Mixed feed additive for fattening beef cattle and preparation method thereof
The mixed feed additive prepared by double-layer coating technology solves the problem of excessively rapid urea release, realizes the slow release of urea and the synergistic effect of nutrients, improves the fattening speed and meat quality of beef cattle, and solves the problems of ammonia poisoning and decreased appetite caused by excessively rapid urea release.
Patent Information
- Application Number
- CN202610115544.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-28
- Publication Date
- 2026-03-17
AI Technical Summary
During the fattening process of beef cattle, the rapid release of ammonia from urea leads to low utilization rate, high risk of ammonia poisoning, decreased appetite, and a lack of balanced supply of other nutrients, affecting growth rate and fattening cycle.
Using a double-layer coating technology, a palm oil-based mixture is first sprayed onto the surface of urea to form a palm oil-based coating, and then a chitosan-based coating is applied to its surface. Combined with β-cyclodextrin and vitamin E, a slow-release mixed feed additive is formed to mask the odor of urea and improve nutrient absorption efficiency.
It achieves slow release of urea, increases feed intake and rumen microbial utilization in beef cattle, enhances antioxidant capacity and immunity, and significantly improves fattening speed and meat yield.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of feed additive technology, specifically to a mixed feed additive for fattening beef cattle and its preparation method. Background Technology
[0002] Beef cattle fattening relies heavily on high-quality feed, but the shortage of protein feed resources leads to slow growth and long fattening cycles, resulting in low productivity. As ruminants, beef cattle utilize non-protein nitrogen as a nitrogen source to synthesize microbial protein from rumen microorganisms. This protein is then digested and absorbed for the body's use. Urea is the most economical and widely used nitrogen source among these feeds.
[0003] However, directly feeding urea to beef cattle presents several problems: First, the rapid release of ammonia from urea in the cattle's body prevents rumen microorganisms from synthesizing all of it into microbial protein, resulting in low utilization and waste. Second, if the ammonia level in the blood exceeds the liver's burden threshold, it can lead to a cumulative increase in blood ammonia concentration, causing poisoning and death in ruminants. Third, urea has a strong bitter taste and is highly volatile, severely affecting animal appetite and reducing feed intake, which is detrimental to fattening. Slow-release urea technology can slow down the release rate of ammonia, making the release of nitrogen more synchronized and improving the utilization efficiency of urea nitrogen by rumen microorganisms. Furthermore, besides urea, other nutrients such as vitamins and fats are also crucial in beef cattle fattening; therefore, it is essential to provide a mixed feed additive for beef cattle fattening. Summary of the Invention
[0004] The purpose of this invention is to provide a mixed feed additive for fattening beef cattle and its preparation method, so as to solve the problems mentioned in the background art.
[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for preparing a mixed feed additive for beef cattle fattening, comprising the following steps: Step 1: Mix hydrogenated palm oil, palm oil, ethyl acetate, and tea polyphenols and heat to 80~100℃. After complete melting, stir to obtain a palm oil-based mixture. Step 2: Take 4-20 mesh granular urea and put it into the coating machine, and make the granular urea fluidize in the coating machine. Use a spraying process to spray the palm oil-based mixture onto the surface of the granular urea and dry it to form a palm oil-based coating, thus obtaining palm oil-based coated urea. Step 3: β-cyclodextrin-encapsulated vitamin E powder and O'O-lauroyl chitosan are dispersed in deionized water and stirred to obtain a chitosan-based coating solution; palm oil-based coated urea is added to the chitosan-based coating solution, and glutaraldehyde is used as a crosslinking agent. The mixture is stirred and reacted at 30-40℃ for 2-3 hours to form a chitosan-based coating; the product is filtered, washed, and freeze-dried to obtain a mixed feed additive for beef cattle fattening.
[0006] Further, in step 1, the content of each component in the palm oil-based mixture, by weight percentage, is 60-70% hydrogenated palm oil, 15-20% palm oil, 10-15% ethyl acetate, and 5-10% tea polyphenols.
