Nano-composite additive, preparation method and application of nano-composite additive in pig feed

Abstract

The invention relates to the technical field of animal feed, in particular to a nano-composite additive, a preparation method and application of the nano-composite additive in pig feed. The nano-composite additive comprises the following components in parts by weight: 10-20 parts of CD-MOF (at) ZnO QDs, 4-7 parts of sugarcane-derived nanofibers, 5-8 parts of sodium alginate, 4-6 parts of portulaca oleracea powder, 4-6 parts of folium isatidis powder, 2-4 parts of origanum oil, 6-8 parts of compound enzyme, 4-6 parts of lysine, 4-6 parts of methionine, 3-6 parts of selenium yeast and 3-5 parts of a yucca extract. The zinc oxide quantum dots are coated with the cyclodextrin MOF material, and the sugarcane-derived nanofibers and other active components are cooperated, so that the morbidity of piglets is reduced, and the quality of raised pork is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of animal feed, in particular to a kind of nano composite additive, preparation method and application in pig feed. BACKGROUND

[0002] In livestock production, feed additives play an important role in improving pig growth performance and disease prevention. However, traditional additives often rely on antibiotics to reduce the incidence of piglets, and the overuse of antibiotics has caused significant problems: on the one hand, antibiotic abuse has led to a sharp increase in bacterial resistance, and drug-resistant genes can be transmitted to the human body through the food chain, severely weakening the therapeutic effect of antibiotics on humans; on the other hand, antibiotic residues enter the environment with animal excrement, causing a significant increase in the density of drug-resistant bacteria in the environment, causing environmental pollution. In addition, the high-dose zinc oxide commonly added to existing feed has low bioavailability, and residual zinc continues to accumulate after being excreted with feces, further increasing the risk of soil and water pollution.

[0003] Therefore, it is of great significance to develop a pig feed additive that reduces the use of antibiotics, reduces the incidence of piglets, optimizes intestinal health, and improves pork quality. SUMMARY

[0004] In view of the above situation, in order to overcome the defects of the prior art, the present application provides a kind of nano composite additive, preparation method and application in pig feed.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows: The present application provides a kind of nano composite additive, the nano composite additive includes the following weight parts of components: CD-MOF@ZnO QDs 10~20 parts, sugarcane derived nanofiber 4~7 parts, sodium alginate 5~8 parts, Gynostemma pentaphyllum powder 4~6 parts, Houttuynia cordata powder 4~6 parts, oregano oil 2~4 parts, composite enzyme 6~8 parts, lysine 4~6 parts, methionine 4~6 parts, selenium yeast 3~6 parts, and Yucca extract 3~5 parts.

[0006] Preferably, the preparation method of CD-MOF@ZnO QDs includes the following steps: A1, mix and dissolve γ-cyclodextrin and KCl in water, ultrasonic mix uniformly to obtain a mixed solution; A2, disperse ZnO QDs in acetone, mix uniformly to obtain a dispersion; A3, under the condition of continuous stirring, add the dispersion to the mixed solution; add ethanol, then stand for 12~24 h at 15~25 ℃, collect the product and wash with water and ethanol alternately, freeze-dry to obtain CD-MOF@ZnO QDs.

[0007] Preferably, in the step A1, the amount ratio of γ-cyclodextrin, KCl and water is 1-2 g: 0.5-1 g: 20-60 mL.

[0008] Preferably, in the step A2, the amount ratio of ZnO QDs and acetone is 20-50 mg: 10 mL.

[0009] Preferably, in the step A3, the volume ratio of the mixed solution and the dispersion is 2-6:1.

[0010] Preferably, the preparation method of the ZnO QDs comprises the following steps: dissolving zinc acetate in anhydrous ethanol to prepare a zinc acetate ethanol solution with a concentration of 50 mM, preparing a KOH ethanol solution with a concentration of 8 g / L, adding 10 mL of the KOH ethanol solution into 60-100 mL of the zinc acetate ethanol solution, magnetically stirring for 6 h, centrifuging to obtain the product, and washing the product with ethanol and water alternately for 3 times to obtain the ZnO QDs.

