A feed additive to improve rumen digestion efficiency in livestock and its preparation method

Abstract

This invention discloses a feed additive for improving rumen digestion efficiency in livestock and its preparation method, belonging to the field of animal feed additive technology. It utilizes nano-magnesium oxide intercalated into bentonite particles as a feed additive to promote food absorption and improve digestion efficiency. Urea is adsorbed into zeolite, and the esterification reaction between the surface hydroxyl groups and the carboxyl groups of acrylic acid solution forms a spatial network structure of starch-grafted modified acrylic acid solution and protein supplement, further enhancing the sustained release of urea. By encapsulating composite amino acid particles within this spatial network structure, amino acid degradation in the rumen is reduced, promoting full absorption of amino acids in the small intestine, thereby improving amino acid utilization and promoting rumen microbial growth. Zeolite and bentonite synergistically reduce ammonia emissions and improve the feeding environment through the adsorption effect of the starch-grafted modified acrylic acid solution resin.

Description

Technical Field

[0001] This invention belongs to the field of animal feed additive technology, specifically relating to a feed additive that improves rumen digestion efficiency in livestock and its preparation method. Background Technology

[0002] Rumination refers to the process of partially digested food being regurgitated and chewed again after a period of time in the stomach. The stomachs of ruminants are typically divided into four chambers (camels have three): the rumen, reticulum, omasum, and abomasum. During rumination, food is slowly chewed to thoroughly mix and further break down fibers before being swallowed again. It then passes through the rumen to the omasum for dehydration, before being sent to the abomasum and finally to the small intestine for absorption. Current ruminant feeds often use crop straw as the main ingredient. However, the lignin, cellulose, and hemicellulose in straw are encapsulated by lignin, hindering enzyme breakdown. Furthermore, lignin itself is indigestible, making it difficult for animals to digest and absorb straw, thus reducing the nutritional value of existing feeds and failing to meet the nutritional needs of ruminants.

[0003] The degradation and utilization rate of nitrogenous substances in the digestive tract of ruminants is not coordinated with the degradation rate of energy carrier substances in the digestive tract. This will cause the degradation of energy carrier substances and nitrogen sources given to rumen microorganisms to be uncoordinated or asynchronous in the short term. Chinese patent announcement number CN106343182B announces a feed additive and its preparation method for reducing nitrogen excretion in ruminants. It involves spraying acrylic resin solution onto the surface of feed-grade urea, drying it, and then coating it with pregelatinized starch liquid. The coating layer is mainly formed by physical adhesion, and the bonding strength is relatively low, which cannot achieve a stable and long-lasting sustained-release effect. Summary of the Invention

[0004] The purpose of this invention is to provide a feed additive that improves the rumen digestion efficiency of livestock and its preparation method. By intercalating nano-magnesium oxide into bentonite particles, it can be used as a feed additive to help promote food absorption and improve digestion efficiency. Urea is adsorbed in zeolite, and the esterification reaction between the hydroxyl groups on the surface and the carboxyl groups of the acrylic acid solution forms a spatial network structure of starch-grafted modified acrylic acid solution and protein supplement, which further enhances the sustained-release effect of urea.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A method for preparing a feed additive that improves rumen digestion efficiency in livestock includes the following steps:

[0007] Step 1: Add an acrylic acid solution with a neutralization degree of 40-50% and deionized water to a reaction vessel and stir to mix. Adsorb urea into zeolite powder to prepare a protein supplement. Then add the protein supplement and gelatinized starch solution to the reaction vessel and stir for 1.5-2 hours at 55-60℃ and 400-500 r / min. Add sodium sulfite and hydroxymethylacrylamide to the reaction vessel and stir for 2-3 hours at 60-75℃ and 400-550 r / min. Filter and wash the filter cake 2-3 times with deionized water and anhydrous ethanol, respectively. Vacuum dry to obtain a composite nutrient slow-release agent.

[0008] Step 2: Nano-magnesium oxide is intercalated into bentonite particles to prepare a digestive aid. The digestive aid, compound nutrient slow-release agent, compound amino acid particles and microbial preparation are then added to a mixer in a mass ratio of 25:50:15:5 and mixed evenly. The mixture is then placed in a feed pellet mill to granulate, resulting in a feed additive that improves the rumen digestion efficiency of livestock.

