Composite pig feed additive containing oligosaccharide

Abstract

The invention discloses a compound pig feed additive containing oligosaccharide, which is used for solving the technical problem that the stability and economical efficiency of oligosaccharide components in compound pig feed in the prior art need to be further improved. The feed comprises the following raw materials in parts by weight: 50-60 parts of encapsulated oligosaccharide, 8-10 parts of probiotics, 3-5 parts of vitamins, 8-10 parts of minerals, 3-5 parts of organic acid, 10-15 parts of dietary fibers and 3-5 parts of a trace element additive. According to the method, the compound fructosease is prepared aiming at fructose, the fructose invertase is assembled in pores of a modified enzyme carrier prepared by the method, the contact area of the fructose and the enzyme is increased, the compound fructosease is convenient to recycle, the cost is saved, and the prepared oligosaccharide is acetylated and coated, so that the property of the oligosaccharide is more stable; and the sustained-release effect enables the absorption of organisms to be more sufficient.

Description

Technical Field

[0001] The invention relates to the technical field of feed processing, and in particular to a composite pig feed additive containing oligosaccharides. Background Art

[0002] The development history of oligosaccharide pig feed can be divided into three main stages. First, at the end of the 20th century, oligosaccharides were discovered as functional prebiotics, which have the functions of promoting the growth of beneficial intestinal bacteria and enhancing immunity. However, their application was mainly limited to experimental research at that time. In the early 21st century, oligosaccharides began to be explored as an alternative to antibiotics, which can effectively improve the intestinal health of pigs and enhance the efficiency of nutrient absorption. In the 2010s, oligosaccharide feed entered the mature stage and the formula was gradually standardized, which not only improved the growth performance of pigs, but also significantly improved the meat quality. With the reduction of production costs, oligosaccharide feed has been widely used in large-scale breeding.

[0003] Prior art CN107821738A discloses a prebiotic additive for pig feed made of mannan oligosaccharide prepared from enzymatically hydrolyzed konjac flour. The feed additive is prepared by hydrolyzing konjac flour to produce mannan oligosaccharide, which is then combined with lactic acid bacteria to form a prebiotic additive. The prebiotic additive can effectively promote protein synthesis, increase lean meat rate, and promote growth. The prebiotic additive is rich in carbohydrates, amino acids, nucleic acids, trace elements, and vitamins, and plays an important role in maintaining the acidic environment of the intestine, regulating the balance of intestinal flora, improving intestinal function, keeping the intestinal mucosa tight and intact, and improving the body's immunity.

[0004] However, the above patent content is to obtain the desired oligosaccharides after enzymatic hydrolysis of konjac flour. However, after the enzymatic hydrolysis is completed, the enzymatic hydrolyzate is boiled to inactivate the enzyme. Although this treatment operation can obtain the desired oligosaccharides, the utilization rate of the enzyme is too low, which will lead to too high a preparation cost of the oligosaccharides. In addition, the prepared oligosaccharides have not been surface-modified and modified for protection, and are easily inactivated by organic reactions in the body, resulting in their beneficial effects in the pig intestine to be further improved.

[0005] In view of the technical defects in this aspect, a solution is now proposed. Summary of the invention

[0006] The object of the present invention is to provide a composite pig feed additive containing oligosaccharides, which is used to solve the technical problem that the stability and economy of the oligosaccharide components in the composite pig feed in the prior art need to be further improved.

[0007] The purpose of the present invention can be achieved by the following technical scheme: a composite pig feed additive containing oligosaccharides, comprising the following raw materials by weight: 50-60 parts of encapsulated oligosaccharides, 8-10 parts of probiotics, 3-5 parts of vitamins, 8-10 parts of minerals, 3-5 parts of organic acids, 10-15 parts of dietary fiber and 3-5 parts of trace element additives;

[0008] The method for preparing encapsulated oligosaccharides comprises the following steps:

[0009] A1. Add oligofructose and pyridine into a reactor, stir at room temperature for 30-40 minutes, lower the temperature of the reactor to 0-10°C, drop acetic anhydride into the reactor, and maintain the dropwise addition for 0.5-1h. After the dropwise addition is completed, keep the temperature for 2-3h, and perform post-treatment to obtain acetylated oligosaccharides;

[0010] A2. Add the sugar solution dropwise to the reactor containing the sodium alginate solution at room temperature, control the dropping time to 30-40 min, maintain ultrasound during the dropping process, obtain the reaction precursor solution after the dropping is completed, continue to add the calcium chloride solution with a concentration of 1-1.5 mol / L into the reactor and stir, continue to stir for 15-20 min after the dropping is completed, and obtain the encapsulated oligosaccharide by post-treatment.

[0011] Reaction principle: The carboxyl groups in the sodium alginate molecules react with the calcium ions in the calcium chloride to form a cross-linking reaction. As a divalent cation, the calcium ion can combine with two carboxyl groups to form a network structure. This ion cross-linking process is very fast and effective, and can make the sodium alginate solution solidify quickly to form a three-dimensional network structure. When the emulsion containing acetylated oligofructose is dropped into the calcium chloride solution, the sodium alginate reacts with the calcium ions to form a gel, and the acetylated oligofructose is wrapped in the gel network to form microcapsules.

[0012] Furthermore, in step A1, the dosage ratio of oligofructose, pyridine and acetic anhydride is: 1-2g: 3-6mL: 2-4mL, and the post-treatment includes: after the reaction is completed, the temperature of the reactor is raised to room temperature, concentrated hydrochloric acid is added to the reactor to adjust the pH of the system to 7, and the reaction solution is transferred to a rotary evaporator at a temperature of 50-60°C, and the reduced pressure distillation is carried out until no liquid is produced, and the distillation product is washed with ethanol 3-5 times, and then the product is placed in a drying oven at a temperature of 60°C and vacuum dried until the product is constant weight to obtain acetylated oligosaccharides; in step A2, the dosage ratio of the sugar solution and the sodium alginate solution is 2-3mL: 4-6mL, and the sugar solution is composed of acetylated oligosaccharides and deionized water in a dosage ratio of 5-8g: 50mL. The sodium alginate solution is prepared by mixing sodium alginate and deionized water in a dosage ratio of 3-5 g:50 mL, the ultrasonic frequency is 20-40 kHz, the stirring rate of the reactor is 80-120 rpm, the dripping rate of the 1-1.5 mol / L calcium chloride solution is 1 drop / s, the dosage ratio of the reaction precursor solution and the 1-1.5 mol / L calcium chloride solution is 5 mL:1 mL, and the post-treatment includes: after the reaction is completed, filtering the reaction liquid, collecting the filter cake, washing the filter cake with ethanol for 3-5 times, placing the filter cake in a spray dryer, setting the inlet temperature to 150° C., setting the outlet temperature to 80° C., controlling the spray rate to 5 mL / min, and drying for 1-2 hours to obtain encapsulated oligosaccharides.