[0007] Furthermore, in step 2, during the spraying process, the spraying speed is 1~5 rpm, the atomization temperature is 75~95℃, and the atomization pressure is 0.1~0.25 MPa.
[0008] Furthermore, in step 3, the mass ratio of β-cyclodextrin-encapsulated vitamin E powder to O'O-lauroyl chitosan in the chitosan-based coating solution is 1:(10~20).
[0009] Furthermore, the preparation method of β-cyclodextrin-encapsulated vitamin E powder is as follows: Prepare a saturated aqueous solution of β-cyclodextrin, add vitamin E while stirring, and heat to 60-70℃ after addition. Stir for 2-3 hours to encapsulate the vitamin E. After encapsulation, store at 1-5℃ for 24 hours and dry in a forced-air environment at 60-80℃ to obtain β-cyclodextrin-encapsulated vitamin E powder.
[0010] Furthermore, the molar ratio of β-cyclodextrin to vitamin E is 1:(3~5).
[0011] Furthermore, the preparation method of O'O-lauroyl chitosan is as follows: Chitosan was dissolved in methanesulfonic acid, lauroyl chloride was added with stirring, and the mixture was stirred and reacted at 25-30°C for 12 hours. The mixture was then transferred to ice water to form a suspension. The lower precipitate was collected by centrifugation, washed with water and saturated sodium bicarbonate solution, and then centrifuged again to collect the lower precipitate. The mixture was washed and dried to obtain O'O-lauroyl chitosan.
[0012] Furthermore, chitosan and lauroyl chloride react at a mass ratio of 1:(1.5~2).
[0013] Furthermore, in step 3, the mixed feed additive for fattening beef cattle contains, by weight percentage, 75-85% urea, 10-15% palm oil-based coating, and 5-15% chitosan-based coating.
[0014] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The present invention uses urea as the main nitrogen source and prepares a mixed feed additive with slow-release function through double-layer coating technology, thereby realizing the slow release of urea in the rumen of beef cattle and avoiding ammonia poisoning in beef cattle caused by excessively fast urea release rate.
[0015] In this invention, a palm oil-based coating is first applied to the surface of urea using a spraying technique. The palm oil-based coating mainly includes hydrogenated palm oil and palm oil, with ethyl acetate and tea polyphenols added as excipients. Ethyl acetate and tea polyphenols have unique aromas that can mask the obvious off-odor of urea, improve the palatability of feed additives, and thus increase the feed intake of beef cattle. Tea polyphenols can significantly increase the ammonia nitrogen level in the rumen of beef cattle, reduce the acetic acid to propionic acid ratio, increase serum SOD activity, reduce serum MDA level, and enhance antioxidant capacity.
[0016] Although existing technologies using palm oil-based materials as wall materials can achieve good coating and sustained-release effects, the present invention introduces tea polyphenols, which have poor compatibility with palm oil, into the system, resulting in a decrease in the effectiveness of a single-layer palm oil-based coating. Therefore, the present invention further coats the surface of the palm oil-based coating with a chitosan-based coating. Since the palm oil-based coating effectively protects the core material urea, preventing it from dissolving and reacting in aqueous solution, this coating process can be carried out in an aqueous solvent. The chitosan-based coating solution is a mixed aqueous solution of O'O-lauroyl chitosan and cyclodextrin-encapsulated vitamin E powder. On the one hand, O'O-lauroyl chitosan has better water solubility than chitosan and is amphiphilic, which not only makes it more compatible with palm oil-based coatings, but also allows it to cross-link with cyclodextrin molecules and coat the surface of palm oil-based coatings under the action of glutaraldehyde. On the other hand, by encapsulating vitamin E with cyclodextrin, the oxidation and inactivation of vitamin E during storage are prevented, reducing the loss of activity. At the same time, the rapid release and metabolism rate of vitamin E in the rumen is slowed down, allowing it to reach the absorption site steadily and continuously, improving its utilization and better exerting its effects on maintaining the growth performance of beef cattle and improving meat quality.
