ultraviolet radiation, ensuring the nutritional quality of the feed. The resulting product is quercetin@ferrous gluconate supramolecular freeze-dried powder.

[0059] S2. Add 0.5g of soybean polysaccharide to 55mL of deionized water, stir magnetically for 1.5h, and adjust the pH to 7.0 to obtain a soybean polysaccharide solution for later use. Dissolve 180mg of polylysine in 45mL of PBS buffer. Polylysine, as a natural cationic antimicrobial peptide, directly inhibits the growth of mold and putrefactive bacteria in high-altitude feed, preventing feed spoilage. Slowly add the polylysine solution dropwise to the soybean polysaccharide solution, stir magnetically for 1.5h, and adjust the pH to 7.0. Centrifuge at 3500rpm for 12.5min, then separate and purify using a Millipore ultrafiltration tube with a molecular weight cutoff of 100kDa to obtain a soybean polysaccharide-based polylysine nanoparticle suspension for later use. Dissolve the quercetin@ferrous gluconate supramolecular lyophilized powder obtained in step S1 in PBS buffer at pH 8.0, and sonicate at 65W to obtain the quercetin@ferrous gluconate supramolecular lyophilized powder. The glycolic acid solution was slowly added to the soybean polysaccharide-based polylysine nanoparticle suspension under magnetic stirring and in the dark. After the addition was complete, stirring was continued for 1.5 h in the dark. The suspension was then separated and purified again using a Millipore ultrafiltration tube with a molecular weight cutoff of 100 kDa. The suspension in the ultrafiltration tube was collected, and 0.4 g of mannitol was added. The suspension was pre-frozen at -80℃ for 2.5 h and then freeze-dried. Polylysine and soybean polysaccharide formed nanoparticles through electrostatic interaction, providing a water-soluble and protective shell for the hydrophobic quercetin@ferrous gluconate supramolecular freeze-dried powder. The nanoparticles greatly increased the specific surface area, improved the dispersibility and mucosal cell contact in the gastrointestinal tract of high-yield pigs, enhanced the absorption efficiency of quercetin and iron, improved blood oxygen carrying capacity, effectively improved intestinal oxygen supply and mucosal health, improved the nutrient absorption efficiency of high-yield pigs, and improved growth performance, resulting in soybean polysaccharide polylysine-based supported nanoparticles.

[0060] S3. Inoculate 2.0g of Aspergillus oryzae cells onto potato dextrose agar slant and incubate at 29℃ for 4 days. Add 15mL of sterile physiological saline containing 0.05% Tween-80 to the activated slant. Gently scrape the surface of the mycelial growth with a sterile L-shaped glass rod to wash away the spores. Then filter through a sterile filter containing defatted cotton, remove the mycelial fragments, add 2 sterile glass beads to the filtrate, and vortex for 7.5min to ensure sufficient spore dispersion. Count the spores under a microscope using a hemocytometer, and dilute with sterile physiological saline containing 0.05% Tween-80 to a bacterial concentration of 2×10⁻⁶. 8Spore count / mL: Aspergillus oryzae improves feed digestibility by producing proteases and amylases through fermentation, reduces the oxygen consumption required to digest the food itself, and can also produce a large number of exogenous enzymes such as proteases, amylases, and cellulases to pre-digest macromolecular nutrients in feed, generating more easily absorbed small peptides, amino acids and oligosaccharides, improving digestive performance, and better improving growth performance, thus obtaining Aspergillus oryzae spore suspension;

[0061] S4. Mix soybean meal powder and manganese-selenium composite modified biochar evenly, add deionized water to adjust the moisture content to 52.5%, autoclave at 121℃ for 25 minutes, cool, and obtain fermentation medium for later use. Inoculate the Aspergillus oryzae spore suspension obtained in step S3 into the fermentation medium, wherein the inoculation amount of Aspergillus oryzae spore suspension is based on 7.5% of the fermentation medium volume. Perform shallow-tray solid-state fermentation at 29℃ and 75% humidity for 60 hours, stirring once during the process. Nine hours before the end of fermentation, evenly sprinkle the soybean polysaccharide polylysine-supported nanoparticles obtained in step S2 into the medium, stir evenly, and continue culturing. After fermentation, dry at 55℃, pulverize and sieve. The mixture of manganese-selenium composite modified biochar, soybean polysaccharide polylysine-supported nanoparticles, Aspergillus oryzae spores, and soybean meal is then fermented. The powders combine with each other through physical adsorption, intermolecular forces, and even mycelial entanglement to form a uniform, stable, loose, and porous three-dimensional network fermentation substrate composite system. The enzymes secreted by microorganisms and the pre-digested nutrients produced are also present in this network. This feed additive integrates multiple functions such as digestive enhancement, anti-oxidation, anti-anemia, and anti-ultraviolet radiation, which significantly improves the digestive performance of pigs, enhances their growth performance, and effectively reduces the adverse effects of low temperature, hypoxia, and ultraviolet radiation on feed and animal growth. The resulting compound functional additive is ready for use. Finally, the compound functional additive is mixed evenly with corn flour, wheat bran, limestone powder, dicalcium phosphate, salt, and compound vitamins. The compound vitamins are pig compound vitamins produced by Shanghai Fulante Animal Health Co., Ltd., to obtain a compound feed for high-altitude pigs.