[0011] In the preparation of the CD-MOF@ZnO QDs, the amount ratio of the CD-MOF and the ZnO QDs is 1-2 g: 0.5-1 g. The ion radius matches the spacing of the hydroxyl groups of the γ-CD, and an octahedral coordination structure can be formed. By reasonably setting the amount of each raw material, it is ensured that each γ-CD unit is saturatedly coordinated to form a complete cubic lattice. If the amount of KCl is excessive, amorphous aggregation will occur. If the amount of water is insufficient, the γ-CD will not be sufficiently dissolved, the crystallization rate will be too fast, and the pore size distribution will be uneven. The amount of the ZnO QDs is matched with the doping ratio of the feed, so that the ZnO QDs will not be excessive or insufficient.

[0012] Preferably, the preparation method of the sugarcane-derived nanofiber comprises the following steps: B1, crushing the sugarcane residue into a powder with a particle size of less than 2 mm, washing the powder with water, and drying the powder to obtain a sugarcane residue powder; B2, adding the sugarcane residue powder prepared in the step B1 into a dilute nitric acid solution with a mass fraction of 3%, stirring and dispersing the mixture uniformly, continuously adding a hydrogen peroxide solution with a mass fraction of 30%, stirring at room temperature for 6-8 h, adding water to terminate the reaction, filtering to obtain a product, washing the product with water and ethanol alternately, dispersing the product in water, and performing a homogenization operation in a high-pressure homogenizer, and after 3-5 cycles of homogenization, freeze-drying to obtain the sugarcane-derived nanofiber.

[0013] In the above preparation method, the concentration of the dilute nitric acid solution is appropriate. If the concentration of the nitric acid is too low (<2%), the lignin-carbohydrate complex (LCC) cannot be effectively broken, resulting in the residual hemicellulose. If the concentration of the nitric acid is too high (>5%), the amorphous region of cellulose is excessively hydrolyzed, reducing the yield of the nanofiber. Subsequently, adding an appropriate amount of hydrogen peroxide solution for bleaching can effectively remove pigments and oxidize and degrade residual lignin.

[0014] Preferably, the usage ratio of the bagasse powder, nitric acid solution and hydrogen peroxide solution is 10 g: 300-500 mL: 10-20 mL. If the usage amount of the hydrogen peroxide solution is too small, the decolorization rate will be reduced, and if too high, the cellulose may be excessively oxidized, reducing the thermal stability.

[0015] Preferably, when the homogenization operation is performed, the homogenization pressure is 1000-1200 bar.

[0016] Preferably, the composite enzyme comprises the following components in parts by weight: 6-8 parts of acid protease, 4-6 parts of amylase, 3-4 parts of pectinase, 3-5 parts of xylanase, 1-2 parts of glucose oxidase.

[0017] Preferably, the particle size of the Gynostemma pentaphyllum powder is less than 2 mm, and the particle size of the bigleaf fig leaf powder is less than 2 mm.

[0018] The application further provides a preparation method of the nano-composite additive, specifically comprising the following steps: S1. CD-MOF@ZnO QDs, bagasse-derived nanofibers and sodium alginate are weighed in parts by weight, and 10 times the weight of water of the total mass of CD-MOF@ZnO QDs, bagasse-derived nanofibers and sodium alginate is added, and homogenization and emulsification are performed to form a gel matrix; S2. Gynostemma pentaphyllum powder, bigleaf fig leaf powder, oregano oil, composite enzyme, lysine, methionine, yeast selenium and Yucca extract are weighed in parts by weight and sequentially added to the gel matrix prepared in step S1, and stirring is performed to obtain a mixture, and spray drying is performed to obtain a nano-composite additive with an average particle size of 50-100 μm.

[0019] Preferably, the spray drying conditions in step S2 are that the inlet air temperature is 150-180℃, and the outlet air temperature is 70-80℃.

[0020] The application further provides an application of the nano-composite additive in pig feed, specifically, the addition amount of the nano-composite additive in pig feed for the nursery period is 0.3-0.35%, and the addition amount of the nano-composite additive in pig feed for the fattening period is 0.2-0.25%.

