A premix for promoting liver health of channel catfish and a preparation method thereof

Abstract

The present application belongs to the technical field of feed, and relates to a premix for promoting liver health of Ictalurus punctatus and a preparation method thereof. The premix comprises the following components in parts by weight: water-soluble vitamins, fat-soluble vitamins, minerals and functional additives, the surface of the water-soluble vitamins is coated with a brittle and hydrophobic coating layer, the elongation at break of the coating layer is less than or equal to 3%, and the elastic modulus of the coating layer is 0.1-1 MPa. After the premix prepared by the present application is put into water as feed, the dissolution of water-soluble vitamins can be effectively inhibited, the waste of water-soluble vitamins is reduced, and the breeding cost is lowered. After the fish feeds, the coating layer is rapidly brittle under the action of gastric peristalsis, so that the Ictalurus punctatus can fully ingest the necessary nutrients required for growth.

Description

Technical Field

[0001] This invention belongs to the field of feed technology and relates to a premix that promotes liver health in channel catfish and its preparation method. Background Technology

[0002] In the farming of channel catfish, the quality of feed and the effective utilization of nutrients play a crucial role in their growth, development, and liver health. Traditional fish feed, once introduced into the water, causes water-soluble vitamins to gradually dissolve, resulting in wasted feed resources, increased farming costs, and preventing channel catfish from fully absorbing the essential nutrients for their growth, thus affecting their growth performance and overall health. Summary of the Invention

[0003] The purpose of this invention is to provide a premixed feed that promotes liver health in channel catfish and its preparation method, which can reduce the dissolution of water-soluble feed in water and further improve the utilization rate of nutrients.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] In a first aspect, the present invention proposes a premix that promotes liver health in channel catfish, employing the following technical solution:

[0006] A premix for promoting liver health in channel catfish comprises the following components: water-soluble vitamins, fat-soluble vitamins, minerals, and functional additives, wherein the surface of the water-soluble vitamins is coated with a brittle and hydrophobic coating layer, and the elongation at break of the coating layer is ≤3%, and the elastic modulus of the coating layer is 0.1-1 MPa.

[0007] The pelleting method used in the process of making the premix into complete compound feed is as follows:

[0008] Feed ingredients and premixed feed are added to a mixer in proportion and mixed evenly at 8-10 rpm. The mixed material is then transferred to a fluidized bed and sprayed with gum arabic solution at a rate of 2-3 mL / min. Granulation and drying are then performed to obtain the target feed.

[0009] The fluidized bed is configured with the following parameters: atomization pressure of 0.1-0.15 MPa and fluidizing gas velocity of 0.5-0.8 m / s.

[0010] Preferably, the coating layer is selected from one or at least two of gelatin-based composite membranes, polysaccharide-polyphenol composite membranes, and protein-polyphenol cross-linked membranes.

[0011] Preferably, the coating layer is a gelatin-based composite film.

[0012] Preferably, the coating layer is dispersed with polydimethylsiloxane.

[0013] Preferably, the coating layer is formed by coating with a coating solution containing gelatin, tannic acid, nano silica and polydimethylsiloxane emulsion;

[0014] The mass ratio of gelatin, tannic acid and nano silica is (65-75):(20-30):(3-8), the solid content of the polydimethylsiloxane emulsion is 25%-40%, and the amount of polydimethylsiloxane emulsion added accounts for 5%-10% of the mass of gelatin.

[0015] Preferably, the water-soluble vitamins comprise the following components in parts by weight: 0.05-0.2 parts vitamin B1, 0.1-0.5 parts vitamin B2, 0.01-0.05 parts vitamin B6, and vitamin B... 12 0.01-0.05 parts, 0.3-1.0 parts, calcium pantothenate 0.2-0.8 parts, vitamin C 1.0-3.0 parts, folic acid 0.05-0.2 parts, and biotin 0.01-0.05 parts.

[0016] Preferably, the fat-soluble vitamin comprises the following components in parts by weight: 0.5-2.0 parts of vitamin A, 0.1-0.5 parts of vitamin D3, 0.5-2.0 parts of vitamin E, and 0.05-0.2 parts of vitamin K3.