[0062] Example 4

[0063] This embodiment proposes a compound feed for raising high-yield pigs, comprising the following components in parts by weight: 3 parts manganese-selenium modified biochar, 6 parts soybean polysaccharide polylysine-supported nanoparticles, 3 parts Aspergillus oryzae, 50 parts soybean meal, 120 parts corn flour, 60 parts wheat bran, 10 parts limestone powder, 30 parts dicalcium phosphate, 10 parts salt, and 5 parts compound vitamins.

[0064] Manganese-selenium composite modified biochar comprises the following components in parts by weight: 40 parts corn straw powder, 10 parts manganese chloride tetrahydrate, 0.1 parts sodium selenite, and 3 parts ascorbic acid.

[0065] The preparation method of manganese-selenium composite modified biochar specifically includes the following steps:

[0066] (1) Manganese chloride tetrahydrate was dissolved in 50 mL of deionized water. The amount of manganese chloride tetrahydrate added was 1.0 g. At high temperature, manganese chloride tetrahydrate was converted into manganese oxide, which can slowly release manganese ions in the intestine of high-altitude pigs, providing a safe and long-lasting manganese supplement, avoiding the problems of acute toxicity and excessive bioavailability of direct use of manganese salt. Then, 4.0 g of washed corn stalk powder was added and stirred for 30 min. The resulting slurry was first dried in an oven at 80 °C for 1 h, and then transferred to a crucible and placed in a tube furnace under nitrogen protection. It was pyrolyzed at 600 °C for 1 h. After cooling, the product was ground and passed through an 80-mesh sieve. The organic matter in the corn stalk powder was carbonized under anaerobic conditions to form a porous biochar framework. At the same time, manganese oxide nanoparticles were loaded on the surface and pores of the biochar, increasing the specific surface area and active sites of the biochar. The porous structure of the biochar provided adsorption, Biochar offers protection and slow-release properties. Its black color and excellent UV absorption capabilities, combined with tiny carbon particles, effectively block and absorb ultraviolet rays, preventing direct exposure to sensitive nutrients in feed and reducing oxidative rancidity. Biochar also serves as an attachment point and growth carrier for beneficial microorganisms such as lactic acid bacteria and bifidobacteria, optimizing intestinal flora structure, adsorbing nutrients, and prolonging their residence time in the intestines. This enhances the absorption and utilization of nutrients in feed, significantly promoting the growth of high-yield pigs in extreme environments. Furthermore, through the slow-release of manganese ions, it ensures that high-yield pigs can still synthesize sufficient manganese superoxide dismutase under hypoxic and low-temperature conditions, enhancing the matrix's antioxidant capacity and mitigating oxidative damage. Manganese is also an activator of various digestive enzymes; sufficient manganese nutrition helps maintain normal digestive function and improves nutrient absorption efficiency, resulting in manganese-doped biochar.