[0013] Furthermore, the probiotics are one or both of Escherichia coli and Bifidobacterium; the vitamins are one or more of vitamin A, vitamin D3 and vitamin E; the minerals are one or more of calcium hydrogen phosphate, zinc oxide and calcium carbonate; the organic acids are one or both of lactic acid and citric acid; the dietary fiber is one or more of soy fiber and beet fiber; and the trace element additives are one or both of selenium yeast and copper sulfate.

[0014] Furthermore, the preparation method of oligofructose is as follows: fructose and buffer are added to a reactor and stirred at room temperature for 15-20 minutes, the temperature of the reactor is increased to 30-40°C, and complex fructose enzyme is added to the reactor, and after the reaction is kept warm for 4-6 hours, oligofructose is obtained by post-treatment and the complex fructose enzyme is recovered.

[0015] Reaction principle: Under the promotion of buffer solution and temperature, complex fructase begins to decompose fructose to produce oligosaccharides.

[0016] Furthermore, the dosage ratio of fructose, buffer and composite fructose enzyme is 8-10g:40-50mL:80-120mg, the stirring rate is 80-120rpm, and the preparation method of the buffer is: after adding sodium acetate and deionized water into a reactor, acetic acid solution is added dropwise into the reactor to adjust the pH value of the system to 5.5-6.5 to obtain a buffer; the post-treatment includes: after the temperature of the reactor is lowered to room temperature, the reaction solution is added into a centrifuge tube with a volume of 5mL, 3mL of the reaction solution is added into each centrifuge tube, the centrifuge tube is added into a centrifuge and balanced, and the centrifuge is adjusted. The machine speed is 4000-6000rpm. After centrifugation, the centrifuge and the precipitate are collected, and the precipitate is washed 3-5 times with a 4°C enzyme buffer, and then the precipitate is placed in a drying oven at a temperature of 4°C and vacuum dried until the precipitate is constant weight, the composite fructose enzyme is recovered, and the composite fructose enzyme is packaged and placed in a constant temperature box at a temperature of -20°C and stored away from light; the centrifuge is placed in a rotary evaporator at a temperature of 60°C and distilled under reduced pressure until no liquid is extracted, and the material is washed 3 times with ethanol, and the material is placed in a drying oven at a temperature of 40°C and vacuum dried until the material is constant weight to obtain oligofructose.

[0017] Further, the preparation method of the composite fructose enzyme is:

[0018] B1, adding sodium dihydrogen phosphate, sodium chloride, disodium hydrogen phosphate, dithiothreitol and deionized water into a reaction kettle, adding 1-3wt% hydrochloric acid solution into the reaction kettle to adjust the pH of the system to 6.5-7.5, to obtain an enzyme buffer;

[0019] B2. Add the pre-treated modified enzyme carrier and enzyme buffer into the reactor and stir. After stirring for 10-15 minutes, lower the temperature of the reactor to 2-6°C, add fructose invertase into the reactor, stir for 5-10 minutes, let it stand for 10-12 hours, and post-treat to obtain composite fructose enzyme.

[0020] Reaction principle: After the modified enzyme carrier is heated, the pores are completely open, ensuring the maximum adsorption capacity of MOF and the active sites on the surface and pores of MOF are in the optimal state. In the buffer, the surfaces of MOF and enzyme carry a certain charge, generating electrostatic attraction, so that the enzyme is firmly adsorbed on the pores and surface of MOF.

[0021] Hydrogen bonds or hydrophobic interactions may form between the amino acid residues in the enzyme molecules and the ligands or pore walls of MOF, which further enhances the loading stability of the enzyme. The 12-hour incubation process at 4°C gives the enzyme molecules enough time to diffuse, penetrate and fully interact with the MOF structure, and finally the composite fructose enzyme is prepared.

[0022] Further, in step B1, the dosage ratio of sodium dihydrogen phosphate, sodium chloride, disodium hydrogen phosphate, dithiothreitol and deionized water is 1.1-1.2g:2.9-3.0g:1.4-1.5g:0.1g:5-8g:900mL; in step B2, the stirring rate of the reactor is 80-120rpm, and the pretreatment operation includes: placing the modified enzyme carrier in a drying oven at a temperature of 60°C and vacuum drying for 2h to obtain a pre-treated modified enzyme carrier; the dosage ratio of the pre-treated modified enzyme carrier, enzyme buffer and fructose invertase is 80-120mg: 10mL:40-60mg, post-treatment includes: after the temperature of the reactor is lowered to room temperature, the reaction solution is added to a centrifuge tube with a volume of 5mL, 3mL of the reaction solution is added to each centrifuge tube, the centrifuge tube is added to the centrifuge for balancing, and the centrifuge speed is adjusted to 4000-6000rpm, after centrifugation, the precipitate is washed 3-5 times with a 4°C enzyme buffer, and the precipitate is placed in a drying oven at a temperature of 4°C and vacuum dried until the precipitate is constant weight to obtain a composite fructose enzyme, and the composite fructose enzyme is encapsulated and placed in a constant temperature box at a temperature of -20°C to avoid light.

[0023] Further, the preparation method of the modified enzyme carrier is:

[0024] C1. Add 4-azobenzoic acid and anhydrous ethanol into a reaction kettle and stir. Raise the temperature of the reaction kettle to 30-50°C and stir for 10-15 minutes to obtain a light-responsive liquid.

[0025] C2, adding zirconium oxychloride and anhydrous ethanol into a reaction kettle, stirring at room temperature for 10-15 minutes to obtain a framework precursor solution;

[0026] C3. Add the light response liquid into the reaction kettle and stir, and add the framework precursor liquid into the reaction kettle during the stirring process. After the framework precursor liquid is added, stir at room temperature for 10-15 minutes, and post-treat to obtain the modified enzyme carrier.

