Eucommia ulmoides leaf compound feed additive and preparation method thereof

Abstract

The invention relates to the field of feed additives, and discloses a folium cortex eucommiae compound feed additive and a preparation method thereof, and the folium cortex eucommiae compound feed additive comprises the following components in parts by weight: 60-90 parts of fermented folium cortex eucommiae powder, 10-20 parts of cortex eucommiae seed meal, 1-5 parts of a traditional Chinese medicine extract, 2-10 parts of a microbial preparation, 5-10 parts of charcoal modified montmorillonite and 2-10 parts of a yeast cell wall extract. The folium cortex eucommiae compound feed additive is prepared by mixing the fermented folium cortex eucommiae with high-activity component content, the treated folium cortex eucommiae seed meal, the traditional Chinese medicine extract, the biochar modified montmorillonite and the yeast cell wall extract, and the folium cortex eucommiae compound feed additive prepared by the method has high-activity components; and under the condition that antibiotics and vaccines are not used, the production performance of the laying hens can be improved, the laying rate of the laying hens is increased, the soft and broken egg rate is reduced, animal health is maintained, the content of total cholesterol, triglyceride and low-density lipoprotein in blood is reduced, the content of high-density lipoprotein is increased, and the death rate of the laying hens is reduced.

Description

Technical Field

[0001] The invention relates to the field of feed additives, and in particular to a eucommia leaf composite feed additive and a preparation method thereof. Background Art

[0002] Eucommia ulmoides has a history of more than 2,000 years of medicinal use, and traditionally, Eucommia ulmoides bark is used as medicine. The active ingredients and pharmacological effects of Eucommia ulmoides leaves are similar to those of Eucommia ulmoides bark. The crude protein content in Eucommia ulmoides leaves is higher than that of corn, millet, sorghum and potatoes, and is comparable to that of barley and wheat. Its active ingredients include flavonoids, cyclopentane ether terpenes, phenylpropanoids, lignans, polysaccharides and Eucommia ulmoides rubber. my country has the habit of feeding pigs and cattle with Eucommia ulmoides leaves. The "Catalogue of Feed Additives (2013)" stipulates that Eucommia ulmoides leaf extracts can be used to fatten pigs, fish and shrimp. Through a large number of animal feeding practices, it has been confirmed that Eucommia ulmoides leaves are non-toxic, can promote animal growth, and improve meat quality and flavor.

[0003] In the prior art, eucommia leaves are also used as a compound feed additive for feeding livestock. The present invention aims to provide an eucommia leaf compound feed additive and a preparation method thereof, which can reduce the use of antibiotics and vaccines, thereby increasing the egg production rate of laying hens, reducing the soft and broken egg rate and the chicken mortality rate. Summary of the invention

[0004] The invention provides a eucommia leaf composite feed additive and a preparation method thereof, which can reduce the use of antibiotics and vaccines, thereby improving the egg production rate of laying hens, and reducing the soft and broken egg rate and the chicken mortality rate.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows: The eucommia leaf composite feed additive of the invention comprises the following components in parts by weight: 60-90 parts of fermented eucommia leaf powder, 10-20 parts of eucommia seed meal, 1-5 parts of traditional Chinese medicine extract, 2-10 parts of microbial preparation, 5-10 parts of biochar modified montmorillonite and 2-10 parts of yeast cell wall extract.

[0006] A method for preparing a eucommia leaf composite feed additive comprises the following steps: S1: preparing fermented Eucommia ulmoides leaf powder; S2: preparing eucommia seed meal; S3: Preparation of Chinese herbal medicine extract: 1.5 kg of Rehmannia root, 1.5 kg of Angelica sinensis, 1.5 kg of Crataegus pinnatifida, and 0.5 kg of Alisma orientalis were taken, crushed, and then extracted with hot water. The extraction conditions were as follows: temperature 60°C, time 3 h, solid-liquid ratio 1:15, and concentrated under reduced pressure, vacuum dried, and then crushed to obtain the Chinese herbal medicine extract; S4: preparing a microbial preparation: uniformly mixing Bifidobacterium adolescentis, Bacillus subtilis, Lactobacillus plantarum and konjac gum solution, and spray drying the mixture; S5: preparing biochar-modified montmorillonite: mixing montmorillonite and plant tannin extract at a mass ratio of 1:1-1:20, and subjecting them to oxygen-free heat treatment at a temperature above 400° C. to obtain biochar-modified montmorillonite containing tannin; S6: The product prepared in S1-S5 is mixed or granulated with the yeast cell wall extract in parts by weight to obtain a eucommia leaf composite feed additive, wherein the β-glucan content of the yeast cell wall extract is greater than 70%.