[0067] (2) Dissolve sodium selenite in 500 mL of deionized water. The amount of sodium selenite added is 10 mg. The introduction of selenium not only promotes the synthesis of glutathione peroxidase, but also helps maintain normal thyroid function. Thyroid hormones promote the absorption and utilization of iron. Sodium selenite solution is obtained and set aside. Add the manganese-doped biochar described in step (1) to the sodium selenite solution, and then place it on a magnetic stirrer. Stir at 60°C for 8 hours at a stirring speed of 800 rpm. Then add 0.3 g of ascorbic acid and continue stirring for 1 hour. Centrifuge at 12000 rpm for 10 minutes. Collect the solid product and wash it with deionized water until no white precipitate is detected in the supernatant by silver nitrate solution. Finally, the product was dried to constant weight in an 80℃ oven. This process deposits the reduced elemental selenium in situ onto manganese-doped biochar. Manganese and selenium construct a synergistic antioxidant system of manganese superoxide dismutase and glutathione peroxidase, which effectively reduces oxidative damage, maintains the integrity of intestinal mucosal cells, and increases the nutrient absorption area and efficiency. This improves nutrient absorption under low temperature and hypoxic conditions, helps improve the energy conversion efficiency of feed, and is beneficial to the growth performance of high-yield pigs. At the same time, it also reduces the inhibition of hematopoietic stem cells by oxidative damage, improves anemia symptoms in high-yield pigs, promotes hematopoiesis and oxygen transport, and thus reduces the adverse effects of hypoxia and loss of appetite on growth performance, resulting in manganese-selenium composite modified biochar.

[0068] This embodiment provides a method for preparing a compound feed for feeding high-altitude pigs, specifically including the following steps:

[0069] S1. Add quercetin to a 1mL centrifuge tube. The amount of quercetin added is 3.02mg. Quercetin can increase the expression of iron transport proteins in intestinal cells, promote iron absorption and transport into the body, fundamentally improve iron deficiency anemia, and improve the blood's oxygen-carrying capacity and nutrient transport capacity. Then add 0.8mL of dimethyl sulfoxide solvent, vortex and heat to 35℃ to completely dissolve it. Use a pH 5.5 buffer solution to make up to 1mL to obtain a quercetin solution for later use. Then add 0. 50g of ferrous gluconate was directly prepared into a 0.5mmol / L ferrous gluconate solution using a pH 5.5 buffer solution. Then, the quercetin solution and ferrous gluconate solution were diluted to 1mmol / L, with each dilution volume being 10mL. The pH of the quercetin dilution was controlled at 5.5. 3mL of the ferrous gluconate dilution was slowly added to 6mL of the quercetin dilution, and the mixture was shaken to mix thoroughly. The reaction system was then incubated at 50℃ and 200rpm. After hot stirring for 1 hour, the solution was dialyzed for 24 hours using a dialysis bag with a molecular weight cutoff of 500 Da. The solution in the dialysis bag was collected and freeze-dried. After being chelated by quercetin, the reactivity of iron ions was encapsulated and stabilized, no longer catalyzing the Fenton reaction to produce hydroxyl radicals. This avoided the adverse effects of traditional iron supplements on feed oxidative rancidity, forming organic iron with higher absorption rate. This effectively improved anemia symptoms in high-altitude environments and reduced hypoxia in pig tissues, thereby improving oxygen supply and function of the intestinal mucosa. At the same time, quercetin protected cell membranes and DNA from oxidative damage, and iron helped the body efficiently remove peroxides such as hydrogen peroxide. Together, they constructed a comprehensive antioxidant defense network from prevention to removal, effectively resisting oxidative stress, thereby protecting intestinal cells, improving nutrient absorption efficiency, and forming a strong antioxidant protective layer at the feed level to directly resist the damage of ultraviolet radiation, ensuring the nutritional quality of the feed. The resulting product is quercetin@ferrous gluconate supramolecular freeze-dried powder.

[0070] S2. Add 0.8g of soybean polysaccharide to 60mL of deionized water, stir magnetically for 1h, and adjust the pH to 7.0 to obtain a soybean polysaccharide solution for later use. Then dissolve polylysine in 50mL of PBS buffer (160mg of polylysine is added). Polylysine, as a natural cationic antimicrobial peptide, directly inhibits the growth of mold and putrefactive bacteria in high-altitude feed, preventing feed spoilage. Then slowly add the polylysine solution dropwise to the soybean polysaccharide solution, stir magnetically for 1h, and adjust the pH to 7.0. Centrifuge at 4000rpm for 10min, and then separate and purify using a Millipore ultrafiltration tube with a molecular weight cutoff of 100kDa to obtain a soybean polysaccharide-based polylysine nanoparticle suspension for later use. Dissolve the quercetin@ferrous gluconate supramolecular lyophilized powder obtained in step S1 in PBS buffer at pH 8.5, and use 80W ultrasonic assistance to obtain quercetin@gluconate supramolecular lyophilized powder. The acid solution was slowly added to the suspension of soybean polysaccharide-based polylysine nanoparticles under magnetic stirring and in the dark. After the addition was completed, stirring was continued for 1 hour in the dark. The suspension was then separated and purified again using a Millipore ultrafiltration tube with a molecular weight cutoff of 100 kDa. The suspension in the ultrafiltration tube was collected, and 0.5 g of mannitol was added. The suspension was pre-frozen at -80℃ for 2 hours and then freeze-dried. Polylysine and soybean polysaccharide formed nanoparticles through electrostatic interaction, providing a water-soluble and protective shell for the hydrophobic quercetin@ferrous gluconate supramolecular freeze-dried powder. The nanoparticles greatly increased the specific surface area, improved the dispersibility and mucosal cell contact in the gastrointestinal tract of high-yield pigs, enhanced the absorption efficiency of quercetin and iron, improved the blood oxygen carrying capacity, effectively improved intestinal oxygen supply and mucosal health, improved the nutrient absorption efficiency of high-yield pigs, and improved growth performance, thus obtaining soybean polysaccharide polylysine-based supported nanoparticles.