[0027] Reaction principle: During the reaction, 4-azobenzoic acid acts as a ligand, and its azobenzene group can undergo cis-trans isomerization under light. The carboxyl group in 4-azobenzoic acid combines with the zirconium ion in zirconium oxychlorate through a coordination bond to form a network structure. With the photoisomerization of the ligand and the stable coordination of the metal ion, the self-assembly process of MOF begins to occur. Due to the multi-point coordination between the zirconium ion and the 4-azobenzoic acid ligand, a metal organic framework with a porous structure is gradually formed. After the illumination is completed, the solution continues to be stirred and reacted for a long time at an appropriate temperature to promote further growth of the crystal. The MOF crystals gradually precipitate from the solution. As the reaction proceeds, the coordination between the ligand and the metal ion reaches equilibrium, forming a stable three-dimensional structure, thereby generating ordered crystals in the solution, and finally preparing a modified enzyme carrier.

[0028] Furthermore, in step C1, the dosage ratio of 4-azobenzoic acid and anhydrous ethanol is 1-2g:8-10mL, and the stirring rate is 80-120rpm; in step C2, the dosage ratio of zirconium oxychlorate and anhydrous ethanol is 1-2g:8-10mL, and the stirring rate is 80-120rpm; in step C3, the dosage ratio of the photoresponsive liquid and the framework precursor liquid is 0.8-1:1, and the stirring rate of the reactor is 80-120rpm. The post-treatment includes: after stirring, irradiating the reactor with an ultraviolet lamp with a wavelength of 300-400nm for 2-3h, raising the temperature of the reactor to 40-60°C, and stirring for 10-12h at the same temperature. After the reaction is completed, after the temperature of the reactor is lowered to room temperature, the reaction liquid is filtered, the filter cake is collected, and the filter cake is placed in a drying oven at a temperature of 50°C and vacuum dried until the filter cake has a constant weight to obtain a modified enzyme carrier.

[0029] Furthermore, a preparation method of a composite pig feed additive containing oligosaccharides is as follows: 10-15 parts of dietary fiber are weighed and added to a double-screw mixer, the power of the double-screw mixer is set to 5.5-6.0 kW, the speed is set to 80-120 rpm, and 8-10 parts of minerals, 3-5 parts of vitamins and 3-5 parts of organic acids are added to the double-screw mixer in sequence. After mixing and stirring for 10-15 minutes, 8-10 parts of probiotics and 50-60 parts of encapsulated oligosaccharides are slowly added to the mixer, the speed is adjusted to 40-60 rpm, and after stirring for 5-8 minutes, 3-5 parts of trace element additives are added to the double-screw mixer. After stirring for 10-15 minutes, the pig feed additive is obtained by extruding directly through a 300 mm pneumatic butterfly valve and vacuum packaging.

[0030] The present invention has the following beneficial effects:

[0031] 1. The composite pig feed additive prepared by the present invention has oligosaccharides as the main component. As a bifidobacterial factor, oligosaccharides are non-digestible carbohydrates. They can selectively promote the proliferation of bifidobacteria in the host intestine and play a role in improving the health of the host. Since the bifidobacterial factor cannot be decomposed, absorbed and utilized by the domestic pig body, it can be decomposed and utilized by the beneficial colon flora after reaching the colon through the digestive tract, thereby promoting the growth of the beneficial colon flora, improving the intestinal microecology, and promoting the metabolism of lipids, proteins and minerals, making the intestinal environment of the domestic pig more stable and reducing the occurrence of diseases. Functional oligosaccharides promote the proliferation of bifidobacteria, the inherent beneficial bacteria in the pig intestine, thereby inhibiting the growth of putrefactive bacteria in the intestine, reducing the formation of toxic substances, and promoting the weight gain of the domestic pig. Bifidobacteria ferment oligosaccharides to produce a large amount of short-chain fatty acids, which can stimulate intestinal peristalsis, increase fecal moisture and maintain a certain osmotic pressure, thereby preventing the occurrence of constipation.

[0032] 2. In the process of preparing a composite pig feed additive containing oligosaccharides, the present invention first selects and prepares a composite fructose enzyme, which uses the MOF material with a large number of pore structures prepared by the present invention as a carrier, and assembles a large number of fructose invertases inside it. Compared with traditional carrier materials, this porous structure greatly increases the contact area between the enzyme and fructose, thereby greatly improving the catalytic efficiency. Fructose can enter the active site of the enzyme at a faster rate, making the conversion reaction of oligosaccharides more efficient and rapid, thereby improving production efficiency; another key advantage of MOF materials is its insolubility. After the catalytic reaction is completed, the composite fructose enzyme can be easily recovered by simple physical separation means, which not only simplifies the operation process, but also significantly reduces the cost of enzyme use. In traditional processes, enzymes are usually unable to be recycled and need to be continuously supplemented with new enzyme sources, resulting in an increase in production costs. Through this innovative carrier design, the composite fructose enzyme can still maintain activity after multiple uses, further improving economic benefits; in summary, this composite fructose enzyme using MOF materials as carriers not only accelerates the catalytic conversion of fructose and improves production efficiency, but also saves the cost of enzyme use through a simple recovery mechanism. This dual advantage undoubtedly provides a more economical and efficient solution for the preparation of compound pig feed additives.

[0033] 3. In the process of preparing a composite pig feed additive containing oligosaccharides, the present invention performs acetylation modification on the oligosaccharides obtained by decomposition of the composite fructose enzyme, thereby enhancing the chemical and physical stability of the oligosaccharides. Oligosaccharide molecules are prone to degradation reactions when encountering external environments such as acids, alkalis or enzymes, and acetylation modification can effectively reduce such degradation, allowing oligosaccharides to maintain their structure and function in more complex or extreme environments. Especially in the application of feed additives or health foods, acetylated oligosaccharides can better resist the erosion of gastric acid, digestive enzymes, etc., ensuring that their efficacy reaches the intestines; and sodium alginate is used to wrap the acetylated oligosaccharides. Sodium alginate has good hydration properties and film-forming properties, and can form a soft protective film on the outside of the oligosaccharides. This film can not only cover up the bitterness or bad taste that may exist in the acetylated oligosaccharides, but also give them a better texture, improve the product's eating experience, and promote the animal's feed intake. At the same time, sodium alginate has good controlled release properties. By coating the acetylated oligosaccharides, a "slow release" mechanism is formed, allowing the oligosaccharides to be gradually released at specific locations in the digestive tract, rather than being decomposed by gastric acid or other digestive enzymes before reaching the intestines. This controlled release effect can ensure that the acetylated oligosaccharides play their role more accurately, improve bioavailability and durability of effect, and ultimately significantly improve the performance of pig feed. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 This is a SEM image of the internal voids of the modified enzyme carrier prepared in the present invention. DETAILED DESCRIPTION

