A feed additive containing alfalfa extract and preparation method and application thereof

Abstract

The present application relates to the technical field of feed additives, and specifically discloses a feed additive containing alfalfa extract, and its preparation method and application. The feed additive of the present application includes the following components: 8-15 parts of banana peel dry powder, 1-5 parts of honeycomb dry powder, 4-6 parts of alfalfa extract, 0.01-0.05 parts of prebiotics, 0.007-0.012 parts of pigskin peptide, and 0.4-0.8 parts of amino acids; the preparation method of alfalfa extract is: add alfalfa hay powder and cellulase to ethanol aqueous solution, heat for 120-180min under the condition of 30-50℃, filter, and dry to obtain; the weight ratio of alfalfa hay powder, cellulase, and ethanol aqueous solution is 8-12: 0.005-0.015: 40-60; prebiotics are selected from straw mushroom polysaccharide and sennoside B. The feed additive provided in the present application is used to prepare laying hen feed, which can significantly improve the egg production rate of laying hens and the quality of eggs.

Description

Technical Field

[0001] The present application relates to the technical field of feed additives, and in particular to a feed additive comprising alfalfa extract and a preparation method and application thereof. Background Art

[0002] Feed is the cornerstone of animal growth and development. Feed can provide animals with various nutrients to support their life activities. The ingredients in feed, such as protein, fat, carbohydrates, vitamins and minerals, are all necessary for the healthy growth of animals.

[0003] Feed affects the physiological functions of animals. Different types of feed have unique effects on the metabolism, immune system and digestive system of animals. For example, some feed ingredients may have antioxidant, anti-inflammatory or antibacterial effects, which can help enhance the resistance of animals and reduce the occurrence of diseases. Therefore, when choosing feed, it is necessary to fully consider its effect on the physiological functions of animals to ensure the health of animals; by carefully formulating feed, it can ensure that animals get comprehensive and balanced nutrition, so as to help them thrive.

[0004] At present, laying hens are popular among farmers. The egg production and egg quality of laying hens mainly depend on the nutritional structure of feed and the feeding situation of the chickens. With the popularization of artificial feeding, various feed additives have emerged one after another. The nutrients contained in them make laying hens have poor digestion and absorption of feed, resulting in nutritional deficiencies in laying hens, resulting in reduced egg production and poor quality of eggs, which cannot meet the needs of consumers and reduce breeding benefits. Summary of the invention

[0005] In order to increase the egg production of laying hens while ensuring the quality of eggs, the present application provides a feed additive comprising alfalfa extract, and a preparation method and application thereof.

[0006] The present application provides a feed additive comprising alfalfa extract, which specifically comprises the following components in parts by weight:

[0007] 8-15 parts of banana peel powder, 1-5 parts of honeycomb powder, 4-6 parts of alfalfa extract, 0.01-0.05 parts of prebiotics, 0.007-0.012 parts of pig skin peptide, and 0.4-0.8 parts of amino acids;

[0008] The preparation method of the alfalfa extract is as follows: adding alfalfa hay powder and cellulase to a 40-60wt% ethanol aqueous solution, heating at 30-50°C for 120-180min, filtering to obtain a crude extract, and drying the crude extract to obtain the alfalfa extract; the weight ratio of the alfalfa hay powder, the cellulase, and the ethanol aqueous solution is 8-12:0.005-0.015:40-60;

[0009] The prebiotics are selected from one or more of Volvariella volvacea polysaccharide and sennoside B.

[0010] The present application optimizes the nutritional structure of animals by adjusting the formula of feed additives by adopting the above-mentioned technical scheme, obtains alfalfa extract by reacting alfalfa hay powder, cellulase and ethanol aqueous solution, and then prepares the feed additive by specific proportion with specific amounts of banana peel dry powder, honeycomb dry powder, prebiotics, pig skin peptides and amino acids as raw material components; the feed additive is used in combination with a basic diet to feed laying hens, which can significantly increase the egg production rate of laying hens, and can significantly increase the Haugh unit value and lecithin content of eggs, reduce the cholesterol content in eggs, and significantly improve the quality of eggs.

