Preparation method and application of monatomic copper feed additive

Abstract

The invention discloses a preparation method and application of a monatomic copper feed additive, and the preparation method comprises the following steps: step 1, preparing a mixed solution A, putting melamine and copper nitrate into a sufficient dimethyl sulfoxide solution, and uniformly stirring to obtain a light green solution; step 2, preparing a mixed solution B, putting cyanuric acid into a sufficient dimethyl sulfoxide solution, and uniformly stirring to obtain a clear transparent solution; 3, mixing the mixed solution A and the mixed solution B, and reacting to obtain a precipitate; 4, filtering, washing and drying the precipitate to obtain a precursor; 5, under the inert atmosphere, the precursor is subjected to heat treatment, and the monatomic copper catalyst is obtained; the prepared monatomic copper feed additive is used in broiler feed. The monatomic copper feed additive is prepared, belongs to nano-enzyme, and has remarkable effects of resisting escherichia coli and reducing ammonia in chicken manure when being used for broiler chicken feeding.

Description

Technical Field

[0001] This invention belongs to the field of feed additive technology, specifically relating to a method for preparing and applying a single-atom copper feed additive. Background Technology

[0002] In recent years, with the gradual expansion of chicken farming scale and the increase in stocking density, coupled with problems such as low management levels, poor environmental hygiene, and numerous stress factors in some chicken farms, the incidence of avian colibacillosis has significantly increased. Avian colibacillosis is a localized or systemic infectious disease caused by avian pathogenic Escherichia coli (APEC). It is the number one bacterial disease threatening the poultry industry, causing huge economic losses to poultry farming every year. E. coli infection leads to a decrease in nitrogen absorption capacity in broiler breeders. After infection, the expression of amino acid transport proteins in the chicken's body is inhibited, resulting in reduced efficiency in amino acid absorption and utilization. E. coli infection leads to the accumulation of nitrogen metabolites (such as urea and uric acid).

[0003] Single-atom copper refers to materials in which copper atoms are dispersed as individual atoms on a substrate. Unlike traditional copper particles or nano-copper, single-atom copper does not exist in clusters or agglomerates, but rather as individual atoms uniformly distributed on a supporting material (such as oxides, carbon materials, silicon dioxide, etc.). Due to its extremely high surface activity and strong electronic interaction capabilities, single-atom copper exhibits stronger antibacterial effects than traditional copper materials in certain situations. Copper-based materials show good activity in catalyzing ammonia degradation reactions, especially in ammonia oxidation reactions at low temperatures. Therefore, we propose a single-atom copper feed additive that reduces ammonia in chicken manure and combats E. coli. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for preparing and applying a single-atom copper feed additive, which addresses the shortcomings of the prior art. The single-atom copper feed additive prepared by this invention has significant anti-Escherichia coli properties and the ability to reduce ammonia in chicken manure.

[0005] The technical solution adopted in this invention is: a method for preparing a single-atom copper feed additive, comprising the following steps:

[0006] Step 1: Prepare mixed solution A by placing melamine and copper nitrate in sufficient dimethyl sulfoxide solution and stirring until homogeneous to obtain a light green solution;

[0007] Step 2: Prepare mixed solution B by placing cyanuric acid in a sufficient amount of dimethyl sulfoxide solution and stirring until homogeneous to obtain a clear and transparent solution;

[0008] Step 3: Mix solution A and solution B, and after reaction, a precipitate is obtained;

[0009] Step 4: Filter, wash, and dry the precipitate to obtain the precursor;

[0010] Step 5: Heat-treat the precursor under an inert atmosphere to obtain a single-atom copper catalyst.

[0011] Preferably, the molar ratio of melamine to copper nitrate is 3-4:1.

[0012] Preferably, the concentration of cyanuric acid in the mixed solution B is 0.5-1.2 mol / L.

[0013] Preferably, the molar ratio of melamine to cyanuric acid is 0.8-1.5:1.

[0014] Preferably, in step 5, the inert atmosphere is nitrogen, and the heat treatment temperature is 500-600℃ for 3-5 hours.