[0021] The application has the following beneficial effects: The application realizes the non-antibiotic breeding through the synergistic effect of nano components, the core component CD-MOF@ZnO QDs utilizes the cyclodextrin MOF to coat zinc oxide quantum dots, wherein the size of the ZnO QDs is small, the specific surface area is large, and the contact efficiency with the cell membrane of pathogenic microorganisms is enhanced; the CD-MOF@ZnO QDs precisely release the zinc oxide quantum dots in the acidic environment, significantly inhibit the escherichia coli and salmonella, replace high-dose zinc oxide or antibiotics, and reduce the diarrhea rate of piglets; the sugarcane derived nanofiber promotes digestion by increasing the chyme volume and accelerating intestinal peristalsis, and effectively prevents constipation, and the spilanthes powder and indigoplant powder added synergistically with the sugarcane derived nanofiber accelerate the elimination of heat toxins in the body.

[0022] The sodium alginate-embedded composite enzyme maintains structural stability in the acidic environment of the stomach, dissolves and releases in the alkaline environment of the small intestine, and significantly improves the protein digestion rate; the oregano oil is continuously inhibited after being released by the nanofiber network, so that the malondialdehyde residue of pork is reduced, and the shelf life of chilled meat is prolonged; the selenium-ylang-ylang extract enhances the transmembrane transport efficiency of selenium through the gel matrix, increases the muscle selenium deposition, and meets the green selenium-rich pork standard. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the present application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only a part of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0024] Figure 1 is the transmission electron microscope image of the ZnO QDs prepared in Example 1; Figure 2 is the scanning electron microscope image of the CD-MOF@ZnO QDs prepared in Example 1; Figure 3 is the scanning electron microscope image of the sugarcane derived nanofiber prepared in Example 1. DETAILED DESCRIPTION

[0025] The present application will be further described in detail through the following examples and comparative examples, but this should not be understood as the scope of the present application being limited to the following examples. Any technology realized based on the above content of the present application belongs to the scope of the present application.

[0026] The experimental methods in the following examples are all conventional methods unless otherwise specified; the experimental materials used in the following examples and comparative examples are all purchased from commercial channels unless otherwise specified.

[0027] Example 1: The embodiment provides a kind of nanocomposite additive, including the following weight parts of components: CD-MOF@ZnO QDs 20 parts, sugarcane derived nanofiber 7 parts, sodium alginate 6 parts, Gynostemma pentaphyllum powder 4 parts, indigoplus powder 5 parts, oregano oil 4 parts, complex enzyme 6 parts, lysine 6 parts, methionine 5 parts, selenium yeast 5 parts, Yucca extract 5 parts.

[0028] The preparation method of the CD-MOF@ZnO QDs has the following steps: A1, zinc acetate is dissolved in anhydrous ethanol to prepare a 50 mM zinc acetate ethanol solution, and a 8 g / L KOH ethanol solution is prepared, 10 mL of the KOH ethanol solution is added to 80 mL of the zinc acetate ethanol solution, magnetic stirring is performed for 6 h, centrifugation is performed to obtain a product, and the product is washed with ethanol and water alternately for 3 times to obtain ZnO QDs; A2, 1 g of γ-cyclodextrin and 1 g of KCl are mixed and dissolved in 60 mL of water, and ultrasonic mixing is performed to obtain a mixed solution; A3, 50 mg of zinc oxide quantum dots ZnO QDs are dispersed in 10 mL of acetone, and a solution is uniformly obtained to obtain a dispersion; A4, under the condition of continuous stirring, 10 mL of the dispersion is added dropwise to 60 mL of the mixed solution, 60 mL of ethanol is further added, and then the mixture is placed at 20°C for 24 h, centrifugation is performed at 4000 rpm for 10 min to collect the product, and the product is washed with water and ethanol alternately for 3 times, and then freeze-drying is performed to obtain CD-MOF@ZnO QDs.

[0029] The preparation method of the sugarcane derived nanofiber has the following steps: B1, sugarcane residue is crushed into powder with a particle size of less than 2 mm, the powder is washed with water and then dried to obtain sugarcane residue powder; B2, 10 g of the sugarcane residue powder prepared in step B1 is added to 500 mL of a 3% nitric acid solution, stirring is performed to uniformly disperse, 20 mL of a 30% hydrogen peroxide solution is further added, stirring is performed at room temperature for 8 h, 2 L of water is added to terminate the reaction, the product is filtered, and then the product is washed with water and ethanol alternately, and then the product is dispersed in 400 mL of water, and then the product is placed in a high-pressure homogenizer for homogenization, the homogenization pressure is 1200 bar, and after 5 cycles of homogenization, freeze-drying is performed to obtain the sugarcane derived nanofiber.