[0036] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] Example 1

[0038] This embodiment provides a composite pig feed additive containing oligosaccharides, and the preparation method thereof comprises the following steps:

[0039] S1. Preparation of modified enzyme carrier

[0040] Weigh: 6.0 g of 4-azobenzoic acid and 35.0 mL of anhydrous ethanol were added to a reaction kettle and stirred. The temperature of the reaction kettle was raised to 30° C., the stirring rate was 80 rpm, and the mixture was stirred for 10 min to obtain a light-responsive liquid.

[0041] Weigh: 5.0 g zirconium oxychloride and 24.0 mL anhydrous ethanol are added into a reaction kettle, stirred at room temperature for 10 min at a stirring rate of 80 rpm to obtain a framework precursor solution;

[0042] Weigh: 40.0 mL of photoresponsive liquid was added to the reactor and stirred, and 50.0 mL of framework precursor liquid was added to the reactor during the stirring process. After the framework precursor liquid was added, it was stirred at room temperature for 10 min at a stirring rate of 80 rpm. After stirring, the reactor was irradiated with an ultraviolet lamp with a wavelength of 300 nm for 2 h, the temperature of the reactor was raised to 40°C, and the mixture was kept warm and stirred for 10 h. After the reaction was completed, the temperature of the reactor was lowered to room temperature, the reaction liquid was filtered, the filter cake was collected, and the filter cake was placed in a drying oven at a temperature of 50°C and vacuum dried until the filter cake had a constant weight to obtain a modified enzyme carrier.

[0043] S2. Preparation of oligofructose

[0044] Weigh: 1.1 g of sodium dihydrogen phosphate, 2.9 g of sodium chloride, 1.4 g of disodium hydrogen phosphate, 0.1 g of dithiothreitol and 900.0 mL of deionized water into a reactor, add 1 wt % hydrochloric acid solution into the reactor to adjust the pH of the system to 7.5, and obtain an enzyme buffer;

[0045] Weigh: 200.0 mg of the modified enzyme carrier was placed in a drying oven at 60° C. and vacuum dried for 2 h to obtain a pre-treated modified enzyme carrier;

[0046] Weigh: 80.0 mg of pre-treated modified enzyme carrier and 10.0 mL of enzyme buffer are added to the reactor and stirred at a stirring rate of 80 rpm. After stirring for 10 min, the temperature of the reactor is lowered to 6°C, 40.0 mg of fructose invertase is added to the reactor, stirred for 5 min, and then left to stand for 10 h. The reaction solution is added to a centrifuge tube with a volume of 5 mL, and 3 mL of reaction solution is added to each centrifuge tube. After the centrifuge tube is added to the centrifuge and balanced, the centrifuge speed is adjusted to 4000 rpm. After centrifugation, the precipitate is washed 3 times with 4°C enzyme buffer, and the precipitate is placed in a drying oven at a temperature of 4°C and vacuum dried until the precipitate is constant weight to obtain a composite fructose enzyme, and the composite fructose enzyme is encapsulated and placed in a constant temperature box at a temperature of -20°C to avoid light;

[0047] After sodium acetate and deionized water are added to the reaction kettle, acetic acid solution is added dropwise to the reaction kettle to adjust the pH of the system to 6.5 to obtain a buffer solution;

[0048] Weigh: 10.0g fructose and 40.0mL buffer solution are added to a reactor and stirred at room temperature for 15min at a stirring rate of 80rpm. The temperature of the reactor is raised to 30°C, and 80.0mg of complex fructose enzyme is added to the reactor. The reaction is kept warm for 4h. After the temperature of the reactor is lowered to room temperature, the reaction solution is added to a centrifuge tube with a volume of 5mL. 3mL of reaction solution is added to each centrifuge tube. After the centrifuge tube is added to the centrifuge and balanced, the centrifuge speed is adjusted to 4000rpm. After centrifugation, the centrifuge liquid and precipitate are collected, and the centrifuge liquid is placed in a rotary evaporator at a temperature of 60°C for reduced pressure distillation. After no liquid is extracted, the material is washed with ethanol 3 times, and the material is placed in a drying oven at a temperature of 40°C and vacuum dried until the material is constant weight to obtain oligofructose;

[0049] After washing the precipitate three times with 4°C enzyme buffer, the precipitate was placed in a drying oven at 4°C for vacuum drying until the precipitate had a constant weight, the composite fructose enzyme was recovered, and the composite fructose enzyme was packaged and stored in a constant temperature box at -20°C in the dark.

[0050] S3. Preparation of encapsulated oligosaccharides

[0051] Weigh: 6.0g oligofructose and 15.0mL pyridine are added to the reactor, stirred at room temperature for 30min, the stirring rate is 80rpm, the temperature of the reactor is lowered to 10°C, 6.0mL acetic anhydride is added dropwise to the reactor, the dropping operation is maintained for 0.5h, and the reaction is kept warm for 0.5h after the addition is completed. After the reaction is completed, the temperature of the reactor is raised to room temperature, concentrated hydrochloric acid is added dropwise to the reactor to adjust the pH of the system to 7, and the reaction solution is transferred to a rotary evaporator at a temperature of 50°C, and distilled under reduced pressure until no liquid is produced, and the distilled product is washed with ethanol 3 times, and the product is placed in a drying oven at a temperature of 60°C and vacuum dried until the product is constant weight to obtain acetylated oligosaccharides;

[0052] Weigh: 6.0 g of acetylated oligosaccharide and 50.0 mL of deionized water to obtain a sugar solution;

[0053] Weigh: 4.0 g of sodium alginate and 50.0 mL of deionized water to prepare a sodium alginate solution;

[0054] At room temperature, 20.0 mL of sugar solution was added dropwise to a reactor containing 40.0 mL of sodium alginate solution. The addition time was controlled to be 30 min. Ultrasonication was maintained during the addition process. The ultrasonic frequency was 20 kHz. After the addition was completed, a reaction precursor solution was obtained.