[0009] Furthermore, in step one, the ratio of acrylic acid solution, deionized water, protein supplement, gelatinized starch solution, sodium sulfite, and hydroxymethylacrylamide is 200-300mL: 400-500mL: 15-18g: 180-200mL: 0.5-0.7g: 0.3-0.5g.

[0010] Furthermore, in step two, the composite amino acid particles are prepared by dry granulation of carboxymethyl cellulose, cysteine, and methionine at a mass ratio of 20-30g: 4-5g: 5-6g.

[0011] Furthermore, the microbial preparation is any one or more of Bacillus subtilis, lactic acid bacteria, and ruminant yeast in any mass ratio.

[0012] Furthermore, the gelatinized starch solution is prepared through the following steps:

[0013] Starch and deionized water are added to a reaction vessel and gelatinized under a nitrogen atmosphere at 80-90℃ and 500-600 r / min for 30-40 min. The mixture is then cooled to 55-65℃ to obtain a gelatinized starch solution.

[0014] Furthermore, the ratio of starch to deionized water is 20-30g: 200-300mL.

[0015] Furthermore, the specific preparation steps for protein supplements are as follows:

[0016] Zeolite powder with a particle size of 4-5 mm, dimethyl sulfoxide, and hexadecyltrimethylammonium bromide were added to a reaction vessel and stirred at 50-60℃ and 500-600 r / min for 1-2 h. Urea was dissolved in anhydrous ethanol and added dropwise to the reaction vessel. Stirring was continued for 4-5 h. The mixture was aged at 65-70℃ for 24-26 h. The product was washed 2-3 times by centrifugation with deionized water and dried under vacuum at 60-80℃ for 1-2 h to obtain the protein supplement.

[0017] Furthermore, the ratio of zeolite powder, dimethyl sulfoxide, hexadecyltrimethylammonium bromide, urea and anhydrous ethanol is 20-30g: 200-300mL: 2-3g: 30-50g: 400-500mL.

[0018] Furthermore, the specific preparation steps for the digestive aid are as follows:

[0019] Bentonite with a particle size of 2-3 μm and anhydrous ethanol were added to a reaction vessel and stirred. Then, anhydrous acetic acid and nitric acid solution with a concentration of 0.5-0.6 mol / L were added. The mixture was stirred at 20-25℃ and 800-900 r / min for 1-2 h. NaOH solution with a concentration of 0.8-0.9 mol / L was added dropwise and the mixture was aged at 65-70℃ for 24-26 h. Magnesium oxide nanoparticles with a particle size of 50-60 nm were ultrasonically dispersed in deionized water and added to the reaction vessel. The mixture was stirred for 40-50 min and aged at 65-70℃ for 24-26 h. The product was washed 2-3 times by centrifugation with deionized water and vacuum dried at 60-80℃ for 1-2 h to obtain a digestive aid.

[0020] Furthermore, the ratio of bentonite, anhydrous ethanol, anhydrous acetic acid, nitric acid solution, NaOH solution, nano magnesium oxide, and deionized water is 20-30g: 400-500mL: 8-10mL: 2-3mL: 1-2mL: 40-50g: 500-600mL.

[0021] The beneficial effects of this invention are:

[0022] 1. The present invention provides a feed additive that improves the rumen digestion efficiency of livestock, facilitates digestion, increases the utilization rate of amino acids, and slows down the loss of urea nitrogen.

[0023] 2. The nano-magnesium oxide of this invention has a negatively charged surface that forms bonds with the cations on the surface of bentonite particles, thereby enhancing the structural stability of the bentonite and allowing it to be uniformly intercalated within the bentonite. The nano-magnesium oxide can promote the dispersion of bentonite particles, making the composition of the feed more uniform, which helps to improve the uniformity and mixability of the feed, ensuring that animals can obtain balanced nutrition when ingesting feed. Furthermore, nano-magnesium oxide is an alkaline substance, and by intercalating within bentonite, it can better neutralize stomach acid, promote the digestion and absorption of food, and improve digestive efficiency.

