Compound feed additive for improving intramuscular fat deposition of beef cattle and preparation method of compound feed additive

Abstract

The invention relates to the technical field of feed, in particular to a compound feed additive for improving intramuscular fat deposition of beef cattle and a preparation method of the compound feed additive. The compound feed additive for improving intramuscular fat deposition of beef cattle is characterized by consisting of the following raw materials in parts by weight: 14-26 parts of coated amino acid, 2-8 parts of complex cellulose lytic enzyme, 2-6 parts of slow-release urea, 30-60 parts of rumen bypass protein or fermented rumen bypass protein and 18-32 parts of corn flour, the coated amino acid is obtained by coating amino acid with zein water. When the prepared compound feed additive for improving intramuscular fat deposition of beef cattle is added into daily ration, the growth of cattle can be effectively promoted, the protein digestibility is improved, and the marbling grade of beef and the intramuscular fat content of longissimus dorsi muscle are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of feed, in particular to a compound feed additive for improving intramuscular fat deposition of beef cattle and a preparation method thereof. BACKGROUND

[0002] In the beef cattle industry, intramuscular fat content is a key indicator for determining beef quality and marbling grade, and is directly related to its economic value and consumer experience. However, under the traditional fattening mode, there are technical bottlenecks such as low feed conversion efficiency and insufficient intramuscular fat deposition, which restrict the production of high-end beef. The existing technology often improves the fattening effect by increasing the proportion of concentrate or using conventional nutritional additives, but often leads to rumen function disorder, unbalanced nutrient utilization, and is difficult to simultaneously achieve efficient growth and high-quality meat quality.

[0003] In the practice of ruminant nutrition, although the application of over-the-rumen protein and coated amino acids can reduce the degradation of protein in the rumen, it cannot effectively eliminate the adverse effects of antinutritional factors such as trypsin inhibitors and lectins in plant protein raw materials on intestinal health and nutrient absorption. At the same time, ordinary urea has a too fast release rate in the rumen, which not only has low utilization efficiency, but also has the risk of ammonia poisoning. The single use of fiber-degrading enzymes or metabolic regulators also cannot achieve systematic regulation from rumen fermentation, intestinal absorption to tissue metabolism.

[0004] Therefore, how to promote intramuscular fat deposition and improve beef quality through scientific nutritional regulation means on the basis of ensuring animal health has become a key problem to be solved in the current beef cattle breeding field. Systematically optimizing the compatibility of feed ingredients and establishing a comprehensive nutritional strategy covering rumen function regulation, nutrient efficient utilization and metabolic directional regulation has important practical significance for achieving the simultaneous improvement of beef cattle growth performance and meat quality. SUMMARY

[0005] In view of the deficiencies in the prior art, the present application provides a compound feed additive for improving intramuscular fat deposition of beef cattle and a preparation method thereof.

[0006] To solve the above technical problems, the technical scheme adopted by the present application is as follows: A compound feed additive for improving intramuscular fat deposition of beef cattle, which is composed of the following raw materials by weight: 14-26 parts by weight of coated amino acids, 2-8 parts by weight of compound fiber-degrading enzyme, 2-6 parts by weight of slow-release urea, 30-60 parts by weight of over-the-rumen protein or fermented over-the-rumen protein, and 18-32 parts by weight of corn flour; the preparation method of the coated amino acids is as follows: adding amino acids into a corn alcohol-soluble protein aqueous solution, stirring to obtain the coated amino acids; the amino acids include at least one of lysine and methionine.

[0007] Methionine: As the main limiting amino acid for the growth of most animals, it is involved in the body's protein metabolism. Supplementing rumen-protected methionine in the diet can effectively pass through the rumen and be absorbed in the intestine, directly promoting the body's protein synthesis and cell proliferation and differentiation, and thus promoting the development of skeletal muscle in animals, thereby effectively improving the meat production performance of animals. At the same time, it is an important methyl donor in the body, which can provide methyl for the synthesis of creatine and phospholipids, and directly participate in and promote the deposition of intramuscular fat.

[0008] Lysine: is a key essential amino acid for protein synthesis in animal bodies, especially muscle tissue, and is one of the main limiting amino acids for beef cattle growth. Supplementing rumen-protected lysine in the diet can make up for the lack of lysine in rumen microbial protein, synergize with methionine, optimize the overall amino acid balance, and significantly improve protein deposition efficiency. Adequate lysine is the basis for building muscle tissue and provides a carbon skeleton for energy and fat metabolism, indirectly creating favorable conditions for the synthesis of intramuscular fat.

