A cordycepin-dextran iron complex preparation, a preparation method and application thereof

Abstract

A cordycepin-dextran iron complex preparation and a preparation method and application thereof, and relate to the technical field of feed additives.The cordycepin-dextran iron complex preparation comprises the following components in parts by weight: cordycepin enriched culture 1-5 parts, dextran iron 20-60 parts, antioxidant protective agent 6-20 parts, metabolism promoter 0.5-2 parts, and carrier 15-75 parts; the content of cordycepin in the cordycepin enriched culture is not less than 10000 mu g / g.The cordycepin-dextran iron complex preparation of the present application organically combines cordycepin and dextran iron; can promote reproductive performance and improve the health status of the mother, and at the same time plays the roles of supplementing hematopoietic raw materials and preventing anemia; and realizes the integrated health care effect of promoting reproductive performance and supplementing iron.The preparation method of the present application forms a preparation with good physical and chemical stability and long-term stability.

Description

Technical Field

[0001] This invention relates to the field of feed additive technology, specifically to a cordycepin-dextran iron compound preparation, its preparation method, and its application. Background Technology

[0002] With the rapid development of modern pig farming in my country, sow reproductive efficiency has become a key indicator for measuring the core competitiveness of pig farms. Sows face two major physiological challenges during gestation: first, their bodies are in a state of immunosuppression, resulting in decreased disease resistance; second, their iron requirements increase dramatically. Iron deficiency not only reduces sow reproductive performance but also affects the early growth and development of piglets, increasing the risk of iron-deficiency anemia. These two issues are interconnected and jointly restrict the full realization of sow reproductive performance.

[0003] Newborn piglets have extremely limited iron reserves at birth (only 30-50 mg), while their daily iron requirement during lactation is as high as 7-16 mg. Studies have confirmed a significant correlation between fetal iron reserves and maternal iron metabolism. The placental transport system constructs a highly efficient physiological channel for iron transfer between mother and fetus through a specific receptor-mediated molecular mechanism. In late pregnancy, maternal iron reserves and fetal iron concentration show a significant positive correlation. Iron malnutrition in sows directly leads to insufficient iron reserves in piglets at birth, affecting their growth, development, and immune function. Iron deficiency not only reduces sow reproductive performance but also affects early growth and development in piglets, increasing the risk of iron deficiency anemia.

[0004] Currently, the most common and effective way to supplement iron for preventing iron deficiency anemia in newborn piglets is by injecting iron dextran or gleptoferron. Iron dextran, as an organic iron complex, can rapidly increase iron levels in sows during late pregnancy via intramuscular injection, promoting iron transport across the placenta to the fetus. While injection is the most common method used in pig farms for rapid iron supplementation, it increases stress on sows, especially in late pregnancy where frequent injections may induce premature birth. Therefore, a simple, safe, and efficient iron supplementation program that avoids injection stress is urgently needed in the industry.

[0005] Cordycepin (3'-deoxyadenosine) is a natural active substance extracted from Cordyceps sinensis or Cordyceps militaris. It is a nucleotide composed of adenosine and a carbon-branched deoxypentose, belonging to the nucleoside antibiotic class. Studies have shown that cordycepin possesses various biological functions, including anti-inflammatory, antiviral, antioxidant, and immunomodulatory effects, playing an important regulatory role in various inflammatory diseases and oxidative stress-related diseases. With the development of cordycepin production methods from extraction to biosynthesis, its cost has been significantly reduced, laying the foundation for its widespread application in livestock and poultry production.

[0006] In recent years, the application of cordycepin in improving the reproductive performance of pigs has gradually attracted attention. Recent studies have also found that cordycepin has biological functions in promoting meiosis, improving oocyte quality, and enhancing the early embryonic developmental potential after parthenogenesis activation during the in vitro maturation of pig oocytes. This provides a research basis for developing safe and effective natural small molecule agents that can be used to improve the reproductive performance of sows.

[0007] Existing Cordyceps ferments are mainly used as general-purpose feed additives, without targeted formulation optimization for the specific physiological needs of pregnant sows. There are no reports on the combined use of cordycepin and dextran iron during sow gestation. Furthermore, the two differ in their physicochemical properties; cordycepin is a small nucleoside molecule, while dextran iron is a high-molecular-weight iron-carbohydrate complex. How to prepare a stable compound formulation and fully utilize its synergistic effect remains an unsolved technical challenge in this field. Summary of the Invention

[0008] To address the aforementioned technical problems in existing technologies, a cordycepin-dextran iron compound preparation is provided, which can improve the health status of pregnant sows and achieve an integrated health care effect of promoting reproductive performance and supplementing iron.

[0009] Another objective of this invention is to provide a method for preparing a cordycepin-dextran iron complex preparation, which has good physicochemical stability and long-term stability.

[0010] Another object of the present invention is to provide the application of the cordycepin-dextran iron compound preparation in the feeding of sows during pregnancy.

[0011] On one hand, the present invention provides a cordycepin-dextran iron complex formulation, comprising the following components in parts by weight:

[0012] Cordycepin enrichment culture 1-5 parts, dextran iron 20-60 parts, antioxidant protectant 6-20 parts, metabolism promoter 0.5-2 parts, carrier 15-75 parts;

[0013] The cordycepin enrichment culture contains no less than 10,000 μg / g of cordycepin.

[0014] Furthermore, the dextran iron is a veterinary-grade dextran iron raw material with an iron content of 15-25 wt%. It is suitable for manufacturing veterinary dextran iron injections or oral preparations for the prevention and treatment of iron deficiency anemia in livestock of all sizes. After sows receive efficient iron supplementation through this compound preparation, the iron reserve level in newborn piglets can be effectively increased. Under certain conditions, it can simplify or even replace the secondary iron supplementation procedure for piglets after birth, reducing the workload of frontline workers in pig farms and stress on piglets.

[0015] Furthermore, the cordycepin enrichment culture was derived from the fermentation culture of Sarocladium terricola (formerly Acremonium terricola) F2652.

[0016] The *Anomala* strain F2652 is a publicly available biological material, disclosed in Chinese patent literature (application number CN202411853271.1, publication number CN119744970A), entitled "Application of *Anomala* F2652 in the Preparation of Agents for Improving the Production Performance, Immunization, or Antioxidant Effects of Weaned Piglets." The *Anomala* strain F2652 has the accession number GDMCC NO:64892, accession date October 9, 2024, and is deposited at the Guangdong Provincial Center for Microbial Culture Collection, located at 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou, Guangdong Province.