[0017] Preferably, the mineral comprises the following components in parts by weight: 5-15 parts calcium dihydrogen phosphate, 0.5-2.0 parts sodium chloride, 1.0-3.0 parts potassium chloride, 0.5-1.5 parts magnesium sulfate, 0.1-0.5 parts ferrous sulfate, 0.05-0.2 parts zinc sulfate, 0.01-0.05 parts copper sulfate, 0.05-0.2 parts manganese sulfate, 0.005-0.02 parts calcium iodate, 0.005-0.01 parts cobalt sulfate, 0.001-0.005 parts sodium selenite, and 5-15 parts zeolite powder.

[0018] Preferably, the functional additive comprises the following components in parts by weight: 1.2-2.0 parts of bile acids and 0.6-1.0 parts of glutathione.

[0019] Secondly, the present invention provides a method for preparing a premix that promotes liver health in channel catfish, using the following technical solution:

[0020] A method for preparing a premix that promotes liver health in channel catfish, comprising the following steps:

[0021] A coating layer is applied to the surface of water-soluble vitamins to obtain coated water-soluble vitamins; then the coated water-soluble vitamins, fat-soluble vitamins, minerals and functional additives are thoroughly mixed to obtain a premix.

[0022] The beneficial effects of this invention are:

[0023] 1. The water-soluble vitamins are covered with a brittle and hydrophobic coating layer, which forms a solid barrier in the water, effectively preventing the water-soluble vitamins from dispersing into the water and reducing the waste of feed resources. Moreover, the coating layer of this invention is highly brittle and can quickly crack under the stress generated by the peristalsis of the fish's stomach, allowing the water-soluble vitamins to be released rapidly into the fish's body.

[0024] 2. Bile acids and glutathione are also added to the premix. Bile acids help with fat digestion and absorption, thus reducing the burden on the liver to metabolize fat; glutathione, with its powerful antioxidant properties, protects liver cells from free radical damage. These substances work together synergistically to comprehensively safeguard the liver health of the channel catfish, thereby enhancing its immunity. Detailed Implementation

[0025] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with embodiments, is provided below.

[0026] [The Creation Process of This Invention]

[0027] Under normal aquaculture conditions, channel catfish typically take 15 to 30 minutes to feed. When water-soluble vitamin premixes are added to the water, the vitamins (such as vitamin C and B vitamins) in the premixes gradually dissolve and are lost due to soaking in the water. This not only wastes a large amount of vitamin resources and significantly increases aquaculture costs, but also makes it difficult for channel catfish to obtain sufficient key nutrients necessary for growth, thus seriously affecting their growth performance and liver health.

[0028] When those skilled in the art face the challenge of improving the bioavailability of water-soluble vitamins, they typically focus on optimizing vitamin ratios and adding stabilizers. For example, increasing the amount of vitamin C or adjusting the proportions of B vitamins can alleviate the loss problem to some extent, but the effect is limited. The reason for this is that the chemical properties of water-soluble vitamins (such as easy solubility in water and easy oxidation) determine their extremely low stability in water; simply relying on component optimization cannot fundamentally solve the problem of dissolution and loss.

[0029] The inventors accidentally discovered that when water-soluble vitamin premixes are formulated into complete feeds, vitamins inevitably suffer dissolution or diffusion loss during the feeding process to fish due to immersion in water. This loss directly reduces vitamin utilization, meaning that the fish actually absorb only a portion of the vitamin content in the premix.

[0030] To address the aforementioned challenges, the inventors employed a method of encapsulating water-soluble vitamins in a protective film. This film isolates the vitamins from the water, thereby reducing losses due to dissolution or diffusion. To ensure this isolation effect, a hydrophobic coating layer is used to prevent water from spreading on the feed surface, thus reducing water diffusion into the feed.

[0031] However, the applicant is also very puzzled. Setting up a coating layer inevitably creates obstacles to the digestion of the feed after it is eaten by the fish, which greatly delays the absorption of water-soluble vitamins by the fish, which is undesirable.

[0032] To eliminate the inventor's above-mentioned confusion, the inventor discovered through painstaking research that after feed enters the body, it undergoes a physiological process of swallowing and being soaked in digestive juices. The inventor found that by utilizing this physiological process as a powerful way to destroy the coating layer, the confusion was solved.