[0009] Complex fiber-degrading enzymes are exogenous biological catalysts designed to efficiently break down the anti-nutritional factors in the diet, cellulose and hemicellulose. Adding xylanase and cellulase can pre-decompose the fiber macromolecules that are difficult for rumen microorganisms to directly degrade into fermentable oligosaccharides and monosaccharides, thereby significantly improving rumen fiber degradation rate (NDF digestibility) and total volatile fatty acid (VFA) production. Not only does it improve the effective energy value of the diet, but more importantly, it significantly increases the proportion of propionic acid, which is a precursor for the synthesis of glucose and glycerol in the liver, ultimately providing sufficient raw materials for the synthesis of triglycerides (intramuscular fat).

[0010] Slow-release urea: is a non-protein nitrogen source designed to provide a stable and continuous supply of nitrogen for rumen microorganisms. Through special coating or slow-release technology, it controls the release rate of ammonia in the rumen, matching the speed of rumen microorganisms utilizing ammonia to synthesize microbial protein. This significantly improves nitrogen utilization efficiency and maximizes the synthesis of microbial protein (MCP). Microbial protein is the most important high-quality protein source for ruminants, and its production provides essential amino acids and peptides for intramuscular fat deposition. When slow-release urea is added in excess or the coating process is not proper, it can cause high ammonia concentration in the rumen, exceeding the utilization capacity of microorganisms, leading to ammonia poisoning. Using ordinary urea is riskier and has lower utilization efficiency due to its rapid release. Conversely, if the nitrogen source is insufficient, it will limit the proliferation of rumen microorganisms, leading to a decrease in microbial protein synthesis, and thus causing energy and fiber degradation disorders in the diet, resulting in low animal growth performance.

[0011] Preferably, the preparation method of the slow-release urea is as follows: 2-5 parts by weight of hydrogenated palm oil and 1-4 parts by weight of hydrogenated soybean oil are weighed, and they are completely melted at 80-100°C, then 0.1-0.5 parts by weight of triethyl citrate and 0.1-0.5 parts by weight of cinnamyl aldehyde are added, and stirring is continued for 20-50 min to obtain a mixed coating liquid; 30-45 parts by weight of urea particles with a particle size of 0.5-1.5 mm are added, and placed in a coating machine, and coated at an atomizing temperature of 78-90°C, an atomizing pressure of 0.1-0.2 MPa, a spraying speed of 3-10 mL / min, and for 30-80 min to obtain the slow-release urea.

[0012] Rumen-protected protein: refers to a protein raw material that is physically or chemically treated to significantly reduce its degradation rate in the rumen. It can effectively escape rumen fermentation and be completely digested into amino acids by digestive enzymes in the small intestine and absorbed. This provides double protein supply guarantee for the animal body, especially in the later fattening period, which can accurately meet the high demand of animals for specific amino acids (such as methionine and lysine) and directly provide effective raw materials for the synthesis of muscle and intramuscular fat.

[0013] Corn meal: mainly functions to carry and dilute active ingredients, and ensure the uniformity and physical stability of the compound additive. Since the core active ingredients, such as amino acids, enzyme preparations, and slow-release urea, account for a small proportion in the formula, if they are directly mixed, they are extremely easy to separate due to differences in particle size and density, resulting in uneven mixing. The addition of corn meal can effectively increase the overall volume, reduce the concentration gradient of trace ingredients, and reduce the electrostatic adsorption and dust of active ingredients through adsorption or adhesion, so as to ensure that the content of various active ingredients in each portion of the finished feed is consistent, thereby ensuring the safety and stability of the feeding effect.

[0014] It also includes 4-8 parts by weight of muscle and fat increasing and flower increasing additives; the muscle and fat increasing and flower increasing additives include betaine, linoleic acid, and ganoderma lucidum polysaccharide, and the mass ratio of the betaine, linoleic acid, and ganoderma lucidum polysaccharide is (1-3):(4-6):(3-5).

[0015] Linoleic acid, as a peroxisome proliferator-activated receptor γ ligand, directly activates the genetic program of intramuscular adipocyte differentiation and initiates fat deposition. Betaine has good lipid-lowering and antioxidant biological activities, improves the antioxidant and lipid metabolism capacity of pigs, improves the oxidative stress and lipid deposition caused by high-fat feed feeding, and thus improves the muscle quality of pork. Linoleic acid and betaine form a complement on the anabolism level and synergistically guide the intramuscular deposition of nutrients. Ganoderma lucidum polysaccharide improves the rumen microecology, improves the fiber degradation rate and volatile fatty acid yield, and provides essential precursors for fat synthesis propionic acid, thereby guaranteeing the substrate demand of anabolism from the energy supply end. At the same time, its immune regulation function can relieve metabolic stress during the fattening period, maintain a healthy anabolism internal environment, and indirectly support the improvement of feed conversion rate.

