Functional feed additive for relieving growth retardation of piglets as well as preparation method and application of functional feed additive

Abstract

The invention provides a functional feed additive for relieving development retardation of piglets as well as a preparation method and application of the functional feed additive. The functional feed additive for relieving development retardation of piglets comprises the following components in parts by weight: 30-50 parts of a polysaccharide-mesoporous silica nanoparticle compound, 0.1-2 parts of tartary buckwheat oligopeptide and 0.1-1 part of hesperetin. The functional feed additive provided by the invention can regulate the redox balance of piglet bodies, enhance the immunity of the piglet bodies, improve the intestinal mucosa injury of the piglets and promote the intestinal development of the piglets, so that the development retardation of the piglets is relieved, and the healthy growth of the piglets with the development retardation is promoted.

Description

Technical Field

[0001] This invention belongs to the field of feed technology, specifically relating to a functional feed additive for alleviating growth retardation in piglets, its preparation method, and its application. Background Technology

[0002] In recent years, with breakthroughs in breeding technology, sows have been producing more and more piglets, and piglet growth retardation has become an increasingly prominent problem. Growth retardation is generally divided into two main categories: intrauterine growth retardation and postnatal growth retardation. Intrauterine growth retardation refers to the hindrance of embryonic or fetal growth and development in the mother's womb, resulting in a newborn piglet with a birth weight significantly lower than the normal standard. Piglets with postnatal growth retardation appear normal in weight and appearance at birth, but insufficient sow's milk, poor feed formulation, and other factors hinder growth, causing their postnatal weight to be below the average level for their age group.

[0003] Delayed growth and development in piglets can reduce the height of the villi in the small intestine, increase the depth of the crypts, cause damage to intestinal function, disrupt metabolism, reduce the absorption of nutrients in the small intestine, and result in extremely poor disease resistance. This seriously affects feed conversion efficiency and piglet survival rate, increases the cost of pig farming, and severely restricts the development of my country's pig industry.

[0004] Therefore, there is an urgent need to develop a functional feed additive that can alleviate growth retardation in piglets, improve their physical growth performance, and promote organ development. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a functional feed additive for alleviating growth retardation in piglets, its preparation method, and its application. The functional feed additive provided by the present invention can regulate the redox balance in piglets, enhance their immunity, improve intestinal mucosal damage, and promote intestinal development, thereby alleviating growth retardation and promoting healthy growth in piglets with growth retardation.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a functional feed additive for alleviating growth retardation in piglets, wherein the functional feed additive for alleviating growth retardation in piglets comprises, by weight, 30-50 parts of polysaccharide-mesoporous silica nanoparticle complex, 0.1-2 parts of tartary buckwheat oligopeptide and 0.1-1 parts of hesperidin.

[0008] The polysaccharide-mesoporous silica nanoparticle composite can be in the following proportions: 30 parts, 35 parts, 40 parts, 45 parts, or 50 parts; the buckwheat oligopeptide can be in the following proportions: 0.1 parts, 0.5 parts, 1 part, 1.5 parts, or 2 parts; and the hesperidin can be in the following proportions: 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, or 1 part. However, these proportions are not limited to the values ​​listed above, and other unlisted values ​​within the above range are also applicable.

[0009] Buckwheat oligopeptides have advantages such as rapid absorption, low energy consumption, and low carrier saturation, exhibiting extremely high activity and biodiversity. This invention, by adding buckwheat oligopeptides, has a protective effect against cell damage caused by growth retardation in piglets, can maintain the body's oxidative balance, and improve the body's health.

[0010] Hesperidin possesses various biological activities, including antioxidant, anti-inflammatory, and anti-cancer properties. This invention, by adding hesperidin, can increase the activity of digestive enzymes, promote nutrient absorption, and thus promote the growth and development of piglets.

[0011] The above products, by using specific raw materials, can regulate the redox balance of piglets, enhance their immunity, improve intestinal mucosal damage, and promote intestinal development, thereby alleviating growth retardation and promoting the healthy growth of piglets with growth retardation.