[0024] 3. The protein supplement of this invention can serve as a nitrogen source, providing animals with the necessary nitrogen element. Zeolite possesses excellent adsorption and cation exchange properties, which can slow down the loss of urea nitrogen. The spatial network structure of the protein supplement and the starch-grafted modified acrylic acid solution further slows down the loss of urea nitrogen and the conversion of urea nitrogen to NH4+. + The conversion rate of -N increases the synthesis rate of rumen microbial proteins; when urea decomposes in animals, it produces ammonia, and zeolite and bentonite can work together with starch-grafted modified acrylic resin to reduce ammonia emissions and reduce odor in the environment.

[0025] 4. Protein supplements can undergo esterification reactions between the hydroxyl groups on their surface and the carboxyl groups of the acrylic acid solution, forming a spatial network structure of starch-grafted modified acrylic acid solution and protein supplements. This further enhances the sustained release of urea. Furthermore, by encapsulating the complex amino acid particles within this spatial network structure, the combined adsorption of resin and zeolite reduces the degradation of amino acids in the rumen, promotes the full absorption of amino acids by the small intestine, thereby improving the utilization rate of amino acids and promoting the growth of rumen microorganisms. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1: A method for preparing a feed additive that improves rumen digestion efficiency in livestock, comprising the following steps:

[0028] S1: 20g of bentonite with a particle size of 2-3μm and 400mL of anhydrous ethanol were added to a reaction vessel and stirred. Then, 8mL of anhydrous acetic acid and 2mL of 0.5mol / L nitric acid solution were added. The mixture was stirred at 20℃ and 800r / min for 1h. 1mL of 0.8mol / L NaOH solution was added dropwise and the mixture was aged at 65℃ for 24h. 40g of nano-magnesium oxide with a particle size of 50-60nm was ultrasonically dispersed in 500mL of deionized water and added to the reaction vessel. The mixture was stirred for 40min and aged at 65℃ for 24h. The product was washed three times by centrifugation with deionized water and vacuum dried at 60℃ for 1h to obtain the digestive aid.

[0029] Nano-magnesium oxide has a negatively charged surface, which can adsorb water molecules and form bonds with cations on the surface of bentonite particles. Through intercalation, the interlayer spacing of bentonite is increased, thereby improving its adsorption performance and strengthening the structural stability of bentonite. Nano-magnesium oxide can also promote the dispersion of bentonite particles, making the composition of feed more uniform. This helps to improve the uniformity and mixability of feed, ensuring that animals can obtain balanced nutrition when ingesting feed. Nano-magnesium oxide is an alkaline substance that can neutralize stomach acid and promote the digestion and absorption of food. Nano-magnesium oxide can stimulate intestinal peristalsis, which helps food move and digest in the intestines, improving digestive efficiency.

[0030] S2: Add 20g of zeolite powder with a particle size of 4-5mm, 200mL of dimethyl sulfoxide and 2g of hexadecyltrimethylammonium bromide to a reaction vessel, stir for 1h at 50℃ and 500r / min, dissolve 30g of urea in 400mL of anhydrous ethanol and add it dropwise to the reaction vessel, continue stirring for 4h, age at 65℃ for 24h, wash the product three times by centrifugation with deionized water, and vacuum dry at 60℃ for 1h to obtain the protein supplement.

[0031] Protein supplements can serve as a nitrogen source, providing animals with the necessary nitrogen. Zeolite possesses excellent adsorption and cation exchange properties, which can slow down the loss of urea nitrogen and reduce its conversion to NH4+. + -N conversion rate; when urea decomposes in animals, it produces ammonia, and the adsorption effect of zeolite can reduce ammonia emissions and reduce odor in the environment.

[0032] S3: Add 20g starch and 200mL deionized water to a reactor. Under a nitrogen atmosphere, gelatinize the starch at 80℃ and 500r / min for 30min. Cool to 55℃ to obtain gelatinized starch solution. Add 200mL acrylic acid solution with a neutralization degree of 40% and 400mL deionized water to the reactor. Add 15g protein supplement and 180mL gelatinized starch solution to the reactor. Stir at 55℃ and 400r / min for 1.5-2h. Add 0.5g sodium sulfite as an initiator and 0.3g hydroxymethylacrylamide as a crosslinking agent to the reactor. Heat to 60℃ and stir at 400r / min for 2h. Filter the mixture. Wash the filter cake twice with deionized water and anhydrous ethanol, respectively. Vacuum dry at 60℃ for 1h to obtain a composite nutrient slow-release agent.