[0015] The single-atom copper feed additive was prepared by the above method and used for daily feeding of broilers or for preparing broiler feed that is anti-E. coli and reduces ammonia in chicken manure.

[0016] The beneficial effects of this invention are as follows:

[0017] (1) When added to broiler feed as a feed additive, it has a significant effect in resisting Escherichia coli, which is superior to the effect of traditional anhydrous copper sulfate and copper nitrate as additives in broiler feeding.

[0018] (2) When added to broiler feed as a feed additive, it can significantly reduce ammonia in chicken manure, thereby effectively improving the feeding environment, improving the health of the flock, and effectively increasing feed conversion rate and egg production rate, thus reducing breeding costs.

[0019] This invention relates to the preparation of a single-atom copper feed additive, which is a nanoenzyme and has significant anti-Escherichia coli and ammonia-reducing effects in chicken manure when used in broiler farming. Attached Figure Description

[0020] Figure 1 The EDS spectrum of a single-atom copper feed additive prepared as an experimental example of the present invention is shown below.

[0021] Figure 2 The elemental mapping distribution of the single-atom copper feed additive prepared as an experimental example of the present invention;

[0022] Figures 3a-3d The crystal lattice analysis diagram of the single-atom copper feed additive prepared in the experimental example of this invention;

[0023] Figure 4 The infrared spectrum of the single-atom copper feed additive prepared in the experimental example of this invention;

[0024] Figure 5 The X-ray diffraction pattern of the single-atom copper feed additive prepared as an experimental example of the present invention;

[0025] Figures 6a-6d X-ray photoelectron spectroscopy of a single-atom copper feed additive prepared as an experimental example of the present invention;

[0026] Figure 7 The graph shows the relationship between the dosage of single-atom copper feed additive and mouse body weight in an acute toxicity test of the single-atom copper feed additive prepared in this invention.

[0027] Figure 8a , Figure 8b , Figure 8c , Figure 8d , Figure 8e , Figure 8f , Figure 8g , Figure 8h , Figure 8j and Figure 8k This is a comparative graph showing the subchronic toxicity of single-atom copper feed additives prepared in the experimental examples of this invention.

[0028] Figures 9a-9c The experimental example of this invention shows the GPX enzyme activity of a single-atom copper feed additive at different time points.

[0029] Figure 10 This is a comparative diagram showing the reduction of ammonia in chicken manure by the single-atom copper feed additive prepared in the experimental example of this invention.

[0030] Figure 11 The experimental example of this invention shows the effect and changes of the single-atom copper feed additive on inhibiting Escherichia coli O-78 in the oviduct of broiler breeders;

[0031] Figure 12 The experimental example of this invention shows the effect and changes of the single-atom copper feed additive in reducing ammonia in chicken manure in broiler breeders. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0033] Example 1

[0034] The method for preparing the single-atom copper feed additive provided in this embodiment includes the following steps:

[0035] Step 1: Prepare mixed solution A by placing melamine and copper nitrate in a molar ratio of 3.2:1 into a sufficient amount of dimethyl sulfoxide solution and stirring until homogeneous to obtain a light green solution;

[0036] Step 2: Prepare mixed solution B. Select cyanuric acid with a molar ratio of 1:1.1 to melamine, that is, the molar ratio of melamine to cyanuric acid is 1.1:1. Place the selected cyanuric acid in a sufficient amount of dimethyl sulfoxide solution and stir evenly to obtain a clear and transparent solution with a cyanuric acid concentration of 0.7 mol / L.

[0037] Step 3: Mix solution A and solution B, and after reaction, a precipitate is obtained;

[0038] Step 4: Filter, wash, and dry the precipitate to obtain the precursor;

[0039] Step 5: The precursor was calcined at 550°C for 4 hours under a nitrogen atmosphere to obtain a single-atom copper catalyst.