[0016] The complex fiber-decomposing enzyme includes at least one of xylanase and cellulase.

[0017] The over-rumen protein includes at least one of soybean meal, rapeseed meal and peanut meal.

[0018] Toxins in the soybean meal, rapeseed meal or peanut meal, such as aflatoxin B1, vomitoxin and the like, not only seriously endanger the liver health and immune function of animals, but also contain antinutritional factors such as trypsin inhibitor and lectin, which can directly lead to the decrease of protein digestion rate and utilization by inhibiting endogenous protease activity and destroying intestinal mucosa morphology. The double negative effects inevitably cause the problems of production performance such as the decrease of feed intake, the hindering of daily weight gain and the decrease of feed conversion rate. Therefore, the common over-rumen protein only realizes the position transfer of protein, but cannot solve the internal quality problem. The microbial fermentation process can not only effectively degrade the above toxins and antinutritional factors to eliminate the implicit constraints on animal production performance, but also can pre-digest macromolecular protein into more easily absorbed bioactive peptides and amino acids, aiming to ensure that protein can be completely absorbed in the small intestine.

[0019] The preparation method of the fermented over-rumen protein is as follows: (1) mixing and crushing the soybean meal, rapeseed meal and peanut meal to obtain mixed meal powder, and steam treating to obtain pretreated mixed meal powder; (2) mixing the pretreated mixed meal powder obtained in step (1) with water, inoculating and fermenting with activated fermentation bacteria liquid with a total mass of 3-6 wt%, and then aging after fermentation, adding antioxidant to the mixed meal powder, and naturally drying to obtain the fermented over-rumen protein.

[0020] Fermented rumen protein can play a beneficial role in reducing feed conversion ratio, increasing intramuscular fat content and improving NDF digestibility. In terms of reducing feed conversion ratio, the easily absorbed peptides and amino acids it provides have higher biological potency, directly improving the deposition efficiency of protein; at the same time, the elimination of anti-nutritional factors reduces the intestinal immune burden and energy consumption for mucosal repair, allowing more nutrients to be used for growth, improving feed conversion efficiency. In terms of increasing intramuscular fat content, in addition to directly providing high-quality protein skeletons for intramuscular fat synthesis, the active peptides it contains may act as signaling molecules to regulate the expression of fat metabolism-related genes, and synergize with ingredients such as linoleic acid and betaine in the formula to promote the generation and filling of intramuscular fat cells. Most importantly, in terms of improving NDF digestibility, fermented protein goes beyond itself: on the one hand, the fermentation process consumes part of the protein and carbohydrates, which may make the fiber structure more exposed, facilitating subsequent attacks by rumen microorganisms; on the other hand, and more importantly, the active microorganisms and their metabolites rich in fermented protein can optimize the rumen microecological environment after entering the rumen, reduce rumen pH fluctuations, and promote the colonization and growth of cellulose-decomposing bacteria, thereby improving the overall ability to decompose dietary fiber. This synergizes with the complex fiber-decomposing enzymes in the formula to achieve a synergistic effect.

[0021] The preparation method of the activated fermentation bacteria solution is as follows: fermenting bacteria, an activating agent and sterile water are mixed in a mass ratio of (0.5-1.2):(0.05-0.2):(7-15), activated at (35-40) ℃ for 20-45 min to obtain the activated fermentation bacteria solution; the activating agent is composed of brown sugar and magnesium sulfate in a mass ratio of 10:1; the fermenting bacteria are a mixture of Lactobacillus helveticus and Inonotus obliquus in a mass ratio of 2:1; the total number of viable bacteria of the fermenting bacteria is ≥1×10 9 CFU / g.

[0022] As a homofermentative lactic acid bacteria, Lactobacillus helveticus can quickly utilize sugars to produce a large amount of lactic acid, rapidly reducing the pH of the system. On the one hand, this inhibits the growth of spoilage bacteria and pathogenic bacteria, creating a safe biological environment for fermentation; on the other hand, the acidic environment provides an advantage for the growth of Inonotus obliquus. As a fungus, Inonotus obliquus has a developed mycelium network that can secrete a large amount of extracellular enzymes such as cellulase and xylanase, effectively destroying the cell wall structure of the bran and degrading the anti-nutritional factors therein, which compensates for the deficiency of lactic acid bacteria in the decomposition of fiber.

[0023] The antioxidant is at least one of glycyrrhizin flavone, astaxanthin and ethoxyquin.