[0055] Weigh: 50.0mL of reaction precursor solution was added to the reactor and stirred at a stirring rate of 80rpm. During the stirring process, 10.0mL of 1mol / L calcium chloride solution was added dropwise to the reactor at a dropping rate of 1 drop / s. After the addition was completed, stirring was continued for 15min. After the reaction was completed, the reaction liquid was filtered and the filter cake was collected. After washing the filter cake with ethanol 3 times, the filter cake was placed in a spray dryer, the inlet temperature was set to 150°C, the outlet temperature was set to 80°C, the spray rate was controlled at 5mL / min, and after drying for 1h, encapsulated oligosaccharides were obtained.

[0056] S4. Preparation of composite additives

[0057] Weigh: 12.0g of soybean fiber is added to a double-helix mixer. The power of the double-helix mixer is set to 5.5kW and the speed is set to 80rpm. 8.0g of calcium carbonate, 3.6g of vitamin E and 4.2g of citric acid are added to the double-helix mixer in sequence. After mixing and stirring for 10 minutes, 8.4g of Escherichia coli and 54.0g of encapsulated oligosaccharides are slowly added to the mixer. The speed is adjusted to 40rpm. After stirring for 6 minutes, 3.6g of selenium yeast is added to the double-helix mixer. After stirring for 10 minutes, the composite additive is obtained by extruding through a 300mm pneumatic butterfly valve and vacuum packaging.

[0058] Example 2

[0059] This embodiment provides a composite pig feed additive containing oligosaccharides, and the preparation method thereof comprises the following steps:

[0060] S1. Preparation of modified enzyme carrier

[0061] Weigh: 6.0 g of 4-azobenzoic acid and 30.0 mL of anhydrous ethanol were added to a reaction kettle and stirred. The temperature of the reaction kettle was raised to 30° C., the stirring rate was 120 rpm, and the mixture was kept warm and stirred for 12 minutes to obtain a light-responsive liquid.

[0062] Weigh: 6.4 g zirconium oxychloride and 36.0 mL anhydrous ethanol are added into a reaction kettle, stirred at room temperature for 15 min at a stirring rate of 120 rpm to obtain a framework precursor solution;

[0063] Weigh: 50.0 mL of photoresponsive liquid was added to the reactor and stirred, and 50.0 mL of framework precursor liquid was added to the reactor during the stirring process. After the framework precursor liquid was added, it was stirred at room temperature for 15 min at a stirring rate of 120 rpm. After stirring, the reactor was irradiated with an ultraviolet lamp with a wavelength of 400 nm for 3 h, the temperature of the reactor was raised to 60°C, and the mixture was kept warm and stirred for 12 h. After the reaction was completed, the temperature of the reactor was lowered to room temperature, the reaction liquid was filtered, the filter cake was collected, and the filter cake was placed in a drying oven at a temperature of 50°C and vacuum dried until the filter cake had a constant weight to obtain a modified enzyme carrier.

[0064] S2. Preparation of oligofructose

[0065] Weigh: 1.2 g of sodium dihydrogen phosphate, 3.0 g of sodium chloride, 1.5 g of disodium hydrogen phosphate, 0.1 g of dithiothreitol and 900.0 mL of deionized water and add them into a reactor, add 3 wt % hydrochloric acid solution into the reactor to adjust the pH of the system to 6.5, and obtain an enzyme buffer;

[0066] Weigh: 200.0 mg of the modified enzyme carrier was placed in a drying oven at 60° C. and vacuum dried for 2 h to obtain a pre-treated modified enzyme carrier;

[0067] Weigh: 120.0 mg of pre-treated modified enzyme carrier and 10.0 mL of enzyme buffer are added to the reactor and stirred at a stirring rate of 120 rpm. After stirring for 15 min, the temperature of the reactor is lowered to 2°C, 50.0 mg of fructose invertase is added to the reactor, stirred for 10 min, and then left to stand for 12 h. The reaction solution is added to a centrifuge tube with a volume of 5 mL, and 3 mL of reaction solution is added to each centrifuge tube. After the centrifuge tube is added to the centrifuge and balanced, the centrifuge speed is adjusted to 6000 rpm. After centrifugation, the precipitate is washed 5 times with 4°C enzyme buffer, and the precipitate is placed in a drying oven at a temperature of 4°C and vacuum dried until the precipitate is constant weight to obtain a composite fructose enzyme, and the composite fructose enzyme is encapsulated and placed in a constant temperature box at a temperature of -20°C to avoid light;

[0068] After sodium acetate and deionized water are added to the reaction kettle, acetic acid solution is added dropwise to the reaction kettle to adjust the pH of the system to 6.5 to obtain a buffer solution;

[0069] Weigh: 20.0g fructose and 80.0mL buffer solution are added to the reactor and stirred at room temperature for 20min at a stirring rate of 120rpm. The temperature of the reactor is raised to 40°C, and 120mg of composite fructose enzyme is added to the reactor. The reaction is kept warm for 6h. After the temperature of the reactor is lowered to room temperature, the reaction solution is added to a centrifuge tube with a volume of 5mL. 3mL of reaction solution is added to each centrifuge tube. After the centrifuge tube is added to the centrifuge and balanced, the centrifuge speed is adjusted to 6000rpm. After centrifugation, the centrifuge liquid and precipitate are collected, and the centrifuge liquid is placed in a rotary evaporator at a temperature of 80°C for reduced pressure distillation. After no liquid is extracted, the material is washed with ethanol 5 times, and the material is placed in a drying oven at a temperature of 40°C and vacuum dried until the material is constant weight to obtain oligofructose;

[0070] After washing the precipitate five times with 4°C enzyme buffer, the precipitate was placed in a drying oven at 4°C for vacuum drying until the precipitate had a constant weight, the composite fructose enzyme was recovered, and the composite fructose enzyme was packaged and stored in a constant temperature box at -20°C in the dark.