[0007] Furthermore, the specific steps of preparing fermented Eucommia leaves in step S1 are as follows: select Eucommia Qinzhong No. 1, a fine variety, plant it in a leaf forest model, harvest it in summer and autumn, and obtain Eucommia leaves with a moisture content of less than 13% through low-temperature drying, microwave drying or vacuum drying; crush and sieve the Eucommia leaves; subject the Eucommia leaves with a high content of active ingredients to solid-state fermentation with enzymes and microbial bacterial liquid, and dry them at low temperature to obtain fermented Eucommia leaf powder.

[0008] Furthermore, after the eucommia leaves are dried, they are crushed twice with a grinder, each time for 30 seconds, and after the crushing, they are sieved through a 30-mesh sieve to remove petioles and veins to obtain eucommia leaf powder, 100g of cellulase and 150g of pectinase are added to 150L of water to prepare an enzyme aqueous solution, 30kg of eucommia leaf powder and the enzyme aqueous solution are mixed, enzymolysis is performed at 50°C for 2.0h, the temperature is lowered to 35-37°C, 5kg of soybean meal and 5kg of corn flour are mixed, and then 20L of microbial culture liquid is mixed, and the mixture is fermented at 35-37°C for 36-48h, and then vacuum dried at 45°C until the moisture content is less than 13% to obtain fermented eucommia leaf powder.

[0009] Furthermore, the cellulase is greater than 0.3u / mg, the pectinase is greater than 0.3u / mg, the microbial liquid includes Lactobacillus plantarum, Enterococcus faecalis and Bifidobacterium adolescentis, wherein Lactobacillus plantarum is not less than 8×10 8 cfu / mL, Enterococcus faecalis not less than 3×10 8 cfu / mL, Bifidobacterium adolescentis not less than 3×10 7 cfu / mL.

[0010] Furthermore, the specific steps of preparing the eucommia seed meal in step S2 are as follows: selecting mature eucommia seeds harvested in the current year, squeezing oil through a low-temperature pressing method to obtain seed meal, crushing 3 kg of the seed meal and mixing it with 20L of plant lactobacillus liquid, fermenting and culturing at 35-37°C for 24 hours, then adding neutral protease at 50°C for protein hydrolysis for 2 hours, finally concentrating at 45°C under reduced pressure, and vacuum drying at 45°C to obtain eucommia seed meal with a high aucubin content.

[0011] Furthermore, the plant lactobacillus liquid is not less than 8×10 8 cfu / mL, and the protein in the neutral protease is greater than 400 u / mg.

[0012] Furthermore, in step S4, the number of Bifidobacterium adolescentis is 10×10 8 cfu / mL, Bacillus subtilis not less than 5×10 8 cfu / mL, Lactobacillus plantarum not less than 10×10 8 cfu / mL, and mixed evenly with 0.02g / mL konjac gum solution.

[0013] Furthermore, the tannin content of the plant tannin extract in step S5 is greater than 500 mg / g.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The invention prepares a composite eucommia leaf feed additive by mixing fermented eucommia leaves with high active ingredient content with processed eucommia seed meal and traditional Chinese medicine extract, biochar-modified montmorillonite and yeast cell wall extract. The composite eucommia leaf feed additive prepared by the method of the invention not only has high active ingredients, but also can improve the production performance of laying hens, increase the egg production rate of laying hens, reduce the soft and broken egg rate, maintain animal health, reduce the total cholesterol, triglyceride and low-density lipoprotein contents in blood, increase the high-density lipoprotein content and reduce the mortality rate without using antibiotics and vaccines. DETAILED DESCRIPTION

[0015] In order to make the purpose and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0016] The eucommia leaf composite feed additive and preparation method of the present embodiment include the following components by weight: 60-90 parts of fermented eucommia leaf powder, 10-20 parts of eucommia seed meal, 1-5 parts of Chinese medicine extract, 2-10 parts of microbial preparation, 5-10 parts of biochar modified montmorillonite, and 2-10 parts of yeast cell wall extract. The eucommia leaves used in this embodiment were collected from 5-year-old eucommia trees in the eucommia forest demonstration base of the North Campus of Northwest Agriculture and Forestry University. The eucommia leaves on the current year branches were randomly selected and dried immediately after collection.