[0033] Based on this, the applicant further discovered that for coating layer destruction triggered by digestive fluid infiltration, the main concern regarding infiltration methods such as gastric-soluble and enteric-soluble coatings is dissolution at specific digestive sites. While gastric-soluble coatings dissolve rapidly in the stomach, some water-soluble vitamins still dissolve prematurely when immersed in water. Enteric-soluble coatings require a specific pH environment in the intestines to dissolve, which hinders the immediate absorption of some water-soluble vitamins by the fish while they remain in the stomach, reducing the absorption efficiency of water-soluble vitamins. More importantly, digestive fluid infiltration is a slow process requiring sufficient time. Even if the digestive fluid comes from a healthy fish, a small amount of undigested coating layer is unavoidable, especially when the fish exhibits digestive dysfunction.

[0034] Furthermore, the inventors have discovered that by preparing the coating layer to be brittle and hydrophobic, they have successfully overcome the limitations of existing technologies. When the feed is added to the water, the coating layer can form a stable protective barrier in the water, effectively preventing the dissolution of water-soluble vitamins and greatly reducing nutrient loss. After the channel catfish feeds, the physical pressure generated by swallowing or stomach peristalsis causes the brittle coating layer to quickly rupture, allowing the water-soluble vitamins in the feed to be rapidly released and efficiently absorbed by the fish.

[0035] Example 1

[0036] A premix for promoting liver health in channel catfish comprises the following components in parts by weight: 15 parts water-soluble vitamins, 8 parts fat-soluble vitamins, 40 parts minerals, and 37 parts functional additives.

[0037] The water-soluble vitamin is covered with a brittle and water-insoluble coating layer, and the elongation at break of the coating layer is ≤3%, and the elastic modulus of the coating layer is 0.1-1 MPa.

[0038] Specifically, the water-soluble vitamin comprises a mixture of the following components in parts by weight: 0.1 parts vitamin B1, 0.3 parts vitamin B2, 0.03 parts vitamin B6, and vitamin B... 12 0.03 parts, 0.3 parts, calcium pantothenate 0.2 parts, vitamin C 2.0 parts, folic acid 0.1 parts and biotin 0.03 parts.

[0039] The fat-soluble vitamin comprises the following components in parts by weight: 1.2 parts vitamin A, 0.3 parts vitamin D3, 1.2 parts vitamin E, and 0.1 parts vitamin K3.

[0040] The mineral is composed of the following components in parts by weight: 10 parts calcium dihydrogen phosphate, 1.2 parts sodium chloride, 2.0 parts potassium chloride, 1.0 part magnesium sulfate, 0.3 parts ferrous sulfate, 0.1 parts zinc sulfate, 0.03 parts copper sulfate, 0.1 parts manganese sulfate, 0.01 parts calcium iodate, 0.005 parts cobalt sulfate, 0.003 parts sodium selenite, and 10 parts zeolite powder.

[0041] The functional additive is composed of the following components in parts by weight: 1.5 parts bile acids and 0.8 parts glutathione.

[0042] In this embodiment, the coating layer is a gelatin-based composite film. The coating layer is formed by coating with a coating solution comprising gelatin, tannic acid, nano-silica, and polydimethylsiloxane emulsion, wherein the mass ratio of gelatin, tannic acid, and nano-silica is 70:25:5, the solid content of the polydimethylsiloxane emulsion is 30%, and the amount of polydimethylsiloxane emulsion added accounts for 8% of the mass of the gelatin.

[0043] The specific method for preparing the coating solution is as follows:

[0044] A1. Add 70g of gelatin to 400mL of ethanol and stir in a 50℃ constant temperature water bath for 30 minutes until completely dissolved;

[0045] A2. Cool down to 40℃, add 25g of tannic acid, and stir continuously for 20 minutes.

[0046] A3. Add 5g of nano-silica and ultrasonically disperse for 15 minutes (power 200W) to form a uniform suspension;

[0047] A4. Add 5.6g of polydimethylsiloxane emulsion with a solid content of 30% and continue stirring for 15 minutes to ensure the emulsion is evenly dispersed.