[0071] S3. Preparation of encapsulated oligosaccharides

[0072] Weigh: 3.6g oligofructose and 12.0mL pyridine are added to the reactor, stirred at room temperature for 40min, the stirring rate is 120rpm, the temperature of the reactor is lowered to 5°C, 12.0mL acetic anhydride is added dropwise to the reactor, the dropping operation is maintained for 1h, and the reaction is kept warm for 3h after the addition is completed. After the reaction is completed, the temperature of the reactor is raised to room temperature, concentrated hydrochloric acid is added dropwise to the reactor to adjust the pH of the system to 7, and the reaction solution is transferred to a rotary evaporator at a temperature of 60°C, and distilled under reduced pressure until no liquid is produced, and the distilled product is washed with ethanol 5 times, and then the product is placed in a drying oven at a temperature of 60°C and vacuum dried until the product is constant weight to obtain acetylated oligosaccharides;

[0073] Weigh: 7.2 g of acetylated oligosaccharide and 50.0 mL of deionized water to obtain a sugar solution;

[0074] Weigh: 4.2 g of sodium alginate and 50.0 mL of deionized water to prepare a sodium alginate solution;

[0075] 30.0 mL of sugar solution was added dropwise to a reactor containing 50.0 mL of sodium alginate solution at room temperature. The adding time was controlled to be 40 min. Ultrasonication was maintained during the adding process. The ultrasonic frequency was 40 kHz. After the adding was completed, a reaction precursor solution was obtained.

[0076] Weigh: 50.0mL of reaction precursor solution was added to the reactor and stirred at a stirring rate of 120rpm. During the stirring process, 10.0mL of 1.5mol / L calcium chloride solution was added dropwise to the reactor at a dropping rate of 1 drop / s. After the addition was completed, stirring was continued for 20min. After the reaction was completed, the reaction liquid was filtered and the filter cake was collected. After washing the filter cake with ethanol 5 times, the filter cake was placed in a spray dryer, the inlet temperature was set to 150°C, the outlet temperature was set to 80°C, the spray rate was controlled at 5mL / min, and after drying for 2h, encapsulated oligosaccharides were obtained.

[0077] S4. Preparation of composite additives

[0078] Weigh: 12.0g of soybean fiber is added to a double-helix mixer. The power of the double-helix mixer is set to 6.0kW and the speed is set to 120rpm. 9.6g of calcium carbonate, 4.2g of vitamin E and 4.2g of citric acid are added to the double-helix mixer in sequence. After mixing and stirring for 15 minutes, 8.4g of Escherichia coli and 54.0g of encapsulated oligosaccharides are slowly added to the mixer. The speed is adjusted to 60rpm. After stirring for 8 minutes, 4.2g of selenium yeast is added to the double-helix mixer. After stirring for 15 minutes, the composite additive is obtained by extruding through a 300mm pneumatic butterfly valve and vacuum packaging.

[0079] Example 3

[0080] This embodiment provides a composite pig feed additive containing oligosaccharides, and the preparation method thereof comprises the following steps:

[0081] S1. Preparation of modified enzyme carrier

[0082] Weigh: 6.0 g of 4-azobenzoic acid and 24.0 mL of anhydrous ethanol were added to a reaction kettle and stirred. The temperature of the reaction kettle was raised to 40° C., the stirring rate was 100 rpm, and the mixture was stirred for 12 min to obtain a light-responsive liquid.

[0083] Weigh: 6.0 g zirconium oxychloride and 24.0 mL anhydrous ethanol are added into a reaction kettle, stirred at room temperature for 12 min at a stirring rate of 100 rpm to obtain a framework precursor solution;

[0084] Weigh: 50.0 mL of photoresponsive liquid was added to the reactor and stirred, and 50.0 mL of framework precursor liquid was added to the reactor during the stirring process. After the framework precursor liquid was added, it was stirred at room temperature for 12 min at a stirring rate of 100 rpm. After stirring, the reactor was irradiated with an ultraviolet lamp with a wavelength of 350 nm for 3 h, the temperature of the reactor was raised to 50°C, and the mixture was kept warm and stirred for 11 h. After the reaction was completed, the temperature of the reactor was lowered to room temperature, the reaction liquid was filtered, the filter cake was collected, and the filter cake was placed in a drying oven at a temperature of 50°C and vacuum dried until the filter cake had a constant weight to obtain a modified enzyme carrier.

[0085] S2. Preparation of oligofructose

[0086] Weigh: 1.2 g of sodium dihydrogen phosphate, 2.9 g of sodium chloride, 1.4 g of disodium hydrogen phosphate, 0.1 g of dithiothreitol and 900.0 mL of deionized water into a reactor, add 2 wt % hydrochloric acid solution into the reactor to adjust the pH of the system to 7, and obtain an enzyme buffer;

[0087] Weigh: 200.0 mg of the modified enzyme carrier was placed in a drying oven at 60° C. and vacuum dried for 2 h to obtain a pre-treated modified enzyme carrier;

[0088] Weigh: 100.0 mg of pre-treated modified enzyme carrier and 10.0 mL of enzyme buffer are added to the reactor and stirred at a stirring rate of 100 rpm. After stirring for 12 minutes, the temperature of the reactor is lowered to 4°C, 50.0 mg of fructose invertase is added to the reactor, stirred for 8 minutes, and then left to stand for 11 hours. The reaction solution is added to a centrifuge tube with a volume of 5 mL, and 3 mL of reaction solution is added to each centrifuge tube. After the centrifuge tube is added to the centrifuge and balanced, the centrifuge speed is adjusted to 5000 rpm. After centrifugation, the precipitate is washed 4 times with a 4°C enzyme buffer, and the precipitate is placed in a drying oven at a temperature of 4°C and vacuum dried until the precipitate is constant weight to obtain a composite fructose enzyme, and the composite fructose enzyme is encapsulated and placed in a constant temperature box at a temperature of -20°C to avoid light;

[0089] After sodium acetate and deionized water are added to the reaction kettle, acetic acid solution is added dropwise to the reaction kettle to adjust the pH of the system to 6 to obtain a buffer solution;

[0090] Weigh: 9.6g fructose and 42.0mL buffer solution are added to the reactor and stirred at room temperature for 18min at a stirring rate of 100rpm. The temperature of the reactor is raised to 30°C, and 100.0mg composite fructose enzyme is added to the reactor. The reaction is kept warm for 5h. After the temperature of the reactor is lowered to room temperature, the reaction solution is added to a centrifuge tube with a volume of 5mL, and 3mL of reaction solution is added to each centrifuge tube. After the centrifuge tube is added to the centrifuge and balanced, the centrifuge speed is adjusted to 5000rpm. After centrifugation, the centrifuge liquid and precipitate are collected, and the centrifuge liquid is placed in a rotary evaporator at a temperature of 70°C for reduced pressure distillation. After no liquid is extracted, the material is washed with ethanol 4 times, and the material is placed in a drying oven at a temperature of 40°C and vacuum dried until the material is constant weight to obtain oligofructose;

[0091] After washing the precipitate 4 times with 4°C enzyme buffer, the precipitate was placed in a drying oven at 4°C for vacuum drying until the precipitate had a constant weight, the composite fructose enzyme was recovered, and the composite fructose enzyme was packaged and stored in a constant temperature box at -20°C in the dark.