[0017] The specific preparation method is as follows: S1: Preparation of fermented Eucommia leaf powder: Select Eucommia Qinzhong No. 1, a fine variety, planted in a leaf forest model, harvested in summer and autumn, and dried at low temperature (shade drying), microwave drying or vacuum drying to obtain Eucommia leaves with a moisture content of less than 13%, crushed twice with a grinder, each time for 30 seconds, and passed through a 30-mesh sieve after the crushing to remove petioles and veins to obtain Eucommia leaf powder with high active ingredient content, add 100 g of cellulase and 150 g of pectinase to 150 L of water to prepare an enzyme aqueous solution, wherein the cellulase is greater than 0.3 u / mg and the pectinase is greater than 0.3 u / mg, mix 30 kg of Eucommia leaf powder with the enzyme aqueous solution, enzymolysis at 50 ° C for 2.0 h, cool to 35-37 ° C, mix in 5 kg of soybean meal and 5 kg of corn flour, and then mix in 20 L of microbial culture solution, the microbial culture solution includes not less than 8×10 8 cfu / mL of Lactobacillus plantarum, not less than 3×10 8 cfu / mL of Enterococcus faecalis and not less than 3×10 7 cfu / mL of Bifidobacterium adolescentis, fermented at 35-37°C for 36-48h, and then vacuum dried at 45°C until the moisture content is less than 13% to obtain fermented Eucommia ulmoides leaf powder; S2: Preparation of Eucommia ulmoides seed meal: Select mature Eucommia ulmoides seeds harvested that year, extract oil by low-temperature pressing to obtain seed meal, grind 3 kg of seed meal and mix with 20 L of Lactobacillus plantarum liquid, wherein the Lactobacillus plantarum liquid is not less than 8×10 8 cfu / mL, fermented and cultured at 35-37℃ for 24 hours, then added neutral protease with a protein content of more than 400 u / mg to hydrolyze the protein at 50℃ for 2 hours, finally concentrated at 45℃ under reduced pressure, and vacuum dried at 45℃ to obtain eucommia seed meal with high aucubin content; S3: preparing Chinese medicine extract: taking 1.5kg of Rehmannia root, 1.5kg of Angelica sinensis, 1.5kg of Crataegus pinnatifida, and 0.5kg of Rhizoma Alismatis, crushing and extracting with hot water, the extraction conditions are temperature 60°C, time 3h, solid-liquid ratio 1:15, decompressing and concentrating, vacuum drying and crushing to obtain Chinese medicine extract; in this embodiment, Rehmannia root and Angelica sinensis, which form a "drug pair" with Eucommia ulmoides, are selected as the raw materials to enhance the effect of nourishing the body, and Crataegus pinnatifida and Rhizoma Alismatis have strong lipid-lowering effect; S4: Preparation of microbial preparation: 10×10 8 cfu / mL Bifidobacterium adolescentis, not less than 5×10 8 cfu / mL of Bacillus subtilis, not less than 10×10 8 cfu / mL of plant lactobacillus and 0.02g / mL of konjac gum solution were evenly mixed and spray-dried to obtain the product; the microbial preparation can maintain and improve the intestinal microbial flora, and konjac is rich in glucomannan, which has good lipid-lowering, toxin-absorbing and digestion-promoting functions; S5: Preparation of biochar-modified montmorillonite: montmorillonite and plant tannin extract are mixed in a mass ratio of 1:1-1:20, and heat-treated at 400°C or above to obtain biochar-modified montmorillonite containing tannin; wherein the tannin content of the plant tannin extract is greater than 500 mg / g, and the adsorption capacity of the montmorillonite modified by biochar is improved, and it can adsorb heavy metal ions in feed and detoxify; S6: The product prepared in S1-S5 is mixed or granulated with the yeast cell wall extract in parts by weight to obtain a eucommia leaf composite feed additive, wherein the β-glucan content of the yeast cell wall extract is greater than 70%.