[0033] Protein supplements can undergo esterification reactions between the hydroxyl groups on their surface and the carboxyl groups of the acrylic solution, forming a spatial network structure of starch-grafted modified acrylic solution and protein supplements. This achieves resin encapsulation and enhances the sustained release of urea.

[0034] S4: 20g of carboxymethyl cellulose, 4g of cysteine ​​and 5g of methionine are processed into compound amino acid granules by dry granulation; digestive aid, compound nutrient slow-release agent, compound amino acid granules and Bacillus subtilis are added to a mixer in a mass ratio of 25:50:15:5 and mixed evenly, and then placed in a feed pellet mill for granulation to obtain a feed additive that improves the rumen digestion efficiency of livestock.

[0035] By encapsulating compound amino acid particles in a spatial network structure of starch-grafted modified acrylic acid solution and protein supplement, the adsorption of resin and zeolite is utilized to reduce the degradation of amino acids in the rumen, promote the full absorption of amino acids by the small intestine, thereby improving the utilization rate of amino acids and promoting the growth of rumen microorganisms.

[0036] Example 2: A method for preparing a feed additive that improves rumen digestion efficiency in livestock, comprising the following steps:

[0037] S1: 25g of bentonite with a particle size of 2-3μm and 450mL of anhydrous ethanol were added to a reaction vessel and stirred. Then, 9mL of anhydrous acetic acid and 2.3mL of 0.55mol / L nitric acid solution were added. The mixture was stirred at 23℃ and 850r / min for 1.5h. 1.2mL of 0.85mol / L NaOH solution was added dropwise and the mixture was aged at 68℃ for 25h. 45g of nano-magnesium oxide with a particle size of 50-60nm was ultrasonically dispersed in 550mL of deionized water and added to the reaction vessel. The mixture was stirred for 45min and aged at 68℃ for 25h. The product was washed three times by centrifugation with deionized water and vacuum dried at 70℃ for 1.2h to obtain the digestive aid.

[0038] S2: Add 25g of zeolite powder with a particle size of 4-5mm, 250mL of dimethyl sulfoxide and 2.3g of cetyltrimethylammonium bromide to a reaction vessel and stir for 1.2h at 55℃ and 550r / min. Dissolve 45g of urea in 450mL of anhydrous ethanol and add it dropwise to the reaction vessel. Continue stirring for 4.5h and age at 68℃ for 25h. Wash the product three times with deionized water by centrifugation and dry it under vacuum at 70℃ for 1.2h to obtain the protein supplement.

[0039] S3: Add 25g starch and 250mL deionized water to a reactor. Under a nitrogen atmosphere, gelatinize the starch at 85℃ and 550r / min for 35min. Cool to 60℃ to obtain a gelatinized starch solution. Add 250mL of acrylic acid solution with a neutralization degree of 45% and 450mL of deionized water to the reactor. Add 17g of protein supplement and 190mL of gelatinized starch solution to the reactor. Stir at 58℃ and 450r / min for 1.8h. Add 0.6g of sodium sulfite as an initiator and 0.4g of hydroxymethylacrylamide as a crosslinking agent to the reactor. Heat to 70℃ and stir at 450r / min for 2.3h. Filter the solution. Wash the filter cake twice with deionized water and anhydrous ethanol, respectively. Dry under vacuum at 70℃ for 1.2h to obtain a composite nutrient slow-release agent.

[0040] S4: 25g of carboxymethyl cellulose was crushed, and 4.5g of cysteine ​​and 5.6g of methionine were processed into compound amino acid granules by dry granulation. The digestive aid, compound nutrient slow-release agent, compound amino acid granules and lactic acid bacteria were added to a mixer in a mass ratio of 25:50:15:5 and mixed evenly. The mixture was then placed in a feed pellet mill for granulation to obtain a feed additive that improves the rumen digestion efficiency of livestock.