[0092] S3. Preparation of encapsulated oligosaccharides

[0093] Weigh: 15.0g oligofructose and 45.0mL pyridine are added to the reactor, stirred at room temperature for 36min, the stirring rate is 100rpm, the temperature of the reactor is lowered to 0℃, 24.0mL acetic anhydride is added dropwise to the reactor, the dropping operation is maintained for 0.8h, and the reaction is kept warm for 3h after the addition is completed. After the reaction is completed, the temperature of the reactor is raised to room temperature, concentrated hydrochloric acid is added dropwise to the reactor to adjust the pH of the system to 7, and the reaction solution is transferred to a rotary evaporator at a temperature of 55℃, and distilled under reduced pressure until no liquid is produced, and the distilled product is washed with ethanol 4 times, and the product is placed in a drying oven at a temperature of 60℃ and vacuum dried until the product is constant weight to obtain acetylated oligosaccharides;

[0094] Weigh: 7.2 g of acetylated oligosaccharide and 50.0 mL of deionized water to obtain a sugar solution;

[0095] Weigh: 3.6 g of sodium alginate and 50.0 mL of deionized water to prepare a sodium alginate solution;

[0096] 24.0 mL of sugar solution was added dropwise to a reactor containing 42.0 mL of sodium alginate solution at room temperature. The adding time was controlled to be 40 min. Ultrasonication was maintained during the adding process. The ultrasonic frequency was 30 kHz. After the adding was completed, a reaction precursor solution was obtained.

[0097] Weigh: 50.0mL of reaction precursor solution was added to the reactor and stirred at a stirring rate of 100rpm. During the stirring process, 10.0mL of 1.2mol / L calcium chloride solution was added dropwise to the reactor at a dropping rate of 1 drop / s. After the addition was completed, stirring was continued for 18min. After the reaction was completed, the reaction liquid was filtered and the filter cake was collected. After washing the filter cake with ethanol 4 times, the filter cake was placed in a spray dryer, the inlet temperature was set to 150°C, the outlet temperature was set to 80°C, the spray rate was controlled at 5mL / min, and after drying for 2h, encapsulated oligosaccharides were obtained.

[0098] S4. Preparation of composite additives

[0099] Weigh: 12.0g of soybean fiber is added to a double-helix mixer. The power of the double-helix mixer is set to 5.5kW and the speed is set to 100rpm. 9.6g of calcium carbonate, 4.2g of vitamin E and 3.6g of citric acid are added to the double-helix mixer in sequence. After mixing and stirring for 12 minutes, 9.6g of Escherichia coli and 54.0g of encapsulated oligosaccharides are slowly added to the mixer. The speed is adjusted to 50rpm. After stirring for 6 minutes, 4.2g of selenium yeast is added to the double-helix mixer. After stirring for 12 minutes, the composite additive is obtained by extruding it directly through a 300mm pneumatic butterfly valve and vacuum packaging.

[0100] Performance Testing:

[0101] The additives prepared in Example 1 and Comparative Example 1 were added to the feed of two groups of weaned pigs, respectively. The growth environment was controlled to maintain the same temperature, humidity, light cycle and sanitary conditions. The pigs were allowed to drink water freely and fed regularly to ensure that the feed was fresh. The two groups were named Experimental Group 1 and Control Group 1, respectively.

[0102] The additives prepared in Example 2 and Comparative Example 2 were added to the feed of two groups of growing pigs, respectively. The growth environment was controlled to maintain the same temperature, humidity, light cycle and sanitary conditions. The pigs were allowed to drink water freely and were fed regularly to ensure that the feed was fresh. The two groups were named Experimental Group 2 and Control Group 2, respectively.

[0103] The additives prepared in Example 3 and Comparative Example 3 were added to the feed of two groups of growing pigs, respectively. The growth environment was controlled to maintain the same temperature, humidity, light cycle and sanitary conditions. The pigs were allowed to drink water freely and were fed regularly to ensure that the feed was fresh. The two groups were named Experimental Group 3 and Control Group 3, respectively.

[0104] Starting from the 10th day after birth and continuing until the 150th day after birth, including: weaning period (10-45 days), growth period (46-108 days) and fattening period (108-150 days), daily record the weight changes and disease conditions (epidemic diarrhea and infectious gastroenteritis, etc.) of domestic pigs;

[0105] Referring to the standard DB35 / T 1737-2018 "High Performance Liquid Chromatography for the Determination of Oligofructose in Feed", the activity of the oligosaccharide components in the encapsulated oligosaccharides after immersion in hydrogen peroxide solution and the conversion rate of the complex fructose enzyme after cyclic catalysis were determined. The specific data are shown in Table 1-2.

[0106] Table 1- Domestic pig breeding situation test data table

[0107]

[0108] Table 2 - Cyclic test data table

[0109]

[0110] Data Analysis:

[0111] Comparative analysis of the data in Table 1 above shows that when the pig feed additive prepared by the present invention is used in pig feed, the weight gain of domestic pigs in the weaning period, fattening period and growth period is 600g / day, 800g / day and 1000g / day respectively, and there is no disease;

[0112] By analyzing the data in Table 2 above, it can be found that after 1h, 3h and 5h of oxidation treatment, the residual amount of oligosaccharides reached 95%, 93% and 90% respectively, and the oligosaccharide conversion rate reached 98%, 94% and 89% after the composite fructose enzyme was recycled for 10 times, 50 times and 100 times;

[0113] Analysis Notes:

[0114] The present invention prepares a composite fructose enzyme from fructose, assembles fructose invertase inside the pores of the modified enzyme carrier prepared by the present invention, increases the contact area between fructose and the enzyme, and facilitates recycling of the composite fructose enzyme, saves costs, acetylates and coats the prepared oligosaccharide to make its properties more stable, and the sustained release effect makes the organism absorb more fully, makes the intestinal environment of domestic pigs more stable, reduces the occurrence of diseases, promotes the fattening of domestic pigs, and finally significantly improves the stability of oligosaccharide components and the economic benefits of feed.