[0011] Alfalfa contains complex ingredients, and effective ingredients and ineffective ingredients coexist. Therefore, the enrichment of effective ingredients and effective parts is the key link that restricts drug development. The application optimizes the process of extracting effective ingredients from alfalfa. The inventor utilizes alfalfa hay powder, cellulase and ethanol aqueous solution of specific ratio to prepare alfalfa extract, which, as a functional additive, can provide multiple specific nutrients for laying hens. Alfalfa extract contains abundant vitamins and minerals, such as vitamin A, C, E and calcium, iron, zinc, etc., which all help to maintain the normal function of the body and enhance immunity. In addition, alfalfa also contains flavonoids and multiple amino acids, and these ingredients have remarkable effects for anti-oxidation, antibacterial, anti-inflammatory and improving cardiovascular health. Therefore, the application uses alfalfa extract as an additive for animal feed, which can improve the immunity of animals and improve their health.

[0012] The use of prebiotics in feed additives can enhance the immunity of laying hens and help them better cope with environmental stress and challenges. These ingredients help maintain the intestinal health of laying hens and promote the reproduction of beneficial bacteria, thereby enhancing the resistance of animals.

[0013] The present application attempts to use plant extracts and prebiotics in combination to examine the effects of the combination on the egg production rate and egg quality of laying hens; the results show that: during the experiment, it was found that: the functions of prebiotics and plant extracts are complex and diverse, different prebiotics and different plant extracts have different immune activation and regulation mechanisms, and the immunoregulatory effects of the combination of plant extracts and prebiotics are multifaceted; therefore, the development of an efficient and compatible prebiotic-plant extract biological preparation is the technical difficulty of the present application.

[0014] After many experiments, the inventors found that the use of one or two of the straw mushroom polysaccharides and sennoside B, which have the ability to improve immunity, as prebiotics, and alfalfa extract compounded, has a good application effect in laying hen production, and has a significant synergistic effect in improving laying hen production. Further, the honeycomb dry powder used in this application includes nutrients such as beeswax, honey, propolis, protein, minerals, and multiple vitamins, which have natural anti-inflammatory and immunity-enhancing properties, can help laying hens resist diseases, and banana peel dry powder, pig skin peptides, amino acids, and the above-developed straw mushroom polysaccharides, sennoside B prebiotic-alfalfa extract preparations can not only provide nutrition for laying hens, but also act as an auxiliary factor of immune stimulation, making the animal's digestive system more robust, thereby significantly improving the animal's body immunity, and then improving the laying rate of laying hens and the quality of eggs.

[0015] Preferably, the feed additive containing alfalfa extract specifically comprises the following components in parts by weight: 10-13 parts of banana peel dry powder, 2-4 parts of honeycomb dry powder, 4.5-5.5 parts of alfalfa extract, 0.02-0.04 parts of prebiotics, 0.008-0.010 parts of pig skin peptide, and 0.5-0.7 parts of amino acids.

[0016] Preferably, the feed additive containing alfalfa extract specifically comprises the following components in parts by weight: 11 parts of banana peel dry powder, 3 parts of honeycomb dry powder, 5 parts of alfalfa extract, 0.03 parts of prebiotics, 0.01 parts of pig skin peptide, and 0.6 parts of amino acids.

[0017] Preferably, in the method for preparing the alfalfa extract, the weight ratio of the alfalfa hay powder, the cellulase, and the ethanol aqueous solution is 9-11:0.008-0.012:45-55.

[0018] Preferably, the prebiotics are composed of a mixture of Volvariella polysaccharide and sennoside B in a weight ratio of 1-3:1-3.

[0019] Preferably, in the prebiotics, the amount of Volvariella volvacea polysaccharide is greater than the amount of sennoside B.

[0020] Preferably, the amino acid is selected from one or more of valine, methionine, lysine, histidine, isoleucine and tryptophan.