[0018] Example 1

[0019] A composite feed additive of eucommia leaves and a preparation method of the present embodiment include the following components in parts by weight: 60 parts of fermented eucommia leaf powder, 15 parts of eucommia seed meal, 3 parts of Chinese medicine extract, 6 parts of microbial preparation, 5 parts of biochar-modified montmorillonite, and 7 parts of yeast cell wall extract. The preparation is carried out according to the aforementioned method, wherein the eucommia leaves harvested in step S1 of the preparation process are dried at low temperature, the eucommia leaf powder is mixed with an aqueous solution of an enzyme and then cooled to 35°C, soybean meal, corn flour, and microbial liquid are mixed and fermented at 35°C for 48h; in step S2, the seed meal is crushed and mixed with a Lactobacillus plantarum liquid, and fermented and cultured at 37°C for 24 hours. The remaining steps can be prepared according to the aforementioned method.

[0020] Example 2

[0021] The eucommia leaf compound feed additive and preparation method of the present embodiment include the following components in weight: 75 parts of fermented eucommia leaf powder, 10 parts of eucommia seed meal, 1 part of Chinese medicine extract, 10 parts of microbial preparation, 8 parts of biochar modified montmorillonite, and 2 parts of yeast cell wall extract. The preparation is carried out according to the above method, wherein the eucommia leaves harvested in step S1 of the preparation process are dried by microwave, the eucommia leaf powder is mixed with the enzyme aqueous solution and then cooled to 36°C, soybean meal, corn flour, and microbial liquid are mixed and fermented at 36°C for 42 hours; in step S2, the seed meal is crushed and mixed with plant lactobacillus liquid, and fermented and cultured at 36°C for 24 hours. The remaining steps are the same as in Example 1.

[0022] Example 3

[0023] The present embodiment of a Eucommia leaf compound feed additive and preparation method comprises the following components in weight: 90 parts of fermented Eucommia leaf powder, 20 parts of Eucommia seed meal, 5 parts of Chinese medicine extract, 2 parts of microbial preparation, 10 parts of biochar modified montmorillonite, and 10 parts of yeast cell wall extract. The preparation is carried out according to the above method, wherein the Eucommia leaf harvested in step S1 of the preparation process is vacuum dried, the Eucommia leaf powder is mixed with the enzyme aqueous solution and then cooled to 37°C, soybean meal, corn flour, and microbial liquid are mixed and fermented at 37°C for 36h; in step S2, the seed meal is crushed and mixed with plant lactobacillus liquid, and fermented and cultured at 35°C for 24 hours. The remaining steps are the same as in Example 1.

[0024] In other embodiments, a composite feed additive of Eucommia leaf may include 60-90 parts of fermented Eucommia leaf powder, 10-20 parts of Eucommia seed meal, 1-5 parts of Chinese medicine extract, 2-10 parts of microbial preparation, 5-10 parts of biochar modified montmorillonite, and 2-10 parts of yeast cell wall extract. A preparation method of a composite feed additive of Eucommia leaf: after mixing the Eucommia leaf powder and the enzyme aqueous solution, the temperature may be lowered to any degree Celsius of 35-37°C, and after mixing with soybean meal, corn flour, and microbial bacterial liquid, the temperature may be fermented at any temperature of 35-37°C for 36-48h; after crushing the seed meal, the seed meal may be mixed with the plant lactobacillus liquid, and fermented and cultured at any temperature of 35-37°C for 24 hours.

