Feed additive for improving reproductive performance of sows and preparation method thereof

Abstract

The invention discloses a feed additive for improving reproductive performance of sows and a preparation method of the feed additive, and particularly relates to the technical field of feed additives, and the feed additive comprises a probiotic composition, an antioxidant, a plant extract, trace elements, a synergist and a carrier. The preparation method comprises the following steps: S1, raw material pretreatment; S2, compound fermentation; S3, microcapsule embedding treatment; and S4, freeze-drying and mixing. The feed additive can significantly shorten the interval from weaning to oestrus of sows, increase the number of live litter birth, increase the weaning survival rate of piglets and optimize the reproductive performance, and the preparation process can effectively release traditional Chinese medicine active ingredients, guarantee stable and accurate release of the active ingredients, also bring significant economic benefits, increase the yield of piglets, reduce the cost and improve the economic benefit. The feed has outstanding environmental protection benefits, reduces waste of wastes and feeds, and reduces environmental pressure.

Description

Technical Field

[0001] The present invention relates to the technical field of feed additives, and more specifically, to a feed additive for improving the reproductive performance of sows and a preparation method thereof. Background Art

[0002] At present, the reproductive performance of sows is crucial for the economic benefits of the pig industry. In modern large-scale pig production, indicators such as the annual litter size of sows and the survival rate of piglets directly affect the production efficiency and economic benefits of pig farms. However, in actual production, the reproductive performance of sows is restricted by various factors, such as the nutritional status of sows, endocrine regulation, intestinal health, and breeding environment, resulting in problems such as irregular estrus, low litter size, and low survival rate of piglets in sows, which limit the development of the pig industry.

[0003] At present, although some feed additives on the market can meet the nutritional needs of sows to a certain extent, the effect of improving the reproductive performance of sows is not significant enough, and the key problems in the reproductive process of sows cannot be fundamentally solved, such as the inability to effectively regulate the reproductive hormone level of sows and improve the reproductive internal environment;

[0004] Moreover, the traditional preparation process of feed additives often cannot fully exert the efficacy of raw materials. For example, for some bioactive components, ordinary processing methods may lead to a decrease or loss of their activity, affecting the actual effect of the additive. Moreover, in terms of the delivery of active components, there is a lack of effective protection and targeted release technologies, making some components not fully utilized in the animal body.

[0005] In view of this, the present invention provides a feed additive for improving the reproductive performance of sows and a preparation method thereof. Summary of the Invention

[0006] In order to overcome the above-mentioned defects of the prior art, the present invention provides a feed additive for improving the reproductive performance of sows and a preparation method thereof to solve the problems raised in the above background art.

[0007] To achieve the above object, the present invention provides the following technical solution: A feed additive for improving the reproductive performance of sows, the addition amount of the feed additive in sow feed is 500 - 1000 g / ton, and continuous feeding can shorten the estrus interval of sows from weaning to more than 30% shorter than that of the control group, increase the number of live piglets per litter by more than 20%, and increase the weaning survival rate of piglets by more than 10%. The feed additive is composed of the following components by weight percentage:

[0008] Probiotic combination: Lactobacillus plantarum 1×10 9 -5×10 9 CFU / g and Clostridium butyricum 5×10 8 -2×10 9CFU / g;

[0009] Antioxidants: vitamin E 30 - 80 IU / kg and nano-selenium 0.2 - 0.5 mg / kg;

[0010] Plant extracts: daidzein 3 - 8 mg / kg and rosemary extract 80 - 150 mg / kg;

[0011] Trace elements: zinc methionine 15 - 30 mg / kg;

[0012] Synergist: inulin 1 - 3%;

[0013] Carrier: wheat bran 10 - 20% and montmorillonite 5 - 10%.

[0014] Preferably, the probiotic combination is prepared by a multi-bacteria co-fermentation process, specifically including the following steps:

[0015] a. Raw material pretreatment: Astragalus membranaceus, Ophiopogon japonicus, Leonurus japonicus, Angelica sinensis, Epimedium brevicornu, Cuscuta chinensis, Lycium barbarum, and Rehmannia glutinosa are mixed in a mass ratio of 1:3:5:7:0.5:0.5:3:5, then pulverized and sieved through a 60-mesh sieve to obtain traditional Chinese medicine powder.