[0017] The cordycepin enrichment culture contains no less than 10,000 μg / g of cordycepin, and is obtained through industrial production according to the fermentation process of the strain described in CN119744970A. The production steps are as follows:

[0018] S1. The fusion strain of *Geotrichum can be activated and cultured to obtain an activated strain;

[0019] Specifically, the *Gastrodinium* fusion strain was activated by slant culture on a comprehensive PDA agar medium. Glyceryl bacteria were inoculated onto PDA agar plates and cultured in an incubator at 24-28°C in the dark for 5-7 days. Conidia were then washed off with sterile physiological saline and transferred to PDA slant medium. The strain was then cultured in an incubator at 24-28°C in the dark for 3-5 days to obtain the activated strain.

[0020] S2. The activated strain is inoculated into millet seed culture medium for cultivation to obtain an enhanced seed culture; wherein, the millet seed culture medium includes the following raw materials: millet, soybean extract powder, sucrose, yeast extract, peptone, potassium dihydrogen phosphate, magnesium sulfate, ferrous sulfate, vitamin B1, vitamin B2, vitamin B6 and vitamin B12.

[0021] Specifically, the activated strain was eluted until the spore concentration in the eluent was (4.5-5.5) × 10⁻⁶. 6 The eluent was then transferred to an eggplant bottle containing millet seed-enhanced culture medium slant and cultured in an incubator at 24-28℃ in the dark for 3 days to obtain the enhanced seed culture.

[0022] The method for preparing the millet seed fortification culture medium includes the following steps:

[0023] Weigh out 15-25 parts soybean extract powder, 5-15 parts sucrose, 5-15 parts yeast extract, 2-5 parts peptone, 0.2-0.6 parts potassium dihydrogen phosphate, 0.05-0.15 parts magnesium sulfate, 0.05-0.15 parts ferrous sulfate, 0.01-0.03 parts vitamin B1, 0.01-0.03 parts vitamin B2, 0.01-0.03 parts vitamin B6, and 0.00002-0.00006 parts vitamin B12, and add water to a final volume of 1000 mL to prepare a nutrient solution. Then weigh out millet at a mass-to-volume ratio of 1:1, mix well, and steam over water for 40-50 minutes. After steaming, weigh out 100 portions into each eggplant bottle and sterilize using conventional methods to obtain the millet seed-enhanced culture medium.

[0024] S3. The enhanced seed culture is subjected to liquid fermentation culture to obtain liquid fermentation product;

[0025] Specifically, the millet seed enhanced culture is inoculated into a fermenter for cultivation. In the initial stage of fermentation, the aeration rate of the fermenter is controlled at 10-20 L / min, the stirring speed at 150-200 r / min, the temperature at 24-28℃, and the initial reducing sugar concentration at 80-100 g / L. The reducing sugar concentration during fermentation is controlled at 0.5-1 g / 100 mL by adding glucose. The initial pH is 6.0-7.5. The pH is controlled at 6.0-7.5 throughout the fermentation process by adding ammonia water. The culture is carried out for 24-48 hours, and then cultivated for 2-3 days under a light intensity of 200-500 Lx to enhance the culture of mycelium and cordycepin. The entire fermentation cycle is 90-120 hours, resulting in the liquid fermentation culture.

[0026] S4. Inoculate the liquid fermentation product into a solid culture medium, carry out solid fermentation under light conditions, remove the solid fermentation product and dry it to obtain the fermentation culture of the *Gastrodinium spp.* fusion strain.

[0027] The conditions for solid-state fermentation are: temperature 25-35℃, humidity 65-75%, fermentation time 4-7 days, light intensity 100-200 Lx, and daily light duration 8-12 hours; wherein, the solid culture medium comprises the following components by weight: 35-45 parts soybean meal powder, 25-35 parts wheat flour and 25-35 parts wheat bran powder.

[0028] Furthermore, the compound preparation contains 200-500 μg / g of cordycepin and 6.0-10.0 wt% of iron.

[0029] Furthermore, the antioxidant is selected from at least one of vitamin E and vitamin C. Vitamin E and vitamin C can protect the structural stability of cordycepin during formulation processing and storage, while enhancing the antioxidant capacity of sows.

[0030] Preferably, the vitamin E is DL-α-tocopherol acetate or natural vitamin E.

[0031] Preferably, the vitamin C is coated vitamin C or ascorbate phosphate.

[0032] Furthermore, the metabolism promoter is selected from B-complex vitamins. B-complex vitamins participate in energy metabolism and hematopoietic function, and synergistically promote hemoglobin synthesis with dextran iron.

[0033] Furthermore, the B-complex vitamins are selected from thiamine (vitamin B1), riboflavin (vitamin B2), pyridoxine (vitamin B6), and cobalamin (vitamin B7). 12 At least one of the following.

[0034] Preferably, the mass ratio of vitamin B1, vitamin B2, vitamin B6 and vitamin B12 is 1:(2-5):(1-3):(0.001-0.01).

[0035] Further, it includes the following components in parts by weight: 1-5 parts cordycepin enrichment culture, 20-60 parts dextran iron, 1-5 parts vitamin E, 5-15 parts vitamin C, and 0.5-2 parts B complex vitamins.

[0036] Furthermore, the carrier is selected from at least one of corn starch, glucose, maltodextrin, lactose, microcrystalline cellulose, talc, silicon dioxide, and magnesium stearate.

[0037] On the other hand, the present invention provides a method for preparing the cordycepin-dextran iron complex preparation, comprising the following steps:

[0038] (1) Add dextran iron to an aqueous solvent and stir to dissolve it under water bath conditions of 40-60℃ to obtain dextran iron solution;

[0039] (2) Add the antioxidant and metabolism promoter to the dextran iron solution and stir until completely dissolved to obtain a composite solution;

[0040] (3) Mix the cordycepin enrichment culture and the carrier evenly to obtain a premixed powder;

[0041] (4) Under continuous stirring, the composite solution is added to the premixed powder and mixed evenly, granulated, and dried to obtain the cordycepin-dextran iron composite preparation.

[0042] Specifically, the preparation method of the cordycepin-dextran iron complex includes the following steps:

[0043] S1, weigh out the cordycepin enrichment culture, dextran iron and all excipients according to the formula;

[0044] S2, dissolve dextran iron in purified water and stir under water bath conditions of 40-60℃ to obtain dextran iron solution;

[0045] S3, add vitamin E, vitamin C, and B complex vitamins sequentially to the dextran iron solution and continue stirring until completely dissolved to obtain a complex solution;

[0046] S4, mix the cordycepin enrichment culture and carrier evenly using the equal-volume incremental addition method to obtain the premixed powder;

[0047] S5. Under stirring conditions, the composite solution is slowly added to the premixed powder and stirred for 15-30 minutes to make it uniformly mixed, thus obtaining a moist soft material.