[0071] S3. Inoculate 3.0g of Aspergillus oryzae cells onto potato dextrose agar slant and incubate at 30℃ for 3 days. Add 20mL of sterile physiological saline containing 0.05% Tween-80 to the activated slant. Gently scrape the surface of the mycelial growth with a sterile L-shaped glass rod to wash away the spores. Then filter through a sterile filter containing defatted cotton, remove the mycelial fragments, add 3 sterile glass beads to the filtrate, and vortex for 5 minutes to ensure sufficient spore dispersion. Count the spores under a microscope using a hemocytometer, and dilute with sterile physiological saline containing 0.05% Tween-80 to a bacterial concentration of 2×10⁻⁶. 8 Spore count / mL: Aspergillus oryzae improves feed digestibility by producing proteases and amylases through fermentation, reduces the oxygen consumption required to digest the food itself, and can also produce a large number of exogenous enzymes such as proteases, amylases, and cellulases to pre-digest macromolecular nutrients in feed, generating more easily absorbed small peptides, amino acids and oligosaccharides, improving digestive performance, and better improving growth performance, thus obtaining Aspergillus oryzae spore suspension;

[0072] S4. Mix soybean meal powder and manganese-selenium composite modified biochar evenly, add deionized water to adjust the moisture content to 55%, autoclave at 121℃ for 20 minutes, cool, and obtain fermentation medium for later use. Inoculate the Aspergillus oryzae spore suspension obtained in step S3 into the fermentation medium, wherein the inoculation amount of Aspergillus oryzae spore suspension is based on 10% of the fermentation medium volume. Perform shallow-tray solid-state fermentation at 30℃ and 80% humidity for 48 hours, stirring twice during the process. Six hours before the end of fermentation, evenly sprinkle the soybean polysaccharide polylysine-supported nanoparticles obtained in step S2 into the medium, stir evenly, and continue culturing. After fermentation, dry at 60℃, pulverize and sieve. The manganese-selenium composite modified biochar, soybean polysaccharide polylysine-supported nanoparticles, Aspergillus oryzae spores, and soybean meal powder are then processed. Through physical adsorption, intermolecular forces, and even hyphal entanglement, a uniform, stable, loose, and porous three-dimensional network fermentation substrate composite system is formed. The enzymes secreted by microorganisms and the pre-digested nutrients produced are also present in this network. This feed additive integrates multiple functions such as digestive enhancement, anti-oxidation, anti-anemia, and anti-ultraviolet radiation, which significantly improves the digestive performance of pigs, enhances their growth performance, and effectively reduces the adverse effects of low temperature, hypoxia, and ultraviolet radiation on feed and animal growth. The resulting compound functional additive is ready for use. Finally, the compound functional additive is mixed evenly with corn flour, wheat bran, limestone powder, dicalcium phosphate, salt, and compound vitamins. The compound vitamins are pig compound vitamins produced by Shanghai Fulante Animal Health Co., Ltd., to obtain a compound feed for high-altitude pigs.

[0073] Comparative Example 1

[0074] This comparative example provides a compound feed for raising high-yield pigs. The difference between this feed and Example 1 is that the manganese-selenium composite modified biochar does not contain manganese chloride tetrahydrate or sodium selenite; the manganese-selenium composite modified biochar preparation method does not include manganese chloride tetrahydrate in step (1) and does not include step (2); the preparation method of the compound feed for raising high-yield pigs is the same as that of Example 1.