[0016] b. Enzymatic hydrolysis treatment: Add a compound enzyme to the obtained traditional Chinese medicine powder and perform enzymatic hydrolysis at 45 ± 2 °C for 15 - 18 h to fully release the flavonoid and polysaccharide active ingredients in the traditional Chinese medicine. Among them, the mass ratio of cellulase to protease in the compound enzyme is 3:1.

[0017] c. Three-stage fermentation: Inoculate Lactobacillus plantarum, Clostridium butyricum, and Rhodotorula rubra in the enzymatic hydrolysis product and ferment at a constant temperature of 25 ± 3 °C for 36 - 40 h. Stir regularly during the fermentation process to ensure uniform growth of the strains, and finally obtain a fermentation product with a short-chain fatty acid content ≥ 50 mg / g.

[0018] Preferably, the nano-selenium in the antioxidant is treated by a double-layer microcapsule targeted delivery technology, and the specific process is as follows:

[0019] a. Wall material preparation: Prepare a 2% sodium alginate aqueous solution as the outer wall material and a 1% chitosan acetate solution as the inner wall material.

[0020] b. Embedding and curing: After mixing nano-selenium with the inner wall material evenly, drop it into the outer wall material solution drop by drop through a peristaltic pump to form primary capsules. Then transfer the primary capsules to a 0.3 M calcium chloride solution and crosslink and cure them in a sterile environment for 30 - 40 minutes to form double-layer microcapsules with a particle size of 50 - 100 μm.

[0021] Preferably, the plant extract is prepared by supercritical CO 2 extraction technology, specifically as follows:

[0022] Using the dried soy isoflavone concentrate and rosemary leaves as raw materials, extraction is carried out under the conditions of an extraction pressure of 20 - 30 MPa and an extraction temperature of 35 - 45 °C. The purity of the obtained soy flavone is ≥95%, and the content of carnosic acid in the rosemary extract is ≥15%, ensuring the high purity and biological activity of the active ingredients.

[0023] The present invention also provides a preparation method for preparing the feed additive for improving the reproductive performance of sows as described above, which specifically includes the following steps:

[0024] S1. Raw material pretreatment: Astragalus membranaceus, Ophiopogon japonicus, Leonurus japonicus, Angelica sinensis, Epimedium brevicornu, Cuscuta chinensis, Lycium barbarum, and Rehmannia glutinosa are mixed in a mass ratio of 1:3:5:7:0.5:0.5:3:5 and then pulverized and sieved. Wheat bran and montmorillonite are respectively pulverized to 80 mesh, and the probiotic freeze-dried powder, inulin, and zinc methionine components are accurately weighed and reserved according to parts by weight.

[0025] S2. Composite fermentation: The pulverized traditional Chinese medicine powder in step S1 is subjected to enzymatic hydrolysis treatment and three-stage fermentation to obtain a fermentation substrate rich in short-chain fatty acids and probiotic metabolites.

[0026] S3. Microencapsulation treatment: Vitamin E, nano-selenium, and the fermentation substrate in S2 are mixed and then subjected to embedding and solidification treatment to form a core functional component.

[0027] S4. Freeze-drying and mixing: The core functional component after embedding in S3 is placed at -40 ± 2 °C for pre-freezing for 2 h, and then sublimation drying is carried out under a vacuum degree of 10 ± 2 Pa for 24 - 26 h to reduce the moisture content to below 3%. After drying, it is mixed evenly with wheat bran and montmorillonite carriers to obtain the feed additive with a particle size of 50 - 200 μm.

[0028] Preferably, during the freeze-drying process, a gradient temperature control technology is adopted, and the temperature in the sublimation stage gradually rises from -40 °C to -10 °C to ensure the integrity of the microcapsule structure and the retention rate of active ingredients ≥90%.

[0029] The technical effects and advantages of the present invention:

[0030] 1. Through the synergistic effect of precisely formulated probiotic combinations, antioxidants, plant extracts and other components, it effectively regulates the endocrine system and reproductive hormone levels of sows. For example, soy flavone mimics the estrogen effect and activates the Leptin signaling pathway, significantly shortening the weaning-to-estrus interval of sows, enabling sows to enter the reproductive cycle faster and improving the overall reproductive efficiency of the pig farm;

[0031] All ingredients work together to optimize the reproductive environment of sows, improve follicle development and embryo implantation conditions. The active substances and trace elements in plant extracts enhance the function of sow reproductive organs, bringing more piglets to pig farms and increasing breeding profits.

