Compound feed additive as well as preparation and application thereof

Abstract

The invention discloses a compound feed additive as well as preparation and application thereof, and belongs to the technical field of feeds. The additive comprises a first composition and a second composition, the first composition comprises microcapsules formed by coating short-chain fatty acid and / or short-chain fatty acid derivatives with triglyceride carrying beta-glucuronide residues, and the second composition comprises microcapsules formed by coating short-chain fatty acid and / or short-chain fatty acid derivatives with triglyceride carrying beta-glucuronide residues. The second composition comprises medium-chain fatty acid and / or medium-chain fatty acid derivatives, and microcapsules formed by coating short-chain fatty acid and / or short-chain fatty acid derivatives with long-chain fatty acid and / or long-chain fatty acid derivatives. The invention effectively solves the problem that short-chain fatty acids and derivatives thereof are decomposed in advance before reaching target sites of intestinal tracts, so that the short-chain fatty acids and derivatives thereof can be transported to the whole course of digestive tracts, realize precise metabolism of parts in colon positions, and are suitable for balance of long-chain, medium-chain and short-chain fatty acids in intestines and stomachs of piglets. The feed can achieve the positive effects of promoting growth, improving the digestibility of nutrient substances, improving intestinal health and the like, and has a good application prospect in animal breeding.

Description

Technical Field

[0001] The invention belongs to the technical field of feed, and in particular relates to a compound feed additive with fatty acid as an active ingredient, and a preparation method and application thereof. Background Art

[0002] Piglets grow and develop quickly and have a high demand for nutrients, but their digestive system is not yet fully developed, and their immunity and disease resistance are poor. Oils and fats can provide animals with a lot of energy, essential fatty acids, and functional ingredients such as minerals, fat-soluble vitamins, and sterols. Therefore, in actual production, it is often necessary to add oils and fats to piglet feed.

[0003] Fatty acids are the most basic components of oils and fats. Fatty acids are divided into short-chain fatty acids, medium-chain fatty acids and long-chain fatty acids according to the length of the carbon chain. Fatty acids composed of less than 6 carbon atoms are called short-chain fatty acids, fatty acids composed of 6-12 carbon atoms are called medium-chain fatty acids, and fatty acids composed of more than 12 carbon atoms are called long-chain fatty acids.

[0004] Existing studies have shown that the intestinal cells of piglets preferentially use short-chain fatty acids as an energy source, but short-chain fatty acids are easily degraded before entering the colon. Coating technology can be used as a way to solve this problem. However, the difficulty in decomposing conventional packaging materials makes the metabolism and utilization efficiency of the coated short-chain fatty acids low, and the easily metabolized packaging materials cannot effectively play the advantages of microcapsules. In addition, mixed oils are more conducive to improving piglet production performance than single oils, but different combinations of various oils will affect their digestion and absorption in the gastrointestinal tract of piglets, and the imbalance of fatty acid intake will affect intestinal homeostasis. Therefore, the regulation of fatty acid balance is still one of the problems that has not been perfectly solved. Summary of the invention

[0005] In view of this, the present invention aims to solve the problem of short-chain fatty acids being decomposed prematurely before reaching the target site in the intestine and the imbalance of medium-chain and short-chain fatty acids, and to provide a feed additive suitable for piglets, which can effectively improve the utilization rate of short-chain fatty acids while ensuring balanced intake of fatty acids.

[0006] In order to achieve the above object, the present invention specifically adopts the following technical solutions: The first aspect of the present invention provides a compound feed additive, comprising a first composition and / or a second composition; wherein: The first composition includes triglycerides carrying β-glucuronide residues and short-chain fatty acids and / or short-chain fatty acid derivatives, and the triglycerides carrying β-glucuronide residues are used as packaging materials, encapsulating the short-chain fatty acids and / or short-chain fatty acid derivatives; The second composition includes medium-chain fatty acids and / or medium-chain fatty acid derivatives, long-chain fatty acids and / or long-chain fatty acid derivatives, short-chain fatty acids and / or short-chain fatty acid derivatives, and the medium-chain fatty acids and / or medium-chain fatty acid derivatives and long-chain fatty acids and / or long-chain fatty acid derivatives are used as packaging materials to encapsulate short-chain fatty acids and / or short-chain fatty acid derivatives.

[0007] In the compound feed additive of the present invention, the short-chain fatty acid derivatives, the medium-chain fatty acid derivatives and the long-chain fatty acid derivatives are respectively selected from one or more of the salts, esters and amides of the corresponding fatty acids.