[0024] The active substances and unsaturated fatty acids produced in the fermentation process are prone to oxidation in an aerobic environment, which not only leads to a decrease in nutritional value, but also generates harmful substances such as aldehydes and ketones, affecting palatability and animal health. Adding high-efficiency antioxidants such as glycyrrhizin flavones can effectively interrupt the oxidation chain reaction, protect beneficial fats and active ingredient bacteria, and stabilize functional peptides, thereby ensuring the nutritional quality, safety and shelf life of the final product.

[0025] The compound feed additive for improving intramuscular fat deposition of beef cattle has an addition amount of 2-3% of the feed during the pre-fattening period of 260-480 kg, and an addition amount of 3-4.5% of the feed during the post-fattening period of 480-700 kg.

[0026] The preparation method of the compound feed additive for improving intramuscular fat deposition of beef cattle comprises the following steps: weighing the raw materials according to the proportion, crushing the soybean meal and rapeseed meal into powder, adding coated amino acids, compound fiber-degrading enzyme, slow-release urea, corn flour, and muscle-fat-flower-increasing additive into a premix tank and mixing for 5-12 min, sealing and storing in a plastic bag to obtain the compound feed additive for improving intramuscular fat deposition of beef cattle.

[0027] The beneficial effects of the present application are as follows: The present application provides a compound feed additive for improving intramuscular fat deposition of beef cattle and a preparation method thereof. The additive builds a high-efficiency small intestine amino acid supply system through the synergistic effect of fermented rumen protein and coated amino acids, significantly improves protein digestibility and deposition efficiency. Slow-release urea and compound fiber-degrading enzyme optimize the rumen fermentation environment, promote microbial protein synthesis and fiber degradation, effectively reduce the feed conversion ratio, and improve the daily gain. The muscle-fat-flower-increasing additive used in the present application promotes the directional deposition of fat in muscle tissue through the scientific compounding of betaine, linoleic acid and ganoderma lucidum polysaccharide. The additive can significantly improve the intramuscular fat content and marbling score, effectively improve the beef quality, improve the growth performance of beef cattle, significantly improve the eating quality and economic value of beef, and provide an effective technical solution for high-quality beef production. DETAILED DESCRIPTION

[0028] The above summary of the present application will be further described in detail in combination with specific embodiments, but it should not be understood that the scope of the above subject matter of the present application is limited to the following examples.

[0029] In this application, some raw materials are introduced, and other raw material substances not introduced are commercially available: Xylanase is purchased from Shanghai Quanyan Biotechnology Co., Ltd., and the enzyme activity is 100,000 u / g.

[0030] Cellulase is purchased from Xiasheng (Beijing) Biotechnology Development Co., Ltd., and the enzyme activity is 40,000 u / g.

[0031] Hydrogenated palm oil was purchased from Wuhan Kemik Biomedicine Technology Co., Ltd., model: Cl73291.

[0032] Hydrogenated soybean oil was purchased from Wuhan Kemik Biomedicine Technology Co., Ltd., model: KMK.

[0033] Lactobacillus helveticus was purchased from China General Microbiological Culture Collection Center, strain number CGMCC 1.9090.

[0034] Inonotus obliquus was purchased from China General Microbiological Culture Collection Center, strain number CGMCC No. 41419.

[0035] Lactobacillus acidophilus was purchased from China General Microbiological Culture Collection Center, strain number: CGMCC 1.12735.

[0036] Betaine was purchased from Jinan Daorong Chemical Co., Ltd., model: CAB-35.

[0037] Ganoderma lucidum polysaccharide was purchased from Shanyang Lianfeng Biotechnology Co., Ltd., mesh number: 80-100.

[0038] Example 1 A compound feed additive for improving intramuscular fat deposition of beef cattle, consisting of the following raw materials by weight: 20 parts by weight of coated amino acid, 6 parts by weight of complex fiber-decomposing enzyme, 4 parts by weight of slow-release urea, 40 parts by weight of fermented rumen protein, 24 parts by weight of corn flour, and 6 parts by weight of muscle and fat increasing additive.

[0039] The preparation method of the coated amino acid is as follows: mix lysine and methionine in a mass ratio of 3:5, then add a 20 g / L corn alcohol-soluble protein aqueous solution, the mass ratio of lysine, methionine and corn alcohol-soluble protein aqueous solution being 3:5:50, stir at 150 rpm for 50 min, freeze-dry to obtain the coated amino acid.