[0030] The complex enzyme includes the following weight parts of components: acid protease 8 parts, amylase 4 parts, pectinase 4 parts, xylanase 4 parts, glucose oxidase 2 parts.

[0031] The embodiment also provides a preparation method of the nanocomposite additive, and specifically includes the following steps: S1, CD-MOF@ZnO QDs, sugarcane-derived nanofiber and sodium alginate were weighed by weight parts, 10 times the weight of water was added to the total mass of CD-MOF@ZnO QDs, sugarcane-derived nanofiber and sodium alginate, and homogenized to form a gel matrix; S2, the powder of perilla, the powder of indigowood leaf, the oil of oregano, the compound enzyme, lysine, methionine, selenium yeast and the extract of yucca were weighed by weight parts and added to the gel matrix prepared in step S1 in turn, and a mixture solution gel solution was obtained by low-speed stirring, and a nano-composite additive with a particle size of 100 μm was obtained by spray drying under the conditions of an inlet air temperature of 180℃ and an outlet air temperature of 80℃.

[0032] Example 2: The present embodiment proposes a nano-composite additive, which comprises the following components by weight parts: CD-MOF@ZnO QDs 10 parts, sugarcane-derived nanofiber 5 parts, sodium alginate 8 parts, perilla powder 6 parts, indigowood leaf powder 4 parts, oregano oil 3 parts, compound enzyme 8 parts, lysine 5 parts, methionine 6 parts, selenium yeast 6 parts, and yucca extract 3 parts.

[0033] The preparation method of the CD-MOF@ZnO QDs has the following steps: A1, zinc acetate was dissolved in anhydrous ethanol to prepare a zinc acetate ethanol solution with a concentration of 50 mM, and an ethanol solution of KOH with a concentration of 8 g / L was prepared, 10 mL of the KOH ethanol solution was added to 60 mL of the zinc acetate ethanol solution, and magnetic stirring was performed for 6 h, centrifugation was performed to obtain the product, and the product was washed with ethanol and water alternately for 3 times to obtain ZnO QDs; A2, 1.4 g of γ-cyclodextrin and 0.5 g of KCl were mixed and dissolved in 20 mL of water, and ultrasonic mixing was performed to obtain a mixed solution; A3, 30 mg of zinc oxide quantum dots ZnO QDs were dispersed in 10 mL of acetone, and the solution was uniformly obtained to form a dispersion liquid; A4, under the condition of continuous stirring, 10 mL of the dispersion liquid was added dropwise into 20 mL of the mixed solution, 70 mL of ethanol was then added, and the mixture was then placed at 20℃ for 12 h, centrifuged at 4000 rpm for 10 min to collect the product, and the product was washed with water and ethanol alternately for 3 times, and then freeze-dried to obtain CD-MOF@ZnO QDs.

[0034] The preparation method of the sugarcane-derived nanofiber has the following steps: B1, the bagasse was crushed into a powder with a particle size of less than 2 mm, and then washed with water and dried to obtain a bagasse powder; B2, 10 g of the bagasse powder prepared in step B1 was added into 300 mL of 3% nitric acid solution, stirred and dispersed uniformly, 10 mL of 30% hydrogen peroxide solution was continuously added, stirred at room temperature for 6 h, terminated by adding 2 L of water, filtered to obtain the product, washed with water and ethanol alternately, re-dispersed in 400 mL of water, and put into a high-pressure homogenizer for homogenization operation, the homogenization pressure was 1100 bar, and after circulating homogenization for 4 times, freeze-drying was performed to obtain the bagasse-derived nanofiber.

[0035] The complex enzyme comprises the following components in parts by weight: 6 parts of acid protease, 6 parts of amylase, 3 parts of pectinase, 5 parts of xylanase, and 1 part of glucose oxidase.

[0036] The embodiment also provides a preparation method of the nanocomposite additive, and specifically includes the following steps: S1, CD-MOF@ZnO QDs, bagasse-derived nanofiber and sodium alginate were weighed according to the weight parts, and were added into water with a weight of 10 times the total mass of the CD-MOF@ZnO QDs, the bagasse-derived nanofiber and the sodium alginate, and were homogenized and emulsified to form a gel matrix; S2, ginkgo powder, big blue leaf powder, oregano oil, complex enzyme, lysine, methionine, yeast selenium and lycas extract were weighed according to the weight parts and were sequentially added into the gel matrix prepared in step S1, and a mixture solution gel solution was obtained by low-speed stirring, and the nanocomposite additive with a particle size of 50 μm was obtained by spray drying under the conditions of an air inlet temperature of 160℃ and an air outlet temperature of 70℃.