[0008] In the compound feed additive of the present invention, the β-glucuronide residue in the triglyceride carrying the β-glucuronide residue is linked to at least one of the three hydroxyl groups of glycerol.

[0009] In the compound feed additive of the present invention, short-chain fatty acids include but are not limited to acetic fatty acids, propionic fatty acids, butyric fatty acids, etc., among which short-chain fatty acids and their derivatives are preferably butyric acid and its derivatives, medium-chain fatty acids and their derivatives include but are not limited to caprylic acid and its derivatives, capric acid and its derivatives, lauric acid and its derivatives, etc., and long-chain fatty acids and their derivatives include but are not limited to oleic acid and its derivatives, linoleic acid and its derivatives, palmitic acid and its derivatives, etc.

[0010] Preferably, in the first composition of the compound feed additive, the mass ratio of triglycerides carrying β-glucuronide residues to short-chain fatty acids and / or short-chain fatty acid derivatives is (55-65):(35-45).

[0011] Preferably, in the second composition of the above-mentioned compound feed additive, short-chain fatty acids and short-chain fatty acid derivatives account for 45-55 wt% of the total mass of the second composition; more preferably, the mass ratio of short-chain fatty acids and short-chain fatty acid derivatives, medium-chain fatty acids and medium-chain fatty acid derivatives to long-chain fatty acids and long-chain fatty acid derivatives is (45-55):(25-38):(15-30).

[0012] It is understood that the first composition and the second composition provided by the present invention can be used alone or in combination; and test data show that when the mass ratio of the first composition to the second composition is (2.5-3.5): (6.5-7.5), the breeding effect on weaned piglets is better. The compound feed additive comprising the first composition and the second composition provided by the present invention can be in the form of an oil, an emulsion or a powder.

[0013] The second aspect of the present invention provides a method for preparing the above-mentioned compound feed additive, which at least comprises the following steps: (1) Preparation of the first composition: adding triglycerides carrying β-glucuronide residues, short-chain fatty acids and / or short-chain fatty acid derivatives into a reaction container, adding an emulsifier and mixing, stirring at high speed, and spray drying to obtain the first composition; (2) Preparation of the second composition: medium-chain fatty acids and / or medium-chain fatty acid derivatives, long-chain fatty acids and / or long-chain fatty acid derivatives, and an emulsifier are prepared into a packaging material solution, and short-chain fatty acids and / or short-chain fatty acid derivatives are mixed with the packaging material solution and homogenized to obtain an emulsion, which is then spray-dried to obtain the second composition.

[0014] Preferably, in the above preparation method, step (1) comprises the following process: (1.1) preparing triglycerides carrying β-glucuronide residues; (1.2) adding the preheated short-chain fatty acids and / or short-chain fatty acid derivatives to the molten triglyceride carrying β-glucuronide residues, stirring to uniformly disperse the short-chain fatty acids in the triglyceride, and forming a preliminary oil phase mixture; (1.3) Add the emulsifier solution to the above oil phase mixture, and stir at high speed to fully mix the oil phase and the water phase to form a stable emulsion; (1.4) A first composition is obtained by a spray drying method.

[0015] In the above preparation method, step (1.1) can be prepared by a biotransformation method, which is specifically performed as follows: a triglyceride, a donor substance containing β-glucuronide and an enzyme are mixed, and the β-glucuronide is transferred from the donor substance to the triglyceride molecule through the catalytic action of the enzyme to form a triglyceride carrying a β-glucuronide residue; wherein the donor substance is one or more of glucuronide, p-nitrophenyl-β-D-glucuronide and methyl-β-D-glucuronide. In order to improve the preparation efficiency, a glycosyltransferase from a microorganism such as Saccharomyces cerevisiae or Escherichia coli with a high affinity for the substrate can be selected, such as a uridine diphosphate glucuronyltransferase (UGT) after targeted screening; or an esterase / lipase from Candida or mold, such as an Antarctic Candida lipase B (CALB) after targeted screening. For example, in one embodiment of the present invention, the donor substance containing β-glucuronide is selected as glucuronide, and the enzyme used is a uridine diphosphate glucuronyltransferase.

[0016] More preferably, in the above preparation method, the emulsifier used in step (1.3) is selected from Tween-20, Tween-80, Span-60, Span-80, and the emulsifier accounts for 1.5-2.5 wt% of the total mass of the mixture (i.e., triglycerides carrying β-glucuronide residues, short-chain fatty acids and / or short-chain fatty acid derivatives, and emulsifier).