[0032] The probiotic combination and enhancer synergistically improve the intestinal microecology of sows, enhance the immunity of sows, and make the maternal antibodies passed to piglets more sufficient. At the same time, antioxidants reduce oxidative stress damage during embryonic development, ensure the healthy growth of piglets, and reduce breeding losses.

[0033] 2. By mixing Chinese medicinal materials such as Astragalus with a specific proportion, accurately enzymolyzing them with a composite enzyme, and then adding a variety of probiotics for tertiary fermentation, the active ingredients such as flavonoids and polysaccharides in the Chinese medicinal materials can be fully released, and a high content of short-chain fatty acids can be produced at the same time. Short-chain fatty acids not only regulate the balance of intestinal flora, but also affect the reproductive system of sows through blood circulation, optimize the quality of probiotic combinations, and enhance the efficacy of feed additives;

[0034] Double-layer microcapsule targeted delivery technology is used for nano-selenium, with 2% sodium alginate aqueous solution as the outer layer and 1% chitosan acetic acid solution as the inner layer for embedding, so that the survival rate of nano-selenium in the gastric acid environment is ≥90%, and the release rate in the small intestine is ≥85%, effectively protecting and accurately releasing nano-selenium, ensuring its biological activity and utilization, and improving the efficacy of the antioxidant system;

[0035] 3. The feed additive of the present invention improves the reproductive performance of sows in all aspects, directly increases the output of piglets, and at the same time improves the weaning survival rate of piglets and reduces the breeding cost loss. After the large-scale pig farm uses the feed additive, the number of piglets sold increases, the input-output ratio is significantly optimized, and the annual income is significantly increased;

[0036] In the preparation process, raw materials can be used efficiently, reducing waste emissions. In addition, the improved reproductive performance of sows increases feed conversion rate, reduces feed waste caused by low breeding efficiency, reduces pressure on the environment from the source, and achieves a win-win situation for breeding and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is the overall flow chart of the present invention.

[0038] Figure 2 The present invention is a fermentation flow chart of the probiotic composition.

[0039] Figure 3 This is a flow chart of the targeted delivery of nano-selenium of the present invention. DETAILED DESCRIPTION

[0040] Embodiment 1,

[0041] This embodiment provides a feed additive for improving the reproductive performance of sows, which is composed of the following components by weight percentage:

[0042] Probiotic combination: Prepare freeze-dried powder of Lactobacillus plantarum, ensuring that the viable count is 1×10 9 -5×10 9 CFU / g, freeze-dried powder of Clostridium butyricum, and the viable count is 5×10 8 -2×10 9 CFU / g;

[0043] Antioxidant: Weigh vitamin E oil agent with a content of 30 - 80 IU / kg and nano-selenium particles with a content of 0.2 - 0.5 mg / kg;

[0044] Plant extract: Obtain dried soy isoflavone-enriched product and rosemary leaves, and use them for supercritical CO 2 extraction to prepare plant extract. Among them, daidzein is 3 - 8 mg / kg and rosemary extract is 80 - 150 mg / kg;

[0045] Trace element: Weigh zinc methionine crystal with a content of 15 - 30 mg / kg;

[0046] Synergist and carrier: Prepare 1 - 3% inulin granules, wheat bran and montmorillonite, each ground to 80 mesh. The proportion of wheat bran is 10 - 20% and the proportion of montmorillonite is 5 - 10%.

[0047] Chinese herbal medicine raw materials: Prepare Astragalus membranaceus, Ophiopogon japonicus, Leonurus japonicus, Angelica sinensis, Epimedium brevicornu, Cuscuta chinensis, Lycium barbarum and Rehmannia glutinosa in a mass ratio of 1:3:5:7:0.5:0.5:3:5. After mixing, crush and pass through a 60-mesh sieve to obtain Chinese medicine powder.

[0048] This embodiment of the present invention also provides a preparation method for preparing the above feed additive for improving the reproductive performance of sows, which specifically includes the following steps:

[0049] Step 1. Preparation of probiotic combination

[0050] Enzymatic hydrolysis treatment: Add a compound enzyme (the mass ratio of cellulase to protease is 3:1) to the prepared Chinese medicine powder above. The addition amount of the enzyme is 2% of the weight of the Chinese medicine powder. Place the mixture in a constant temperature water bath at 45°C and perform enzymatic hydrolysis for 16 h. Stir regularly during this period to fully release the flavonoid and polysaccharide active ingredients in the Chinese medicine;