[0041] Example 3: A method for preparing a feed additive that improves rumen digestion efficiency in livestock, comprising the following steps:

[0042] S1: 30g of bentonite with a particle size of 2-3μm and 500mL of anhydrous ethanol were added to a reaction vessel and stirred. Then, 10mL of anhydrous acetic acid and 3mL of 0.6mol / L nitric acid solution were added. The mixture was stirred at 25℃ and 900r / min for 2h. 2mL of 0.9mol / L NaOH solution was added dropwise and the mixture was aged at 70℃ for 26h. 50g of nano-magnesium oxide with a particle size of 50-60nm was ultrasonically dispersed in 600mL of deionized water and added to the reaction vessel. The mixture was stirred for 50min and aged at 70℃ for 26h. The product was washed three times by centrifugation with deionized water and vacuum dried at 80℃ for 2h to obtain the digestive aid.

[0043] S2: Add 30g of zeolite powder with a particle size of 4-5mm, 300mL of dimethyl sulfoxide and 3g of hexadecyltrimethylammonium bromide to a reaction vessel, stir for 2h at 60℃ and 600r / min, dissolve 50g of urea in 500mL of anhydrous ethanol and add it dropwise to the reaction vessel, continue stirring for 5h, age at 70℃ for 26h, wash the product three times by centrifugation with deionized water, and vacuum dry at 80℃ for 2h to obtain the protein supplement.

[0044] S3: Add 30g starch and 300mL deionized water to a reactor. Under a nitrogen atmosphere, gelatinize the starch at 90℃ and 600r / min for 40min. Cool to 65℃ to obtain gelatinized starch solution. Add 300mL acrylic acid solution with a neutralization degree of 50% and 500mL deionized water to the reactor. Add 18g protein supplement and 200mL gelatinized starch solution to the reactor. Stir at 60℃ and 500r / min for 2h. Add 0.7g sodium sulfite as an initiator and 0.5g hydroxymethylacrylamide as a crosslinking agent to the reactor. Heat to 75℃ and stir at 550r / min for 3h. Filter the solution. Wash the filter cake three times with deionized water and anhydrous ethanol, respectively. Vacuum dry at 80℃ for 2h to obtain a composite nutrient slow-release agent.

[0045] S4: 30g of carboxymethyl cellulose, 5g of cysteine ​​and 6g of methionine are processed into compound amino acid granules by dry granulation; Bacillus subtilis, lactic acid bacteria and ruminant yeast are mixed in a mass ratio of 1:1:3 to obtain a microbial preparation; digestive aid, compound nutrient slow-release agent, compound amino acid granules and microbial preparation are added to a mixer in a mass ratio of 25:50:15:5 and mixed evenly, and then granulated in a feed pellet mill to obtain a feed additive that improves the rumen digestion efficiency of livestock.

[0046] In the examples, the raw materials such as Bacillus subtilis, lactic acid bacteria, and ruminant yeast were all commercially available products.

[0047] Comparative Example 1: Based on Example 3, according to the feed additive for reducing nitrogen excretion in ruminants and its preparation method disclosed in CN106343182B, the compound nutrient slow-release agent in step S3 was sprayed on the surface of commercially available urea, dried, and then coated with gelatinized starch liquid. The remaining steps remained unchanged, and a feed additive that improves rumen digestion efficiency in livestock was prepared.

[0048] Comparative Example 2: Based on Example 3, the digestive aid in step S1 was replaced with a mixture of bentonite and nano-magnesium oxide in a mass ratio of 3:5, while the other steps remained unchanged, to prepare a feed additive that improves the rumen digestion efficiency of livestock.

[0049] Comparative Example 3: Based on Example 3, the protein supplement in step S2 was replaced with a mixture of zeolite and urea in a mass ratio of 3:5, while the other steps remained unchanged, to prepare a feed additive that improves the rumen digestion efficiency of livestock.

[0050] Comparative Example 4: Based on Example 3, the compound nutrient slow-release agent in step S4 was omitted, while the other steps remained unchanged, to prepare a feed additive that improves the rumen digestion efficiency of livestock.

[0051] The reagents used in the examples and comparative examples were all purchased from commercially available sources.