[0021] In a second aspect, the present application provides a method for preparing the above-mentioned feed additive containing alfalfa extract, which specifically comprises the following steps:

[0022] According to the ratio, the corresponding weight portions of the raw material components are weighed respectively, and the banana peel dry powder, honeycomb dry powder, alfalfa extract, prebiotics, pig skin peptide and amino acids are evenly mixed to obtain the feed additive.

[0023] In a third aspect, the present application provides a laying hen feed, which comprises the above-mentioned feed additive.

[0024] Preferably, the laying hen feed is composed of a mixture of the feed additive and the basic diet in a weight ratio of 1-2:93-97; the basic diet is composed of the following components in parts by weight: 65-75 parts of corn, 10-20 parts of soybean meal, 8-12 parts of bran, 3-8 parts of distiller's grains, 0.3-0.8 parts of soybean oil, and 2-6 parts of fish meal.

[0025] In summary, the technical solution of this application has the following effects:

[0026] The present application utilizes alfalfa hay powder, cellulase and ethanol aqueous solution to react to obtain alfalfa extract, and skillfully integrates the alfalfa extract with banana peel dry powder, honeycomb dry powder, prebiotics, pig skin peptides and amino acids into a feed formula to provide all-round health care effects for laying hens; thereby enhancing the gastrointestinal function of laying hens, improving the body's immunity, inhibiting or reducing the reproduction of Escherichia coli, Salmonella and the like, and having an antibacterial effect; at the same time, providing nutrition to the body, improving feed conversion rate, and maintaining the stability of egg production rate and the quality of the eggs produced.

[0027] The feed additive provided in the present application is used to prepare laying hen feed, which can enhance the gastrointestinal function of laying hens, improve the body's immunity, inhibit or reduce the reproduction of Escherichia coli, Salmonella, etc., and has an antibacterial effect. At the same time, it provides nutrition to the body, improves feed conversion rate, maintains the stability of egg production rate, and improves the egg production rate of laying hens and the quality of eggs. DETAILED DESCRIPTION

[0028] Beehive powder was purchased from Anguo Xuancao Trading Co., Ltd.; Volvariella volvacea polysaccharide (specification: 60%), elm ear polysaccharide (specification: 60%), bovine liver peptide, and pig skin peptide (product number: MF-010059) were purchased from Xinyang Mufan Biotechnology Co., Ltd.; sennoside B (B20381) and acanthoside B (B2168) were purchased from Shanghai Yuanye Biological Co., Ltd.; cellulase (enzyme activity: 3500u / g) and pectinase (enzyme activity: 35000u / g) were purchased from Cangzhou Xiasheng Enzyme Biotechnology Co., Ltd.; the remaining raw materials or reagents used can be obtained commercially.

[0029] The present application is further described in detail below in conjunction with examples, comparative examples and performance testing experiments. These examples should not be construed as limiting the scope of protection claimed in the present application. Example

[0030] Examples 1-7

[0031] Examples 1-7 provide a feed additive and laying hen feed, respectively.

[0032] The difference between the above embodiments is that the dosage of each component in the feed additive is different, as shown in Table 1.

[0033] The preparation method of the feed additive in the above embodiment is:

[0034] Preparation of alfalfa extract: add 10kg of alfalfa hay powder (≤40 mesh) and 0.01kg of cellulase to 50kg of 50wt% ethanol aqueous solution, heat at 65°C for 160min, filter to obtain a crude extract, dry the crude extract to obtain an alfalfa extract; the weight ratio of alfalfa hay powder, cellulase, and ethanol aqueous solution is 10:0.1:50.

[0035] According to Table 1, respectively weigh corresponding weights of banana peel dry powder (≤40 mesh), honeycomb dry powder, alfalfa extract, prebiotics (composed of a mixture of Volvariella volvacea polysaccharide and sennoside B in a weight ratio of 3:1), pig skin peptide, and amino acids (composed of a mixture of valine, methionine, lysine, histidine, isoleucine, and tryptophan glycoside in a weight ratio of 1:1:1:1:1:1) and mix them evenly to obtain a feed additive;

[0036] The preparation method of laying hen feed in the above embodiment is:

[0037] Preparation of basic daily diet: Weigh 70kg of corn, 15kg of soybean meal, 10kg of bran, 5kg of distiller's grains, 0.5kg of soybean oil, and 5kg of fish meal respectively, and mix them evenly.