[0115] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

[0116] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0117] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A composite pig feed additive containing oligosaccharides, characterized in that: The raw material composition includes the following by weight: 50-60 parts of encapsulated oligosaccharides, 8-10 parts of probiotics, 3-5 parts of vitamins, 8-10 parts of minerals, 3-5 parts of organic acids, 10-15 parts of dietary fibers and 3-5 parts of trace element additives; The method for preparing encapsulated oligosaccharides comprises the following steps: A1. Add oligofructose and pyridine into a reactor, stir at room temperature for 30-40 minutes, lower the temperature of the reactor to 0-10°C, drop acetic anhydride into the reactor, and maintain the dropwise addition for 0.5-1h. After the dropwise addition is completed, keep the temperature for 2-3h, and perform post-treatment to obtain acetylated oligosaccharides; A2. Add the sugar solution dropwise to the reactor containing the sodium alginate solution at room temperature, control the dropping time to 30-40 min, maintain ultrasound during the dropping process, obtain the reaction precursor solution after the dropping is completed, continue to add the calcium chloride solution with a concentration of 1-1.5 mol / L into the reactor and stir, continue to stir for 15-20 min after the dropping is completed, and obtain the encapsulated oligosaccharide by post-treatment.

2. The composite pig feed additive containing oligosaccharides according to claim 1, characterized in that: In step A1, the stirring rate of the reactor is 80-120rpm, and the dosage ratio of oligofructose, pyridine and acetic anhydride is: 1-2g:3-6mL:2-4mL; in step A2, the dosage ratio of sugar solution and sodium alginate solution is 2-3mL:4-6mL, the sugar solution is prepared by acetylated oligosaccharide and deionized water in a dosage ratio of 5-8g:50mL, the sodium alginate solution is prepared by sodium alginate and deionized water in a dosage ratio of 3-5g:50mL, the ultrasonic frequency is 20-40kHz, the stirring rate of the reactor is 80-120rpm, the dripping rate of 1-1.5mol / L calcium chloride solution is 1 drop / s, and the dosage ratio of the reaction precursor solution and the 1-1.5mol / L calcium chloride solution is 5mL:1mL.

3. The composite pig feed additive containing oligosaccharides according to claim 1, characterized in that: The preparation method of oligofructose is as follows: fructose and buffer are added into a reaction kettle and stirred at room temperature for 15-20 minutes, the temperature of the reaction kettle is increased to 30-40°C, and composite fructose enzyme is added into the reaction kettle, after heat preservation reaction for 4-6 hours, post-processing is performed to obtain oligofructose and the composite fructose enzyme is recovered.

4. The composite pig feed additive containing oligosaccharides according to claim 3, characterized in that: The dosage ratio of fructose, buffer and complex fructose enzyme is 8-10g:40-50mL:80-120mg, the stirring rate is 80-120rpm, and the preparation method of the buffer is: after adding sodium acetate and deionized water into the reactor, acetic acid solution is added dropwise into the reactor, and the pH of the system is adjusted to 5.5-6.5 to obtain the buffer.

5. The oligosaccharide-containing composite pig feed additive according to claim 1, characterized in that: The preparation method of the composite fructose enzyme is as follows: B1, adding sodium dihydrogen phosphate, sodium chloride, disodium hydrogen phosphate, dithiothreitol and deionized water into a reaction kettle, adding 1-3wt% hydrochloric acid solution into the reaction kettle to adjust the pH of the system to 6.5-7.5 to obtain an enzyme buffer; B2. Add the pre-treated modified enzyme carrier and enzyme buffer into the reactor and stir. After stirring for 10-15 minutes, lower the temperature of the reactor to 2-6°C, add fructose invertase into the reactor, stir for 5-10 minutes, let it stand for 10-12 hours, and post-treat to obtain composite fructose enzyme.

6. The oligosaccharide-containing composite pig feed additive according to claim 5, characterized in that: In step A1, the dosage ratio of sodium dihydrogen phosphate, sodium chloride, disodium hydrogen phosphate, dithiothreitol and deionized water is 1.1-1.2g:2.9-3.0g:1.4-1.5g:0.1g:5-8g:900mL; in step A2, the stirring rate of the reactor is 80-120rpm, and the pretreatment operation includes: placing the modified enzyme carrier in a drying oven at a temperature of 60°C and vacuum drying for 2h to obtain a pretreated modified enzyme carrier; the dosage ratio of the pretreated modified enzyme carrier, enzyme buffer and fructose invertase is 80-120mg:10mL:40-60mg.

7. The oligosaccharide-containing composite pig feed additive according to claim 5, characterized in that: The preparation method of the modified enzyme carrier is: C1. Add 4-azobenzoic acid and anhydrous ethanol into a reaction kettle and stir. Raise the temperature of the reaction kettle to 30-50°C and stir for 10-15 minutes to obtain a light-responsive liquid. C2, adding zirconium oxychloride and anhydrous ethanol into a reaction kettle, stirring at room temperature for 10-15 minutes to obtain a framework precursor solution; C3. Add the light response liquid into the reaction kettle and stir, and add the framework precursor liquid into the reaction kettle during the stirring process. After the framework precursor liquid is added, stir at room temperature for 10-15 minutes, and post-treat to obtain the modified enzyme carrier.

8. The oligosaccharide-containing composite pig feed additive according to claim 7, characterized in that: The dosage ratio of nitrogen benzoic acid and anhydrous ethanol is 1-2g:8-10mL, and the stirring rate of the reactor is 80-120rpm; in step B2, the dosage ratio of zirconium oxychlorate and anhydrous ethanol is 1-2g:8-10mL, and the stirring rate is 80-120rpm; in step B3, the dosage ratio of the photoresponsive liquid and the framework precursor liquid is 0.8-1:1, and the stirring rate of the reactor is 80-120rpm.

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