[0037] Embodiment 3: The embodiment provides a nanocomposite additive, which comprises the following components in parts by weight: 15 parts of CD-MOF@ZnO QDs, 4 parts of bagasse-derived nanofiber, 5 parts of sodium alginate, 5 parts of ginkgo powder, 6 parts of big blue leaf powder, 2 parts of oregano oil, 7 parts of complex enzyme, 4 parts of lysine, 4 parts of methionine, 3 parts of yeast selenium and 4 parts of lycas extract.

[0038] The preparation method of the CD-MOF@ZnO QDs has the following steps: A1, zinc acetate was dissolved in anhydrous ethanol to prepare a 50 mM zinc acetate ethanol solution, and a 8 g / L KOH ethanol solution was prepared at the same time, 10 mL of the KOH ethanol solution was added into 100 mL of the zinc acetate ethanol solution, and magnetic stirring was performed for 6 h, centrifugation was performed to obtain the product, and the product was washed with ethanol and water alternately for 3 times to obtain ZnO QDs; A2, 1 g of γ-cyclodextrin and 0.6 g of KCl were mixed and dissolved in 40 mL of water, and ultrasonic mixing was performed to obtain a mixed solution; A3, 20 mg of zinc oxide quantum dots ZnO QDs were dispersed in 10 mL of acetone to obtain a dispersion solution; A4, 10 mL of the dispersion solution was added dropwise to 40 mL of the mixed solution under continuous stirring, 65 mL of ethanol was continuously added, and then the mixture was placed at 20 DEG C for 16 h, centrifuged at 4000 rpm for 10 min to collect the product, washed with water and ethanol alternately for three times, and freeze-dried to obtain CD-MOF@ZnO QDs.

[0039] The preparation method of the sugarcane-derived nanofiber has the following steps: B1, the sugarcane residue was crushed into a powder with a particle size of less than 2 mm, washed with water and dried to obtain a sugarcane residue powder; B2, 10 g of the sugarcane residue powder prepared in step B1 was added to 400 mL of a 3% nitric acid solution, stirred and dispersed uniformly, 15 mL of a 30% hydrogen peroxide solution was continuously added, stirred at room temperature for 7 h, 2 L of water was added to terminate the reaction, filtered to obtain the product, washed with water and ethanol alternately, redispersed in 400 mL of water, and subjected to homogenization operation in a high-pressure homogenizer, the homogenization pressure was 1000 bar, and the homogenization was repeated for 3 times, and then freeze-dried to obtain the sugarcane-derived nanofiber.

[0040] The composite enzyme comprises the following components by weight: 7 parts of acid protease, 5 parts of amylase, 4 parts of pectinase, 3 parts of xylanase, and 2 parts of glucose oxidase.

[0041] The embodiment also provides a preparation method of the nanocomposite additive, which specifically comprises the following steps: S1, CD-MOF@ZnO QDs, sugarcane-derived nanofiber and sodium alginate were weighed according to the weight parts, and water was added in an amount of 10 times the total mass of CD-MOF@ZnO QDs, sugarcane-derived nanofiber and sodium alginate, and then homogenized and emulsified to form a gel matrix; S2, ginkgo biloba powder, indigowood leaf powder, oregano oil, composite enzyme, lysine, methionine, yeast selenium and lycas extract were weighed according to the weight parts and sequentially added to the gel matrix prepared in step S1, and a mixture solution gel solution was obtained by low-speed stirring, and spray drying was performed under the conditions of an air inlet temperature of 150 DEG C and an air outlet temperature of 75 DEG C to obtain a nanocomposite additive with a particle size of 70 μm.

[0042] Comparative Example 1: The comparative example provides a nanocomposite additive, which is different from the example 1 only in that CD-MOF@ZnO QDs are not added, and the other components, component contents and experimental steps are the same as those of the example 1.

[0043] Comparative Example 2: The comparative example proposes a kind of nanocomposite additive, and the difference with example 1 is only that no sugarcane derived nanofiber is added, and the rest of component, component content, experimental procedure are same with example 1.