[0012] Preferably, the polysaccharide includes any one or a combination of at least two of the following: Bletilla striata polysaccharide, Coralaria scabra polysaccharide, or Tribulus terrestris polysaccharide.

[0013] Coralwort polysaccharide has the effects of promoting blood circulation, removing blood stasis, clearing heat and detoxifying. The addition of Coralwort polysaccharide in this invention can effectively remove free radicals in piglets, maintain the oxidative balance of piglets, alleviate stress in piglets, and promote growth and development.

[0014] Tribulus terrestris polysaccharides have antiviral and immune-enhancing effects. The Tribulus terrestris polysaccharide additive of this invention can enhance the immunity of piglets and promote their growth and development.

[0015] Bletilla striata polysaccharides possess antioxidant, anti-inflammatory, and tissue repair-promoting effects. The addition of Bletilla striata polysaccharides in this invention can reduce oxidative stress damage to the gastrointestinal mucosa of piglets, protect intestinal epithelial cells from oxidative damage, and promote intestinal development in piglets.

[0016] Preferably, the polysaccharide includes Bletilla striata polysaccharide, Coralberry polysaccharide, and Tribulus terrestris polysaccharide.

[0017] This invention, by employing specific polysaccharides, can further enhance the efficacy of the product.

[0018] Preferably, the mass ratio of Bletilla striata polysaccharide, Sargassum fusiforme polysaccharide and Tribulus terrestris polysaccharide is (1-3):(2-5):(2-3).

[0019] The proportions of Bletilla striata polysaccharide can be 1, 1.5, 2, 2.5 or 3, the proportions of Sarcandra glabra polysaccharide can be 2, 2.5, 3, 3.5, 4, 4.5 or 5, and the proportions of Tribulus terrestris polysaccharide can be 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9 or 3, but are not limited to the values ​​listed above. Other unlisted values ​​within the above range are also applicable.

[0020] Preferably, the polysaccharide-mesoporous silica nanoparticle composite is prepared by a method comprising the following steps:

[0021] (1) After crushing the plant raw materials, mix them with an aqueous acetic acid solution for extraction, then mix them with an enzyme for ultrasonic extraction, take the liquid part for alcohol precipitation, and collect the precipitate to obtain polysaccharides;

[0022] (2) The polysaccharide was dissolved in water and then mixed with mesoporous silica nanoparticles and separated into solid and liquid phases to obtain the polysaccharide-mesoporous silica nanoparticle complex.

[0023] The plant materials include any one or a combination of at least two of the following: coral grass, tribulus terrestris, or white ginseng.

[0024] When the polysaccharide in step (2) includes a combination of at least two of the following: Bletilla striata polysaccharide, Sargassum fusiforme polysaccharide, or Tribulus terrestris polysaccharide, the plant material in step (1) includes a combination of at least two of the following: Sargassum fusiforme, Tribulus terrestris, or Bletilla striata, or the corresponding polysaccharide is prepared from the plant material and then used in step (2).

[0025] The polysaccharide-mesoporous silica nanoparticle complex prepared by the above specific method has a high content of active ingredients. Combined with mesoporous silica nanoparticles, it can effectively slow down the release of active ingredients, avoid rapid absorption, and effectively improve the product's efficacy.

[0026] Preferably, the ratio of plant material to acetic acid aqueous solution in step (1) is 1:(20-40) g / mL, such as 1:20 g / mL, 1:25 g / mL, 1:30 g / mL, 1:35 g / mL or 1:40 g / mL, but not limited to the values ​​listed above. Other values ​​not listed above are also applicable.

[0027] Preferably, the volume fraction of the acetic acid aqueous solution in step (1) is 5-15%, such as 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14% or 15%, etc., but not limited to the values ​​listed above. Other unlisted values ​​within the above range are also applicable.