[0017] The mixed feed additive prepared by this invention has a double-layer coating, enabling a dual slow-release effect of vitamin E and urea. The additive is rich in nutrients, and its components exhibit synergistic effects: vitamin E and tea polyphenols both possess antioxidant properties, enhancing the immunity of beef cattle, improving digestive absorption, and increasing protein utilization; while the palm oil-based coating, after disintegrating in the digestive tract, promotes the absorption of fat-soluble vitamin E by the beef cattle. Through the synergistic effect of its various nutrient components, this invention achieves a synergistic effect greater than the sum of its parts, significantly improving the fattening speed and meat yield of beef cattle. Detailed Implementation
[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0019] All materials used in this invention are commercially available products.
[0020] Example 1: A mixed feed additive for fattening beef cattle and its preparation method, comprising the following steps: Step 1: Hydrogenated palm oil, palm oil, ethyl acetate, and tea polyphenols are mixed and heated to 80°C. After complete melting, the mixture is stirred to obtain a palm oil-based mixture. The content of each component in the palm oil-based mixture, by weight percentage, is 60% hydrogenated palm oil, 15% palm oil, 15% ethyl acetate, and 10% tea polyphenols. Step 2: Four-mesh granular urea is fed into a coating machine and fluidized. A palm oil-based mixture is sprayed onto the surface of the granular urea to form a palm oil-based coating. The urea is then dried to obtain palm oil-based coated urea. In the spraying process, the spraying speed is 1 rpm, the atomization temperature is 75°C, and the atomization pressure is 0.1 MPa. Step 3: S1: Prepare a saturated aqueous solution of β-cyclodextrin, add vitamin E while stirring, and heat to 60°C after the addition is complete. Stir and encapsulate for 2 hours. After encapsulation, store at 1°C for 24 hours and dry in a forced-air environment at 60°C to obtain β-cyclodextrin-encapsulated vitamin E powder. The molar ratio of β-cyclodextrin to vitamin E is 1:3. S2: Chitosan was dissolved in methanesulfonic acid, lauroyl chloride was added with stirring, and the mixture was stirred at 25°C for 12 hours to form a suspension. The mixture was then centrifuged and the lower precipitate was collected. The precipitate was washed with water and then washed with saturated sodium bicarbonate solution. The mixture was centrifuged again and the lower precipitate was collected. The precipitate was washed and dried to obtain O'O-lauroyl chitosan. The chitosan and lauroyl chloride were reacted at a mass ratio of 1:1.5. S3: β-cyclodextrin-encapsulated vitamin E powder and O'O-lauroyl chitosan are dispersed in deionized water at a mass ratio of 1:10 and stirred to obtain a chitosan-based coating solution; palm oil-based coated urea is added to the chitosan-based coating solution, and glutaraldehyde is used as a crosslinking agent. The mixture is stirred at 30°C for 2 hours to form a chitosan-based coating; the product is filtered, washed, and freeze-dried to obtain a mixed feed additive for fattening beef cattle; the mixed feed additive for fattening beef cattle contains, by weight percentage, 75% urea, 10% palm oil-based coating, and 15% chitosan-based coating.