[0051] Three-stage fermentation: Inoculate Lactobacillus plantarum, Clostridium butyricum and Rhodotorula rubra into the enzymatic hydrolysis product, and ferment in a constant temperature incubator at 25°C for 38 h. Stir mechanically for 5 min every 2 h to ensure uniform growth of the strains. Finally, obtain a fermentation product with a short-chain fatty acid content of 55 mg / g, and this product is the basic raw material of the probiotic combination;

[0052] Step 2: Preparation of Nano-Selenium Microcapsules

[0053] Wall material preparation: preparing a 2% sodium alginate aqueous solution as an outer wall material and a 1% chitosan acetate solution as an inner wall material;

[0054] Embedding and curing: nano-selenium and the inner wall material are mixed evenly in proportion, and dripped into the outer wall material solution drop by drop at a speed of 25 drops per minute through a peristaltic pump to form a primary capsule, and then the primary capsule is transferred to a 0.3M calcium chloride solution, cross-linked and cured for 35 minutes under a sterile environment to form a double-layer microcapsule with a particle size of 70-90μm;

[0055] Step 3: Preparation of plant extracts

[0056] The dried soybean isoflavones enriched material and rosemary leaves were used as raw materials and placed in supercritical CO 2 In the extraction equipment, the extraction was carried out under the conditions of extraction pressure of 25 MPa, extraction temperature of 40°C and extraction time of 2.5 h, and the purity of the obtained soybean flavonoids was 96%, and the content of carnosic acid in the rosemary extract was 18%;

[0057] Step 4: Preparation of feed additives

[0058] Pretreatment of raw materials, weighing the prepared probiotic combination, nano-selenium microcapsules, vitamin E oil, plant extracts, zinc methionine, inulin, wheat bran and montmorillonite;

[0059] Composite fermentation and mixing, fully mixing the probiotic combination with other raw materials to ensure uniform dispersion;

[0060] Freeze-drying treatment: the mixed material is placed in a freezing device at -40°C for pre-freezing for 2 hours, and then transferred to a vacuum drying device for sublimation drying under a vacuum degree of 10Pa. The temperature in the sublimation stage is gradually increased from -40°C to -10°C at a rate of 5°C per hour, and dried for 25 hours to reduce the moisture content to 2.5%;

[0061] Finished product packaging: after testing the dried material, 98% of the particle sizes are within the range of 50-200 μm, which meets the requirements. The material is packaged to obtain a finished feed additive for improving the reproductive performance of sows.

[0062] The performance test of the feed additive prepared in this embodiment is as follows:

[0063] 1. Experimental design: 100 healthy sows with similar weight and parity were selected and randomly divided into a control group and an experimental group, with 50 sows in each group. The control group was fed with a basic sow feed, and the experimental group was added with the feed additive prepared in this embodiment in the basic feed, with an addition amount of 750 g / ton;

[0064] 2. Data collection and analysis: After continuous feeding for 3 months, the following data were collected and analyzed:

[0065] Weaning to estrus interval: The average weaning to estrus interval of sows in the experimental group was 5 days, which was 33.3% shorter than the 7.5 days in the control group;

[0066] Number of live piglets born per litter: The average number of live piglets born per litter of sows in the experimental group was 13, which was 23.8% higher than the 10.5 in the control group;

[0067] Weaning survival rate of piglets: The weaning survival rate of piglets in the experimental group was 93%, which was 12% higher than the 83% in the control group;

[0068] Serum hormone levels: Blood samples of sows were collected for detection. The level of follicle-stimulating hormone in the serum of sows in the experimental group increased by 25%, and the level of luteinizing hormone increased by 20%.

[0069] It can be seen from this example that the feed additive prepared by the present invention can significantly improve the reproductive performance of sows.

[0070] Example 2

[0071] This example provides a feed additive for improving the reproductive performance of sows, which is composed of the following components by weight percentage:

[0072] Probiotic combination: Lyophilized powder of Lactobacillus plantarum was selected, with the viable count reaching 3×10 9 CFU / g, and the viable count of lyophilized powder of Clostridium butyricum was 1×10 9 CFU / g;

[0073] Antioxidant: Vitamin E oil was accurately weighed, with a content of 50 IU / kg, and the content of nano-selenium particles was 0.3 mg / kg;

[0074] Plant extract: Sufficient dried soy isoflavone-rich extract and rosemary leaves were prepared for subsequent supercritical CO 2 extraction;