[0040] The preparation method of the slow-release urea is as follows: weigh 4 parts by weight of hydrogenated palm oil and 2 parts by weight of hydrogenated soybean oil, completely melt them at 90°C, then add 0.3 parts by weight of triethyl citrate and 0.3 parts by weight of cinnamyl aldehyde, continue to stir for 30 min to obtain a mixed coating solution; add 38 parts by weight of urea particles with a particle size of 1 mm, place them in a coating machine, and coat them at a atomization temperature of 85°C, an atomization pressure of 0.15 MPa, and a spraying speed of 5 mL / min for 50 min to obtain slow-release urea.

[0041] The complex fiber-decomposing enzyme is a mixture of xylanase and cellulase in a mass ratio of 1:2. ​

[0042] The muscle fat and flower increasing additive is a mixture of betaine, linoleic acid and ganoderma lucidum polysaccharide in a mass ratio of 2:5:4.

[0043] The preparation method of the fermented rumen protein is as follows: (1) soybean meal, rapeseed meal and peanut meal are mixed in a mass ratio of 1:1:1 to obtain mixed meal powder, which is pulverized to 1 mm, and then steam treated at 100℃ for 8 min to obtain pretreated mixed meal powder; (2) the pretreated mixed meal powder obtained in step (1) and water are mixed in a mass ratio of 7:10, then inoculated with activated fermentation bacteria liquid with a total mass of 4wt%, and placed at 37℃ for fermentation for 72h, with a ventilation rate of 0.4m³ / (kg·h); after fermentation, it is placed at 45℃ for 48h, 0.15% antioxidant is added based on the mass of the mixed meal powder, and then naturally dried to obtain the fermented rumen protein.

[0044] The preparation method of the activated fermentation bacteria liquid is as follows: fermentation bacteria, activator and sterile water are mixed in a mass ratio of 1:0.1:10, and then activated at 37℃ for 30min to obtain the activated fermentation bacteria liquid; the activator is composed of brown sugar and magnesium sulfate in a mass ratio of 10:1.

[0045] The antioxidant is composed of glycyrrhizin and astaxanthin in a mass ratio of 1:1.

[0046] The fermentation bacteria is a mixture of lactobacillus helveticus and inonotus obliquus in a mass ratio of 2:1.

[0047] The preparation method of the compound feed additive for improving intramuscular fat deposition of beef cattle comprises the following steps: weighing each raw material according to the proportion, pulverizing soybean meal and rapeseed meal into powder, adding coated amino acid, compound fiber-decomposing enzyme, slow-release urea, corn flour and muscle fat and flower increasing additive into a premix tank for mixing for 8min, then sealing and storing in a plastic bag to obtain the compound feed additive for improving intramuscular fat deposition of beef cattle.

[0048] Example 2 The preparation method of the fermented rumen protein is as follows:

[0049] Example 3 The preparation method of the fermented rumen protein is as follows:

[0050] Example 4 The same as example 1, the difference is that the preparation method of the fermented rumen protein is as follows: (1) soybean meal, rapeseed meal and peanut meal are mixed according to the mass ratio of 1:1:1 to obtain mixed meal powder, which is crushed to 1 mm, and then steam treated at 100 DEG C for 8 min to obtain pretreated mixed meal powder; (2) the pretreated mixed meal powder obtained in step (1) and water are mixed according to the mass ratio of 7:10, then inoculated with activated fermentation bacteria liquid with a total mass of 4wt%, and placed at 37 DEG C for fermentation for 72h, with a ventilation rate of 0.4m³ / kg·h; after fermentation, it is placed at 45 DEG C for 48h, and then naturally dried to obtain fermented rumen protein.

[0051] The preparation method of the activated fermentation bacteria liquid is as follows: fermentation bacteria, activator and sterile water are mixed according to the mass ratio of 1:0.1:10, and then activated at 37 DEG C for 30 min to obtain activated fermentation bacteria liquid; the activator is composed of brown sugar and magnesium sulfate according to the mass ratio of 10:1.

[0052] The fermentation bacteria are a mixture of lactobacillus helveticus and inonotus obliquus according to the mass ratio of 2:1.

[0053] Example 5 The same as example 1, the difference is that the preparation method of the slow-release urea is as follows: 4 parts by weight of hydrogenated palm oil and 2 parts by weight of hydrogenated soybean oil are weighed, and then completely dissolved at 90 DEG C to obtain a mixed coating liquid; 38 parts by weight of urea particles with a particle size of 1mm are added, and then placed in a coating machine for coating at an atomization temperature of 85 DEG C, an atomization pressure of 0.15MPa and a spraying speed of 5mL / min for 50min to obtain slow-release urea.

[0054] Comparative example 1 The same as example 1, the difference is that the compound feed additive for improving intramuscular fat deposition of beef cattle does not add muscle fat and flower increasing additive.