[0040] Example 2

[0041] This embodiment is basically the same as Embodiment 1, except that the proportions and concentrations of each raw material are changed. The molar ratio of melamine to copper nitrate is 3:1; the molar ratio of melamine to cyanuric acid is 0.8:1; and the concentration of cyanuric acid in the mixed solution B is 1.2 mol / L.

[0042] Example 3

[0043] This embodiment is basically the same as Embodiment 1, except that the proportions and concentrations of each raw material are changed. The molar ratio of melamine to copper nitrate is 4:1; the molar ratio of melamine to cyanuric acid is 1.5:1; and the concentration of cyanuric acid in the mixed solution B is 0.5 mol / L.

[0044] Experimental Example

[0045] Take 5g of melamine and 3g of copper nitrate and place them in 50mL of dimethyl sulfoxide solution. Mix them with a magnetic stirrer to obtain a light green solution, i.e., mixed solution A.

[0046] Take 4.5g of cyanuric acid and place it in 50mL of dimethyl sulfoxide solution. Mix and stir with a magnetic stirrer to obtain a clear and transparent solution, i.e., mixed solution B.

[0047] Mixed solution A and mixed solution B were stirred to obtain a precipitate. The precipitate was filtered, washed, dried, and calcined at 550°C for 4 hours in a nitrogen atmosphere to obtain a single-atom copper feed additive.

[0048] Characterization of the single-atom copper feed additive prepared in the experimental example:

[0049] (1) Elemental composition and distribution analysis

[0050] The composition of single-atom copper feed additives was analyzed using scanning electron microscopy, such as... Figure 1 As shown, the main elements and composition of the single-atom copper feed additive prepared in the experimental example include: Cu (16.82%), C (49.92%), O (24.87%), and minor elements are Cl (6.76%) and Si (1.65%).

[0051] The presence of C and O as the main peaks indicates that the sample is loaded on a carbon-containing substrate (such as activated carbon or graphene) and that surface oxidation exists. The low Cu content is consistent with the "atomic-level dispersion" characteristic of single-atom materials, rather than a nanoparticle agglomeration.

[0052] (2) Verification of elemental uniformity

[0053] The uniformity of single-atom copper feed additives was verified and analyzed using scanning electron microscopy, such as... Figure 2 As shown, the elemental mapping distribution of the single-atom copper feed additive prepared in the experimental example is as follows:

[0054] Cu distribution: The copper signal is discretely distributed with no obvious agglomeration regions, which directly proves that it is dispersed at the single atom level (if it were nanoparticles, there would be bright spots in the aggregated state).

[0055] O and Si distribution: The O signal partially overlaps with the Cu signal, which may correspond to the oxidation sites of copper or functional groups on the surface of the support; the Si signal is weak and dispersed, ruling out the possibility of it being the main support.

[0056] (3) Structural scale and lattice analysis

[0057] like Figure 3a and Figure 3b As shown, the low-magnification scale bar indicates an imaging field of view of 50-100 nm, meaning the observation range covers areas from tens to hundreds of nanometers.

[0058] like Figure 3c As shown, the single-atom level is demonstrated: the scale bar "1nm" in the figure, combined with HAADF imaging, shows isolated Cu atoms, proving the existence of single-atom copper.

[0059] like Figure 3d As shown, the lattice parameter "2.3332nm" is the lattice fringe spacing corresponding to the carrier, not the copper lattice, indicating that Cu is adsorbed on the carrier surface in the form of single atoms and has not formed crystalline copper particles.

[0060] (4) Infrared spectroscopy analysis

[0061] like Figure 4 As shown, the single-atom copper feed additives prepared in the experimental examples contain various functional groups and chemical bonds such as hydroxyl groups, carbonyl groups, hydrocarbon chains, and CO bonds on their surface or in the system.

[0062] (5) X-ray diffraction analysis

[0063] The single-atom copper feed additive prepared in the experimental example was determined using X-ray diffraction. Figure 5 As shown, the single-atom copper feed additive prepared in the experimental example has a copper crystal structure, and the (111) crystal plane is more prominent.