[0048] S6, the moist soft material is granulated through a 10-20 mesh sieve to obtain wet granules;

[0049] S7, dry the wet granules at 40-60℃ until the moisture content does not exceed 5% to obtain dried granules;

[0050] S8. The dried granules are sieved through a 20-40 mesh sieve, mixed evenly, and then packaged to obtain the cordycepin-dextran iron compound preparation.

[0051] Preferably, in step S4, the equal-volume incremental method refers to first mixing the cordycepin enrichment culture with an equal amount of carrier, then mixing the mixture with an equal amount of carrier, and repeating this operation until all the carrier is added and mixed evenly.

[0052] This invention provides the application of the cordycepin-dextran iron compound preparation in the feeding of sows during gestation.

[0053] Furthermore, the content of the cordycepin-dextran iron compound preparation in the basal diet of sows during gestation is 0.5-4.0 g / kg, preferably 0.6-2.5 g / kg.

[0054] Furthermore, the compound preparation adopts a phased, step-by-step feeding scheme, adjusting the concentration stepwise according to the physiological needs of different stages of pregnancy. Within each stage, a fixed dosage can be selected within the corresponding range based on the sow's parity and body condition.

[0055] The first stage (early pregnancy, from mating to day 30 of pregnancy): the cordycepin-dextran iron compound preparation is added at a rate of 0.5-1.5 g / kg of basal diet; preferably 0.5-1.0 g / kg of basal diet.

[0056] Second stage (mid-pregnancy, days 31-84 of gestation): The amount of the cordycepin-dextran iron compound preparation added is 1.0-2.5 g / kg of basal diet; preferably 1.0-2.0 g / kg of basal diet.

[0057] The third stage (late pregnancy to lactation, from day 85 of gestation to weaning of piglets): The cordycepin-dextran iron compound preparation is added at a rate of 2.0-4.0 g / kg of basal diet. Preferably, it is 2.0-3.0 g / kg of basal diet.

[0058] Preferably, the amount of cordycepin-dextran iron compound preparation added during the late pregnancy to lactation period is greater than the amount used in the mid-pregnancy period, and the amount of cordycepin-dextran iron compound preparation added during the mid-pregnancy period is greater than the amount used in the early pregnancy period.

[0059] This invention employs a phased feeding program, precisely controlling the dosage of the compound preparation based on the different physiological needs of sows at different stages of gestation: moderate addition in early gestation to promote embryo implantation and early development; increased addition in mid-gestation to meet the needs of rapid fetal growth; and high addition from late gestation to lactation to meet the critical period for fetal iron reserves and postpartum lactation. This program achieves precise nutrient supply, avoiding waste or deficiency.

[0060] Preferably, the compound preparation is administered by mixing it into feed.

[0061] Preferably, during the late stages of pregnancy (from the 85th day of pregnancy to delivery), a combination of feed mixing and water administration can be used. The water administration regimen involves dissolving the compound preparation in drinking water at a concentration of 0.5-1.0 g / L, allowing the patient to drink freely daily or administering it orally in divided doses.

[0062] When administered via feed mixing or drinking water, this oral administration regimen avoids the stress response of traditional dextran iron injections in sows. It is particularly suitable for sows in late pregnancy that require frequent iron supplementation but should minimize human intervention, thus improving the safety, convenience, and animal welfare of the medication.

[0063] There are no particular restrictions on the breed of sows, including but not limited to Landrace, Large White, Duroc, Pietrain, Hampshire and their two- or three-way crossbred sows.

[0064] The present invention has, but is not limited to, the following beneficial technical effects:

[0065] This invention discloses a cordycepin-dextran iron compound preparation, which organically combines cordycepin and dextran iron. Cordycepin, as an immunomodulatory and antioxidant active molecule, functions by promoting reproductive performance and improving maternal health. Dextran iron, as an iron supplement, functions by replenishing hematopoietic raw materials and preventing anemia. The two work synergistically through different biological pathways to improve the health of pregnant sows, achieving an integrated health-promoting effect of "promoting reproduction + iron supplementation." Attached Figure Description

[0066] Figure 1 This is a bar chart comparing serum immunoglobulin and inflammatory factor levels in sows on the day of farrowing in Experiment Example 1 of this invention, including five indicators: IgG, IgM, IgA, TNF-α, and IL-10. Detailed Implementation

[0067] The specific embodiments of the present invention are explained with the aid of examples. Except for the detection technology, which does not limit the present invention in any way, some of the solutions in the described embodiments are part of the embodiments of the invention. All embodiments obtained by ordinary people in the art without creative results are within the protection scope of the present invention.

[0068] The experimental materials used in the following examples: the production process of cordycepin enrichment culture (cordycepin ≥10000 μg / g) includes the following steps:

[0069] S1. The fusion strain of *Geotrichum can be activated and cultured to obtain an activated strain;

[0070] Specifically, the fusion strain F2652 of *Gastrodinium glomeratum* (accession number GDMCC NO:64892) was activated by slant culture on a comprehensive PDA agar medium. Glyceryl bacteria were then inoculated onto PDA agar plates and cultured in an incubator at 25°C in the dark for 7 days. Conidia were then washed off with sterile physiological saline and transferred to 18×180mm test tube slant culture. The samples were then cultured in an incubator at 27°C in the dark for 4 days to obtain the activated strain.

[0071] S2. The activated strain is inoculated into millet seed culture medium for cultivation to obtain an enhanced seed culture; wherein, the millet seed culture medium includes the following raw materials: millet, soybean extract powder, sucrose, yeast extract, peptone, potassium dihydrogen phosphate, magnesium sulfate, ferrous sulfate, vitamin B1, vitamin B2, vitamin B6 and vitamin B12.

[0072] Specifically, the activated strains were eluted with 20 mL of sterile physiological saline until the spore concentration in the eluent was 5.0 × 10⁻⁶. 6The elution buffer was transferred to an eggplant-shaped flask containing millet seed-enhanced medium slant and incubated at 25°C in the dark for 3 days to obtain an enhanced seed culture with a maximum spore concentration of 1.0 × 10⁻⁶ spores per mL. 11 1 / gram of culture.