[0028] Preferably, the extraction temperature in step (1) is 50-70℃ and the time is 30-60 min. The temperature can be 50℃, 55℃, 60℃, 65℃ or 70℃, etc., and the time can be 30 min, 35 min, 40 min, 45 min, 50 min, 55 min or 60 min, etc., but is not limited to the values ​​listed above. Other unlisted values ​​within the above range are also applicable.

[0029] Preferably, the enzymes in step (1) include cellulase, hemicellulase and papain.

[0030] Preferably, the mass ratio of cellulase, hemicellulase and papain is (1-3):(1-2):(2-3).

[0031] Preferably, the amount of enzyme used in step (1) is 1-5% of the mass of the plant raw material, such as 1%, 2%, 3%, 4% or 5%, but not limited to the values ​​listed above. Other values ​​not listed above are also applicable.

[0032] Preferably, the ultrasonic extraction in step (1) is an intermittent ultrasonic extraction, with a single ultrasonic time of 10-15 s, an interval of 20-30 s, a cycle of 30-50 times, and a power of 300-500W. The single ultrasonic time can be 10 s, 11 s, 12 s, 13 s, 14 s or 15 s, etc., the interval can be 20 s, 22 s, 24 s, 26 s, 28 s or 30 s, etc., the cycle can be 30 times, 35 times, 40 times, 45 times or 50 times, etc., and the power can be 300 W, 350 W, 400 W, 450 W or 500 W, etc., but is not limited to the values ​​listed above. Other unlisted values ​​within the above range are also applicable.

[0033] Preferably, the mass ratio of the polysaccharide to the mesoporous silica nanoparticles in step (2) is 2:3-3:2.

[0034] Secondly, the present invention provides a method for preparing the functional feed additive for alleviating growth retardation in piglets as described above, the preparation method comprising the following steps:

[0035] The functional feed additive is obtained by mixing polysaccharide-mesoporous silica nanoparticle complex, buckwheat oligopeptide and hesperidin.

[0036] Thirdly, the present invention also provides the application of the functional feed additives for alleviating growth retardation in piglets as described above in the preparation of piglet feed.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] This invention provides a functional feed additive that alleviates growth retardation in piglets. By using specific raw materials, it can regulate the redox balance of piglets, enhance their immunity, improve intestinal mucosal damage, and promote intestinal development, thereby alleviating growth retardation and promoting the healthy growth of piglets with growth retardation. Detailed Implementation

[0039] To further illustrate the technical means and effects of the present invention, the following describes the technical solution of the present invention in conjunction with preferred embodiments of the present invention. However, the present invention is not limited to the scope of the embodiments.

[0040] In the following examples, the mesoporous silica nanoparticles were purchased from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd.

[0041] The buckwheat oligopeptides were purchased from Baoji Liupanyun Biotechnology Co., Ltd.

[0042] Hesperidin was purchased from Chengdu Manster Biotechnology Co., Ltd.

[0043] Cellulase was purchased from Guangdong Yiduoli Biotechnology Co., Ltd.

[0044] Hemicellulase was purchased from Guangdong Yiduoli Biotechnology Co., Ltd.

[0045] Papain was purchased from Guangdong Yiduoli Biotechnology Co., Ltd.

[0046] Preparation Example 1

[0047] This preparation example provides a polysaccharide-mesoporous silica nanoparticle composite, prepared by the following method:

[0048] (1) After drying Bletilla striata, it is pulverized and passed through a 60-mesh sieve to obtain powder. The powder is extracted with 10% acetic acid for 45 min at a material-to-liquid ratio of 1:30 (g / mL) at a temperature of 60℃. Then, the extracted sample is placed in an ultrasonic device and a compound enzyme (3% of the mass of Bletilla striata, cellulase, hemicellulase, papain = 2:1.5:2.5) is added. Intermittent ultrasonic-assisted extraction is performed: power 400W, single ultrasonic 13s, interval 25s, 40 cycles, temperature set to 50℃. Then, the mixture is centrifuged and the liquid is evaporated and concentrated. 95% ethanol is added to the concentrate at a volume ratio of 1:4 for alcohol precipitation. Then, the precipitate is collected by centrifugation, which is Bletilla striata polysaccharide.