[0064] (6) X-ray photoelectron spectroscopy analysis

[0065] The single-atom copper feed additive prepared in the experimental example was determined by X-ray photoelectron spectroscopy:

[0066] like Figure 6a As shown in the XPS full spectrum, the single-atom copper feed additive prepared in the experimental example contains copper, oxygen, and carbon elements.

[0067] like Figure 6b As shown in the C 1s spectrum of XPS, the C on the surface or in the system of the single-atom copper feed additive prepared in the experimental example mainly exists in the form of C-C bonds, and there are also a certain amount of COC and OC=O structures.

[0068] like Figure 6c As shown in the XPS Cu 2p spectrum, the copper element in the single-atom copper feed additive prepared in the experimental example exists mostly in the Cu²⁺ oxidation state;

[0069] like Figure 6d As shown in the XPS O 1s spectrum, the surface or system of the single-atom copper feed additive prepared in the experimental example contains a variety of oxygen chemical environments, mainly carbonyl groups (C=O) formed with carbon, CO bonds in ethers / alcohols, and Cu-O bonds formed with copper.

[0070] From the analysis of the single-atom copper feed additives prepared in the experimental examples in (1)-(5) above, it can be concluded that:

[0071] (1) Atomic-level dispersion

[0072] Single-atom level: The low Cu content (16.82%) in EDS and the discrete distribution shown in the mapping plot, with no clustered state signal, prove that copper exists in single-atom form rather than nanoparticles or clusters;

[0073] The role of the carrier: The presence of C and O elements as the main components indicates that the material may be a "single-atom Cu / carbon-based composite material". The carbon carrier stabilizes the single atoms through coordination and inhibits sintering agglomeration.

[0074] (2) Surface chemical state

[0075] Oxidized copper: The presence of O element may correspond to Cu⁺ or Cu²⁺ oxidation state. Oxidized copper can enhance reaction activity in catalysis.

[0076] (3) Structural stability

[0077] No obvious lattice signal: No crystalline lattice fringes of copper were observed (only carrier or oxide signals were seen), indicating that copper did not form a crystalline phase, but was anchored on the carrier surface in the form of single atoms or atomic clusters, and the structure is consistent with the characteristics of single-atom materials;

[0078] Size effect: Single-atom scale (<0.5 nm) gives materials a high surface atomic ratio, which can theoretically maximize the density of active sites, making them suitable for high-sensitivity catalysis or sensing applications.

[0079] The safety of the single-atom copper feed additives prepared in the experimental examples was analyzed.

[0080] (1) Acute toxicity test

[0081] Sixty C57BL / 6 mice, weighing 20±2g, were randomly divided into 5 groups with 12 replicates per group. There were no significant differences in body weight between groups (P>0.05). An acute toxicity experiment was conducted on the single-atom copper feed additive prepared in the experimental example. The experimental design and results are shown in the table below:

[0082]

[0083] like Figure 7 As shown, the weight changes of the experimental group mice were basically the same as those of the control group, and there was no significant difference between the two groups.

[0084] LD was calculated using the modified Koel's method. 50 The LD50 of the single-atom copper feed additive prepared in the experimental example was calculated. 50 =358.4 mg / kg BW, compared to the LD of common copper nanomaterials 50 Compared to other ranges, it is at a medium level and has relatively high security.

[0085] (2) Subchronic toxicity test

[0086] Sixty healthy male C57BL / 6 mice aged 8-12 weeks, weighing 20±2g, were randomly divided into 5 treatment groups with 12 replicates per group. No significant difference in body weight was observed between groups (P>0.05). A subchronic toxicity experiment was conducted on the single-atom copper feed additive prepared in the experimental case. The 5 treatment groups were further divided into a saline control group and four dosage groups (10, 20, 30, and 40 mg / kg, respectively). The single-atom copper feed additive was administered to each mouse in the 5 groups via gavage for 7 consecutive days per week for 30 days. During the experiment, the animals' poisoning symptoms were observed daily, feed utilization was calculated, and body weight was measured weekly. After the experiment, liver and spleen function and serum biochemical indicators were measured, and organ indices and histological examinations were performed.