[0073] The preparation method of the millet seed-enhanced culture medium is as follows: Weigh 20g of soybean extract powder, 10g of sucrose, 5.0g of yeast extract, 3.0g of peptone, 0.5g of potassium dihydrogen phosphate, 0.1g of magnesium sulfate, 100mg of ferrous sulfate, 20mg of vitamin B1, 10mg of vitamin B2, 10mg of vitamin B6, and 10mg of vitamin B2. 12 Prepare a nutrient solution by mixing 50 μg of commercial millet at pH 6 with a final volume of 1000 mL. Then, weigh out 1000 g of millet (1:1 mass-to-volume ratio) for every 1000 mL of nutrient solution. Mix thoroughly and steam over a water bath for 45 minutes. After steaming, weigh 100 g of the mixture into each eggplant-shaped flask and autoclave at 121°C for 20-30 minutes using standard methods. This results in a millet seed-enhanced culture medium with a large surface area, good aeration, and favorable conditions for spore germination and mycelial growth.

[0074] S3. The enhanced seed culture is subjected to liquid fermentation culture to obtain liquid fermentation product;

[0075] Specifically, the above-mentioned millet seed enhanced culture was directly inoculated into a fermenter. Approximately 100g of millet seed culture was inoculated into a 30L fermenter containing 15L of liquid culture medium for cultivation. At the beginning of fermentation, the aeration rate was controlled at 15L / min, the stirring speed at 150r / min, the temperature at 25℃, and the initial reducing sugar concentration at 100g / L. The reducing sugar concentration was controlled to 0.7g / 100mL by adding 70% glucose. The initial pH was 7.0, and the pH was maintained at 7.0 throughout fermentation by adding ammonia. After 24 hours of cultivation, diffused light was applied for 2-3 days at a light intensity of 400Lx to enhance the culture of mycelium and cordycepin. The dissolved oxygen (DO) saturation was controlled at 30% throughout the process, and the fermentation cycle was 5 days. Fermentation was then stopped, yielding a liquid fermentation culture. Liquid fermentation mycelium can be collected by centrifuging at 3000 r / min for 15 min and then dried at 60-80℃ until the moisture content is less than 10% for the purpose of detecting biomass, mycelial polysaccharide and adenosine content.

[0076] The above liquid culture medium, by weight, comprises: glucose 8%, peptone 1.5%, yeast extract 1.5%, corn flour 5.5%, soybean flour 2.0%, wheat flour 0.5%, ammonium sulfate 0.5%, potassium dihydrogen phosphate 0.5%, magnesium sulfate 0.3%, amino acid nutrient stock solution 0.5%, trace element stock solution 10mL, vitamin B1 2mg / 100mL, vitamin B2 1mg / 100mL, and vitamin B... 12 Add 1 mg / 100 mL of tap water to 100%, adjust the pH to 6.5-7.0, and autoclave at 121℃ for 25 min using standard methods.

[0077] S4. Inoculate the liquid fermentation product into a solid culture medium, carry out solid fermentation under light conditions, remove the solid fermentation product and dry it to obtain the fermentation culture of the *Gastrodinium spp.* fusion strain.

[0078] The conditions for solid-state fermentation were: temperature 30℃, humidity 70%, fermentation time 5 days, light intensity 150Lx, and light duration 10 hours per day.

[0079] The mixing ratio of the liquid fermentation broth to the solid culture medium is 1L of liquid fermentation product to 5kg of solid culture medium; the solid culture medium includes the following components by weight: 40 parts soybean meal powder, 30 parts wheat flour and 30 parts wheat bran powder.

[0080] The collection of fermentation products refers to the collection of solid fermentation products after solid fermentation, which are then dried directly at 60°C until the moisture content is 7%, pulverized and passed through a 40-mesh sieve to obtain cordycepin enrichment culture.

[0081] The cordycepin enrichment culture was analyzed by high performance liquid chromatography according to the agricultural industry standard NY / T 2116-2012, "Determination of Cordycepin and Adenosine in Cordyceps Products," and the cordycepin content was 13233 μg / g.

[0082] Dextran iron: iron content 20wt%; Guangxi Weikete Biotechnology Co., Ltd., VT-TDS-20.

[0083] Unless otherwise specified, all other raw materials were purchased from conventional biochemical reagent manufacturers. Quantitative experiments in the following examples were performed in triplicate, and the results were averaged.

[0084] Example 1

[0085] A cordycepin-dextran iron complex preparation, by weight, comprises the following components: 3 parts cordycepin enrichment culture, 40 parts dextran iron (iron content 20wt%), 3 parts DL-α-tocopherol acetate (vitamin E), 10 parts ascorbate phosphate (vitamin C), and a complex of B vitamins (containing B1, B2, B6, and B6).12 1 part corn starch, 30 parts corn starch, 10 parts maltodextrin, and 3 parts microcrystalline cellulose.

[0086] Among them, the complex B vitamins include vitamin B1, vitamin B2, vitamin B6 and vitamin B1. 12 The mass ratio of B1:B2:B6:B 12 =1:3.6:2:0.015.

[0087] The preparation method of the cordycepin-dextran iron complex preparation includes the following steps:

[0088] (1) Dissolve dextran iron in an appropriate amount of purified water and stir at 300 r / min for 25 min in a 50℃ water bath to obtain a dextran iron solution.

[0089] (2) Add vitamin E, vitamin C and B complex vitamins to the dextran iron solution in sequence, and continue stirring until completely dissolved to obtain a complex solution.

[0090] (3) The cordycepin enrichment culture and the carrier (corn starch, maltodextrin, microcrystalline cellulose) are mixed evenly using the equal-volume incremental addition method to obtain a premixed powder. The equal-volume incremental addition method means that the cordycepin enrichment culture is first mixed with an equal amount of carrier, and then the mixture is mixed with an equal amount of carrier. This process is repeated until all the carrier is added and mixed evenly to obtain the premixed powder.

[0091] (4) Under stirring conditions (250 r / min), the composite solution is slowly added to the premixed powder and stirred for 20 min to make it uniformly mixed to obtain a moist soft material.

[0092] (5) The moist soft material is granulated through a 16-mesh sieve to obtain wet granules.

[0093] (6) The wet particles are dried at 50°C until the moisture content is 3.5% to obtain dried particles.

[0094] (7) The dried granules are sieved through a 30-mesh sieve, mixed evenly, and then packaged to obtain the cordycepin-dextran iron compound preparation.