[0038] Take 1.5 kg of feed additive and mix it evenly with 95 kg of basic diet to obtain laying hen feed.

[0039] Table 1 The dosage of each component in the feed additive in Examples 1-7 and Comparative Examples 1-3

[0040]

[0041] Embodiment 8-11

[0042] Examples 8-11 provide a feed additive and laying hen feed, respectively.

[0043] The difference between the above embodiment and embodiment 1 is that the preparation method of alfalfa extract is different, as shown below.

[0044] In Example 8: The preparation method of alfalfa extract is as follows: 8 kg of alfalfa hay powder (≤40 mesh) and 0.015 kg of cellulase are added to 50 kg of 50 wt% ethanol aqueous solution, heated at 40°C for 160 min, filtered to obtain a crude extract, and dried the crude extract to obtain an alfalfa extract; the weight ratio of alfalfa powder, honeycomb powder, and ethanol aqueous solution is 10:0.1:50.

[0045] In Example 9: The preparation method of alfalfa extract is as follows: 12 kg of alfalfa hay powder (≤40 mesh) and 0.005 kg of cellulase are added to 50 kg of 50 wt% ethanol aqueous solution, heated at 40°C for 160 min, filtered to obtain a crude extract, and dried the crude extract to obtain an alfalfa extract; the weight ratio of alfalfa powder, honeycomb powder, and ethanol aqueous solution is 10:0.1:50.

[0046] In Example 10: The preparation method of alfalfa extract is as follows: 9 kg of alfalfa hay powder (≤40 mesh) and 0.012 kg of cellulase are added to 50 kg of 50 wt% ethanol aqueous solution, heated at 40° C. for 160 min, filtered to obtain a crude extract, and dried the crude extract to obtain an alfalfa extract; the weight ratio of alfalfa powder, honeycomb powder, and ethanol aqueous solution is 10:0.1:50.

[0047] In Example 11: The preparation method of alfalfa extract is as follows: 11 kg of alfalfa hay powder (≤40 mesh) and 0.008 kg of cellulase are added to 50 kg of 50 wt% ethanol aqueous solution, heated at 40°C for 160 min, filtered to obtain a crude extract, and dried the crude extract to obtain an alfalfa extract; the weight ratio of alfalfa powder, honeycomb powder, and ethanol aqueous solution is 10:0.1:50.

[0048] The other raw materials and their amounts, feed additives and the preparation method of laying hen feed in the above examples are the same as those in Example 1.

[0049] Examples 12-17

[0050] Examples 12-17 provide a feed additive and laying hen feed, respectively.

[0051] The difference between the above embodiment and embodiment 1 is that the composition of prebiotics is different, as shown below.

[0052] In Example 12: the prebiotics are composed of a mixture of Volvariella polysaccharide and sennoside B in a weight ratio of 3:2.

[0053] In Example 13: the prebiotics are composed of a mixture of Volvariella polysaccharide and sennoside B in a weight ratio of 2:1.

[0054] In Example 14: the prebiotics are composed of a mixture of Volvariella polysaccharide and sennoside B in a weight ratio of 1:1.

[0055] In Example 15: the prebiotics are composed of a mixture of Volvariella polysaccharide and sennoside B in a weight ratio of 1:3.

[0056] In Example 16: the prebiotic is Volvariella volvacea polysaccharide.

[0057] In Example 17: the prebiotic is sennoside B.

[0058] The other raw materials and their amounts, feed additives and the preparation method of laying hen feed in the above examples are the same as those in Example 1. Comparative Example

[0059] Comparative Examples 1-3

[0060] Comparative Examples 1-3 provide a feed additive and laying hen feed, respectively.

[0061] The difference between the comparative example and Example 1 is that the dosage of each component in the feed additive is different, as shown in Table 1.