[0075] Comparative Example 2

[0076] This comparative example provides a compound feed for raising high-altitude pigs, which differs from Example 1 in that the soybean polysaccharide polylysine-supported nanoparticles do not contain quercetin or ferrous gluconate; the preparation method of manganese-selenium composite modified biochar is the same as in Example 1; and the preparation method of the compound feed for raising high-altitude pigs does not include step S1.

[0077] Comparative Example 3

[0078] This comparative example provides a compound feed for raising high-altitude pigs. The difference between this feed and Example 1 is that the compound functional additive does not contain manganese-selenium modified biochar or soybean polysaccharide polylysine-supported nanoparticles. Instead, soybean meal powder and Aspergillus oryzae spore suspension are cultured and fermented. The preparation method of manganese-selenium modified biochar is the same as in Example 1. In step S4 of the preparation method of the compound feed for raising high-altitude pigs, soybean meal powder and Aspergillus oryzae spore suspension are first cultured and fermented to obtain the compound functional additive. Then, the compound functional additive is mixed evenly with manganese-selenium modified biochar, soybean polysaccharide polylysine-supported nanoparticles, corn flour, wheat bran, limestone powder, dicalcium phosphate, salt, and compound vitamins.

[0079] Experimental Example 1

[0080] Anti-anemia experiment

[0081] Test samples: Compound feeds for feeding high-yield pigs prepared in Examples 1-4 and Comparative Examples 1-3.

[0082] Test Method: Fifty-six healthy Tibetan piglets from the plateau region, with an initial weight of 25-30 kg and a hemoglobin concentration of 130±5 g / L, were selected and randomly divided into 7 groups of 8 piglets each. Before the experiment, the pigpens were cleaned and disinfected. During the experiment, the feeding and management conditions, such as temperature, ventilation, and altitude (3000 meters), were kept consistent across all groups. A 5-7 day pre-feeding period was conducted before the experiment, during which all piglets were fed only basal feed. After the experiment began, the test samples were fed at 7:00, 12:00, and 18:00 daily, at 110% of the daily feed intake. Leftover feed was collected before the next feeding. The piglets had free access to water, and manure was removed by machine. The experiment lasted for 42 days. On the 42nd day, fasting blood samples were collected from the anterior vena cava to detect and analyze the hemoglobin concentration (g / L) of the piglets.

[0083] Figure 1The graph shows the hemoglobin concentration results for Examples 1-4 and Comparative Examples 1-3. As shown, the hemoglobin concentration in Examples 1-4 was 169-178 g / L, indicating effective improvement of anemia; the hemoglobin concentration in Comparative Examples 1-3 was 146-157 g / L, indicating no effective improvement of anemia. The manganese-selenium composite modified biochar in Comparative Example 1 did not contain manganese chloride tetrahydrate or sodium selenite, and therefore could not reduce the inhibition of oxidative damage on hematopoietic stem cells by constructing an antioxidant system, resulting in no effective improvement of anemia. The soybean polysaccharide polylysine-supported nanoparticles in Comparative Example 2... The granules do not contain quercetin or ferrous gluconate, so they cannot directly supplement highly bioavailable organic iron, which is not conducive to correcting hypoxic iron deficiency anemia and thus cannot effectively improve anemia. The compound functional additive in Comparative Example 3 does not contain manganese-selenium composite modified biochar or soybean polysaccharide polylysine-supported nanoparticles. Manganese-selenium composite modified biochar and soybean polysaccharide polylysine-supported nanoparticles do not participate in the fermentation of Aspergillus oryzae and cannot form a three-dimensional network fermentation matrix composite system for targeted release in the intestine, which reduces the absorption and bioavailability of iron and thus cannot effectively improve anemia.

[0084] Experiment Example 2

[0085] Growth performance experiment

[0086] Test samples: Compound feeds for feeding high-yield pigs prepared in Examples 1-4 and Comparative Examples 1-3.