[0095] According to the test results, the compound preparation prepared in this embodiment has a cordycepin content of 300 μg / g, an iron content of 8.0%, a moisture content of 3.5%, and a particle size distribution (passing through a 30-mesh sieve) of ≥95%.

[0096] Example 2

[0097] A cordycepin-dextran iron complex preparation differs from Example 1 in that the carrier in this example is glucose, corn starch, talc and silicon dioxide.

[0098] Specifically, by weight, the cordycepin-dextran iron complex preparation comprises the following components: 2 parts cordycepin enrichment culture, 50 parts dextran iron (iron content 20wt%), 2 parts DL-α-tocopherol acetate (vitamin E), 8 parts coated vitamin C, and a complex of B vitamins (containing B1, B2, B6, and B6). 12 0.8 parts, glucose 25 parts, corn starch 10 parts, talc 1.2 parts, silicon dioxide 1 part.

[0099] The difference between the preparation method of the cordycepin-dextran iron compound preparation in this embodiment and that in Example 1 is that in step (6), the drying condition is 45°C, which further reduces the risk of degradation of active ingredients.

[0100] Testing revealed that the compound preparation prepared in this embodiment contained 200 μg / g cordycepin and 10.0% iron.

[0101] Example 3

[0102] A cordycepin-dextran iron complex formulation differs from Example 1 in that the carrier in this example is lactose, microcrystalline cellulose, magnesium stearate, and silicon dioxide.

[0103] Specifically, by weight, the cordycepin-dextran iron complex preparation comprises the following components: 5 parts cordycepin enrichment culture, 30 parts dextran iron (iron content 20wt%), 5 parts DL-α-tocopherol acetate (vitamin E), 15 parts coated vitamin C, and a complex of B vitamins (containing B1, B2, B6, and B6). 12 1.5 parts, lactose 20 parts, microcrystalline cellulose 15 parts, magnesium stearate 3.5 parts, silicon dioxide 5 parts.

[0104] The preparation method of the cordycepin-dextran iron complex in this embodiment is the same as that in Example 1.

[0105] The compound preparation prepared in this embodiment was found to contain 500 μg / g cordycepin and 6.0% iron.

[0106] Comparative Example 1

[0107] A dextran iron preparation differs from Example 1 in that this example does not contain cordycepin enrichment culture.

[0108] The preparation method of the dextran iron preparation in this comparative example is as follows:

[0109] (1) Dissolve dextran iron in an appropriate amount of purified water and stir at 300 r / min for 25 min in a 50℃ water bath to obtain a dextran iron solution.

[0110] (2) Add vitamin E, vitamin C and B complex vitamins to the dextran iron solution in sequence, and continue stirring until completely dissolved to obtain a complex solution.

[0111] (3) Mix the carrier (corn starch, maltodextrin, microcrystalline cellulose) evenly to obtain premixed powder.

[0112] (4) Under stirring conditions (250 r / min), the composite solution is slowly added to the premixed powder and stirred for 20 min to make it uniformly mixed to obtain a moist soft material.

[0113] (5) The moist soft material is granulated through a 16-mesh sieve to obtain wet granules.

[0114] (6) The wet particles are dried at 50°C until the moisture content is 3.5% to obtain dried particles.

[0115] (7) The dried granules are sieved through a 30-mesh sieve, mixed evenly, and then packaged to obtain the dextran iron compound preparation.

[0116] Testing revealed that the iron content in the dextran iron preparation prepared in this embodiment was 8.0%.

[0117] Comparative Example 2

[0118] A cordycepin preparation, which differs from Example 1 in that this example does not contain dextran iron.

[0119] The preparation method of the dextran iron preparation in this comparative example is as follows:

[0120] (1) Add vitamin E, vitamin C and B complex vitamins to an appropriate amount of purified water in sequence, and continue stirring until completely dissolved to obtain a complex solution.

[0121] (2) The cordycepin enrichment culture and the carrier (corn starch, maltodextrin, microcrystalline cellulose) are mixed evenly using the equal-volume incremental addition method to obtain a premixed powder. The equal-volume incremental addition method refers to first mixing the cordycepin enrichment culture with an equal amount of carrier, then mixing the mixture with an equal amount of carrier, and repeating this operation until all the carrier is added and mixed evenly to obtain the premixed powder.

[0122] (3) Under stirring conditions (250 r / min), the composite solution is slowly added to the premixed powder and stirred for 20 min to make it uniformly mixed to obtain a moist soft material.

[0123] (4) The moist soft material is granulated through a 16-mesh sieve to obtain wet granules.

[0124] (5) The wet particles are dried at 50°C until the moisture content is 3.5% to obtain dried particles.

[0125] (6) The dried granules are sieved through a 30-mesh sieve, mixed evenly, and then packaged to obtain the cordycepin preparation.

[0126] The cordycepin preparation prepared in this embodiment was tested and found to contain 300 μg / g of cordycepin.

[0127] Performance testing

[0128] The cordycepin-dextran iron complex preparation from Example 1 was subjected to the following physical stability tests:

[0129] (1) Accelerated stability test: Three batches of compound preparation samples were stored at a temperature of 40℃±2℃ and a relative humidity of 75%±5% for 6 months. Samples were taken at 0, 3 and 6 months to test the cordycepin content, iron content and moisture content.

[0130] The results showed that after 6 months, the cordycepin retention rate was ≥92% and the iron content fluctuation was <5%, indicating that the compound preparation had good physicochemical stability under these conditions.

[0131] (2) Long-term stability test: Three batches of samples were stored at a temperature of 25℃±2℃ and a relative humidity of 60%±10% for 24 months. Samples were taken at 0, 6, 12, 18 and 24 months to test the cordycepin content, iron content and moisture content.

[0132] The results showed that none of the indicators showed a significant trend of change, and the cordycepin retention rate remained above 95%.

[0133] Experimental Example 1

[0134] This study investigated the effects of cordycepin-dextran iron compound preparation on the reproductive performance, immune function, and iron metabolism in pregnant sows and piglets.

[0135] 1. Test materials

[0136] Cordycepin-dextran iron complex preparation: prepared by the method of Example 1, with a cordycepin content of 300 μg / g and an iron content of 8.0%.

[0137] Control formulation 1# (dextran iron preparation): prepared by the method of Comparative Example 1, with an iron content of 8.0%.

[0138] Control formulation 2# (cordycepin preparation): prepared by the method of comparative example 1, with a cordycepin content of 300 μg / g.

[0139] Basal diet: Corn-soybean meal compound feed is formulated according to the NRC (2012) nutritional standards for pregnant sows. The base iron content of the diet is 80-100 mg / kg, and no additional exogenous iron or cordyceps-based active additives are added.