[0062] The composition of the raw materials, the preparation method of the feed additive and the preparation method of the laying hen feed in the above comparative example are the same as those in Example 1.

[0063] Comparative Examples 4-8

[0064] Comparative Examples 4-8 provide a feed additive and laying hen feed, respectively.

[0065] The differences between the above comparative example and Example 1 are specifically as follows.

[0066] In Comparative Example 4: The preparation method of alfalfa extract is as follows: 10 kg of alfalfa hay powder (≤40 mesh) is added to 50 kg of 50 wt% ethanol aqueous solution, heated at 65° C. for 160 min, filtered to obtain a crude extract, and dried the crude extract to obtain an alfalfa extract.

[0067] In Comparative Example 5: The preparation method of alfalfa extract is as follows: 10 kg of alfalfa hay powder (≤40 mesh) and 0.001 kg of pectinase are added to 50 kg of 50 wt% ethanol aqueous solution, heated at 65° C. for 160 min, filtered to obtain a crude extract, and dried the crude extract to obtain an alfalfa extract.

[0068] In Comparative Example 6, the prebiotics are composed of a mixture of ulmus auricula polysaccharide and sennoside B in a weight ratio of 3:1.

[0069] In Comparative Example 7: the prebiotics are composed of a mixture of Volvariella polysaccharide and Acanthopanax senticosus glycoside B in a weight ratio of 3:1.

[0070] In Comparative Example 8: an equal amount of bovine liver peptide was used to replace pig skin peptide.

[0071] The dosage of each raw material, the preparation method of the feed additive and the preparation method of the laying hen feed in the above comparative example are the same as those in Example 1.

[0072] Performance testing

[0073] The laying hen feed provided in Examples 1-17 and Comparative Examples 1-8 was used as the test object, and the egg production rate and egg quality of the laying hens after eating the laying hen feed were tested.

[0074] Experimental method: 48-week-old Hy-Line brown laying hens were selected and observed for one week. The egg production was roughly similar, the hens were healthy and disease-free, and the body shape was basically the same. The pre-trial period was 10 days. After adjusting the feed intake and egg production rate of the laying hens and finding no significant differences, the formal experiment began.

[0075] The laying hens were divided into 26 groups, each with 100 chickens. The feeding and management were carried out according to the routine: artificial lighting was supplemented in the morning and evening and natural lighting was combined during the day, with artificial lighting and natural lighting for 16 hours. The laying hens were fed with natural ventilation, feeding water and laying hen feed provided by Examples 1-17 and Comparative Examples 1-8. At the same time, the laying hens were fed with a basic diet as a control. The chickens were fed once at 8 am and 16 pm every day. At the same time, the chicken house environment was cleaned and disinfected every day according to the conventional method. The experimental period was 21 days; the feeding temperature was 25°C and the relative humidity was 50%. The health of the chickens was observed every day and the following indicators were tested.

[0076] The specific measurement indicators are:

[0077] (1) Egg production rate of laying hens

[0078] Eggs were collected once at 11:00 a.m. and 18:00 p.m. every day, the total number of eggs laid was collected, and the average daily egg production rate was calculated.

[0079] (2) Haff unit of egg

[0080] The Haugh unit of eggs is tested according to the method specified by the USDA egg standards to indicate the freshness of the eggs. The test method is: break the eggs and spread them on a platform, randomly select three equidistant points, use an albumen height meter to measure the albumen height, calculate the average of the three points, record it as the albumen height, and then calculate the Haugh unit value according to the following formula: Haugh unit value = 100 × lg (h + 7.57-1.7 × w 0.37 ), where h is the height of the egg white spread on the platform / mm; w is the mass of the egg / g.

[0081] The fresher the egg, the higher the egg white and the greater the Haugh Unit value of the egg; generally speaking, when the Haugh Unit value of an egg is lower than 70, it is assessed as not fresh.

[0082] (3) Lecithin content in eggs

[0083] With reference to the academic paper “Technology Research on Ultrasonic-Assisted Extraction of Egg Lecithin” (Food Industry Science and Technology, Issue 31, 2010), the organic solvent ultrasonic extraction method was used to determine the content of lecithin in eggs.