[0055] Comparative example 2 The same as example 1, the difference is that a compound feed additive for improving intramuscular fat deposition of beef cattle is composed of the following raw materials by weight: 20 parts by weight of amino acid, 6 parts by weight of compound fiber decomposing enzyme, 4 parts by weight of slow-release urea, 40 parts by weight of fermented rumen protein, 24 parts by weight of corn flour and 6 parts by weight of muscle fat and flower increasing additive; the amino acid is a mixture of lysine and methionine with a mass ratio of 3:5.

[0056] The compound fiber decomposing enzyme is the same as that in example 1.

[0057] The slow-release urea is the same as that in example 1.

[0058] The fermented rumen protein is the same as that in example 1.

[0059] The muscle fat and flower increasing additive is the same as that in Example 1.

[0060] Comparative Example 3 The same as Example 1, except that a compound feed additive for improving intramuscular fat deposition of beef cattle is composed of the following raw materials in parts by weight: 20 parts by weight of coated amino acid, 6 parts by weight of compound fiber-decomposing enzyme, 4 parts by weight of urea, 40 parts by weight of fermented rumen bypass protein, 24 parts by weight of corn flour, and 6 parts by weight of muscle fat and flower increasing additive.

[0061] The compound fiber-decomposing enzyme is the same as that in Example 1.

[0062] The coated amino acid is the same as that in Example 1.

[0063] The fermented rumen bypass protein is the same as that in Example 1.

[0064] The muscle fat and flower increasing additive is the same as that in Example 1.

[0065] Comparative Example 4 The same as Example 1, except that a compound feed additive for improving intramuscular fat deposition of beef cattle is composed of the following raw materials in parts by weight: 20 parts by weight of coated amino acid, 6 parts by weight of compound fiber-decomposing enzyme, 4 parts by weight of urea, 40 parts by weight of rumen bypass protein, 24 parts by weight of corn flour, and 6 parts by weight of muscle fat and flower increasing additive.

[0066] The compound fiber-decomposing enzyme is the same as that in Example 1.

[0067] The coated amino acid is the same as that in Example 1.

[0068] The muscle fat and flower increasing additive is the same as that in Example 1.

[0069] The rumen bypass protein is prepared as follows: soybean meal, rapeseed meal and peanut meal are mixed in a mass ratio of 1:1:1 to obtain mixed meal powder, which is pulverized to 1 mm, and then subjected to steam treatment at 100℃ for 8 min to obtain pretreated mixed meal powder; 0.15% antioxidant agent by mass of the mixed meal powder is added, and then naturally dried to obtain the rumen bypass protein.

[0070] Comparative Example 5 The same as Example 1, except that a compound feed additive for improving intramuscular fat deposition of beef cattle is composed of the following raw materials in parts by weight: 20 parts by weight of amino acid, 6 parts by weight of compound fiber-decomposing enzyme, 4 parts by weight of urea, 40 parts by weight of rumen bypass protein, and 24 parts by weight of corn flour.

[0071] The amino acid is a mixture of lysine and methionine in a mass ratio of 3:5.

[0072] The method for preparing the rumen bypass protein is the same as Comparative Example 4.

[0073] Comparative Example 6 The method for preparing the fermented rumen bypass protein is basically the same as Example 1, except that the fermentation bacteria in the method are Lactobacillus acidophilus.

[0074] Comparative Example 7 The method for preparing the fermented rumen bypass protein is basically the same as Example 1, except that the fermentation bacteria are a mixture of Lactobacillus acidophilus and Inonotus obliquus at a mass ratio of 2:1.

[0075] Test Example 1 Healthy 9-month-old bulls with an initial body weight of 350±5 kg were selected from a certain breeding farm company for the test, and were randomly divided into 13 groups (12 test groups and 1 control group), 10 heads per group. The daily rations of the test were the same, and the reference standards were NY / T815-2004 “Beef Cattle Feeding Standard” and Chinese Feed Ingredients and Nutritional Values (28th edition, 2017). Water was taken freely during the period, and the feeding time was 90 days.

[0076] The composition of the daily ration was: 30.00% of corn silage, 20.00% of corn stalks, 38.00% of corn, 5.50% of soybean meal, 2.00% of wheat bran, 0.50% of salt, 0.50% of stone powder, 0.50% of calcium bicarbonate, 0.50% of baking soda, 2.5% of the compound feed additive for improving intramuscular fat deposition of beef cattle of Examples 1-5 and Comparative Examples 1-7, and a total of 100%. The blank group only consumed the daily ration without any additives, twice a day. The 12 test groups were fed the compound feed additives for improving intramuscular fat deposition of beef cattle prepared in Examples 1-5 and Comparative Examples 1-7, twice a day, for a test period of 30 days. All test cattle were allowed to freely eat and drink water, and ventilation and temperature were paid attention to, with an average shed temperature of 25℃.