[0140] Carrier powder: Corn starch + maltodextrin + microcrystalline cellulose are mixed in the proportions claimed in the claims. It contains no active ingredients and is used as an equal substitute for the blank group.

[0141] 2. Experimental animals and grouping

[0142] Seventy-five pregnant sows of the same breed (Landrace × Large White crossbred), with similar parities (2nd-3rd litter), similar mating dates, and good health were selected and randomly divided into 5 treatment groups of 15 sows each, based on backfat thickness and body weight. The experimental treatments are as follows:

[0143] (1) Blank control group (Group A): Basal diet + equal amount of maltodextrin carrier powder added in stages (0.7 g / kg in early pregnancy, 1.5 g / kg in mid pregnancy, and 2.5 g / kg in late pregnancy and lactation), without adding any active ingredients;

[0144] (2) Single dextran iron group (Group B): basal diet + phased addition of control preparation 1# (0.7 g / kg in early pregnancy, 1.5 g / kg in mid pregnancy, and 2.5 g / kg in late pregnancy to lactation), with iron supplementation of 56, 120 and 200 mg / kg of diet for each phase, respectively.

[0145] (3) Single cordycepin group (C group): basal diet + phased addition of control preparation 2# (0.7 g / kg in early pregnancy, 1.5 g / kg in mid pregnancy, and 2.5 g / kg in late pregnancy to lactation period), with cordycepin addition amounts of 0.21, 0.45 and 0.75 mg / kg of diet in each phase;

[0146] (4) Low-dose compound preparation group (Group D): Basal diet + compound preparation of Example 1 added in stages (0.7 g / kg in early pregnancy, 1.5 g / kg in mid pregnancy, and 2.5 g / kg in late pregnancy to lactation). The cordycepin addition amount in each stage was 0.21, 0.45 and 0.75 mg / kg of diet, and the iron supplementation amount was 56, 120 and 200 mg / kg of diet, respectively.

[0147] (5) High-dose compound preparation group (Group E): Basal diet + compound preparation of Example 1 added in stages (1.2 g / kg in early pregnancy, 2.5 g / kg in mid pregnancy, and 4.0 g / kg in late pregnancy to lactation). The cordycepin addition amount in each stage was 0.36, 0.75 and 1.20 mg / kg of diet, and the iron supplementation amount was 96, 200 and 320 mg / kg of diet, respectively.

[0148] Among them, the early pregnancy period refers to the period from mating to the 30th day of pregnancy, the mid-pregnancy period refers to the 31st to 84th day of pregnancy, the late pregnancy period refers to the 85th day of pregnancy to farrowing, and the lactation period refers to the period from farrowing to weaning of piglets.

[0149] The trial lasted approximately 114 days, starting from the confirmation of pregnancy in sows after mating (confirmed by ultrasound on day 21 post-mating) and ending at 21 days post-partum weaning of piglets. The basal diet was a compound feed for pregnant sows formulated according to NRC (2012) standards, with an iron content of approximately 80-100 mg / kg (from conventional feed ingredients). This was insufficient to meet the high iron requirements in late pregnancy, thus requiring additional iron supplementation.

[0150] 3. Feeding and Management

[0151] The experimental sows were housed individually in gestation crates and fed a basal diet in stages and in fixed quantities. The basal diet feeding plan was as follows: 2.0 kg per day during early gestation (mating to day 30 of gestation), 2.5 kg per day during mid-gestation (days 31-84 of gestation), 3.0 kg per day during late gestation (day 85 of gestation to farrowing), and 4.5 kg per day during lactation (from farrowing to weaning of piglets) (if free access was available, the average daily feed intake was used). Sows were fed twice daily, in the morning and evening, and had free access to water.

[0152] Each treatment group adopted a phased fixed-concentration addition method: the concentration of additives in the diet was kept constant within the same gestation stage, and adjusted stepwise between stages; the actual daily amount of additives fed = the fixed concentration for that stage × the daily basal diet amount. Before feeding, the required formulation was weighed according to the corresponding group, corresponding stage and daily feed amount, and premixed with a small amount of basal diet in stages, and then evenly mixed into the total amount of basal diet for that day to ensure that the formulation was evenly distributed in the diet.

[0153] The immunization program was carried out according to the standard procedures for pig farms. The temperature in the pigsty was controlled at 21±4℃, and the relative humidity was controlled at 55%-70%. The pigsty was disinfected once a week.

[0154] After farrowing, sows are moved to elevated farrowing pens for free access to lactating sow feed and are monitored around the clock. Human intervention is minimized during farrowing, and the progress of labor is recorded.

[0155] Newborn piglets should not receive iron injections within 24 hours of birth to evaluate the relationship between maternal iron transfer and iron reserves. Colostrum intake (within 2 hours of birth), teeth clipping, tail docking, and ear tagging should be performed according to standard operating procedures. At 72 hours post-birth, blood should be drawn from the anterior vena cava to test hemoglobin levels. Dextran iron should then be administered as needed (this can be omitted if the newborn piglet's hemoglobin is ≥90 g / L) to ensure animal welfare. Piglets are weaned at 21 days of age.

[0156] 4. Measurement Indicators and Methods

[0157] (1) Sow reproductive performance: Record the total number of piglets born, the number of live piglets born, the number of healthy piglets born (weight ≥1.0kg), the number of stillbirths, and the number of mummified litters for each sow. Weigh the birth weight of each live piglet and calculate the average birth weight per litter and the coefficient of variation (CV, %). Weigh the piglets at 21 days of age at weaning, record the number of piglets that survive weaning, and calculate the mortality rate of piglets during lactation.

[0158] (2) Blood parameters of sows: On the 30th day of gestation, the 110th day of gestation and the day of farrowing, about 10 mL of blood was collected from the marginal ear vein of the sow before feeding in the morning. 2 mL of the blood was injected into an EDTA-K2 anticoagulant tube for routine blood tests (hemoglobin Hb, red blood cell count RBC, hematocrit HCT) and 8 mL of the blood was injected into a vacuum blood collection tube without anticoagulant. After standing at room temperature for 30 min, the blood was centrifuged at 3500 r / min for 10 min to collect the serum, which was then stored at -80℃ for testing.