[0048] A5. Vacuum degassing for 5 minutes (-0.1MPa), then set aside.

[0049] The specific method for preparing coated water-soluble vitamins is as follows:

[0050] The premixed water-soluble vitamin powder was placed in a fluidized bed coating machine and preheated to 40°C for 10 minutes. Then, the coating solution was sprayed at a rate of 2 mL / min for 120 minutes to form a uniform coating layer. After coating, the temperature was raised to 50°C and dried for 30 minutes. After cooling to 25°C, the powder was passed through a 20-mesh sieve to obtain water-soluble vitamin granules with a brittle hydrophobic film coating on the surface.

[0051] A method for preparing a premix to promote liver health in channel catfish includes the following steps: coating water-soluble vitamins with a coating layer to obtain coated water-soluble vitamins; then adding the coated water-soluble vitamins, fat-soluble vitamins, minerals, and functional additives into a mixer, mixing at a low speed of 10 rpm for 10 minutes, then gradually increasing the speed to 20 rpm and mixing for 20 minutes to ensure thorough mixing; after mixing, passing the mixture through a 20-mesh sieve to remove uncoated or clumped particles to obtain the premix.

[0052] The specific steps for preparing a premix that promotes liver health in channel catfish into a complete feed are as follows:

[0053] Add 25 parts fishmeal, 23 parts soybean meal, 6.5 parts wheat bran, 13 parts corn, 2.5 parts soybean oil, and 6 parts premix to a mixer and mix at 25°C and 8 rpm for 12 minutes to obtain a uniform mixture. Then, place the mixture into a fluidized bed, start the airflow to suspend and fluidize the powder, and spray the binder solution at a rate of 3 mL / min for 10-15 minutes until the granules are initially formed. Then, stop spraying and dry for 10 minutes to solidify the granule surface. Finally, screen the granules through a 20-mesh sieve to remove unbonded powder or oversized particles, cool to room temperature, and seal and package to obtain the target feed.

[0054] The adhesive is gum arabic, which is prepared as follows: 2.5 parts of gum arabic are dissolved in deionized water to make a 5% aqueous solution; the fluidized bed setting parameters are: inlet air temperature: 35±2℃, atomization pressure: 0.15MPa, fluidizing gas velocity: 0.8m / s, drying time: continuous drying for 10 minutes after spraying.

[0055] Example 2

[0056] A premix for promoting liver health in channel catfish comprises the following components in parts by weight: 15 parts water-soluble vitamins, 8 parts fat-soluble vitamins, 40 parts minerals, and 37 parts functional additives.

[0057] The water-soluble vitamin is covered with a brittle and water-insoluble coating layer, and the elongation at break of the coating layer is ≤3%, and the elastic modulus of the coating layer is 0.1-1 MPa.

[0058] Specifically, the water-soluble vitamin comprises a mixture of the following components in parts by weight: 0.15 parts vitamin B1, 0.4 parts vitamin B2, 0.04 parts vitamin B6, and vitamin B... 12 0.04 parts, 0.8 parts, calcium pantothenate 0.5 parts, vitamin C 2.5 parts, folic acid 0.15 parts and biotin 0.04 parts.

[0059] The fat-soluble vitamin comprises the following components in parts by weight: 1.5 parts vitamin A, 0.4 parts vitamin D3, 1.5 parts vitamin E, and 0.15 parts vitamin K3.

[0060] The mineral is a mixture of the following components in parts by weight: 12 parts calcium dihydrogen phosphate, 1.5 parts sodium chloride, 2.5 parts potassium chloride, 1.2 parts magnesium sulfate, 0.4 parts ferrous sulfate, 0.15 parts zinc sulfate, 0.04 parts copper sulfate, 0.15 parts manganese sulfate, 0.015 parts calcium iodate, 0.007 parts cobalt sulfate, 0.004 parts sodium selenite, and 5 parts zeolite powder.

[0061] The functional additive is composed of the following components in parts by weight: 1.2 parts bile acids and 0.6 parts glutathione.

[0062] The surface of the premix is ​​covered with a brittle and water-insoluble coating layer, and the elongation at break of the coating layer is ≤3%, and the elastic modulus of the coating layer is 0.1-1 MPa.