[0087] like Figure 8a The image shows a comparison of alanine transaminase levels in the serum of mice in the control and dosage groups.

[0088] like Figure 8b The figure shown is a comparison of serum aspartate aminotransferase levels in mice in the control group and the dosage group.

[0089] like Figure 8c The image shows a comparison of alkaline phosphatase levels in the serum of mice in the control group and the dosage group.

[0090] like Figure 8d The image shows a comparison of total protein levels in the serum of mice in the control group and the dosage group.

[0091] like Figure 8e The image shows a comparison of serum albumin levels in mice from the control group and the dosage group.

[0092] like Figure 8f The image shows a comparison of the body weights of mice in the control group and the dosage group.

[0093] like Figure 8g The image shows a comparison of spleen organ indices between the control group and the dosage group mice.

[0094] like Figure 8h The image shows a comparison of liver organ indices between the control group and the dosage group mice.

[0095] like Figure 8j The figure shown is a comparison of the kidney organ indices of mice in the control group and the dosage group.

[0096] like Figure 8k The image shown is a histopathological examination of mice in the control group and the dosage group.

[0097] The results showed that there were no significant differences in the levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total protein, and albumin between the dosage group and the control group (P>0.05). There were also no significant differences in body weight, spleen organ index, liver organ index, and kidney organ index between the dosage group and the control group (P>0.05). Pathological examination indicated that the liver and kidneys, as important metabolic and excretory organs, showed relatively small ranges of pathological changes with no significant differences between groups, suggesting that single-atom copper did not cause significant, dose-dependent toxic damage to the liver and kidneys, and had low subchronic toxicity.

[0098] Analysis of the enzyme-like activity of the single-atom copper feed additives prepared in the experimental example:

[0099] The activity of single-atom copper enzymes was detected using reduced glutathione (GSH), 5,5'-dinitro-2,2'-dithiobiphenyl (DTNB), hydrogen peroxide (H2O2), and PBS buffer.

[0100] (1) GSH stock solution (10mM): Weigh 18.9mg GSH, dissolve in 10mL PBS, and use immediately (protect from light and refrigerate).

[0101] (2) DTNB stock solution (10mM): Weigh 39.6mg DTNB, dissolve in 10mL PBS (add 5% DMSO to aid dissolution), and store in the dark;

[0102] (3) H2O2 working solution (10mM): Take 10.2μL of 30% H2O2, dissolve it in 10mL of PBS, and prepare fresh;

[0103] (4) Cu-SAC solution: Disperse the single-atom copper feed additive in PBS at a concentration of 10 μg / mL;

[0104] The reaction system is shown in the table below:

[0105]

[0106] Reaction process:

[0107] (1) Pre-incubation: Incubate the 96-well plate at 37℃ (or room temperature) for 5 min to equilibrate the temperature;

[0108] (2) Start the reaction: Add PBS, GSH and DTNB in ​​sequence, mix well and then add H2O2. Immediately add Cu-SAC solution (or PBS) and gently shake for 10s.

[0109] (3) Incubation reaction: Incubate at 37℃ in the dark for 10-30 min (time interval: 0, 1, 2, 3, 5, 8, 10, 15);

[0110] (4) Absorbance detection: The absorbance (OD412) was measured at 412 nm using an ELISA reader, with 3 replicates for each sample;

[0111] See results Figure 9a , Figure 9b and Figure 9c As shown, the results indicate that single-atom copper inhibits GSH oxidation (protective effect): single-atom copper preferentially decomposes H2O2 (2H2O2→2H2O+O2), reducing the chance of direct reaction between H2O2 and GSH, thereby retaining GSH, resulting in more DTNB chromogenic products (TNB) and a slower decrease in absorbance (inhibitory effect). Therefore, the single-atom copper feed additive prepared in the experimental example has peroxidase-like activity.

[0112] In the experimental example, the single-atom copper feed additive was tested in vitro in broilers for its anti-E. coli activity and its ability to reduce ammonia levels in chicken feces.