[0075] Synergist and carrier raw materials: Inulin granules were prepared at 2% of the weight of the final feed additive. Wheat bran and montmorillonite were respectively pulverized to 80 meshes, with wheat bran accounting for 15% and montmorillonite accounting for 8%;

[0076] Traditional Chinese medicine raw materials: Astragalus membranaceus, Ophiopogon japonicus, Leonurus japonicus, Angelica sinensis, Epimedium brevicornu, Cuscuta chinensis, Lycium barbarum, and Rehmannia glutinosa were strictly mixed in a mass ratio of 1:3:5:7:0.5:0.5:3:5, and pulverized through a 60-mesh sieve to obtain traditional Chinese medicine powder.

[0077] The embodiment of the present invention also provides a preparation method for preparing the above-mentioned feed additive for improving the reproductive performance of sows, which specifically comprises the following steps:

[0078] Step 1: Preparation of probiotic combination

[0079] Enzymatic hydrolysis: add 2% of the weight of compound enzyme (cellulase: protease = 3:1) to the traditional Chinese medicine powder, and enzymolyze in a constant temperature water bath at 44°C for 17 hours, stirring once every half an hour during the process to fully release the active ingredients;

[0080] In the third stage of fermentation, Lactobacillus plantarum, Clostridium butyricum and marine red yeast were added to the enzymatic hydrolysate, and fermented in a constant temperature incubator at 24°C for 37 hours, with mechanical stirring for 5 minutes every 1.5 hours, to finally obtain a fermentation product with a short-chain fatty acid content of 53 mg / g, which served as the basis of the probiotic combination agent;

[0081] Step 2: Preparation of Nano-Selenium Microcapsules

[0082] Wall material preparation: 2% sodium alginate aqueous solution as outer wall material, 1% chitosan acetic acid solution as inner wall material;

[0083] Embedding and curing: mix the nano-selenium with the inner wall material, drip the outer wall material solution at a rate of 22 drops per minute using a peristaltic pump to form a primary capsule, and then transfer the primary capsule to a 0.3M calcium chloride solution, cross-link and cure in a sterile environment for 32 minutes to obtain a double-layer microcapsule with a particle size of 75-95μm;

[0084] Step 3: Preparation of plant extracts

[0085] The dried raw materials are placed in supercritical CO 2 Extraction equipment, extraction under the conditions of extraction pressure 22MPa, temperature 38°C, extraction time 2.2h, obtained soybean flavonoids purity 95.5%, rosemary extract carnosic acid content 16%;

[0086] Step 4: Preparation of feed additives

[0087] Raw material pretreatment, accurate weighing of each raw material

[0088] Compound fermentation and mixing, fully mixing the probiotic combination with other raw materials;

[0089] For freeze-drying, the mixture was pre-frozen at -41°C for 2 hours, and then sublimated and dried at a vacuum of 10.5 Pa. The temperature was raised from -41°C to -10°C at a rate of 4.5°C per hour, and dried for 24.5 hours until the moisture content dropped to 2.8%.

[0090] The finished product is packaged and the material is tested. 97% of the particles have a particle size within the range of 50-200 μm. The finished feed additive is packaged.

[0091] The performance of the feed additive prepared in this example is tested as follows:

[0092] 1. Experimental design: Select 120 healthy sows with similar body weights and parities, and randomly divide them into a control group and an experimental group. The control group is fed with a basal diet, and the feed additive of this example is added to the basal diet of the experimental group at an addition amount of 600 g / ton;

[0093] 2. Data collection and analysis: Collect data after continuous feeding for 3.5 months:

[0094] Interval from weaning to estrus: The average in the experimental group is 5.5 days, and in the control group is 7.8 days, a reduction of 29.5%;

[0095] Number of live piglets born per litter: The average in the experimental group is 12.5, and in the control group is 10.2, an increase of 22.5%;

[0096] Survival rate of piglets at weaning: In the experimental group is 92%, and in the control group is 82%, an increase of 12.2%;

[0097] Serum hormone level: The level of follicle-stimulating hormone in the serum of sows in the experimental group increased by 23%, and the level of luteinizing hormone increased by 18%.