[0052] The performance of the feed additives for improving rumen digestion efficiency in livestock prepared in Examples 1-3 and Comparative Examples 1-4 was tested. The test method is as follows: The feed additives were formulated according to the nutritional requirements of sheep by the US NRC (1998). The nutritional levels of each group were exactly the same. The feed additives were added strictly in accordance with the "Chinese Feed Additive Additive Standard". The daily feed contained the following components by percentage: 40 wt% hay, 32 wt% corn flour, 8 wt% soybean meal, 2 wt% limestone, 1 wt% salt and 1 wt% mineral mixture (mineral mixture includes niacin, manganese, zinc, iron, copper, selenium, iodine, cobalt, vitamin E, vitamin D and vitamin A). The daily diet of each group was accurately weighed and mixed in a mixer for 5 minutes. After sampling and testing, the qualified feed additives were fed to the test animals. The feed additives for reducing nitrogen excretion in ruminants prepared in Examples 1, 2 and 3 were fed according to conventional feeding management and immunization. The animals were fed concentrates first and roughage later at 5:00 and 17:00 every day. Water was available freely. The results are shown in Table 1.

[0053] Table 1 Performance Test Table of Feed Additives for Improving Rumen Digestion Efficiency in Livestock

[0054]

[0055]

[0056] As shown in Table 1, the feed additives for improving rumen digestion efficiency of livestock prepared in Examples 1-3, after being added to feed, showed significantly higher stomach pH, ​​ammonia nitrogen content, and microbial protein concentration than the comparative example, and significantly lower total nitrogen excretion than the comparative example. This indicates that the feed additives for improving rumen digestion efficiency of livestock prepared in this invention have good digestion-promoting ability, high protein utilization efficiency, and low urea nitrogen loss.

[0057] In Comparative Example 1, a compound nutrient slow-release agent was sprayed onto the surface of urea. After drying, it was coated with gelatinized starch solution. This coating layer was mainly formed by physical adhesion, with relatively low bonding strength. It was easily hydrolyzed by enzymes in the rumen. Under the action of rumen urease, urea would rapidly decompose into ammonia and carbon dioxide. The rate of ammonia release was much higher than the rate of absorption and utilization in the rumen, and it also exceeded the fermentation rate of carbohydrates in the rumen. This would lead to the accumulation of ammonia in the rumen, which could cause ammonia poisoning, resulting in a decrease in nitrogen content and an increase in total nitrogen excretion.

[0058] In Comparative Example 2, the digestive aid replaced the mixture of bentonite and nano-magnesium oxide. Through intercalation, the magnesium oxide particles were evenly dispersed in the interlayer structure of the bentonite, thereby enhancing the structural stability of the bentonite, reducing the aggregation of nano-magnesium oxide particles, and enabling it to better neutralize stomach acid. Furthermore, the intercalation increased the interlayer spacing of the bentonite, thus improving its adsorption performance. As a result, it could not better exert its adsorption effect, leading to a higher content of ammonia in the environment.

[0059] In Comparative Example 3, the protein supplement was replaced with a mixture of zeolite and urea. The surface-treated zeolite, through adsorption, allowed urea to be evenly dispersed in the structure of the zeolite, thereby slowing down the loss of urea.

[0060] In Comparative Example 4, the compound nutrient slow-release agent was omitted. The protein supplement can undergo an esterification reaction between the hydroxyl groups on its surface and the carboxyl groups of the acrylic solution, forming a spatial network structure of starch-grafted modified acrylic solution and protein supplement. The compound amino acid particles are coated in the spatial network structure, which reduces the degradation of amino acids in the rumen, promotes the full absorption of amino acids by the small intestine, thereby improving the utilization rate of amino acids and promoting the growth of rumen microorganisms.