[0084] (4) Cholesterol content in eggs

[0085] Five laying hens in good basic condition were randomly selected from each experimental group, and 5 mL of blood was collected from the subwing vein and placed in a sodium heparin anticoagulant tube. After gently inverting twice, the tube was immediately centrifuged at 3000 rpm / min for 15 min to separate the serum, and the supernatant was aspirated to obtain the test serum; then the cholesterol content in the test serum was detected by an automatic biochemical analyzer and a kit. The cholesterol detection kit was purchased from Nanjing Jiancheng Bioengineering Research Institute (the specific operation was in accordance with the instructions of the manufacturer's product manual).

[0086] Test results: as shown in Table 2.

[0087] Table 2 Test results of egg production rate and egg quality of laying hens in Examples 1-17 and Comparative Examples 1-8

[0088]

[0089] Combined with Table 2, by comparing the test results of Examples 1-17 with Comparative Examples 1-8 and the control examples, the present application uses alfalfa hay powder, cellulase and ethanol aqueous solution to react to obtain alfalfa extract, and then prepares a feed additive with a specific amount of banana peel dry powder, prebiotics, pig skin peptides, and amino acids as raw material components in a specific ratio; the feed additive is used in combination with the basic diet for feeding laying hens, and the laying rate of laying hens is ≥88.1%, and the Haff unit value of the produced eggs is ≥84.5, the content of lecithin in the eggs is higher than 13.4wt%, and the content of cholesterol in the eggs is lower than 3.3wt‰. The above test results show that the use of the feed additives and laying hen feed provided by the present application can significantly improve the laying rate of laying hens, and can significantly improve the Haff unit value and lecithin content of eggs, reduce the cholesterol content in eggs, and significantly improve the quality of eggs.

[0090] By comparing the test results of Example 1-7 with that of Comparative Example 1-2, it can be seen that the dosage ratio of each raw material component in Comparative Example 1-2 is not appropriate, the content of lecithin in eggs is ≤10.02wt%, and the content of cholesterol in eggs is ≥3.96wt‰; in contrast, Example 1-7, through the specific dosage ratio relationship, makes the various components in the feed additive reasonably synergistic, so that the egg production rate of laying hens and the quality of eggs are significantly improved.

[0091] By comparing the test results of Examples 1, 8-11 with Comparative Examples 3-5, the feed additive in Comparative Example 3 does not contain alfalfa extract, the egg production rate of laying hens is 84.7%, and the Haugh unit value of the produced eggs is 80.1, the content of lecithin in the eggs is 8.09wt%, and the content of cholesterol in the eggs is 5.09wt‰, indicating that the egg production rate of laying hens and the quality of eggs are poor; in Comparative Example 4, cellulase is not added during the preparation of alfalfa extract, the content of lecithin in the eggs is 10.71wt%, and the content of cholesterol in the eggs is 3.64wt‰; Comparative Example 5 In the process of preparing alfalfa extract, the ratio of alfalfa hay powder, cellulase and ethanol aqueous solution is not appropriate, the content of lecithin in eggs is 11.28wt%, and the content of cholesterol in eggs is 3.46wt‰; In contrast, the embodiment of the present application uses alfalfa hay powder, cellulase and ethanol aqueous solution with a weight ratio of 8-12: 0.05-0.15: 40-60 to prepare alfalfa extract as a raw material for feed additives, so that the egg production rate and egg quality of laying hens are significantly improved. Further, the present application controls the weight ratio of alfalfa hay powder, cellulase and ethanol aqueous solution to 9-11: 0.08-0.12: 45-55.