[0087] Test Method: Fifty-six healthy Tibetan piglets from high-altitude areas, with an initial weight of 25-30 kg and a hemoglobin concentration of 130±5 g / L, were randomly divided into 7 groups of 8 piglets each. Before the experiment, the pigpens were cleaned and disinfected. During the experiment, the feeding and management conditions, including temperature, ventilation, and altitude (3000 meters), were kept consistent across all groups. A 5-7 day pre-feeding period was conducted before the experiment, during which all piglets were fed only basal feed. After the experiment began, the test samples were fed at 7:00, 12:00, and 18:00 daily, at 110% of the daily feed intake. Leftover feed was collected before the next feeding. The piglets had free access to water, and manure was removed by machine. The experiment lasted for 30 days. The fattening status of the piglets was monitored on days 1 and 15. Before the morning feeding on day 30, each piglet was weighed and the average weight was calculated. The average daily feed intake, average daily weight gain, and feed conversion ratio were then calculated using the following formulas:

[0088] Average daily feed intake (ADFI): During the experiment, the amount of feed given to the experimental piglets and the amount of leftover feed were recorded, and the average daily feed intake (g / d) was calculated.

[0089] Average daily weight gain (ADG) (g / d) = (final weight - initial weight) / 30

[0090] Material weight ratio = ADFI / ADG

[0091] Figure 2 The figures show the growth performance results of Examples 1-4 and Comparative Examples 1-3. As shown, the average daily feed intake, average daily weight gain, and feed conversion ratio of Examples 1-4 were 308-310 g / d, 142-160 g / d, and 1.9-2.2, respectively, indicating good growth performance. The average daily feed intake, average daily weight gain, and feed conversion ratio of Comparative Examples 1-3 were 308-310 g / d, 105-128 g / d, and 2.4-2.9, respectively, indicating poor growth performance. The manganese-selenium composite modified biochar of Comparative Example 1 did not contain manganese chloride tetrahydrate or sodium selenite, thus failing to construct a synergistic antioxidant system of manganese superoxide dismutase and glutathione peroxidase to reduce oxidative damage. This is detrimental to maintaining the integrity and health of intestinal mucosal cells, thereby reducing... The limited nutrient absorption area and efficiency resulted in poor growth performance. Comparative Example 2, containing soybean polysaccharide polylysine-supported nanoparticles, lacked quercetin and ferrous gluconate, which hindered the improvement of blood oxygen-carrying capacity, intestinal oxygen supply, and mucosal health, thus reducing the nutrient absorption efficiency of the high-yield pigs and leading to poor growth performance. Comparative Example 3, containing manganese-selenium composite modified biochar and soybean polysaccharide polylysine-supported nanoparticles, only mixed with Aspergillus oryzae fermentation products, failing to form a three-dimensional network fermentation matrix composite system. This increased the damage of gastric acid to functional components and prevented targeted release into the intestines, reducing nutrient absorption and resulting in poor growth performance.

[0092] Experimental Example 3

[0093] Feed quality experiment

[0094] Test samples: Compound feeds for feeding high-yield pigs prepared in Examples 1-4 and Comparative Examples 1-3.

[0095] Test method: Spread the test sample evenly on a clean petri dish or special tray, maintaining a thickness of 2-3 mm, and place it in a UV aging chamber to simulate the UV radiation intensity of high-altitude areas. Set the parameter to 0.7 W / m². 2 @340nm, samples were taken and tested after 28 days. The peroxide value (meq / kg) was calculated by referring to "GB5009.6-2016 Determination of Fat in Food" or "GB / T6433-2006 Determination of Crude Fat in Feed".

[0096] Figure 3The peroxide value results for Examples 1-4 and Comparative Examples 1-3 are shown in the figure. As shown, the peroxide value for Examples 1-4 is 5-9 meq / kg, indicating good feed quality; the peroxide value for Comparative Examples 1-3 is 15-25 meq / kg, indicating poor feed quality. The manganese-selenium composite modified biochar in Comparative Example 1 does not contain manganese chloride tetrahydrate or sodium selenite, and therefore cannot increase adsorption sites and specific surface area by loading manganese and selenium onto the biochar. This is detrimental to improving the biochar's absorption capacity for ultraviolet light, accelerating the oxidative rancidity of the feed, resulting in poor feed quality. The soybean polysaccharide polylysine in Comparative Example 2... The base-supported nanoparticles do not contain quercetin or ferrous gluconate, thus failing to form a second antioxidant protective layer. This reduces resistance and protection against ultraviolet radiation, increases the risk of oxidative rancidity, and results in poor feed quality. The composite functional additive in Comparative Example 3 does not contain manganese-selenium composite modified biochar or soybean polysaccharide polylysine-supported nanoparticles. Therefore, it cannot form a uniform, stable, loose, and porous three-dimensional network fermentation substrate composite system through co-cultivation and fermentation. Consequently, it cannot delay the process of oil oxidation and rancidity caused by ultraviolet radiation through the constructed three-dimensional, multi-layered antioxidant network, resulting in poor feed quality.