[0049] By replacing Bletilla striata with equal amounts of Tribulus terrestris and Sarcandra glabra using the method described above, Tribulus terrestris polysaccharide and Sarcandra glabra polysaccharide were obtained.

[0050] The polysaccharides of Bletilla striata, Sargassum fusiforme, and Tribulus terrestris were mixed in a mass ratio of 2:3:2.5 to obtain a polysaccharide complex.

[0051] (2) Dissolve the polysaccharide complex in water and stir continuously for 30 minutes. Add mesoporous silica nanoparticles (mass ratio 2.5:2.5) while stirring. After all the polysaccharide is adsorbed by the mesoporous silica nanoparticles, perform solid-liquid separation and dry the solid part to remove moisture to obtain the polysaccharide-mesoporous silica nanoparticles.

[0052] Preparation Example 2

[0053] This preparation example provides a polysaccharide-mesoporous silica nanoparticle composite, prepared by the following method:

[0054] (1) After drying Bletilla striata, it is pulverized and passed through a 60-mesh sieve to obtain powder. The powder is extracted with 5% acetic acid for 60 min at a material-to-liquid ratio of 1:20 (g / mL) and the temperature is 70℃. Then the extracted sample is placed in an ultrasonic device and a compound enzyme (1% of the mass of Bletilla striata, cellulase, hemicellulase, papain = 1:1:2) is added. Intermittent ultrasonic-assisted extraction is performed: power 300W, single ultrasonic 15s, interval 30s, 30 cycles, temperature set to 40℃. Then the mixture is centrifuged and the liquid is evaporated and concentrated. 95% ethanol is added to the concentrate at a volume ratio of 1:3 for alcohol precipitation. Then the mixture is centrifuged and the precipitate is collected, which is Bletilla striata polysaccharide.

[0055] By replacing Bletilla striata with equal amounts of Tribulus terrestris and Sarcandra glabra using the method described above, Tribulus terrestris polysaccharide and Sarcandra glabra polysaccharide were obtained.

[0056] The polysaccharides of Bletilla striata, Sargassum fusiforme, and Tribulus terrestris were mixed in a mass ratio of 1:2:2 to obtain a polysaccharide complex.

[0057] (2) Dissolve the polysaccharide complex in water and stir continuously for 30 minutes. Add mesoporous silica nanoparticles (mass ratio 3:2) while stirring. After all the polysaccharide is adsorbed by the mesoporous silica nanoparticles, perform solid-liquid separation and dry the solid part to remove moisture to obtain the polysaccharide-mesoporous silica nanoparticles.

[0058] Preparation Example 3

[0059] This preparation example provides a polysaccharide-mesoporous silica nanoparticle composite, prepared by the following method:

[0060] (1) After drying Bletilla striata, it is pulverized and passed through a 60-mesh sieve to obtain powder. The powder is extracted with 15% acetic acid for 30 min at a material-to-liquid ratio of 1:40 (g / mL) at a temperature of 50℃. Then, the extracted sample is placed in an ultrasonic device and a compound enzyme (3% of the mass of Bletilla striata, cellulase, hemicellulase, papain = 3:2:3) is added. Intermittent ultrasonic-assisted extraction is performed: power 500W, single ultrasonic 10s, interval 20s, 50 cycles, temperature set to 60℃. Then, the mixture is centrifuged and the liquid is evaporated and concentrated. 95% ethanol is added to the concentrate at a volume ratio of 1:5 for alcohol precipitation. Then, the mixture is centrifuged and the precipitate is collected, which is Bletilla striata polysaccharide.

[0061] By replacing Bletilla striata with equal amounts of Tribulus terrestris and Sarcandra glabra using the method described above, Tribulus terrestris polysaccharide and Sarcandra glabra polysaccharide were obtained.

[0062] The polysaccharides of Bletilla striata, Sargassum fusiforme, and Tribulus terrestris were mixed in a mass ratio of 3:5:3 to obtain a polysaccharide complex.