[0017] More preferably, in the above preparation method, the high-speed stirring parameters in step (1.3) are: 4000-6000 rpm, and the stirring is continued for 10-20 min. During this process, the mixture gradually forms a delicate emulsion-like substance, and the emulsifier molecules form a stable interface film at the oil-water interface, encapsulating the triglyceride carrying β-glucuronide residues and short-chain fatty acids and / or short-chain fatty acid derivatives in tiny droplets.

[0018] More preferably, in the above preparation method, the inlet air temperature of the spray drying in step (1.4) is 170-190°C, and the outlet air temperature is 75-95°C.

[0019] Preferably, in the above preparation method, step (2) comprises the following process: (2.1) dissolving the medium-chain fatty acid and / or medium-chain fatty acid derivative, the long-chain fatty acid and / or long-chain fatty acid derivative in an organic solvent, and then adding an emulsifier to prepare a packaging material solution; (2.2) mixing the short-chain fatty acid and / or the short-chain fatty acid derivative with the packaging material solution and homogenizing to form an emulsion; (2.3) A second composition is obtained by spray drying.

[0020] In the above preparation method, the organic solvent used in step (2.1) includes but is not limited to ethanol, propylene glycol, etc.

[0021] More preferably, in the above preparation method, the emulsifier used in step (2.1) is selected from Tween-20, Tween-80, Span-60, and Span-80. In actual operation, it is also necessary to adjust the type and amount of the emulsifier, the stirring speed and duration of the emulsification process, and other parameters according to the specific fatty acid formula to ensure the formation of a uniform emulsion. For example, in one embodiment of the present invention, the emulsifier is Tween-80, and the total mass ratio of the emulsifier to the medium-chain fatty acid and / or medium-chain fatty acid derivative and the long-chain fatty acid and / or long-chain fatty acid derivative is 3:7.

[0022] More preferably, in the above preparation method, the inlet air temperature of the spray drying in step (2.3) is 170-190°C, and the outlet air temperature is 75-95°C.

[0023] In the preparation method of the present invention, the first composition and the second composition prepared by spray drying are both in the form of microcapsules with a size of 1-100 μm, and preferably 40-60 μm.

[0024] The third aspect of the present invention provides the use of the above-mentioned compound feed additive, which at least includes the following: a) Use in preparing feed; preferably, the feed is pig feed; more preferably, the pig feed is suitable for weaned piglets; b) Application in improving growth performance of piglets; c) Application in improving the digestibility of nutrients in piglets; d) Application in maintaining intestinal health of piglets.

[0025] Preferably, in the above application, the compound feed additive is added to the feed in an amount of 0.05-0.25wt%.

[0026] Compared with the prior art, the present invention has the following beneficial effects: The present invention uses triglycerides carrying β-glucuronide residues as packaging materials to prepare a first composition encapsulating short-chain fatty acids and / or short-chain fatty acid derivatives; the β-glucuronide residues can bind to β-glucuronidase present in large quantities in the colon, thereby inducing the decomposition of triglycerides, and then releasing the short-chain fatty acids and / or short-chain fatty acid derivatives therein in the colon, effectively achieving the precise release of short-chain fatty acids and / or short-chain fatty acid derivatives in the colon.

[0027] The present invention simultaneously uses medium-chain fatty acids and / or medium-chain fatty acid derivatives, long-chain fatty acids and / or long-chain fatty acid derivatives that can be absorbed and utilized by the intestine as another packaging material, so that the short-chain fatty acids and / or short-chain fatty acid derivatives encapsulated therein can be sustained-released; on the one hand, the metabolic rate of the short-chain fatty acids and / or short-chain fatty acid derivatives after entering the digestive system can be delayed to a greater extent, and on the other hand, the medium- and long-chain fatty acids required for animal growth can be provided, so that different types of fatty acids can be ingested.

[0028] The compound feed additive obtained by compounding the first composition and the second composition in a certain proportion can achieve the sustained release of short-chain fatty acids and their derivatives, and efficiently deliver short-chain fatty acids to the colon; when applied to the feeding feed during the growth process of piglets, it greatly improves the absorption and utilization efficiency of short-chain fatty acids, and can achieve the sustained release and synergistic effect of functional fatty acids in the intestine to a certain extent, more accurately solve the intestinal problems of piglets and prevent diseases. DETAILED DESCRIPTION

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs. The term "comprises" and any variations thereof in the specification and claims of the present invention are intended to cover non-exclusive inclusions.