[0097] The above experimental results show that the anti-anemia, growth-promoting, and feed quality of Examples 1-4 of this invention are significantly better than those of Comparative Examples 1-3. Among them, Example 1, which uses manganese-selenium composite modified biochar, soybean polysaccharide polylysine-supported nanoparticles, and co-cultured with Aspergillus oryzae, exhibits better anti-anemia properties, better growth performance, and better feed quality. By co-fermenting and culturing manganese-selenium composite modified biochar, soybean polysaccharide polylysine-supported nanoparticles, and Aspergillus oryzae, the components are combined with each other through physical adsorption, intermolecular forces, and hyphal entanglement, forming a uniform, stable, loose, and porous three-dimensional network fermentation matrix composite system. This not only reduces the damage of gastric acid to the components and achieves targeted release in the intestine, but also provides an environment for the activation, growth, and enzyme production of Aspergillus oryzae spores. This results in a multifunctional additive with high nutritional value, easy absorption, antioxidant properties, anti-anemia properties, and resistance to ultraviolet radiation. It significantly improves the digestive performance of high-yield pigs and effectively reduces the adverse effects of low temperature, hypoxia, and ultraviolet radiation on animal growth and feed oxidative rancidity.

[0098] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

[0099] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention. The actual application is not limited to this. In conclusion, if those skilled in the art are inspired by this description and design similar methods and embodiments without departing from the spirit of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A compound feed for raising high-altitude pigs, characterized in that: The compound feed for raising pigs in the highlands comprises the following components in parts by weight: 3-5 parts of manganese-selenium modified biochar, 3-6 parts of soybean polysaccharide polylysine-supported nanoparticles, 1-3 parts of Aspergillus oryzae, 40-50 parts of soybean meal, 80-120 parts of corn flour, 50-60 parts of wheat bran, 8-10 parts of limestone powder, 20-30 parts of dicalcium phosphate, 5-10 parts of salt, and 3-5 parts of compound vitamins; the manganese-selenium modified biochar comprises the following components in parts by weight: 30-40 parts of corn stalk powder, 10-30 parts of manganese chloride tetrahydrate, 0.1-0.3 parts of sodium selenite, and 1-3 parts of ascorbic acid.

2. A method for preparing a compound feed for feeding high-altitude pigs according to claim 1, characterized in that: Specifically, the following steps are included: S1. Add quercetin to a 1 mL centrifuge tube, then add 0.5-0.8 mL of dimethyl sulfoxide (DMSO) solvent. Vortex and heat to 35°C to completely dissolve the quercetin. Dilute to 1 mL with a pH 5.5 buffer solution to obtain a quercetin solution for later use. Then, directly prepare a 0.5 mmol / L ferrous gluconate solution using a pH 5.5 buffer solution. Finally, dilute both the quercetin solution and the ferrous gluconate solution to 1 mmol / L. / L, the volume of the diluent is 10mL, and the pH of the quercetin diluent is controlled at 5.