[0063] (2) Dissolve the polysaccharide complex in water and stir continuously for 30 minutes. Add mesoporous silica nanoparticles (mass ratio 2:3) while stirring. After all the polysaccharide is adsorbed by the mesoporous silica nanoparticles, perform solid-liquid separation and dry the solid part to remove moisture to obtain the polysaccharide-mesoporous silica nanoparticles.

[0064] Preparation Example 4

[0065] This preparation example provides a polysaccharide-mesoporous silica nanoparticle composite. Except for step (1), in which the polysaccharide composite does not contain Bletilla striata polysaccharide and the reduced portion is allocated proportionally to Sarcandra glabra polysaccharide and Tribulus terrestris polysaccharide, the preparation method is the same as in preparation example 1.

[0066] Preparation Example 5

[0067] This preparation example provides a polysaccharide-mesoporous silica nanoparticle composite. The preparation method is the same as in preparation example 1, except that step (1) does not contain the herb *Sarcandra glabra* polysaccharide in the polysaccharide composite and the reduced portion is allocated to *Bletilla striata* polysaccharide and *Tribulus terrestris* polysaccharide.

[0068] Preparation Example 6

[0069] This preparation example provides a polysaccharide-mesoporous silica nanoparticle composite. The preparation method is the same as in Preparation Example 1, except that in step (1), the polysaccharide composite does not contain Tribulus terrestris polysaccharide and the reduced portion is allocated to Cordyceps sinensis polysaccharide and Bletilla striata polysaccharide in proportion.

[0070] Preparation Example 7

[0071] This preparation example provides a polysaccharide-mesoporous silica nanoparticle composite. The preparation method is the same as in Example 1, except that no composite enzyme is added in step (1).

[0072] Preparation Example 8

[0073] This preparation example provides a polysaccharide-mesoporous silica nanoparticle composite. The preparation method is identical to Example 1, except for the ultrasonic-assisted extraction parameters in step (1).

[0074] Ultrasonic-assisted extraction: power 400W, one ultrasound session 520s, temperature set to 50℃.

[0075] Example 1

[0076] This embodiment provides a functional feed additive to alleviate growth retardation in piglets, and the raw materials for preparation are as follows (by weight):

[0077] Preparation Example 1: 40 parts of polysaccharide-mesoporous silica nanoparticle composite, 1 part of tartary buckwheat oligopeptide, and 0.5 parts of hesperidin.

[0078] The functional feed additive is prepared by mixing the raw materials.

[0079] Example 2

[0080] This embodiment provides a functional feed additive to alleviate growth retardation in piglets, and the raw materials for preparation are as follows (by weight):

[0081] Preparation Example 2 provided 30 parts of polysaccharide-mesoporous silica nanoparticle composite, 0.1 parts of tartary buckwheat oligopeptide, and 0.1 parts of hesperidin.

[0082] The functional feed additive is prepared by mixing the raw materials.

[0083] Example 3

[0084] This embodiment provides a functional feed additive to alleviate growth retardation in piglets, and the raw materials for preparation are as follows (by weight):

[0085] Preparation Example 3 included 50 parts of polysaccharide-mesoporous silica nanoparticle composite, 2 parts of tartary buckwheat oligopeptide, and 1 part of hesperidin.

[0086] The functional feed additive is prepared by mixing the raw materials.

[0087] Examples 4-8

[0088] Examples 4-8 provide functional feed additives to alleviate growth retardation in piglets. The raw materials are the same as in Example 1, except that the polysaccharide-mesoporous silica nanoparticle composite provided in Example 1 is replaced with an equal amount of the polysaccharide-mesoporous silica nanoparticle composite provided in Examples 4-8.

[0089] Comparative Example 1

[0090] This comparative example provides a functional feed additive to alleviate growth retardation in piglets. The raw materials used in its preparation are identical to those in Example 1, except that the polysaccharide-mesoporous silica nanoparticle complex provided in Preparation Example 1 is not added and is replaced with the polysaccharide complex and mesoporous silica nanoparticles in the same amount as those in Preparation Example 1.