[0063] In this embodiment, the coating layer is a gelatin-based composite film. The coating layer is formed by coating with a coating solution comprising gelatin, tannic acid, nano-silica, and polydimethylsiloxane emulsion, wherein the mass ratio of gelatin, tannic acid, and nano-silica is 65:20:3, the solid content of the polydimethylsiloxane emulsion is 25%, and the amount of polydimethylsiloxane emulsion added accounts for 5% of the mass of the gelatin.

[0064] The specific method for preparing the coating solution is as follows:

[0065] A1. Add 65g of gelatin to 370mL of ethanol and stir in a 50℃ constant temperature water bath for 30 minutes until completely dissolved.

[0066] A2. Cool down to 40℃, add 20g of tannic acid, and stir continuously for 20 minutes.

[0067] A3. Add 3g of nano-silica and ultrasonically disperse for 15 minutes (power 200W) to form a uniform suspension;

[0068] A4. Add 13g of polydimethylsiloxane emulsion with a solid content of 25% and continue stirring for 15 minutes to make the emulsion evenly dispersed.

[0069] A5. Vacuum degassing for 5 minutes (-0.1MPa), then set aside.

[0070] The specific method for preparing coated water-soluble vitamins is as follows:

[0071] The premixed water-soluble vitamin powder was placed in a fluidized bed coating machine and preheated to 40°C for 10 minutes. Then, the coating solution was sprayed at a rate of 2 mL / min for 120 minutes to form a uniform coating layer. After coating, the temperature was raised to 50°C and dried for 30 minutes. After cooling to 25°C, the powder was passed through a 20-mesh sieve to obtain water-soluble vitamin granules with a brittle hydrophobic film coating on the surface.

[0072] A method for preparing a premix to promote liver health in channel catfish includes the following steps: coating water-soluble vitamins with a coating layer to obtain coated water-soluble vitamins; then adding the coated water-soluble vitamins, fat-soluble vitamins, minerals, and functional additives into a mixer, mixing at a low speed of 10 rpm for 10 minutes, then gradually increasing the speed to 20 rpm and mixing for 20 minutes to ensure thorough mixing; after mixing, passing the mixture through a 20-mesh sieve to remove uncoated or clumped particles to obtain the premix.

[0073] The specific steps for preparing a premix that promotes liver health in channel catfish into a complete feed are as follows:

[0074] Add 25 parts fishmeal, 23 parts soybean meal, 6.5 parts wheat bran, 13 parts corn, 2.5 parts soybean oil, and 6 parts premix to a mixer and mix at 25°C and 8 rpm for 12 minutes to obtain a uniform mixture. Then, place the mixture into a fluidized bed, start the airflow to suspend and fluidize the powder, and spray the binder solution at a rate of 3 mL / min for 10-15 minutes until the granules are initially formed. Then, stop spraying and dry for 10 minutes to solidify the granule surface. Finally, screen the granules through a 20-mesh sieve to remove unbonded powder or oversized particles, cool to room temperature, and seal and package to obtain the target feed.

[0075] The adhesive is gum arabic, which is prepared as follows: 2.5 parts of gum arabic are dissolved in deionized water to make a 5% aqueous solution; the fluidized bed setting parameters are: inlet air temperature: 35±2℃, atomization pressure: 0.15MPa, fluidizing gas velocity: 0.8m / s, drying time: continuous drying for 10 minutes after spraying.

[0076] Example 3

[0077] A premix for promoting liver health in channel catfish comprises the following components in parts by weight: 15 parts water-soluble vitamins, 8 parts fat-soluble vitamins, 40 parts minerals, and 37 parts functional additives.

[0078] The water-soluble vitamin is coated with a brittle, water-insoluble coating layer, and the elongation at break of the coating layer is ≤3%, and the elastic modulus of the coating layer is 0.1-1 MPa. Specifically, the water-soluble vitamin comprises the following components in parts by weight: 0.18 parts vitamin B1, 0.45 parts vitamin B2, 0.045 parts vitamin B6, and vitamin B... 12 0.045 parts, 1.0 part nicotinamide, 0.8 parts calcium pantothenate, 2.8 parts vitamin C, 0.18 parts folic acid and 0.045 parts biotin.