5. Measure 3mL of ferrous gluconate diluent and slowly add it to 6mL of quercetin diluent. Shake and mix well. Heat and stir the reaction system at 40-50℃ and 100-200rpm for 1-2h. Use a dialysis bag with a molecular weight cutoff of 100-500Da for dialysis treatment for 24-48h. Collect the solution in the dialysis bag and freeze-dry it to obtain quercetin@ferrous gluconate supramolecular lyophilized powder. S2. Add 0.2-0.8g of soybean polysaccharide to 50-60mL of deionized water, stir magnetically for 1-2 hours, adjust the pH to 7.0, and obtain a soybean polysaccharide solution for later use. Dissolve polylysine in 40-50mL of PBS buffer, then slowly add the polylysine solution dropwise to the soybean polysaccharide solution, stir magnetically for 1-2 hours, adjust the pH to 7.0, centrifuge at 3000-4000rpm for 10-15min, and then separate and purify using a Millipore ultrafiltration tube with a molecular weight cutoff of 100kDa to obtain a soybean polysaccharide-based polylysine nanoparticle suspension for later use. (This is related to step S1.) The quercetin@ferrous gluconate supramolecular lyophilized powder was dissolved in PBS buffer at pH 7.5-8.5 and sonicated at 50-80W. The resulting quercetin@ferrous gluconate solution was slowly added to a suspension of soybean polysaccharide-based polylysine nanoparticles under magnetic stirring and in the dark. After the addition was complete, stirring was continued for 1-2 hours in the dark. The suspension was then separated and purified again using a Millipore ultrafiltration tube with a molecular weight cutoff of 100kDa. The suspension in the ultrafiltration tube was collected, and 0.3-0.5g of mannitol was added. The suspension was pre-frozen at -80℃ for 2-3 hours and then freeze-dried to obtain soybean polysaccharide-based polylysine-supported nanoparticles. S3. Inoculate 1.0-3.0g of Aspergillus oryzae cells onto potato dextrose agar slant medium and incubate at 28-30℃ for 3-5 days. Add 10-20mL of sterile physiological saline containing 0.05% Tween-80 to the activated slant. Gently scrape the surface of the mycelial growth with a sterile L-shaped glass rod to wash off the spores. Then filter through a sterile filter containing defatted cotton, remove the mycelial fragments, add 2-3 sterile glass beads to the filtrate, and vortex for 5-10 minutes to ensure sufficient spore dispersion. Count the spores under a microscope using a hemocytometer, and dilute with sterile physiological saline containing 0.05% Tween-80 to a bacterial concentration of 2×10⁻⁶. 8 Count of spores / mL to obtain a suspension of Aspergillus oryzae spores; S4. Mix soybean meal powder and manganese-selenium composite modified biochar evenly, add deionized water to adjust the moisture content to 50-55%, autoclave at 121℃ for 20-30 minutes, cool, and obtain the fermentation medium for later use. Inoculate the Aspergillus oryzae spore suspension obtained in step S3 into the fermentation medium, wherein the inoculation amount of Aspergillus oryzae spore suspension is based on 5-10% of the fermentation medium volume. Perform shallow-tray solid-state fermentation at 28-30℃ and 70-80% humidity for 48-72 hours, stirring 1-2 times during the process. 6-12 hours before the end of fermentation, the soybean polysaccharide polylysine-supported nanoparticles described in step S2 are evenly sprinkled into the mixture, stirred evenly, and then cultured. After fermentation, the mixture is dried at a low temperature of 50-60℃, pulverized, and sieved to obtain a compound functional additive for later use. Finally, the compound functional additive is mixed evenly with corn flour, wheat bran, limestone powder, dicalcium phosphate, salt, and compound vitamins. The compound vitamins are pig compound vitamins produced by Shanghai Fulante Animal Health Co., Ltd., to obtain a compound feed for high-altitude pigs.

3. The method for preparing compound feed for high-altitude pigs according to claim 2, characterized in that: In step S1, the amount of quercetin added is 3.02-3.22 mg.

4. The method for preparing compound feed for high-altitude pigs according to claim 3, characterized in that: In step S2, the amount of polylysine added is 160-200 mg.

5. The method for preparing compound feed for high-altitude pigs according to claim 4, characterized in that: The preparation method of the manganese-selenium composite modified biochar specifically includes the following steps: (1) Dissolve manganese chloride tetrahydrate in 50 mL of deionized water, then add 3.0-4.0 g of washed corn stalk powder, stir for 30-40 min, and dry the resulting slurry in an oven at 60-80℃ for 1-2 h, then transfer it to a crucible and place it in a tube furnace under nitrogen protection, and pyrolyze it at 500-600℃ for 1-2 h. After cooling, grind the product and pass it through a 60-80 mesh sieve to obtain manganese-doped biochar. (2) Dissolve sodium selenite in 500 mL of deionized water to obtain a sodium selenite solution for later use. Add the manganese-doped biochar described in step (1) to the sodium selenite solution, and then place it on a magnetic stirrer. Stir at 50-60℃ for 8-12 h at a stirring speed of 600-800 rpm. Then add 0.1-0.3 g of ascorbic acid and continue stirring for 1-2 h. Centrifuge at 8000-12000 rpm for 10-15 min. Collect the solid product and wash it with deionized water until no white precipitate is detected in the supernatant using silver nitrate solution. Finally, dry the product in an oven at 60-80℃ to constant weight to obtain manganese-selenium composite modified biochar.

6. The method for preparing compound feed for high-altitude pigs according to claim 5, characterized in that: In step (1), the amount of manganese chloride tetrahydrate added is 1.0-3.0g.

7. The method for preparing compound feed for high-altitude pigs according to claim 6, characterized in that: In step (2), the amount of sodium selenite added is 10-30 mg.

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