[0025] The content of active ingredients in the whole leaf of Eucommia ulmoides after crushing in step S1 in Examples 1 to 3 was determined, including chlorogenic acid, rutin, geniposide, aucubin, total polyphenols, and total flavonoids, wherein chlorogenic acid, rutin, geniposide, and aucubin were determined by liquid spectrometry-mass spectrometry (LC-MS); the determination of total polyphenol content was carried out in accordance with GBT8313-2018, with gallic acid as the standard, and its absorbance was determined at 760 nm by an ultraviolet spectrophotometer to draw a standard curve, the regression equation was y=9.5917x + 0.0164, R²= 0.9993, and the linear range was 0.01-0.06 mg / mL. The sample determination method is the same as the standard curve determination method, and the total polyphenol content of Eucommia ulmoides leaves is calculated according to the standard curve. The determination results are expressed as the polyphenol content per gram of dried Eucommia ulmoides leaves; the total flavonoid content is determined using rutin as the standard, and its absorbance is measured at 506 nm by an ultraviolet spectrophotometer and a standard curve is drawn. The regression equation is y = 10.063x + 0.0154, R² = 0.9997, and the linear range is 0.01-0.06 mg / mL. The sample determination method is the same as the standard curve determination method, and the total flavonoid content of Eucommia ulmoides leaves under different drying methods is calculated according to the standard curve. The determination results are expressed as the flavonoid content per gram of dried Eucommia ulmoides leaves. The results are shown in Table 1: Table 1 Content of active ingredients in crushed whole leaves of Eucommia ulmoides (mg / g)

[0026] According to the above method, the mean values ​​of chlorogenic acid, rutin, geniposide, aucubin, total polyphenols and total flavonoids of the eucommia leaf powder after crushing and sieving the eucommia leaves in Examples 1 to 3 and the fermented eucommia leaves were respectively measured. The results are shown in Table 2: Table 2 Contents of active ingredients in Eucommia ulmoides leaves under different treatments

[0027] As shown in Tables 1 and 2, the Eucommia leaf powder after crushing and sieving to remove petioles and veins is Eucommia leaf powder with high active ingredient content, and the active ingredient content of Eucommia leaf powder and fermented Eucommia leaf is better than the active ingredient content of the whole leaf of Eucommia leaf crushed, which shows that the fermented Eucommia leaf after being treated by the method of this embodiment is a fermented Eucommia leaf with high active ingredient content, which can be industrialized and mass-produced. And Eucommia leaf can promote the reproduction of probiotics, with a high probiotic content, and can also improve the reproductive performance, body immunity, reduce stress, antibacterial and antiviral, improve production performance, and improve product quality of animals.

[0028] The contents of α-linolenic acid, polypeptide, aucubin and amino acid in the Eucommia seed meal before and after the treatment in step S2 in Examples 1 to 3 were determined, and the average values ​​were taken. The results are shown in Table 3. Among them, α-linolenic acid was detected by gas chromatography, the polypeptide content was determined by the biuret method, aucubin was extracted by ultrasound-assisted method, and the amino acid content was determined by a fully automatic amino acid analyzer.

[0029] Table 3 Content of active ingredients in Eucommia ulmoides seed meal before and after treatment (mg / g)

[0030] It can be seen from the above table that after the treatment in step S2 of the preparation method of this embodiment, the active ingredients of the eucommia seed meal after treatment are significantly increased, among which the content of aucubin in the eucommia seed meal after the treatment in step S2 is increased, and part of the protein is decomposed into small molecule polypeptides. It has a good diuretic function, prevents the increase of uric acid, and causes gout. The method of this embodiment mixes the eucommia seed meal, fermented eucommia leaves with traditional Chinese medicine extracts, biochar-modified montmorillonite, and yeast cell wall extract according to a weight fraction ratio to obtain a eucommia leaf composite feed additive of this embodiment. The eucommia leaf composite feed additive prepared in this embodiment was used for feeding experiments on laying hens, and the feeding process and results are as follows: 960 healthy 26-week-old Hailan brown-shell laying hens with similar egg production rate and body weight were selected and randomly divided into 4 groups, with 6 replicates in each group and 40 hens in each replicate. There was no significant difference in body weight and egg production between groups and replicates (P>0.05). A single-factor completely randomized experimental design was used, with group A as the control group, and groups B, C, and D adding 0.2%, 0.4%, and 0.8% additives to their feed, respectively. The pre-test period was 2 weeks, and the full test period was 10 weeks.

[0031] During the experiment, the health status of laying hens was observed every day, and the egg quality, egg production, and number of soft and broken eggs were recorded. The feed consumption was recorded every week, and the average egg quality, egg production rate, daily feed intake, and feed-to-egg ratio were calculated.