[0021] Example 2: A mixed feed additive for fattening beef cattle and its preparation method, comprising the following steps: Step 1: Hydrogenated palm oil, palm oil, ethyl acetate, and tea polyphenols are mixed and heated to 90°C. After complete melting, the mixture is stirred to obtain a palm oil-based mixture. The content of each component in the palm oil-based mixture, by weight percentage, is 65% hydrogenated palm oil, 18% palm oil, 12% ethyl acetate, and 5% tea polyphenols. Step 2: Ten-mesh granular urea is fed into a coating machine and fluidized. A palm oil-based mixture is sprayed onto the surface of the granular urea to form a palm oil-based coating. The urea is then dried to obtain palm oil-based coated urea. In the spraying process, the spraying speed is 3 rpm, the atomization temperature is 85°C, and the atomization pressure is 0.15 MPa. Step 3: S1: Prepare a saturated aqueous solution of β-cyclodextrin, add vitamin E while stirring, and heat to 65°C after addition. Stir and encapsulate for 2.5 hours. After encapsulation, store at 3°C for 24 hours and dry in a forced-air environment at 70°C to obtain β-cyclodextrin-encapsulated vitamin E powder. The molar ratio of β-cyclodextrin to vitamin E is 1:4.5. S2: Chitosan was dissolved in methanesulfonic acid, lauroyl chloride was added with stirring, and the mixture was stirred at 28°C for 12 hours to form a suspension. The mixture was then centrifuged and the lower precipitate was collected. The precipitate was washed with water and then washed with saturated sodium bicarbonate solution. The mixture was centrifuged again and the lower precipitate was collected. The precipitate was washed and dried to obtain O'O-lauroyl chitosan. The chitosan and lauroyl chloride were reacted at a mass ratio of 1:1.8. S3: β-cyclodextrin-encapsulated vitamin E powder and O'O-lauroyl chitosan are dispersed in deionized water at a mass ratio of 1:16 and stirred to obtain a chitosan-based coating solution; palm oil-based coated urea is added to the chitosan-based coating solution, and glutaraldehyde is used as a crosslinking agent. The mixture is stirred at 35°C for 2.5 hours to form a chitosan-based coating; the product is filtered, washed, and freeze-dried to obtain a mixed feed additive for fattening beef cattle; the mixed feed additive for fattening beef cattle contains, by weight percentage, 80% urea, 12% palm oil-based coating, and 8% chitosan-based coating.
[0022] Example 3: A mixed feed additive for beef cattle fattening and its preparation method, comprising the following steps: Step 1: Hydrogenated palm oil, palm oil, ethyl acetate, and tea polyphenols are mixed and heated to 100°C. After complete melting, the mixture is stirred to obtain a palm oil-based mixture. The content of each component in the palm oil-based mixture, by weight percentage, is 70% hydrogenated palm oil, 15% palm oil, 10% ethyl acetate, and 5% tea polyphenols. Step 2: 20-mesh granular urea is fed into a coating machine and fluidized. A palm oil-based mixture is sprayed onto the surface of the granular urea to form a palm oil-based coating. After drying, palm oil-based coated urea is obtained. In the spraying process, the spraying speed is 5 rpm, the atomization temperature is 95℃, and the atomization pressure is 0.25 MPa. Step 3: S1: Prepare a saturated aqueous solution of β-cyclodextrin, add vitamin E while stirring, and heat to 70°C after addition. Stir and encapsulate for 3 hours. After encapsulation, store at 5°C for 24 hours and dry in a forced-air environment at 80°C to obtain β-cyclodextrin-encapsulated vitamin E powder. The molar ratio of β-cyclodextrin to vitamin E is 1:5. S2: Chitosan was dissolved in methanesulfonic acid, lauroyl chloride was added with stirring, and the mixture was stirred at 30°C for 12 hours to form a suspension. The mixture was then transferred to ice water to separate the precipitate by centrifugation and collection. The precipitate was washed with water and then washed with saturated sodium bicarbonate solution. The mixture was then centrifuged again and the precipitate was collected. The precipitate was washed and dried to obtain O'O-lauroyl chitosan. Chitosan and lauroyl chloride were reacted at a mass ratio of 1:2. S3: β-cyclodextrin-encapsulated vitamin E powder and O'O-lauroyl chitosan are dispersed in deionized water at a mass ratio of 1:20 and stirred to obtain a chitosan-based coating solution; palm oil-based coated urea is added to the chitosan-based coating solution, and glutaraldehyde is used as a crosslinking agent. The mixture is stirred at 40°C for 3 hours to form a chitosan-based coating; the product is filtered, washed, and freeze-dried to obtain a mixed feed additive for fattening beef cattle; the mixed feed additive for fattening beef cattle contains, by weight percentage, 85% urea, 10% palm oil-based coating, and 5% chitosan-based coating.