[0113] (1) In vitro antibacterial test of the single-atom copper feed additive prepared in the experimental example: The antibacterial activity of the single-atom copper feed additive against Escherichia coli O-78 was studied using the paper disc diffusion method, as shown in the table below:

[0114]

[0115]

[0116] As shown in the table above, the single-atom copper feed additive prepared in the experimental example has the effect of inhibiting Escherichia coli, and its antibacterial effect is more significant than that of copper nitrate and copper sulfate.

[0117] (2) The single-atom copper feed additive prepared in the experimental example was used for in vitro ammonia reduction test in chicken feces:

[0118] Procedure for determining ammonia in chicken manure: Weigh 50g of chicken manure into a 500ml Erlenmeyer flask, seal it with a rubber stopper, and place it in a 32℃ water bath. Prepare a 2% boric acid solution in a 500ml Erlenmeyer flask to absorb the ammonia gas produced by the chicken manure. Connect an air compressor and the Erlenmeyer flask using a plastic hose. Add different doses of monatomic copper to the chicken manure and mix well. Blow the ammonia gas produced by the chicken manure into the boric acid solution for absorption. Five replicates are set for each dosage group. The ammonia yield in the absorbent is determined using the Kjeldahl method. Results are as follows: Figure 10 As shown, the single-atom copper feed additive prepared in the experimental example has a significant ammonia-reducing effect.

[0119] In the experimental example, the single-atom copper feed additive was added to broiler chicken diets for tests on anti-E. coli activity and reduction of ammonia in chicken feces.

[0120] The *E. coli* strain used in the broiler breeder experiments was O-78. The bacterial suspension was prepared as follows: *E. coli* was removed from a -80°C freezer. A small amount of the bacterial suspension was streaked onto an LB (Luria-Bertani broth) plate using a sterile inoculation loop. The plate was then incubated at 37°C for 12 h. A single colony was then picked from the LB plate and placed in 200 mL of LB medium. The plate was placed on a shaker and incubated at 37°C and 180 rpm for 12 h. The cultured bacterial suspension was then transferred to centrifuge tubes and centrifuged at 8000-10000 rpm for 5-10 min at 4°C. The bacterial pellet was resuspended using sterile physiological saline or PBS (phosphate-buffered saline). Gently pipetting was used to ensure uniform bacterial dispersion.

[0121] Take 0.1 mL of bacterial culture and serially dilute it 10-fold in 0.9 mL of PBS. Select an appropriate dilution, take 10 µL of each dilution, and spread it evenly on EMB selective medium. Set up 3 replicates for each dilution. Incubate anaerobically at 37°C for 24 h, and then count the bacteria. Based on the counting results, dilute the bacterial culture to 5 × 10⁸ CFU / mL for later use.

[0122] Three hundred and twenty healthy Cobb broiler hens of similar weight and age at first laying, aged 55 weeks, were selected and randomly divided into five treatment groups, with eight replicates in each group and eight chickens in each replicate. Forty breeding roosters were used for artificial insemination.

[0123] Escherichia coli was administered via intraperitoneal injection at a dose of 5*10⁸ CFU / mL, with 1 mL injected intraperitoneally. The specific experimental design is shown in the table below.

[0124]

[0125] The table below shows the composition and nutrient levels of the basic diet for breeder chickens:

[0126]

[0127] Feeding and Management: This experiment was conducted at the Sheep and Horse Research and Experiment Base of the Academy of Agricultural and Forestry Sciences. Daily management followed standard feeding and management procedures. Free access to feed and water was provided. Feeding and management were carried out according to routine procedures. Waste feed and leftover feed at each stage were recorded. The number of dead or culled broiler breeders, their weight, time of death, and cause of death were recorded daily. Temperature was maintained between 20 and 24°C, and humidity was controlled at 60% to 70%. A combination of natural and artificial lighting was used to ensure 16 hours of light per day. Manure was promptly removed to maintain hygienic conditions in the coop. Following the daily feeding and management practices of Kobo broiler breeders, water was provided before feeding. During the feeding process, ambient air quality was monitored, and ventilation was ensured to maintain a good chicken coop environment. The coop was cleaned daily, and regular spray disinfection was carried out. Immunization was conducted according to the standard immunization program.