[0091] Effect test:

[0092] The experiment selected 21-day-old Duroc-Landrace-Large White crossbred normally weaned piglets (weighing approximately 6.5 kg) and stunted weaned piglets (average weight less than 30% of normal weaned piglets, weighing approximately 4.5 kg). They were divided into a normal piglet control group, a stunted piglet control group, and a stunted piglet experimental group (9 groups in total), with 3 replicates (pens) per group and 10 piglets (half male and half female) per replicate (pens). The normal piglet group and the stunted piglet control group were fed a basal diet, while the stunted piglet experimental group was supplemented with 500 mg / kg of the product provided in Examples 1-8 and Comparative Example 1, respectively, to their basal diet. The experiment lasted for 28 days. Twenty-eight days later, six piglets were randomly selected from each group to collect blood from the anterior vena cava. The blood samples were centrifuged at 3000 r / min at 4°C. The serum was aliquoted and stored at -80°C for blood index testing. After slaughter, the piglets were anesthetized and their abdominal cavity was quickly opened to expose and separate the intestines. The duodenum, jejunum, and ileum were taken and the intestinal contents were rinsed with PBS. The intestines were then placed in paraformaldehyde fixative and stored at 4°C for subsequent index determination.

[0093] Calculation of growth performance

[0094] Record the body weight and daily feed intake of weaned piglets on days 0 and 28 of the experimental period. Calculate parameters such as average daily weight gain, average daily feed intake, and feed conversion ratio for each piglet. The calculation formulas are as follows:

[0095] Average daily feed intake = Total feed intake / (Number of feeding days × Number of piglets)

[0096] Average daily weight gain = (final weight - initial weight) / number of feeding days

[0097] Feed conversion ratio = Average feed intake / Average daily weight gain

[0098] Antioxidant capacity determination

[0099] The activities of antioxidant enzymes (superoxide dismutase SOD, catalase CAT, and glutathione peroxidase GSH-Px) and the content of malondialdehyde (MDA) in plasma were determined using a specific commercial assay kit purchased from Nanjing Jiancheng Biotechnology Institute, China. The assay procedure was performed in accordance with the instructions.

[0100] Intestinal villi structure

[0101] Intestinal histomorphology

[0102] The duodenum, jejunum, and ileum, stored in paraformaldehyde fixative, were trimmed to an appropriate size (between 2 and 3 cm). The tissues were rinsed under running water for 24 hours to remove the fixative. After dehydration and clearing with 70%, 80%, 90%, and 100% alcohol respectively, the samples were embedded in paraffin, sectioned, and stained with hematoxylin and eosin (HE). Using ImageJ software, villus height and crypt depth were measured, and the villus-crypt ratio (V / C) was calculated. V / C = villus height (μm) / crypt depth (μm).

[0103] The results are as follows:

[0104] Table 1 Effects on growth performance of piglets

[0105]

[0106] Table 2 Effects on antioxidant indices in piglet plasma

[0107]

[0108] Table 3 Effects on intestinal morphology of piglets

[0109]

[0110] The data above show that the functional feed additive provided by this invention can regulate the redox balance of piglets, enhance their immunity, improve intestinal mucosal damage, and promote intestinal development, thereby alleviating growth retardation and promoting healthy growth in piglets with growth retardation. Comparative Examples 1-8 show that by selecting specific polysaccharides and using specific preparation methods, this invention can further improve the product's effectiveness. Comparative Examples 1 and 1 show that by combining polysaccharides and mesoporous silica nanoparticles to form sugar-mesoporous silica nanoparticles, this invention not only enhances the bioactivity of polysaccharides but also has a sustained-release effect in piglets, improving product quality and thus effectively improving piglet production performance.

[0111] The applicant declares that this invention illustrates the functional feed additive for alleviating growth retardation in piglets, its preparation method, and its application through the above embodiments. However, this invention is not limited to the above embodiments, meaning that this invention does not necessarily rely on the above embodiments for implementation. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of the raw materials in the product, addition of auxiliary components, and selection of specific methods, all fall within the protection and disclosure scope of this invention.