[0030] In view of the problems in the prior art that short-chain fatty acids and their derivatives are decomposed in large quantities before reaching the target site (such as the colon), the incompatibility between the decomposition rate and functionality of existing packaging materials, and the balance regulation of medium-chain and short-chain fatty acids, the present invention provides a compound feed additive suitable for solving and improving the intestinal health of piglets by developing new packaging materials, optimizing the fatty acid ratio, and encapsulating short-chain fatty acids and their derivatives. The compound feed additive mainly consists of a first composition and a second composition.

[0031] In the first composition of the present invention, triglycerides carrying β-glucuronide residues are used as packaging materials, which carry specific groups that can bind to β-glucuronidase widely present in the colon, so that the packaging material is decomposed in large quantities in the colon, thereby ensuring that some short-chain fatty acids and their derivatives can be retained in the colon for release; in the second composition of the present invention, medium-chain fatty acids and their derivatives are used as packaging materials, and medium-chain fatty acids and their derivatives are also high-quality fatty acids that can provide nutrients for piglet growth. Through the compounding of the first composition and the second composition, short-chain fatty acids and their derivatives can be transported to the entire digestive tract, while ensuring the balance of long, medium and short-chain fatty acids suitable for the piglet's stomach.

[0032] The technical solution of the present invention will be described clearly and completely below in conjunction with specific embodiments. It should be understood that the embodiments described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0033] If no specific techniques or conditions are specified in the following examples, the procedures are carried out in accordance with the techniques or conditions described in the literature in the art or in accordance with the product instructions; if no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be obtained commercially.

[0034] Example 1 This example provides a compound feed additive, which is prepared by compounding a first composition and a second composition in a mass ratio of 3:7, and the preparation process includes the following: (1) Preparation of the first composition.

[0035] Triglyceride, glucuronolactone and UDP-glucuronyltransferase were mixed in a solution (28°C, pH 8) at a molar ratio of 1:1.5:0.15 for enzyme catalysis, and after the reaction was completed, the mixture was purified by chromatography to a purity greater than 95%. In the obtained triglyceride substance carrying β-glucuronide residue, the β-glucuronide residue was connected to one of the three hydroxyl groups of glycerol.

[0036] Preheat the triglyceride with β-glucuronide residues at 40°C and add tributyrin to the reaction vessel at a ratio of 60:40, and then add the emulsifier Tween-80 solution so that the emulsifier accounts for 2% of the total mass of the mixture. After mixing, stir at 800 rpm for 10 minutes to mix the three evenly. Then gradually increase the stirring speed to 5000 rpm and continue stirring for 15 minutes to gradually form a fine emulsion-like substance.

[0037] The emulsion-like substance is prepared into a first microcapsule composition by using a spray drying device, wherein the air inlet temperature is 180°C and the air outlet temperature is 85°C.

[0038] (2) Preparation of the second composition.

[0039] The types and proportions of various fatty acids used in the second composition of this example are shown in Table 1: Table 1 Types and ratios of fatty acids in the second composition

[0040] Preparation of packaging material solution: The total amount of fatty acids is 100 parts, 12 parts of caprylic acid, 16 parts of lauric acid monoglyceride, 10 parts of oleic acid and 8 parts of linoleic acid are dissolved in 80% propylene glycol, and then Tween-80 is added and mixed so that the mass ratio of caprylic acid, lauric acid monoglyceride, oleic acid and linoleic acid is 3:7.

[0041] The total amount of fatty acids is 100 parts, and 54 parts of tributyrin are taken and mixed with the prepared packaging material solution. After mixing, the mixture is homogenized at a pressure of 30 MPa to form an emulsion.

[0042] The emulsion is passed through a spray drying device to prepare a second microcapsule composition, wherein the inlet air temperature of the spray drying device is 180°C and the outlet air temperature is 85°C.

[0043] Example 2 This example provides a piglet feed, which includes a basic diet and the compound feed additive provided in Example 1, wherein the addition amount of the compound feed additive is in two cases, namely 0.1% and 0.2%.

[0044] The following feeding experiments were conducted using the two piglet feeds mentioned above: A total of 120 weaned piglets (Du × Chang × Da) were randomly divided into three treatments (i.e., CON, T1, and T2 treatment groups, see Table 1) according to their weight and sex, with 5 replicates in each treatment (8 pigs in each replicate).