[0079] The fat-soluble vitamin comprises the following components in parts by weight: 1.8 parts vitamin A, 0.45 parts vitamin D3, 1.8 parts vitamin E, and 0.18 parts vitamin K3.

[0080] The mineral is a mixture of the following components in parts by weight: 14 parts calcium dihydrogen phosphate, 1.8 parts sodium chloride, 2.8 parts potassium chloride, 1.4 parts magnesium sulfate, 0.45 parts ferrous sulfate, 0.18 parts zinc sulfate, 0.045 parts copper sulfate, 0.18 parts manganese sulfate, 0.018 parts calcium iodate, 0.01 parts cobalt sulfate, 0.005 parts sodium selenite, and 15 parts zeolite powder.

[0081] The functional additive is composed of the following components in parts by weight: 2.0 parts bile acids and 1.0 parts glutathione.

[0082] In this embodiment, the coating layer is a gelatin-based composite film. The coating layer is formed by coating with a coating solution comprising gelatin, tannic acid, nano-silica, and polydimethylsiloxane emulsion, wherein the mass ratio of gelatin, tannic acid, and nano-silica is 75:20:8, the solid content of the polydimethylsiloxane emulsion is 40%, and the amount of polydimethylsiloxane emulsion added accounts for 10% of the mass of the gelatin.

[0083] The specific method for preparing the coating solution is as follows:

[0084] A1. Add 75g of gelatin to 430mL of ethanol and stir in a 50℃ constant temperature water bath for 30 minutes until completely dissolved.

[0085] A2. Cool down to 40℃, add 20g of tannic acid, and stir continuously for 20 minutes.

[0086] A3. Add 8g of nano-silica and ultrasonically disperse for 15 minutes (power 200W) to form a uniform suspension;

[0087] A4. Add 18.75g of polydimethylsiloxane emulsion with a solid content of 40%, and continue stirring for 15 minutes to ensure that the emulsion is evenly dispersed.

[0088] A5. Vacuum degassing for 5 minutes (-0.1MPa), then set aside.

[0089] The specific method for preparing coated water-soluble vitamins is as follows:

[0090] The premixed water-soluble vitamin powder was placed in a fluidized bed coating machine and preheated to 40°C for 10 minutes. Then, the coating solution was sprayed at a rate of 2 mL / min for 120 minutes to form a uniform coating layer. After coating, the temperature was raised to 50°C and dried for 30 minutes. After cooling to 25°C, the powder was passed through a 20-mesh sieve to obtain water-soluble vitamin granules with a brittle hydrophobic film coating on the surface.

[0091] A method for preparing a premix to promote liver health in channel catfish includes the following steps: coating water-soluble vitamins with a coating layer to obtain coated water-soluble vitamins; then adding the coated water-soluble vitamins, fat-soluble vitamins, minerals, and functional additives into a mixer, mixing at a low speed of 10 rpm for 10 minutes, then gradually increasing the speed to 20 rpm and mixing for 20 minutes to ensure thorough mixing; after mixing, passing the mixture through a 20-mesh sieve to remove uncoated or clumped particles to obtain the premix.

[0092] The specific steps for preparing a premix that promotes liver health in channel catfish into a complete feed are as follows:

[0093] Add 25 parts fishmeal, 23 parts soybean meal, 6.5 parts wheat bran, 13 parts corn, 2.5 parts soybean oil, and 6 parts premix to a mixer and mix at 25°C and 8 rpm for 12 minutes to obtain a uniform mixture. Then, place the mixture into a fluidized bed, start the airflow to suspend and fluidize the powder, and spray the binder solution at a rate of 3 mL / min for 10-15 minutes until the granules are initially formed. Then, stop spraying and dry for 10 minutes to solidify the granule surface. Finally, screen the granules through a 20-mesh sieve to remove unbonded powder or oversized particles, cool to room temperature, and seal and package to obtain the target feed.

[0094] The adhesive is gum arabic, which is prepared as follows: 2.5 parts of gum arabic are dissolved in deionized water to make a 5% aqueous solution; the fluidized bed setting parameters are: inlet air temperature: 35±2℃, atomization pressure: 0.15MPa, fluidizing gas velocity: 0.8m / s, drying time: continuous drying for 10 minutes after spraying.