[0077] 1. Growth indicators were recorded: average body weight, feed-to-gain ratio F / G, and protein digestibility. The results are shown in Table 1.

[0078] 2. Protein digestibility test: reference standard GB / T6432-2018 “Determination of Crude Protein in Feed by Kjeldahl Nitrogen Method”, internal standard: titanium dioxide added at 0.5%; each sample was determined in triplicate, and the average value was taken. Protein digestibility = (crude protein amount in feed TiO2 content - crude protein amount in feces TiO2) x 100%, and the results are shown in Table 1. Table 1. Growth indicators Test Example 2 3, Marble pattern grade division: Marble pattern is evaluated according to NY / T676-2010 standard, scoring, and the score grade is from low to high in turn for 1 to 5 points, and the results are shown in Table 2.

[0079] 4, Muscle fat content determination, after slaughter, directly sent to the slaughterhouse, immediately after slaughter, fresh meat sample is taken from the carcass, the position is the longest muscle of the thoracic spine, the muscle fat content is determined, %, 3 times are tested for each group, and the average value is taken, and the results are shown in Table 2.

[0080] Table 2. Muscle fat content and score results From the above examples, it can be seen that the composite feed additive for improving beef muscle fat deposition prepared by the present application added to the daily ration can effectively promote the growth of cattle, and improve the protein digestibility, improve the marble pattern grade of beef and the intramuscular fat content of the longest muscle of the back. The specific analysis is as follows: Example 1 adopts the optimal material combination, has the best material weight ratio 7.51 and protein digestibility 91.3%, the reason is that the rumen-fermented protein can degrade the anti-nutritional factors and produce active peptides, the coated amino acids avoid rumen degradation, and both of them guarantee the efficient supply of amino acids at the small intestine end; the slow-release urea and the composite fiber-decomposing enzyme optimize the rumen microecology and fermentation efficiency. In comparison, the comparative example 2 uses uncoated amino acids, which leads to a sharp drop in protein digestibility to 82.3% due to the large loss of amino acids in the rumen; the comparative example 3 uses ordinary urea, which affects the synthesis of rumen microbial protein due to the imbalance of nitrogen source release, and the material weight ratio deteriorates to 8.82. Example 4 does not add antioxidants, resulting in a decrease in protein digestibility to only 85.2%, which shows the influence of oxidation loss of the fermentation product in the post-processing stage. The comparative example 4 uses ordinary rumen-fermented protein, and the material weight ratio 8.58 and protein digestibility 80.1% are significantly worse than example 1, the key difference is that the raw materials still contain trypsin inhibitors and other anti-nutritional factors, which continue to damage the intestinal health and inhibit protein digestion, and cannot provide active peptides and probiotics, and has no positive regulation effect on rumen microecology. The comparative example 5 lacks the core functional group and has the worst performance, which confirms the indivisibility of the system as a whole. The comparative example 6 uses ordinary lactobacillus, and the comparative example 7 uses ordinary lactobacillus and birch polyporus in improper combination, the effect is between example 1 and comparative example 4, which shows that improper combination of fermentation bacteria leads to low efficiency of the fermentation system, cannot fully realize the biological transformation function, causes incomplete fermentation, and produces antagonistic effect, and reduces nutrient utilization rate.

[0081] Table 2 shows that Example 1 has the highest intramuscular fat content of 4.96% and marbling score of 4.86. The reason is that the addition of betaine, linoleic acid, and ganoderma polysaccharide as muscle fat and marbling additives can provide clear metabolic regulation signals for intramuscular fat synthesis. The intramuscular fat content of Comparative Example 1, which lacks this additive, is 4.45%, which is significantly lower than that of Example 1, directly proving that this component plays a significant role in improving fat deposition. However, the intramuscular fat scores of Comparative Example 2, which uses uncoated amino acids, and Comparative Example 3, which does not use slow-release urea, are reduced to 4.12 and 4.08, respectively, indicating that when there is a lack of amino acids that directly reach the small intestine or stable rumen ammonia nitrogen supply, the anabolism is hindered due to insufficient raw materials. The intramuscular fat score of Comparative Example 4 is 4.20, which is lower than that of Example 1, because the general rumen protein fails to provide functional ingredients such as active peptides produced by fermentation, and the anti-nutritional factors present interfere with the overall energy metabolism efficiency. The deficiencies of Comparative Example 6 and Comparative Example 7 stem from the incomplete fermentation system, which cannot completely degrade cellulose and anti-nutritional factors in the raw materials, resulting in limited improvement in NDF digestibility and insufficient supply of key precursor substances such as propionic acid for fat synthesis, leading to poor results.