[0044] Comparative example 3: The comparative example proposes a kind of nanocomposite additive, and the difference with example 1 is only that CD-MOF@ZnO QDs is replaced by ZnO QDs, and the rest of component, component content, experimental procedure are same with example 1.

[0045] Comparative example 4: The comparative example proposes a kind of nanocomposite additive, and the difference with example 1 is only that sugarcane derived nanofiber is replaced by common market hydroxymethyl cellulose, and the rest of component, component content, experimental procedure are same with example 1.

[0046] Comparative example 5: The comparative example proposes a kind of nanocomposite additive, and the difference with example 1 is only that no ginkgo biloba powder and indigowood leaf powder is added.

[0047] Comparative example 6 The comparative example proposes a kind of nanocomposite additive, and the difference with example 1 is only that ZnO QDs is replaced by common market zinc oxide.

[0048] Experimental example 1: The micro-morphology of ZnO QDs, CD-MOF@ZnO QDs and sugarcane derived nanofiber prepared in example 1 is observed.

[0049] Figure 1 is the transmission electron microscope graph of ZnO QDs prepared in example 1, Figure 2 is the scanning electron microscope graph of CD-MOF@ZnO QDs prepared in example 1, Figure 3 is the scanning electron microscope graph of sugarcane derived nanofiber prepared in example 1.As shown in figure 1, zinc oxide quantum dots are spherical, and the particle size is small.As shown in figure 2, CD-MOF@ZnO QDs are block structure, the surface is rough and has concave-convex structure, provides larger specific surface area;As shown in figure 3, sugarcane derived nanofiber is filamentous winding network structure, Figure 1 、 Figure 2 and Figure 3 indicate the successful preparation of ZnO QDs, CD-MOF@ZnO QDs and sugarcane derived nanofiber.

[0050] Experimental example 2: Breeding comparative experiment: Two hundred weaned piglets were randomly divided into 10 groups and fed with the nanocomposite additives prepared in Examples 1-3 and Comparative Examples 1-6, as well as a blank group (without additives). During the nursery period, the nanocomposite additives were added to the feed at a weight ratio of 0.3%, and during the fattening period, the nanocomposite additives were added to the feed at a weight ratio of 0.2%. The feeding was carried out for 100 days, and the effects of the additives on the feeding of commercial pigs were recorded.

[0051]

[0052] Table 1 shows the practical application test results of the nanocomposite additives prepared in Examples 1-3, Comparative Examples 1-6, and the blank group. As shown in the table, the daily weight gain of Examples 1-3 was significantly higher than that of the control group, and the control group was significantly higher than that of the blank group. The zinc oxide quantum dot sustained-release technology reduced the intestinal pathogen load and reduced growth retardation caused by bacterial infection. At the same time, sugarcane-derived nanofibers can promote digestion and reduce the feed conversion ratio. In addition, the other added nutrients can further improve the growth effect of the pigs and improve the nutrient utilization rate. The diarrhea rate of piglets fed in Examples 1-3 was significantly lower than that of Comparative Examples 1-6 and the blank group. The zinc oxide quantum dot sustained-release technology can reduce bacterial infection, sugarcane-derived nanofibers can accelerate peristalsis and promote digestion, and the effective ingredients such as purslane powder and indigo leaf powder can also prevent diarrhea in piglets.

[0053] Continue feeding until the pigs reach market weight, then slaughter them and record the pre-slaughter live weight, dressing percentage, lean meat percentage, fat percentage, and average backfat thickness. The effects of specific additives on the quality of the fed pork are shown in Table 2.

[0054]

[0055] Table 2 shows the meat quality test results of pork fed with the nanocomposite additives prepared in Examples 1-3, Comparative Examples 1-6, and the blank group. The slaughter rate of Examples 1-3 was significantly higher than that of the comparative examples and the blank group, mainly because the nanocomposite components synergistically enhanced the effect and reduced the risk of visceral lesion removal in piglets. At the same time, the lean meat percentage of pork fed with Examples 1-3 was increased and the fat percentage was decreased. This is because CD-MOF@ZnO QDs, sugarcane-derived nanofibers, and other effective components improved protein digestibility, promoted muscle synthesis, effectively reduced backfat thickness, and effectively regulated fat metabolism.