[0061] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0062] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a feed additive that improves rumen digestion efficiency in livestock, characterized in that, Includes the following steps: Step 1: Add an acrylic acid solution with a neutralization degree of 40-50% and deionized water to a reaction vessel and stir to mix. Adsorb urea into zeolite powder to prepare a protein supplement. Then add the protein supplement and gelatinized starch solution to the reaction vessel and stir at 55-60℃ and 400-500 r / min for 1.5-2 h. Add sodium sulfite and hydroxymethylacrylamide to the reaction vessel and stir at 60-75℃ and 400-550 r / min for 2-3 h. Filter and wash the filter cake 2-3 times with deionized water and anhydrous ethanol, respectively. Vacuum dry to obtain a composite nutrient slow-release agent. Step 2: Nano-magnesium oxide is intercalated into bentonite particles to prepare a digestive aid. The digestive aid, compound nutrient slow-release agent, compound amino acid particles and microbial preparation are added to a mixer in a mass ratio of 25:50:15:5 and mixed evenly. The mixture is then placed in a feed pellet mill to granulate, thus obtaining a feed additive that improves the rumen digestion efficiency of livestock. The specific preparation steps for the protein supplement are as follows: Zeolite powder with a particle size of 4-5 mm, dimethyl sulfoxide, and hexadecyltrimethylammonium bromide were added to a reaction vessel and stirred at 50-60℃ and 500-600 r / min for 1-2 h. Urea was dissolved in anhydrous ethanol and added dropwise to the reaction vessel. Stirring was continued for 4-5 h. The product was aged at 65-70℃ for 24-26 h. The product was washed 2-3 times by centrifugation with deionized water and vacuum dried at 60-80℃ for 1-2 h to obtain the protein supplement. The specific preparation steps of the digestive aid are as follows: Bentonite with a particle size of 2-3 μm and anhydrous ethanol were added to a reaction vessel and stirred. Then, anhydrous acetic acid and nitric acid solution with a concentration of 0.5-0.6 mol / L were added. The mixture was stirred at 20-25℃ and 800-900 r / min for 1-2 h. NaOH solution with a concentration of 0.8-0.9 mol / L was added dropwise and the mixture was aged at 65-70℃ for 24-26 h. Magnesium oxide nanoparticles with a particle size of 50-60 nm were ultrasonically dispersed in deionized water and added to the reaction vessel. The mixture was stirred for 40-50 min and aged at 65-70℃ for 24-26 h. The product was washed 2-3 times by centrifugation with deionized water and vacuum dried at 60-80℃ for 1-2 h to obtain a digestive aid.

2. The method for preparing a feed additive to improve rumen digestion efficiency in livestock according to claim 1, characterized in that, The ratio of the amount of acrylic acid solution, deionized water, protein supplement, gelatinized starch solution, sodium sulfite and hydroxymethylacrylamide is 200-300mL: 400-500mL: 15-18g: 180-200mL: 0.5-0.7g: 0.3-0.5g.

3. The method for preparing a feed additive to improve rumen digestion efficiency in livestock according to claim 1, characterized in that, The ratio of the amount of zeolite powder, dimethyl sulfoxide, hexadecyltrimethylammonium bromide, urea and anhydrous ethanol is 20-30g: 200-300mL: 2-3g: 30-50g: 400-500mL.

4. The method for preparing a feed additive to improve rumen digestion efficiency in livestock according to claim 1, characterized in that, The ratio of bentonite, anhydrous ethanol, anhydrous acetic acid, nitric acid solution, NaOH solution, nano magnesium oxide and deionized water is 20-30g: 400-500mL: 8-10mL: 2-3mL: 1-2mL: 40-50g: 500-600mL.

5. The method for preparing a feed additive to improve rumen digestion efficiency in livestock according to claim 1, wherein the gelatinized starch solution in step one is prepared by the following steps: Starch and deionized water are added to a reaction vessel and gelatinized under a nitrogen atmosphere at 80-90℃ and 500-600r / min for 30-40 minutes. The mixture is then cooled to 55-65℃ to obtain a gelatinized starch solution. The ratio of starch to deionized water is 20-30g: 200-300mL.

6. The method for preparing a feed additive to improve rumen digestion efficiency in livestock according to claim 1, characterized in that, The composite amino acid particles described in step two are prepared by dry granulation of carboxymethyl cellulose, cysteine, and methionine in a mass ratio of 20-30:4-5:5-6.

7. The method for preparing a feed additive to improve rumen digestion efficiency in livestock according to claim 1, characterized in that, The microbial preparation mentioned in step two is any one or more of Bacillus subtilis, lactic acid bacteria, and ruminant yeast in any mass ratio.

8. A feed additive for improving rumen digestion efficiency in livestock, characterized in that, It is prepared by the preparation method described in any one of claims 1-7.

Images