[0098] Example 3

[0099] This example provides a feed additive for improving the reproductive performance of sows, which is composed of the following components by weight percentage:

[0100] Probiotic combination: The viable count of freeze-dried powder of Lactobacillus plantarum is 4×10 9 CFU / g, and the viable count of freeze-dried powder of Clostridium butyricum is 1.5×10 9 CFU / g;

[0101] Antioxidant: Weigh vitamin E oil agent with a content of 60 IU / kg and nano-selenium particles with a content of 0.4 mg / kg;

[0102] Plant extract: Prepare dry soybean isoflavone concentrate and rosemary leaves for extraction;

[0103] Trace element: Weigh zinc methionine crystal with a content of 25 mg / kg;

[0104] Synergist and carrier raw materials: Inulin is prepared at 1.5% of the final weight of the feed additive, wheat bran and montmorillonite are ground to 80 mesh, the proportion of wheat bran is 18%, and the proportion of montmorillonite is 6%;

[0105] Traditional Chinese medicine raw materials: Mix traditional Chinese medicines such as Astragalus membranaceus according to a specific mass ratio, and grind them through a 60-mesh sieve to obtain traditional Chinese medicine powder.

[0106] The embodiment of the present invention also provides a preparation method for preparing the above-mentioned feed additive for improving the reproductive performance of sows, which specifically comprises the following steps:

[0107] Step 1: Preparation of probiotic combination

[0108] Enzymatic hydrolysis: add 2% of complex enzyme (cellulase: protease = 3:1) to the traditional Chinese medicine powder, perform enzymatic hydrolysis in a constant temperature water bath at 46°C for 15.5h, and stir regularly to release the active ingredients;

[0109] The third-stage fermentation was carried out by inoculating the strains in a constant temperature incubator at 26°C for 39 hours, stirring for 5 minutes every 2.5 hours, and obtaining a fermentation product with a short-chain fatty acid content of 57 mg / g;

[0110] Step 2: Preparation of Nano-Selenium Microcapsules

[0111] Wall material preparation: prepare 2% sodium alginate aqueous solution and 1% chitosan acetate solution;

[0112] Embedding and curing: After the nano-selenium is mixed with the inner wall material, it is dripped into the outer wall material solution at a rate of 28 drops per minute. The primary capsule is cross-linked and cured in a 0.3M calcium chloride solution for 38 minutes to form a double-layer microcapsule with a particle size of 65-85μm.

[0113] Step 3: Preparation of plant extracts

[0114] Under the conditions of extraction pressure of 28 MPa, temperature of 42 °C and extraction time of 2.8 h, supercritical CO 2 Extraction, soy flavonoids purity 96.5%, rosemary extract carnosic acid content 17%;

[0115] Step 4: Preparation of feed additives

[0116] Raw material pretreatment, accurate weighing of each raw material;

[0117] Compound fermentation and mixing, fully mixing all raw materials;

[0118] Freeze-drying treatment: pre-freeze at -39℃ for 2h, sublimate and dry at a vacuum of 9.5Pa, the temperature rises from -39℃ to -10℃ at a rate of 5.5℃ per hour, dry for 25.5h, and the moisture content drops to 2.3%;

[0119] Finished product packaging, after testing, 99% of the particle size is 50-200μm, packaged into finished feed additives.

[0120] The performance test of the feed additive prepared in this embodiment is as follows:

[0121] 1. Experimental design: 80 eligible sows were selected and randomly divided into a control group and an experimental group. The control group was fed with a basic feed, and the basic feed of the experimental group was supplemented with the feed additive of this embodiment, with an addition amount of 900 g / ton;

[0122] 2. Data collection and analysis: Data were collected after 2.5 months of continuous feeding:

[0123] The interval from weaning to estrus was 4.8 days in the experimental group and 7.2 days in the control group, which was shortened by 33.3%;

[0124] The number of live piglets born in the litter: 13.2 in the experimental group and 10.3 in the control group, an increase of 28.2%;

[0125] Piglet weaning survival rate: 94% in the experimental group and 84% in the control group, an increase of 11.9%;

[0126] Serum hormone levels: The serum follicle-stimulating hormone level of sows in the experimental group increased by 27%, and the luteinizing hormone level increased by 22%.

[0127] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A feed additive for improving the reproductive performance of sows, wherein the feed additive is added in an amount of 500-1000 g / ton in sow feed, and continuous feeding can shorten the interval from weaning to estrus of sows by more than 30% compared with the control group, increase the number of live piglets per litter by more than 20%, and increase the weaning survival rate of piglets by more than 10%, characterized in that: The feed additive consists of the following ingredients by weight percentage: Probiotic combination: Lactobacillus plantarum 1×10 9 -5×10 9 CFU / g and Clostridium butyricum 5×10 8 -2×10 9 CFU / g; Antioxidants: Vitamin E 30-80 IU / kg and nano-selenium 0.2-0.5 mg / kg; Plant extracts: soy flavonoids 3-8 mg / kg and rosemary extract 80-150 mg / kg; Trace elements: zinc methionine 15-30 mg / kg; Synergist: Inulin 1-3%; Carrier: wheat bran 10-20% and montmorillonite 5-10%.