[0159] (3) Blood iron metabolism indicators of newborn piglets: 72 hours after birth, 2 piglets with a weight close to the litter average were randomly selected from each litter, and 3 mL of blood was collected from the jugular vein (1 mL of anticoagulated blood was used for Hb detection and 2 mL of serum was separated). Serum iron concentration and total iron binding capacity (TIBC) were detected, and transferrin saturation (TSAT) was calculated as (serum iron concentration / TIBC) × 100%.

[0160] (4) Serum immune indicators of sows: The serum levels of immunoglobulin G (IgG), immunoglobulin M (IgM), immunoglobulin A (IgA), tumor necrosis factor-α (TNF-α), and interleukin-10 (IL-10) of sows on the day of farrowing were measured by ELISA. The kits were purchased from Jiangsu Enzyme Immunoassay Co., Ltd.

[0161] (5) Antioxidant indicators in sow serum: The total antioxidant capacity (T-AOC) and malondialdehyde (MDA) levels in serum were measured on the day of farrowing, as well as the activities of glutathione peroxidase (GSH-Px), total superoxide dismutase (T-SOD), and catalase (CAT). All kits were purchased from Nanjing Jiancheng Biotechnology Institute and the detection was performed using a Thermo Multiskan FC microplate reader.

[0162] 5. Data Statistical Analysis

[0163] Experimental data were initially processed using Excel, and one-way ANOVA was performed using SPSS 26.0 software. Multiple comparisons were conducted using Duncan's method. P < 0.05 indicated a significant difference, and P < 0.01 indicated an extremely significant difference. Different lowercase letters above the data in the same row indicated significant differences (P < 0.05). All results are expressed as mean ± standard deviation (Mean ± SD).

[0164] 6. Experimental Results and Analysis

[0165] (1) Sow reproductive performance

[0166] Table 1. Effects of different formulations on the reproductive performance of pregnant sows

[0167]

[0168] As shown in Table 1, the total number of piglets born in the compound preparation groups (groups D and E), especially the high-dose compound group (group E), was significantly higher than that in the blank group (group A), the single iron group (group B), and the single cordycepin group (group C). Among them, the single cordycepin group (group C) could slightly improve the weight of piglets, but failed to effectively reduce the stillbirth rate of weak piglets.

[0169] The single-iron group (Group B) slightly improved the initial weight and survival rate, but the improvement was much lower than that of the compound groups (Group D and Group E).

[0170] The results showed that cordycepin and dextran iron had a synergistic effect. The high-dose group had the highest number of healthy piglets, the lowest stillbirth rate of weak piglets, and the best weaning weight and survival rate. At the same time, it significantly shortened the labor process and alleviated the stress of parturition in sows.

[0171] (2) Hemoglobin concentration in sows during pregnancy

[0172] Table 2. Blood iron metabolism-related indicators in sows at 110 days of gestation.

[0173]

[0174] As shown in Table 2, there were no significant differences in iron levels between the blank group (Group A) and the cordycepin-only group (Group C) (P>0.05), proving that cordycepin has no iron supplementation effect. The dextran-only iron group (Group B) showed a significant increase in iron levels, but 20% of sows still had anemia, indicating a limited iron supplementation effect.

[0175] The low- and high-dose combined groups (groups D and E) showed significantly better results than the other groups in terms of hemoglobin, serum iron, and ferritin, with an anemia rate of only 6.7%, confirming that cordycepin and dextran iron have a synergistic effect and can improve iron absorption and utilization.

[0176] The high-dose group (Group E) only slightly increased iron reserves, and the incidence of anemia was the same as that of the low-dose group. The 1.5g / kg dosage strikes a balance between effectiveness and cost, making it more suitable for large-scale farming. In summary, compound formulations can synergistically improve iron nutrition in sows, and single ingredients cannot achieve the same effect.

[0177] (3) Iron metabolism indicators of newborn piglets

[0178] Table 3. Indicators related to iron metabolism in newborn piglets

[0179]

[0180] As shown in Table 3, feeding the mothers with the compound preparations in groups D and E significantly improved intrauterine iron transport in the fetus and increased iron reserves in the piglets' livers; group B showed limited improvement when supplemented with iron alone, and group C could not increase iron reserves in piglets when only cordycepin was used, proving that the combination of the two synergistically promotes placental iron transport.

[0181] (4) Immune function indicators of sows

[0182] like Figure 1 As shown, there were no significant differences in various immune and inflammatory indicators between the blank group (Group A) and the single dextran iron group (Group B), indicating that supplementation with dextran iron alone cannot improve humoral immunity or alleviate chronic inflammation in pregnant sows. The single cordycepin group (Group C) showed a slight increase in IgG, IgM, and IgA, a significant decrease in the pro-inflammatory factor TNF-α, and a significant increase in the anti-inflammatory factor IL-10, but the overall improvement was limited, indicating insufficient regulatory effect when used alone. The low- and high-dose combined preparation groups (Groups D and E) had significantly higher immunoglobulin levels than the first three groups, significantly lower TNF-α, and significantly higher IL-10, with no statistically significant difference between the two groups. This confirms that the combination of cordycepin and dextran iron has a synergistic effect, simultaneously improving humoral immunity and alleviating chronic inflammation in pregnant sows. An addition of 1.5 g / kg is sufficient to achieve the desired effect, and increasing the addition dose did not provide significant benefit.

[0183] (5) Antioxidant indicators in sows

[0184] Table 4 Serum antioxidant indices of sows before farrowing

[0185]

[0186] Note: If the same letter is in the superscript of the same data in the same row, the difference is not significant (P>0.05); if no letter is in the superscript, the difference is significant (P<0.05).

[0187] Table 4 shows that there were no significant differences in T-SOD, GSH-Px, CAT, and MDA between the blank group (Group A) and the single dextran iron group (Group B), indicating that iron supplementation alone could not alleviate oxidative stress in sows during pregnancy. The single cordycepin group (Group C) showed a slight increase in antioxidant enzymes and a significant decrease in MDA, but the improvement was limited. The low- and high-dose combined preparation groups (Groups D and E) showed significantly higher activities of the three antioxidant enzymes than the other groups, and a significant decrease in lipid peroxidation product MDA, with no significant difference between the low- and high-dose groups. This indicates that cordycepin can neutralize oxidative damage generated during iron supplementation, and the combination of the two can synergistically enhance the overall antioxidant capacity of sows, reduce free radical accumulation, and alleviate oxidative stress damage in the mid-to-late stages of pregnancy.

[0188] Experimental Example 2

[0189] This experimental case aims to investigate the stability of the compound formulation and the consistency between different batches.