[0023] Comparative Example 1: Only palm oil-based coating was prepared, and the other parameters were the same as in Example 1.
[0024] Step 1: Hydrogenated palm oil, palm oil, ethyl acetate, and tea polyphenols are mixed and heated to 80°C. After complete melting, the mixture is stirred to obtain a palm oil-based mixture. The content of each component in the palm oil-based mixture, by weight percentage, is 60% hydrogenated palm oil, 15% palm oil, 15% ethyl acetate, and 10% tea polyphenols. Step 2: Four-mesh granular urea is fed into a coating machine and fluidized. A palm oil-based mixture is sprayed onto the surface of the granular urea to form a palm oil-based coating. After drying, a mixed feed additive for fattening beef cattle is obtained. In the spraying process, the spraying speed is 1 rpm, the atomization temperature is 75℃, and the atomization pressure is 0.1 MPa.
[0025] Comparative Example 2: Chitosan was used instead of O'O-lauroyl chitosan, and the other parameters were the same as in Example 2.
[0026] Step 1: Hydrogenated palm oil, palm oil, ethyl acetate, and tea polyphenols are mixed and heated to 90°C. After complete melting, the mixture is stirred to obtain a palm oil-based mixture. The content of each component in the palm oil-based mixture, by weight percentage, is 65% hydrogenated palm oil, 18% palm oil, 12% ethyl acetate, and 5% tea polyphenols. Step 2: Ten-mesh granular urea is fed into a coating machine and fluidized. A palm oil-based mixture is sprayed onto the surface of the granular urea to form a palm oil-based coating. The urea is then dried to obtain palm oil-based coated urea. In the spraying process, the spraying speed is 3 rpm, the atomization temperature is 85°C, and the atomization pressure is 0.15 MPa. Step 3: S1: Prepare a saturated aqueous solution of β-cyclodextrin, add vitamin E while stirring, and heat to 65°C after addition. Stir and encapsulate for 2.5 hours. After encapsulation, store at 3°C for 24 hours and dry in a forced-air environment at 70°C to obtain β-cyclodextrin-encapsulated vitamin E powder. The molar ratio of β-cyclodextrin to vitamin E is 1:4.5. S2: β-cyclodextrin-encapsulated vitamin E powder and chitosan are dispersed in acetic acid solution at a mass ratio of 1:16 and stirred to obtain a chitosan-based coating solution; palm oil-based coated urea is added to the chitosan-based coating solution, and glutaraldehyde is used as a crosslinking agent. The mixture is stirred at 35°C for 2.5 hours to form a chitosan-based coating; the product is filtered, washed, and freeze-dried to obtain a mixed feed additive for fattening beef cattle; the mixed feed additive for fattening beef cattle contains, by weight percentage, 80% urea, 12% palm oil-based coating, and 8% chitosan-based coating.
[0027] Comparative Example 3: Vitamin E was not encapsulated with β-cyclodextrin, and all other parameters were the same as in Example 3.