2. The feed additive for improving sow reproductive performance according to claim 1, characterized in that: The probiotic combination is prepared by a multi-bacteria cooperative fermentation process, which specifically includes the following steps: a. Pretreatment of raw materials: mixing astragalus, ophiopogon, motherwort, angelica, epimedium, dodder seed, wolfberry fruit and rehmannia root in a mass ratio of 1:3:5:7:0.5:0.5:3:5, crushing and passing through a 60-mesh sieve to obtain Chinese medicine powder; b. Enzymatic hydrolysis, adding compound enzyme to the obtained traditional Chinese medicine powder, enzymolysis for 15-18h at 45±2°C to fully release the flavonoids and polysaccharide active ingredients in the traditional Chinese medicine, wherein the mass ratio of cellulase to protease in the compound enzyme is 3:1; c. In the third fermentation, Lactobacillus plantarum, Clostridium butyricum and marine red yeast are added to the enzymatic hydrolysate and fermented at a constant temperature of 25±3°C for 36-40 hours. During the fermentation process, stirring is performed regularly to ensure uniform growth of the bacteria, and finally a fermentation product with a short-chain fatty acid content of ≥50 mg / g is obtained.

3. The feed additive for improving sow reproductive performance according to claim 2, characterized in that: The nano-selenium in the antioxidant is processed by double-layer microcapsule targeted delivery technology, and the specific process is as follows: a. Wall material preparation: prepare a 2% sodium alginate aqueous solution as the outer wall material and a 1% chitosan acetic acid solution as the inner wall material; b. Encapsulation and curing: After the nano-selenium is evenly mixed with the inner wall material, it is dripped into the outer wall material solution drop by drop through a peristaltic pump to form a primary capsule. The primary capsule is then transferred to a 0.3M calcium chloride solution and cross-linked and cured in a sterile environment for 30-40 minutes to form a double-layer microcapsule with a particle size of 50-100μm.

4. The feed additive for improving sow reproductive performance according to claim 3, characterized in that: The plant extract is prepared by supercritical CO2 extraction technology, specifically: Using dried soybean isoflavones enriched material and rosemary leaves as raw materials, extraction is carried out at an extraction pressure of 20-30MPa and an extraction temperature of 35-45°C. The purity of the obtained soybean isoflavones is ≥95%, and the content of carnosic acid in the rosemary extract is ≥15%, ensuring the high purity and biological activity of the active ingredients.

5. A preparation method for preparing the feed additive for improving sow reproductive performance according to claim 4, characterized in that: The specific steps include: S1, raw material pretreatment, astragalus, ophiopogon, motherwort, angelica, epimedium, dodder seed, wolfberry fruit and rehmannia root in a mass ratio of 1:3:5:7:0.5:0.5:3:5, crush and sieve, wheat bran and montmorillonite are crushed to 80 mesh respectively, and the probiotic freeze-dried bacterial powder, inulin and zinc methionine components are accurately weighed by weight for later use; S2, composite fermentation, enzymatically hydrolyzing the crushed Chinese medicine powder in step S1 and performing tertiary fermentation to obtain a fermentation substrate rich in short-chain fatty acids and probiotic metabolites; S3, microcapsule embedding treatment, mixing vitamin E, nano-selenium and the fermentation substrate in S2, and then embedding and solidifying the mixture to form a core functional component; S4, freeze-drying and mixing, pre-freeze the embedded core functional components in S3 at -40±2°C for 2 hours, then sublimate and dry for 24-26 hours under a vacuum of 10±2Pa to reduce the moisture content to below 3%, and evenly mix with wheat bran and montmorillonite carriers after drying to obtain the feed additive with a particle size of 50-200 μm.

6. The preparation method according to claim 5, characterized in that: During the freeze-drying process, gradient temperature control technology is used, and the temperature in the sublimation stage gradually increases from -40°C to -10°C, ensuring that the microcapsule structure is intact and the active ingredient retention rate is ≥90%.

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