[0092] By comparing the test results of Examples 1, 12-17 with Comparative Examples 6-8, the feed additives in Comparative Examples 6-7 are prebiotics composed of elm ear polysaccharides and sennoside B or prebiotics composed of volvacea polysaccharides and acanthoside B, the egg production rate of laying hens is ≤85.1%, and the Haff unit value of the produced eggs is ≤83.5, the content of lecithin in the eggs is 8.25wt%, and the content of cholesterol in the eggs is ≥3.46wt‰, indicating that the egg production rate of laying hens and the quality of eggs are poor; Comparative Example 8 replaces pig skin peptides with an equal amount of bovine liver peptides, and the Haff unit value of the produced eggs is 86.1, the content of lecithin in the eggs is 10.12wt%, and the content of cholesterol in the eggs is 5.05wt‰, indicating that the quality of the eggs is poor. In contrast, the feed additives prepared by using one or more of volvacea polysaccharides and sennoside B as prebiotics in the present application embodiment significantly improve the egg production rate and egg quality of laying hens. Furthermore, the present application utilizes a mixture of Volvariella polysaccharide and sennoside B in a weight ratio of 1-3:1-3 to form prebiotics.

[0093] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made thereto based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A feed additive comprising alfalfa extract, characterized in that: Specifically include the following components by weight: 8-15 parts of banana peel powder, 1-5 parts of honeycomb powder, 4-6 parts of alfalfa extract, 0.01-0.05 parts of prebiotics, 0.007-0.012 parts of pig skin peptide, and 0.4-0.8 parts of amino acids; The preparation method of the alfalfa extract is as follows: adding alfalfa hay powder and cellulase to a 40-60wt% ethanol aqueous solution, heating at 30-50°C for 120-180min, filtering to obtain a crude extract, and drying the crude extract to obtain the alfalfa extract; the weight ratio of the alfalfa hay powder, the cellulase, and the ethanol aqueous solution is 8-12: 0.005-0.015：40-60； The prebiotics are composed of a mixture of Volvariella polysaccharide and sennoside B in a weight ratio of 1-3:1-3.

2. The feed additive comprising alfalfa extract according to claim 1, characterized in that: Specifically, the invention comprises the following components in parts by weight: 10-13 parts of banana peel dry powder, 2-4 parts of honeycomb dry powder, 4.5-5.5 parts of alfalfa extract, 0.02-0.04 parts of prebiotics, 0.008-0.010 parts of pig skin peptide, and 0.5-0.7 parts of amino acids.

3. The feed additive comprising alfalfa extract according to claim 1, characterized in that: Specifically, the invention comprises the following components in parts by weight: 11 parts of banana peel dry powder, 3 parts of honeycomb dry powder, 5 parts of alfalfa extract, 0.03 parts of prebiotics, 0.01 parts of pig skin peptides, and 0.6 parts of amino acids.

4. The feed additive comprising alfalfa extract according to claim 1, characterized in that: In the preparation method of the alfalfa extract, the weight ratio of the alfalfa hay powder, the cellulase, and the ethanol aqueous solution is 9-11: 0.008-0.012: 45-55.

5. The feed additive comprising alfalfa extract according to claim 1, characterized in that: In the prebiotics, the amount of the Volvariella volvacea polysaccharide is greater than the amount of sennoside B.

6. The feed additive comprising alfalfa extract according to claim 1, characterized in that: The amino acid is selected from one or more of valine, methionine, lysine, histidine, isoleucine and tryptophan.

7. The method for preparing a feed additive comprising alfalfa extract according to any one of claims 1 to 6, characterized in that: The specific steps include: According to the ratio, the corresponding weight portions of the raw material components are weighed respectively, and the banana peel dry powder, honeycomb dry powder, alfalfa extract, prebiotics, pig skin peptide and amino acids are evenly mixed to obtain the feed additive.

8. A laying hen feed, characterized in that: The laying hen feed comprises the feed additive according to any one of claims 1 to 6.

9. The laying hen feed according to claim 8, characterized in that The laying hen feed is composed of a mixture of the feed additive and a basic diet in a weight ratio of 1-2:93-97; the basic diet is composed of the following components in weight parts: 65-75 parts of corn, 10-20 parts of soybean meal, 8-12 parts of bran, 3-8 parts of distiller's grains, 0.3-0.8 parts of soybean oil, and 2-6 parts of fish meal.

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