[0045] Table 2 Grouping information

[0046] Among them, the basic diet information used in this experiment is shown in Table 3: Table 3 Basic diet composition and nutrient levels

[0047] After the feeding experiment started, the following tests were performed on the three treatment groups: (1) Growth performance test. The pigs were weighed on days 0, 14, and 28, and the average daily weight gain, average daily feed intake, and feed-to-meat ratio were calculated. The test results are shown in Table 4.

[0048] Table 4 Growth performance test results of weaned piglets

[0049] (2) Total intestinal apparent digestibility of nutrients. Fresh feces of piglets were collected on days 12-14 and 26-28, and the apparent digestibility of nutrients such as dry matter, organic matter, crude protein, crude fat and gross energy was measured. The results are shown in Table 5.

[0050] Table 5 Apparent digestibility of nutrients

[0051] (3) Antioxidant capacity test of liver and intestinal tissues, including malondialdehyde content, total antioxidant capacity, superoxide dismutase, catalase and glutathione peroxidase. The test results at the end of the 28-day test are shown in Table 6.

[0052] Table 6 Test results of antioxidant capacity of piglet liver and intestine

[0053] (4) At the end of the 28-day trial, intestinal mucosa-related digestive enzymes were tested, and the test results are shown in Table 7.

[0054] Table 7 Intestinal mucosal digestive enzymes in weaned piglets

[0055] (5) Intestinal morphology was measured at the end of the 28-day trial, including villus height and crypt depth, and the villus height / crypt depth ratio was calculated. The results are shown in Table 8.

[0056] Table 8 Intestinal morphology of weaned piglets

[0057] It can be seen from Table 4-8 that after adding the additive of the present invention to the feed, the activity of endogenous digestive enzymes in the intestine can be improved, and changes in intestinal flora and metabolites can be induced, thereby promoting the growth of piglets; at the same time, test data show that an additive concentration of 1kg / T can improve the intestinal health of piglets and promote the growth of piglets, so during use, the addition ratio can be changed appropriately according to actual conditions.

[0058] Comparative Example 1 Different from Example 1, the compound feed additive provided in this example is a simple mixture of triglycerides carrying β-glucuronide residues, tributyrin and various types of fatty acids in the second composition, and the amount of each raw material is consistent with that in Example 1.

[0059] Comparative Example 2 The difference from Example 1 is that the compound feed additive provided in this example only has the second composition, and the preparation of the second composition is exactly the same as that of Example 1.

[0060] Referring to Example 2, another 160 weaned piglets (Du×Chang×Da) were randomly divided into four treatments (see Table 9) according to body weight and gender, with 5 replicates in each treatment (8 pigs in each replicate), and feeding experiments were carried out and tested.

[0061] Table 9 Comparative test group information

[0062] Note: Basic diet is the same as Table 3.

[0063] The detection indicators are as in Example 2, and the specific results are shown in Tables 10-13 respectively.

[0064] Table 10 Growth performance of weaned piglets in comparative test

[0065] Table 11 Apparent digestibility of nutrients in comparative experiments

[0066] Table 12 Intestinal mucosal digestive enzymes in weaned piglets in comparative test

[0067] Table 13 Intestinal morphology of weaned piglets in comparative test

[0068] It can be seen from Tables 10-13 that adding oil additives to the feed has a promoting effect on the growth and digestive function of piglets. More importantly, compared with the use of the second composition alone and the simple mixing of various substances, the compound feed additive provided by the present invention has a significant promoting effect.

[0069] Example 3 This example verifies the antibiotic replacement effect of the compound feed additive of the present invention in piglet feed. The specific test is as follows: 120 weaned piglets (Du×Chang×Da) were selected and randomly divided into four treatments according to body weight and sex, with 6 replications in each treatment (5 pigs in each replication); the details of the four treatments are shown in Table 14.

[0070] Table 14 Grouping information of Example 3

[0071] Note: Basic diet is the same as Table 3.

[0072] After the feeding experiment started, the pigs were weighed on days 0, 14, and 28 to calculate the average daily gain (ADG), average daily feed intake (ADFI), feed-to-meat ratio (FCR), and diarrhea rate. The growth performance experimental results are shown in Table 15.

[0073] Table 15 Comparison of piglet growth performance in Example 3

[0074] As can be seen from Table 15, compared with the antibiotic group, the compound feed additive of the present invention significantly improves intestinal health, and the compound feed additive is more effective when used in combination with antibiotics. It can be seen that the compound feed additive of the present invention can replace a part of antibiotics, solve the intestinal health problems of weaned piglets, improve intestinal development, alleviate intestinal damage caused by antibiotics, and improve the growth performance of piglets.