Claims

1. A compound feed additive for improving intramuscular fat deposition in beef cattle, characterized in that, It is composed of the following raw materials in parts by weight: 14-26 parts by weight of coated amino acids, 2-8 parts by weight of compound cellulase, 2-6 parts by weight of slow-release urea, 30-60 parts by weight of rumen-protected protein or fermented rumen-protected protein, and 18-32 parts by weight of corn flour; wherein the coated amino acids are obtained by coating amino acids with corn gliadin; wherein the amino acids include at least one of lysine and methionine.

2. The compound feed additive for improving intramuscular fat deposition in beef cattle as described in claim 1, characterized in that, It also includes 4-8 parts by weight of a muscle-building fat-enhancing additive; the muscle-building fat-enhancing additive includes betaine, linoleic acid, and Ganoderma lucidum polysaccharide, and the mass ratio of betaine, linoleic acid and Ganoderma lucidum polysaccharide is (1-3):(4-6):(3-5).

3. The compound feed additive for improving intramuscular fat deposition in beef cattle as described in claim 1, characterized in that, The composite cellulase includes at least one of xylanase and cellulase.

4. The compound feed additive for improving intramuscular fat deposition in beef cattle as described in claim 1, characterized in that, The rumen-protected protein includes at least one of soybean meal, rapeseed meal, and peanut meal.

5. The compound feed additive for improving intramuscular fat deposition in beef cattle as described in claim 1, characterized in that, The preparation method of the sustained-release urea is as follows: the coating matrix and the sustained-release agent are mixed and melted to form a mixed coating liquid; in a fluidized state, the mixed coating liquid is atomized and sprayed onto the surface of urea particles to form a sustained-release layer, thereby obtaining the sustained-release urea.

6. The compound feed additive for improving intramuscular fat deposition in beef cattle as described in claim 5, characterized in that, The coating matrix comprises hydrogenated vegetable oil, with a mass ratio of (5-20):100 to urea particles; the slow-release agent is an organic slow-release agent, and its addition amount is 1-10% of the mass of the coating matrix; the coating conditions are: coating for 30-80 min at an atomization temperature of 78-90℃, an atomization pressure of 0.1-0.2MPa, and a spray rate of 3-10mL / min.

7. The compound feed additive for improving intramuscular fat deposition in beef cattle as described in claim 1, characterized in that, The method for preparing the fermented rumen-protected protein is as follows: (1) Mix and grind soybean meal, rapeseed meal and peanut meal to obtain mixed meal powder, and steam treat to obtain pretreated mixed meal powder; (2) Mix the pretreated mixed meal powder obtained in step (1) with water, add 3-6 wt% of activated fermentation liquid to ferment for 48-96 h; after fermentation, mature the mixture, add antioxidants to the mixed meal powder, and air dry to obtain fermented rumen protein.

8. The compound feed additive for improving intramuscular fat deposition in beef cattle as described in claim 7, characterized in that, The preparation method of the activated fermentation liquid is as follows: Fermentation bacteria, activator and sterile water are mixed in a mass ratio of (0.5-1.2):(0.05-0.2):(7-15), and activated at 35-40℃ for 20-45 min to obtain activated fermentation liquid; the activator is composed of brown sugar and magnesium sulfate in a mass ratio of (5-12):1; the fermentation bacteria is a mixture of Lactobacillus helveticus and Inonotus obliquus in a mass ratio of (1-3):1; the antioxidant is at least one of glycyrrhizin, astaxanthin and ethoxyquinoline.

9. The compound feed additive for improving intramuscular fat deposition in beef cattle as described in any one of claims 1-8, characterized in that, During the early fattening stage (260-480kg), the amount added should be 2-3% of the feed, and during the later fattening stage (480-700kg), the amount added should be 3-4.5% of the feed.

10. The method for preparing the compound feed additive for improving intramuscular fat deposition in beef cattle as described in any one of claims 1-8, characterized in that, The process includes the following steps: weigh each raw material according to the proportion, crush soybean meal and rapeseed meal into powder, add coated amino acids, compound fiber decomposing enzyme, slow-release urea, corn flour, and muscle fat and fat-increasing additives into a premix tank and mix, then pack into a plastic bag and seal for storage to obtain a compound feed additive that improves intramuscular fat deposition in beef cattle.

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