[0056] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention. The actual application is not limited to this. In conclusion, if those skilled in the art are inspired by this description and design similar methods and embodiments without departing from the spirit of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A nanocomposite additive, characterized in that, The nanocomposite additive comprises the following components in parts by weight: 10-20 parts of CD-MOF@ZnO QDs, 4-7 parts of sugarcane-derived nanofibers, 5-8 parts of sodium alginate, 4-6 parts of purslane powder, 4-6 parts of Isatis indigotica leaf powder, 2-4 parts of oregano oil, 6-8 parts of compound enzyme, 4-6 parts of lysine, 4-6 parts of methionine, 3-6 parts of yeast selenium, and 3-5 parts of yucca extract; The preparation method of the CD-MOF@ZnO QDs includes the following steps: A1. Mix γ-cyclodextrin and KCl in water, and sonicate to mix evenly to obtain a mixed solution; A2. Disperse ZnO QDs in acetone and mix thoroughly to obtain a dispersion. A3. Under continuous stirring, the dispersion was added dropwise to the mixed solution; ethanol was added, and then the mixture was allowed to stand at 15~25 ℃ for 12~24 h. The product was collected and washed alternately with water and ethanol. After freeze-drying, CD-MOF@ZnO QDs were obtained.

2. The nanocomposite additive according to claim 1, characterized in that, In step A1, the ratio of γ-cyclodextrin, KCl, and water is 1~2 g: 0.5~1 g: 20~60 mL; In step A2, the ratio of ZnO QDs to acetone is 20-50 mg: 10 mL. In step A3, the volume ratio of the mixed solution to the dispersion is 2~6:

1.

3. The nanocomposite additive according to claim 1, characterized in that, The method for preparing the sugarcane-derived nanofibers includes the following steps: B1. Crush sugarcane bagasse into powder with a particle size of less than 2 mm, wash it with water and then dry it to obtain sugarcane bagasse powder. B2. Add the sugarcane bagasse powder prepared in step B1 to a 3% (w / w) dilute nitric acid solution, stir and disperse evenly, continue to add a 30% (w / w) hydrogen peroxide solution, stir at room temperature for 6-8 h, add water to terminate the reaction, filter to obtain the product, wash with water and ethanol alternately, disperse in water again, put into a high-pressure homogenizer for homogenization, cycle homogenize 3-5 times, freeze dry to obtain sugarcane-derived nanofibers.

4. The nanocomposite additive according to claim 3, characterized in that, The ratio of sugarcane bagasse powder, nitric acid solution, and hydrogen peroxide solution is 10 g: 300~500 mL: 10~20 mL.

5. The nanocomposite additive according to claim 3, characterized in that, When performing homogenization, the homogenization pressure is 1000~1200 bar.

6. The nanocomposite additive according to claim 1, characterized in that, The complex enzyme comprises the following components in parts by weight: 6-8 parts acidic protease, 4-6 parts amylase, 3-4 parts pectinase, 3-5 parts xylanase, and 1-2 parts glucose oxidase.

7. The nanocomposite additive according to claim 1, characterized in that, The particle size of the purslane powder is less than 2 mm; the particle size of the indigo leaf powder is less than 2 mm.

8. A method for preparing a nanocomposite additive as described in any one of claims 1 to 7, characterized in that, Specifically, the following steps are included: S1. Weigh CD-MOF@ZnO QDs, sugarcane-derived nanofibers and sodium alginate by weight, add them to water at 10 times the total weight of CD-MOF@ZnO QDs, sugarcane-derived nanofibers and sodium alginate, and homogenize and emulsify to form a gel matrix. S2. Weigh out purslane powder, indigo leaf powder, oregano oil, compound enzyme, lysine, methionine, yeast selenium, and yucca extract by weight, and add them sequentially to the gel matrix prepared in step S1. Stir to obtain a mixture, and spray dry to obtain a nanocomposite additive with an average particle size of 50~100 μm.

9. The method for preparing a nanocomposite additive according to claim 8, characterized in that, The inlet air temperature of the spray dryer in step S2 is 150~180℃, and the outlet air temperature is 70~80℃.

10. The application of a nanocomposite additive as described in any one of claims 1-7 or as described in any one of claims 8-9 in pig feed, characterized in that, The amount of the nanocomposite additive added to pig feed during the nursery period is 0.3% to 0.35%; the amount of the nanocomposite additive added to pig feed during the fattening period is 0.2% to 0.25%.

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