[0095] Example 4

[0096] A premix for promoting liver health in channel catfish comprises the following components in parts by weight: 15 parts water-soluble vitamins, 8 parts fat-soluble vitamins, 40 parts minerals, and 37 parts functional additives.

[0097] The water-soluble vitamin is covered with a brittle and water-insoluble coating layer, and the elongation at break of the coating layer is ≤3%, and the elastic modulus of the coating layer is 0.1-1 MPa.

[0098] Specifically, the water-soluble vitamin comprises a mixture of the following components in parts by weight: 0.08 parts vitamin B1, 0.25 parts vitamin B2, 0.02 parts vitamin B6, and vitamin B... 12 0.02 parts, 0.5 parts, calcium pantothenate, 1.5 parts, folic acid, 0.1 parts, and biotin, 0.02 parts.

[0099] The fat-soluble vitamins comprise the following components in parts by weight: 1.0 part of vitamin A, 0.2 parts of vitamin D3, 1.0 part of vitamin E, and 0.1 parts of vitamin K3.

[0100] The minerals comprise the following components in parts by weight: 8 parts calcium dihydrogen phosphate, 1 part sodium chloride, 2.0 parts potassium chloride, 0.8 parts magnesium sulfate, 0.2 parts ferrous sulfate, 0.1 parts zinc sulfate, 0.02 parts copper sulfate, 0.1 parts manganese sulfate, 0.01 parts calcium iodate, 0.008 parts cobalt sulfate, 0.002 parts sodium selenite, and 8 parts zeolite powder.

[0101] The functional additive is composed of the following components in parts by weight: 1.8 parts bile acids and 0.7 parts glutathione.

[0102] In this embodiment, the coating layer is a gelatin-based composite film. The coating layer is formed by coating with a coating solution comprising gelatin, tannic acid, nano-silica, and polydimethylsiloxane emulsion, wherein the mass ratio of gelatin, tannic acid, and nano-silica is 70:20:8, the solid content of the polydimethylsiloxane emulsion is 30%, and the amount of polydimethylsiloxane emulsion added accounts for 8% of the mass of the gelatin.

[0103] The specific method for preparing the coating solution is as follows:

[0104] A1. Add 70g of gelatin to 400mL of ethanol and stir in a 50℃ constant temperature water bath for 30 minutes until completely dissolved;

[0105] A2. Cool down to 40℃, add 20g of tannic acid, and stir continuously for 20 minutes.

[0106] A3. Add 8g of nano-silica and ultrasonically disperse for 15 minutes (power 200W) to form a uniform suspension;

[0107] A4. Add 5.6g of polydimethylsiloxane emulsion with a solid content of 30% and continue stirring for 15 minutes to ensure the emulsion is evenly dispersed.

[0108] A5. Vacuum degassing for 5 minutes (-0.1MPa), then set aside.

[0109] The specific method for preparing coated water-soluble vitamins is as follows:

[0110] The premixed water-soluble vitamin powder was placed in a fluidized bed coating machine and preheated to 40°C for 10 minutes. Then, the coating solution was sprayed at a rate of 2 mL / min for 120 minutes to form a uniform coating layer. After coating, the temperature was raised to 50°C and dried for 30 minutes. After cooling to 25°C, the powder was passed through a 20-mesh sieve to obtain water-soluble vitamin granules with a brittle hydrophobic film coating on the surface.

[0111] A method for preparing a premix to promote liver health in channel catfish includes the following steps: coating water-soluble vitamins with a coating layer to obtain coated water-soluble vitamins; then adding the coated water-soluble vitamins, fat-soluble vitamins, minerals, and functional additives into a mixer, mixing at a low speed of 10 rpm for 10 minutes, then gradually increasing the speed to 20 rpm and mixing for 20 minutes to ensure thorough mixing; after mixing, passing the mixture through a 20-mesh sieve to remove uncoated or clumped particles to obtain the premix.