[0028] Step 1: Hydrogenated palm oil, palm oil, ethyl acetate, and tea polyphenols are mixed and heated to 100°C. After complete melting, the mixture is stirred to obtain a palm oil-based mixture. The content of each component in the palm oil-based mixture, by weight percentage, is 70% hydrogenated palm oil, 15% palm oil, 10% ethyl acetate, and 5% tea polyphenols. Step 2: 20-mesh granular urea is fed into a coating machine and fluidized. A palm oil-based mixture is sprayed onto the surface of the granular urea to form a palm oil-based coating. After drying, palm oil-based coated urea is obtained. In the spraying process, the spraying speed is 5 rpm, the atomization temperature is 95℃, and the atomization pressure is 0.25 MPa. Step 3: S1: Chitosan was dissolved in methanesulfonic acid, lauroyl chloride was added with stirring, and the mixture was stirred at 30°C for 12 hours to form a suspension. The mixture was then centrifuged and the lower precipitate was collected. The precipitate was washed with water and then washed with saturated sodium bicarbonate solution. The mixture was centrifuged again and the lower precipitate was collected. The precipitate was washed and dried to obtain O'O-lauroyl chitosan. Chitosan and lauroyl chloride were reacted at a mass ratio of 1:2. S2: Vitamin E powder and O'O-lauroyl chitosan are dispersed in deionized water at a mass ratio of 1:20 and stirred to obtain a chitosan-based coating solution; palm oil-based coated urea is added to the chitosan-based coating solution, and glutaraldehyde is used as a crosslinking agent. The mixture is stirred at 40°C for 3 hours to form a chitosan-based coating; the product is filtered, washed, and freeze-dried to obtain a mixed feed additive for fattening beef cattle; the mixed feed additive for fattening beef cattle contains, by weight percentage, 85% urea, 10% palm oil-based coating, and 5% chitosan-based coating.
[0029] experiment: Storage stability test: The products of Examples 1-3 and Comparative Examples 1-3 were stored at 0°C for one week, then transferred to 25°C for one week, then transferred to 40°C for one week, and finally stored at 25°C for one week. The apparent coating state was observed and the coating was rubbed by hand. The experimental results are shown in Table 1.
[0030] Table 1. The results in Table 1 show that the double-layer coating method used in Examples 1-3 achieved excellent urea coating effects. In Comparative Example 1, only a mixture of hydrogenated palm oil, palm oil, ethyl acetate, and tea polyphenols was used as the coating material. Due to the poor dispersibility of tea polyphenols in oils, the coating material had poor adhesion, resulting in coating peeling after cold and hot cycling storage, and significant peeling after hand rubbing. In Comparative Example 2, chitosan was used as the outer coating material. Because chitosan has strong hydrophilicity and weak lipophilicity, its coating effect on palm oil-based coated urea was not as good as that of O'O-lauroyl chitosan.
[0031] In vitro rumen-simulated environment sustained-release performance test: The sustained-release rates of Examples 1-3, Comparative Examples 1-3, and urea granules (control group) were tested. 5g of sample was accurately weighed from each group and placed in a 700mL ddH2O dissolution vessel. The temperature was set at 39℃ and the rotation speed at 70r / min. 10.0mL samples were taken at 0, 2, 4, 8, and 12 hours, and the nitrogen content was determined using a Kjeldahl nitrogen analyzer. The sustained-release rate of urea was calculated based on this. The experimental results are shown in Table 2. Table 2. The data in Table 2 show that the uncoated urea particles achieved a sustained release rate of 95% after 2 hours and were completely released within 4 hours. Based on the sustained release rates in Comparative Examples 1 and 2, the sustained release effect of the coating material is poor. Combined with the results in Table 1, it can be inferred that this is mainly due to the poor coating effect of the coating material. In contrast, the products prepared using the methods in Examples 1-3 effectively achieved the sustained release effect of urea.
[0032] Beef cattle fattening experiment: Simmental crossbred bulls of similar weight and approximately 13 months of age were selected for the experiment, which lasted from June 1, 2025 to September 30, 2025 (a total of 122 days). The control group consisted of one group, fed a basal diet with soybean meal as the nitrogen source. Following the principle of isoenergetic and isonitrogenous feeding, the experimental groups were fed mixed feed additives from Examples 1-3 and Comparative Examples 1-3, respectively, in equal proportions to replace the soybean meal in the basal diet. The experimental results are shown in Table 3. Table 3. As shown in Table 3, the mixed feed additive prepared using the method of this invention has a significant effect on the growth and fattening of beef cattle. Furthermore, the beef quality of the feeds used in Examples 1-3 was sampled and evaluated according to the standards in NY / T676-2010 "Beef Grading Specifications". The meat quality grade was assessed using indicators such as marbling, bovine physiological maturity, muscle color, and fat color. The marbling of the tenderloin, sirloin, chuck, and ribeye cuts in Examples 1-3 was all grade 5, with uniform marbling distribution and a cherry-red muscle color, meeting the premium grade standard.