[0032] Egg quality index: On the 35th and 70th days of the formal test, 15 eggs were randomly selected from each repetition, and the egg quality indexes such as albumen height, Haugh unit, yolk color, and egg shape index were measured using the EMT5200 egg quality tester; 10 eggs were randomly selected from each repetition to measure the cholesterol and triglyceride content of eggs. The eggshell strength and eggshell thickness were measured using a series of egg quality testers produced by ORKA, Israel; the cholesterol determination method was as follows: 3 g of egg liquid was weighed, diluted with 27 mL of 2% NaCl solution, shaken on a shaker at room temperature for 2 hours, 1.0 mL of the mixed solution was taken, and 9 mL of 2% NaCl dilution was added to prepare the sample to be tested, and the operation was carried out according to the instructions of the total cholesterol kit, which was purchased from Nanjing Jiancheng Biological Research Institute.

[0033] Blood biochemical indices: On the 35th and 70th days of the experiment, 5 chickens were randomly selected from each replicate, blood was collected from the wing vein on an empty stomach, serum was separated by centrifugation and stored at -20°C, and the concentrations of triglyceride, total cholesterol, high-density lipoprotein and low-density lipoprotein in serum were measured by automatic biochemical analyzer (Hitachi 7180, Beijing). The triglyceride kit and total cholesterol kit were purchased from Shanghai Kehua Reagent, and the high-density lipoprotein cholesterol kit and low-density lipoprotein cholesterol kit were purchased from Zhejiang Yilikang Biotechnology Co., Ltd. The triglyceride concentration was determined by the GPO-PAP method, the total cholesterol concentration was determined by the COD-PAP method, the high-density lipoprotein cholesterol concentration was determined by the phosphotungstic acid-magnesium precipitation method, and the low-density lipoprotein cholesterol concentration was determined by the polyethylene sulfate precipitation method.

[0034] The obtained data were processed and analyzed by SPSS10.0 Oneway ANOVA procedure, and Duncan's method was used for multiple comparisons. P<0.05 was considered significant difference. The results were expressed as "mean ± standard deviation". See Tables 4 to 6 below: Table 4 Production performance of laying hens treated with different contents of Eucommia leaf compound feed additives

[0035] Table 5 Egg quality of laying hens treated with different contents of Eucommia leaf compound feed additives

[0036] Table 6 Blood fat metabolism indexes of laying hens treated with different contents of Eucommia leaf compound feed additives

[0037] Among them, different letters in the same row indicate significant differences (P < 0.05), and the same or no letters indicate no significant differences (P > 0.05).

[0038] As shown in Tables 4 to 6, the food intake of laying hens fed with the Eucommia leaf composite feed additive prepared in this embodiment did not change, the egg production rate increased, the soft egg breakage rate and the chicken mortality rate decreased, antibiotics were not required, and vaccines were basically not required. The Haugh index of eggs was improved, cholesterol was significantly reduced, triglycerides were reduced, and there was no fishy smell. The total cholesterol and triglyceride levels in the blood of laying hens were reduced, the high-density lipoprotein content was increased, and the low-density lipoprotein content was reduced.

[0039] It can be seen that the eucommia leaf composite feed additive prepared by the preparation method of this embodiment not only has highly active ingredients, but also can improve the production performance of laying hens, increase the egg production rate of laying hens, reduce the rate of soft and broken eggs, maintain animal health, reduce total cholesterol, triglycerides, and low-density lipoprotein levels in the blood, increase the high-density lipoprotein content, and reduce its mortality rate without the use of antibiotics and vaccines.

[0040] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solutions formed by the specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A composite feed additive of Eucommia ulmoides leaves, characterized in that: The invention comprises the following components in parts by weight: 60-90 parts of fermented eucommia leaf powder, 10-20 parts of eucommia seed meal, 1-5 parts of traditional Chinese medicine extract, 2-10 parts of microbial preparation, 5-10 parts of biochar modified montmorillonite and 2-10 parts of yeast cell wall extract.