[0075] In summary, the compound feed additive provided by the present invention has at least the following effects on piglets: (1) Promote the growth performance of piglets, increase the average daily weight gain of piglets, and reduce the feed-to-meat ratio. As in Example 2, after adding the compound feed additive of the present invention, the average daily weight gain of piglets 1-28 days after weaning was significantly higher than that of the control group, and the feed-to-meat ratio was significantly reduced.

[0076] (2) Improving the digestibility of nutrients can increase the total intestinal apparent digestibility of nutrients such as dry matter, organic matter, crude protein and gross energy. For example, in Example 2, after piglets were fed with feed containing compound feed additives, the apparent digestibility of these nutrients was significantly better than that of the control group within a specific period of time.

[0077] (3) Maintain intestinal health. The compound feed additive provided by the present invention can improve intestinal morphology, increase the ratio of villus height to crypt depth, and promote intestinal development; at the same time, it improves the activity of endogenous digestive enzymes in the intestine (such as lipase, trypsin, chymotrypsin, etc.), which is helpful for the digestion and absorption of nutrients; it also enhances the antioxidant capacity of the intestine and liver, reduces the content of oxidation products such as malondialdehyde, and increases the activity of antioxidant enzymes such as superoxide dismutase and glutathione peroxidase; in addition, it can also replace antibiotics, regulate the balance of intestinal flora, and inhibit the proliferation of harmful bacteria.

[0078] It should be noted that the above embodiments are only part of the embodiments of the present invention rather than all the embodiments, and are only used to illustrate the technical solution of the present invention rather than to limit it. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

Claims

1. A compound feed additive, characterized in that: comprising a first composition and a second composition; The first composition comprises triglycerides carrying β-glucuronide residues and short-chain fatty acids and / or short-chain fatty acid derivatives, and the triglycerides are coated with short-chain fatty acids and / or short-chain fatty acid derivatives; The second composition includes medium-chain fatty acids and / or medium-chain fatty acid derivatives, long-chain fatty acids and / or long-chain fatty acid derivatives, short-chain fatty acids and / or short-chain fatty acid derivatives, and the medium-chain fatty acids and / or medium-chain fatty acid derivatives, long-chain fatty acids and / or long-chain fatty acid derivatives are coated with short-chain fatty acids and / or short-chain fatty acid derivatives.

2. The compound feed additive according to claim 1, characterized in that: The short-chain fatty acid derivatives, medium-chain fatty acid derivatives and long-chain fatty acid derivatives are respectively selected from salts, esters and / or amides of the corresponding fatty acids.

3. The compound feed additive according to claim 1, characterized in that: In the first composition, the mass ratio of triglycerides carrying β-glucuronide residues to short-chain fatty acids and / or short-chain fatty acid derivatives is (55-65):(35-45).

4. The compound feed additive according to claim 1, characterized in that: In the second composition, the mass ratio of short-chain fatty acids and short-chain fatty acid derivatives, medium-chain fatty acids and medium-chain fatty acid derivatives, and long-chain fatty acids and long-chain fatty acid derivatives is (45-55):(25-38):(15-30).

5. The compound feed additive according to claim 2, characterized in that: The mass ratio of the first composition to the second composition is (2.5-3.5):(6.5-7.5).

6. Use of the compound feed additive according to any one of claims 1 to 5 in preparing feed.

7. The use according to claim 6, characterized in that: In the feed, the added amount of the compound feed additive is 0.05-0.25%.

8. Use of the compound feed additive according to any one of claims 1 to 5 in the preparation of a product for improving the intestinal health of weaned piglets.

9. A method for preparing the compound feed additive according to any one of claims 1 to 5, characterized in that: Adding triglycerides carrying β-glucuronide residues, short-chain fatty acids and / or short-chain fatty acid derivatives into a reaction container, adding an emulsifier and mixing, stirring at high speed, and spray drying to obtain a first composition; Medium-chain fatty acids and / or medium-chain fatty acid derivatives, long-chain fatty acids and / or long-chain fatty acid derivatives and emulsifiers are prepared into packaging material solutions, short-chain fatty acids and / or short-chain fatty acid derivatives are mixed and homogenized with the packaging material solution to obtain an emulsion, and spray-dried to obtain a second composition.

10. The method according to claim 9, characterized in that The emulsifier is selected from one or more of Tween-20, Tween-80, Span-60 and Span-80.

Images