[0033] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for preparing a mixed feed additive for fattening beef cattle, characterized by: The preparation method comprises the following steps: Step 1: hydrogenated palm oil, palm oil, ethyl acetate, tea polyphenol are mixed and heated to 80-100 DEG C, completely dissolved after stirring to obtain palm oil-based mixture; Step 2: 4-20 mesh granular urea is put into a coating machine, and the granular urea is fluidized in the coating machine; the palm oil-based mixture is sprayed onto the surface of the granular urea by using a spraying process to dry to form a palm oil-based coating, and a palm oil-based coated urea is obtained; Step 3: β-cyclodextrin inclusion vitamin E powder and O'O-lauric acid chitosan are dispersed in deionized water, and a chitosan-based coating solution is obtained by stirring; the palm oil-based coated urea is added into the chitosan-based coating solution, and a chitosan-based coating is formed by using glutaraldehyde as a crosslinking agent, stirring at 30-40 DEG C for 2-3h; the product is filtered, washed and freeze-dried to obtain a beef fattening mixed feed additive.
2. The method of claim 1, wherein the beef fattening mixed feed additive is prepared by the steps of: In step 1, the content of each component in the palm oil-based mixture is 60-70% hydrogenated palm oil, 15-20% palm oil, 10-15% ethyl acetate and 5-10% tea polyphenol. 3. The method for preparing the mixed feed additive for beef cattle fattening according to claim 1, characterized in that: In step 2, in the spraying process, the spraying speed is 1-5 rpm, the atomization temperature is 75-95 DEG C, and the atomization pressure is 0.1-0.25 Mpa.
4. The method of claim 1, wherein the beef-fattening mixed feed additive is prepared by the steps of: In step 3, in the chitosan-based coating solution, the mass ratio of β-cyclodextrin inclusion vitamin E powder to O'O-lauric acid chitosan is 1: (10-20). 5. The method of claim 1, wherein the beef-fattening mixed feed additive is prepared by the steps of: In step 3, the preparation method of the β-cyclodextrin inclusion vitamin E powder is as follows: β-cyclodextrin is configured into a saturated aqueous solution, vitamin E is added by stirring, the temperature is raised to 60-70 DEG C, and the inclusion treatment is carried out for 2-3h; after the inclusion treatment is completed, it is stored at 1-5 DEG C for 24h, and is dried by blowing at 60-80 DEG C to obtain β-cyclodextrin inclusion vitamin E powder.
6. The method of claim 5, wherein the beef fattening mixed feed additive is prepared by the steps of: The molar ratio of β-cyclodextrin to vitamin E is 1: (3-5). 7. The method of claim 1, wherein the beef-fattening mixed feed additive is prepared by the steps of: In step 3, the preparation method of O'O-lauric acid chitosan is as follows: Chitosan is dissolved in methanesulfonic acid, and lauroyl chloride is added by stirring; after stirring at 25-30 DEG C for 12h, the mixture is transferred to an ice water suspension; the lower precipitate is collected by centrifugal separation, washed with water, and then washed with saturated sodium bicarbonate solution; the lower precipitate is collected again by centrifugal separation, washed and dried to obtain O'O-lauric acid chitosan.
8. The method of claim 7, wherein the beef fattening mixed feed additive is prepared by the steps of: Chitosan and lauroyl chloride are reacted at a mass ratio of 1: (1.5-2). 9. The method of claim 1, wherein the beef-fattening mixed feed additive is prepared by the steps of: In step 3, in the beef fattening mixed feed additive, the content of each component is 75-85% urea, 10-15% palm oil-based coating and 5-15% chitosan-based coating. 10. The beef fattening mixed feed additive prepared by the preparation method of any one of claims 1-9.
10. The beef fattening mixed feed additive prepared by the preparation method of any one of claims 1-9.