[0190] 1. Accelerated stability test

[0191] Experimental method: Three batches of cordycepin-dextran iron composite preparations prepared in Examples 1, 2 and 3 were placed in a constant temperature and humidity chamber at 40℃±2℃ and 75%±5% relative humidity. Samples were taken at 0 days, 30 days, 90 days and 180 days to test the appearance, cordycepin content, iron content, moisture and particle size distribution.

[0192] The detection method is as follows:

[0193] (1) Appearance: Visually observe the color, shape and flowability of the sample under natural light, and check for lumps, mold and odor.

[0194] (2) Cordycepin content: The high performance liquid chromatography (HPLC) method was used to determine the content of cordycepin in feed. The method was performed in accordance with NY / T 2116-2012 "Determination of Cordycepin in Feed by High Performance Liquid Chromatography". The retention rate of cordycepin at each time point relative to day 0 was calculated.

[0195] (3) Total iron content: The total iron content was determined by atomic absorption spectrophotometry in accordance with GB / T 13885-2017 "Determination of iron, copper, manganese and zinc in feed by atomic absorption spectrometry". The iron content retention rate at each time point relative to day 0 was calculated.

[0196] (4) Moisture: The drying method at 105℃ and normal pressure was adopted, in accordance with GB / T 6435-2014 "Determination of Moisture in Feed".

[0197] (5) Particle size distribution: The standard test sieve method was adopted, and the passing rate of the sample through the 40-mesh and 80-mesh standard sieves was tested according to GB / T 5917.1-2008 "Determination of particle size of feed powder - Part 1: Percentage of material on sieve".

[0198] Evaluation criteria:

[0199] After 180 days of accelerated testing, samples that simultaneously meet the following conditions are considered to be of stable quality:

[0200] The powder should be uniformly brownish-yellow in appearance, without lumps, mold, or odor.

[0201] Cordycepin content retention rate ≥90% (relative to the initial content at day 0);

[0202] Total iron content retention rate ≥95% (relative to the initial content at day 0);

[0203] Moisture ≤10.0%;

[0204] The particle size should be maintained at 30 mesh for full pass and 40 mesh for ≥95% pass rate.

[0205] If the relative deviation of the same indicator between different batches is ≤5%, it is judged as good batch consistency.

[0206] The results showed that the appearance of each sample remained largely unchanged; the cordycepin retention rate was ≥95% at 90 days and ≥92% at 180 days; iron content fluctuated by <5%; moisture content increased slightly but remained below the 5% limit; and particle size distribution remained stable. These results indicate that the compound formulation of this invention exhibits good physicochemical stability under accelerated conditions. Vitamin E and Vitamin C, as antioxidant protective components, jointly play a role in protecting the stability of cordycepin in the formulation.

[0207] 2. Batch consistency assessment

[0208] Five batches of compound preparations were continuously prepared based on the formulation of Example 1. Three parallel samples were randomly selected from each batch, and the cordycepin content and iron content of each batch were tested.

[0209] Cordycepin content: determined by high performance liquid chromatography, in accordance with NY / T 2116-2012 "Determination of Cordycepin in Feed by High Performance Liquid Chromatography";

[0210] Total iron content: determined by atomic absorption spectrophotometry, in accordance with GB / T 13885-2017 "Determination of iron, copper, manganese and zinc in feed by atomic absorption spectrometry".

[0211] Evaluation criteria

[0212] The relative standard deviation (RSD) of cordycepin content in the 5 batches of samples was ≤3.0%, and the relative standard deviation (RSD) of total iron content was ≤2.0%, which indicates that the content consistency between batches was good and the preparation process was stable and controllable.

[0213] The results showed that the average cordycepin content of the five batches of samples was 298.4 μg / g (RSD=1.86%), and the average iron content was 7.97% (RSD=1.54%). The consistency between batches was good, indicating that the preparation process of the compound formulation of the present invention is stable, reliable, and controllable, and is suitable for large-scale production.

Claims

1. A cordycepin-dextran iron complex preparation, characterized in that, Includes the following components in parts by weight: Cordycepin enrichment culture 1-5 parts, dextran iron 20-60 parts, antioxidant protectant 6-20 parts, metabolism promoter 0.5-2 parts, carrier 15-75 parts; The cordycepin enrichment culture contains no less than 10,000 μg / g of cordycepin.

2. The cordycepin-dextran iron complex preparation as described in claim 1, characterized in that, The iron content in the dextran iron is 15-25 wt%.

3. The cordycepin-dextran iron complex preparation as described in claim 1, characterized in that, The cordycepin enrichment culture was derived from the fermentation culture of Sarocladonia terricola strain F2652.

4. The cordycepin-dextran iron complex preparation as described in claim 1, characterized in that, The compound preparation contains 200-500 μg / g of cordycepin and 6.0-10.0 wt% of iron.

5. The cordycepin-dextran iron complex preparation as described in claim 1, characterized in that, The carrier is selected from at least one of corn starch, glucose, maltodextrin, lactose, microcrystalline cellulose, talc, silicon dioxide, and magnesium stearate; and / or, The antioxidant is selected from at least one of vitamin E and vitamin C; and / or, The metabolism promoter is selected from B vitamins.

6. The cordycepin-dextran iron complex preparation as described in claim 5, characterized in that, The complex B vitamins are selected from at least one of thiamine, riboflavin, pyridoxine, and cobalamin.

7. The cordycepin-dextran iron complex preparation as described in claim 1, characterized in that, It includes the following components by weight: 1-5 parts cordycepin enrichment culture, 20-60 parts dextran iron, 1-5 parts vitamin E, 5-15 parts vitamin C, and 0.5-2 parts B complex vitamins.

8. A method for preparing the cordycepin-dextran iron complex formulation according to any one of claims 1-7, characterized in that, Includes the following steps: (1) Add dextran iron to an aqueous solvent and stir to dissolve it under water bath conditions of 40-60℃ to obtain dextran iron solution; (2) Add the antioxidant and metabolism promoter to the dextran iron solution and stir until completely dissolved to obtain a composite solution; (3) Mix the cordycepin enrichment culture and the carrier evenly to obtain a premixed powder; (4) Under continuous stirring, the composite solution is added to the premixed powder and mixed evenly, granulated, and dried to obtain the cordycepin-dextran iron composite preparation.

9. The use of the cordycepin-dextran iron compound preparation according to any one of claims 1-7 in the feeding of sows during gestation.

10. The application as described in claim 9, characterized in that, The cordycepin-dextran iron compound preparation is added to the basal diet of sows during gestation at a rate of 0.5-4.0 g / kg.

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