[0112] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0113] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

Claims

1. A functional feed additive for alleviating growth retardation in piglets, characterized in that, The functional feed additive for alleviating growth retardation in piglets comprises, by weight, 30-50 parts of polysaccharide-mesoporous silica nanoparticle complex, 0.1-2 parts of tartary buckwheat oligopeptide, and 0.1-1 parts of hesperidin.

2. The functional feed additive for alleviating growth retardation in piglets according to claim 1, characterized in that, The polysaccharide includes any one or a combination of at least two of the following: Bletilla striata polysaccharide, Sargassum fusiforme polysaccharide, or Tribulus terrestris polysaccharide.

3. The functional feed additive for alleviating growth retardation in piglets according to claim 2, characterized in that, The polysaccharides include Bletilla striata polysaccharide, Sargassum fusiforme polysaccharide, and Tribulus terrestris polysaccharide.

4. The functional feed additive for alleviating growth retardation in piglets according to claim 3, characterized in that, The mass ratio of Bletilla striata polysaccharide, Sargassum fusiforme polysaccharide and Tribulus terrestris polysaccharide is (1-3):(2-5):(2-3).

5. The functional feed additive for alleviating growth retardation in piglets according to any one of claims 1-4, characterized in that, The polysaccharide-mesoporous silica nanoparticle composite was prepared by a method comprising the following steps: (1) After crushing the plant raw materials, mix them with an aqueous acetic acid solution for extraction, then mix them with an enzyme for ultrasonic extraction, take the liquid part for alcohol precipitation, and collect the precipitate to obtain polysaccharides; (2) The polysaccharide was dissolved in water and then mixed with mesoporous silica nanoparticles and separated into solid and liquid phases to obtain the polysaccharide-mesoporous silica nanoparticle complex. The plant materials include any one or a combination of at least two of the following: Sargassum fusiforme, Tribulus terrestris, or Bletilla striata. When the polysaccharide in step (2) includes a combination of at least two of the following: Bletilla striata polysaccharide, Sargassum fusiforme polysaccharide, or Tribulus terrestris polysaccharide, the plant material in step (1) includes a combination of at least two of the following: Sargassum fusiforme, Tribulus terrestris, or Bletilla striata, or the corresponding polysaccharide is prepared from the plant material and then used in step (2).

6. The functional feed additive for alleviating growth retardation in piglets according to claim 5, characterized in that, In step (1), the ratio of the plant material to the acetic acid aqueous solution is 1:(20-40) g / mL; Preferably, the volume fraction of the acetic acid aqueous solution in step (1) is 5-15%; Preferably, the extraction temperature in step (1) is 50-70°C and the extraction time is 30-60 min.

7. The functional feed additive for alleviating growth retardation in piglets according to claim 5 or 6, characterized in that, The enzymes mentioned in step (1) include cellulase, hemicellulase and papain; Preferably, the mass ratio of cellulase, hemicellulase, and papain is (1-3):(1-2):(2-3); Preferably, the amount of enzyme used in step (1) is 1-5% of the mass of the plant raw material; Preferably, the ultrasonic extraction in step (1) is an intermittent ultrasonic extraction, with a single ultrasonic time of 10-15 s, an interval of 20-30 s, a cycle of 30-50 times, and a power of 300-500W.

8. The functional feed additive for alleviating growth retardation in piglets according to any one of claims 5-7, characterized in that, The mass ratio of the polysaccharide to the mesoporous silica nanoparticles in step (2) is 2:3-3:

2.

9. A method for preparing a functional feed additive for alleviating growth retardation in piglets according to any one of claims 1-8, characterized in that, The preparation method includes the following steps: The functional feed additive is obtained by mixing polysaccharide-mesoporous silica nanoparticle complex, buckwheat oligopeptide and hesperidin.

10. The application of a functional feed additive for alleviating growth retardation in piglets according to any one of claims 1-8 in the preparation of piglet feed.

Images