[0128] Prepare 40 breeding roosters and artificially inseminate them every three days. Artificial insemination method:

[0129] Prepare sterile semen collection equipment, syringes, culture medium, etc. Use a temperature controller to maintain the semen at 4°C. Stimulate the rooster's abdomen manually to induce ejaculation. Collect the semen using sterile instruments, minimizing contamination. Dilute the semen with the culture medium proportionally to improve survival rate. Store at a suitable temperature; it can usually be preserved for several hours at 4°C. For artificial insemination, select healthy hens and examine their reproductive system. Gently insert a specialized insemination device into the hen's oviduct. Slowly inject the diluted semen, ensuring even distribution.

[0130] The experiment lasted for 8 weeks. At the end of the 8th week, E. coli was challenged with a dose and method of 5*108 CFU / mL, 1mL was injected intraperitoneally. Blood collection and slaughter sampling began on the third day after the single challenge, 12 hours after fasting.

[0131] Tissues collected for the antibacterial effect test: fallopian tube, ovary, egg, duodenum, jejunum, ileum;

[0132] Samples collected for the fecal ammonia reduction effect test: feces.

[0133] The antibacterial effect of single-atom copper on the oviduct of broiler breeders, i.e., its in vivo antibacterial effect, is shown in the table below:

[0134]

[0135] like Figure 11 As shown, the single-atom copper feed additive prepared in the experimental example, when added to broiler feed, can significantly inhibit Escherichia coli O-78 in the oviduct of broilers, and the antibacterial effect shows a linear increasing trend with the increase of dosage.

[0136] The effects of single-atom copper on reducing ammonia in chicken feces, i.e., its effect on reducing ammonia in chicken feces in vivo, are shown in the table below:

[0137]

[0138] like Figure 12 As shown, the single-atom copper feed additive prepared in the experimental example, when added to broiler feed, can significantly reduce the ammonia emissions from broiler feces, showing a linear decreasing trend with increasing dosage. Therefore, the single-atom copper feed additive prepared in the experimental example can achieve the effect of inhibiting bacteria and reducing ammonia when used in livestock and poultry feed.

[0139] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications and substitutions based on the technical solutions and inventive concepts provided by the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a single-atom copper feed additive, characterized in that: Includes the following steps, Step 1: Prepare mixed solution A by placing melamine and copper nitrate in sufficient dimethyl sulfoxide solution and stirring until homogeneous to obtain a light green solution; Step 2: Prepare mixed solution B by placing cyanuric acid in a sufficient amount of dimethyl sulfoxide solution and stirring until homogeneous to obtain a clear and transparent solution; Step 3: Mix solution A and solution B, and after reaction, a precipitate is obtained; Step 4: Filter, wash, and dry the precipitate to obtain the precursor; Step 5: Heat-treat the precursor under an inert atmosphere to obtain a single-atom copper catalyst.

2. The method for preparing a single-atom copper feed additive according to claim 1, characterized in that: The molar ratio of melamine to copper nitrate is 3-4:

1.

3. The method for preparing a single-atom copper feed additive according to claim 2, characterized in that: The concentration of cyanuric acid in the mixed solution B is 0.5-1.2 mol / L.

4. The method for preparing a single-atom copper feed additive according to claim 3, characterized in that: The molar ratio of melamine to cyanuric acid is 0.8-1.5:

1.

5. The method for preparing a single-atom copper feed additive according to claim 1, characterized in that: In step 5, the inert atmosphere is nitrogen, and the heat treatment temperature is 500-600℃ for 3-5 hours.

6. A single-atom copper feed additive, wherein the single-atom copper feed additive is prepared by any one of the single-atom copper feed additive preparation methods according to claims 1-5.

7. The application of the single-atom copper feed additive according to claim 6, characterized in that: Used to prepare broiler feed that is resistant to E. coli and reduces ammonia in chicken feces.

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