2. A method for preparing the Eucommia leaf composite feed additive according to claim 1, characterized in that: The steps include: S1: preparing fermented Eucommia ulmoides leaf powder; S2: preparing eucommia seed meal; S3: Preparation of Chinese herbal medicine extract: 1.5 kg of Rehmannia root, 1.5 kg of Angelica sinensis, 1.5 kg of Crataegus pinnatifida, and 0.5 kg of Alisma orientalis were taken, crushed, and then extracted with hot water. The extraction conditions were as follows: temperature 60°C, time 3 h, solid-liquid ratio 1:15, and concentrated under reduced pressure, vacuum dried, and then crushed to obtain the Chinese herbal medicine extract; S4: preparing a microbial preparation: uniformly mixing Bifidobacterium adolescentis, Bacillus subtilis, Lactobacillus plantarum and konjac gum solution, and spray drying the mixture; S5: preparing biochar-modified montmorillonite: mixing montmorillonite and plant tannin extract at a mass ratio of 1:1-1:20, and heat-treating at above 400°C in an oxygen-free environment to obtain biochar-modified montmorillonite; S6: The products prepared in S1-S5 are mixed or granulated with the yeast cell wall extract according to weight proportions to obtain the Eucommia leaf composite feed additive.

3. The method for preparing a composite feed additive of Eucommia ulmoides leaves according to claim 2, characterized in that: The specific steps of preparing the fermented eucommia leaves in step S1 are as follows: selecting the eucommia Qinzhong No. 1 improved variety, planting in a leaf forest model, harvesting in summer and autumn, and low-temperature drying, microwave drying or vacuum drying to obtain eucommia leaves with a moisture content of less than 13%, crushing and sieving the eucommia leaves, and then solid-state fermenting them with enzymes and microbial bacterial liquid, and low-temperature drying to obtain fermented eucommia leaf powder.

4. A composite feed additive of Eucommia ulmoides leaves and a preparation method thereof according to claim 3, characterized in that: The dried eucommia leaves are crushed twice with a grinder, each time for 30 seconds, and then passed through a 30-mesh sieve to remove petioles and veins to obtain eucommia leaf powder. 100g of cellulase and 150g of pectinase are added to 150L of water to prepare an enzyme aqueous solution. 30kg of eucommia leaf powder and the enzyme aqueous solution are mixed evenly, and enzymolysis is performed at 50°C for 2.0h. The mixture is cooled to 35-37°C, 5kg of soybean meal and 5kg of corn flour are added, and then 20L of microbial culture liquid is added. The mixture is fermented at 35-37°C for 36-48h, and then vacuum dried at 45°C until the moisture content is less than 13% to obtain the fermented eucommia leaf powder.

5. A composite feed additive of Eucommia ulmoides leaves and a preparation method thereof according to claim 4, characterized in that: The cellulase is greater than 0.3u / mg, the pectinase is greater than 0.3u / mg, the microbial liquid includes plant lactobacillus, enterococcus faecalis and bifidobacterium adolescentis, wherein the plant lactobacillus is not less than 8×10 8 cfu / mL, Enterococcus faecalis not less than 3×10 8 cfu / mL, Bifidobacterium adolescentis not less than 3×10 7 cfu / mL.

6. A composite feed additive of Eucommia ulmoides leaves and a preparation method thereof according to claim 2, characterized in that: The specific steps of preparing the eucommia seed meal in step S2 are as follows: selecting mature eucommia seeds harvested in the current year, squeezing oil through a low-temperature pressing method to obtain seed meal, crushing 3 kg of seed meal and mixing it with 20 L of plant lactobacillus liquid, fermenting and culturing at 35-37° C. for 24 hours, then adding neutral protease to enzymatically hydrolyze the protein at 50° C. for 2 hours, finally concentrating at 45° C. under reduced pressure, and vacuum drying at 45° C. to obtain the eucommia seed meal.

7. A composite feed additive of Eucommia ulmoides leaves and a preparation method thereof according to claim 6, characterized in that: The plant lactobacillus liquid is not less than 8×10 8 cfu / mL, and the protein in the neutral protease is greater than 400 u / mg.

8. A Eucommia leaf composite feed additive and preparation method according to claim 2, characterized in that: In step S4, the amount of Bifidobacterium adolescentis is 10×10 8 cfu / mL, Bacillus subtilis not less than 5×10 8 cfu / mL, Lactobacillus plantarum not less than 10×10 8 cfu / mL, and mixed evenly with 0.02g / mL konjac gum solution.

9. A Eucommia leaf composite feed additive and preparation method according to claim 2, characterized in that: The tannin content of the plant tannin extract in step S5 is greater than 500 mg / g.

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