[0112] The specific steps for preparing a premix that promotes liver health in channel catfish into a complete feed are as follows:

[0113] Add 25 parts fishmeal, 23 parts soybean meal, 6.5 parts wheat bran, 13 parts corn, 2.5 parts soybean oil, and 6 parts premix to a mixer and mix at 25°C and 8 rpm for 12 minutes to obtain a uniform mixture. Then, place the mixture into a fluidized bed, start the airflow to suspend and fluidize the powder, and spray the binder solution at a rate of 3 mL / min for 10-15 minutes until the granules are initially formed. Then, stop spraying and dry for 10 minutes to solidify the granule surface. Finally, screen the granules through a 20-mesh sieve to remove unbonded powder or oversized particles, cool to room temperature, and seal and package to obtain the target feed.

[0114] The adhesive is gum arabic, which is prepared as follows: 2.5 parts of gum arabic are dissolved in deionized water to make a 5% aqueous solution; the fluidized bed setting parameters are: inlet air temperature: 35±2℃, atomization pressure: 0.15MPa, fluidizing gas velocity: 0.8m / s, drying time: continuous drying for 10 minutes after spraying.

[0115] Comparative Example 1

[0116] The difference from Example 1 is that the water-soluble vitamins are not coated.

[0117] Comparative Example 2

[0118] The difference from Example 1 is that the mass ratio of gelatin, tannic acid and nano silica in the coating solution is 65:25:10, the solid content of the polydimethylsiloxane emulsion is 30%, and the amount of polydimethylsiloxane emulsion added accounts for 8% of the mass of gelatin.

[0119] Experimental Example 1

[0120] Film forming:

[0121] 1. Use a pipette to draw up the coating solution of each example and Comparative Example 2, and inject it into a stainless steel casting frame (inner diameter 80mm×80mm, with silicone strips raised 0.10±0.01mm on all four sides), and then place it in a forced-air drying oven (temperature 50℃, wind speed 0.5m / s) for 12h.

[0122] 2. Film thickness calibration: Use a micrometer (accuracy 0.001mm) to measure 5 points (center + four corners) along the diagonal of the film. The average thickness should be 0.10±0.005mm (if it does not meet the standard, discard the film).

[0123] Sample cutting:

[0124] 1. Pattern cutting mold:

[0125] Use a manual punching machine for sample cutting. The punch conforms to the ASTM D882 standard. The punching machine pressure is controlled at 2-3 MPa. The gauge length of the punch is 50mm × 6mm, with a total length of 115mm and a 14mm radius transition fillet. Before use, the punch must be checked for its integrity and sharpness to ensure the sample cutting effect.

[0126] 2. Sample Cutting: Lay the prepared film flat on the rubber pad of the manual punching machine, ensuring the film is flat and wrinkle-free. Then, press the punch vertically downwards to complete the sample cutting in one go. Each film needs to prepare 10 parallel samples. After cutting, observe the cut. If the sample has defects such as edge curling or cracks, it should be rejected. If the defect rate is >10%, the film needs to be remade and the sample cutting operation needs to be performed again.

[0127] Testing: The coating performance was tested using a universal testing machine (Instron 5967). The prepared specimens were mounted on the universal testing machine, and their positions were adjusted to ensure uniform stress during tensile testing. The tensile rate was set to 100 mm / min. The universal testing machine was started to stretch the specimens. During the stretching process, the stress and deformation of the specimens were recorded in real time. When the specimen broke, the elongation at break and the modulus of elasticity were recorded. Ten parallel specimens of the coating film for each embodiment were tested according to the above steps. Finally, the average of the ten parallel data for each sample was calculated as the final test result for that sample.

[0128] A higher elongation at break indicates that the material can withstand greater deformation before fracture, meaning the material has higher ductility and flexibility. A lower elongation at break indicates that the material is more brittle and will fracture under relatively small deformations, meaning the material is more fragile.

[0129] A higher elastic modulus indicates that the material is harder or more rigid, and will deform less under the same external force. A lower elastic modulus indicates that the material is relatively softer and is more prone to deformation under external force.

[0130] The data for Experiment Example 1 are shown in Table 1.

[0131] Table 1:

[0132] Group Elongation at break (%) Elastic modulus (MPa) Example 1 2.8 0.6 Example 2 2.5 0.8 Example 3 2.9 0.4 Example 4 2.2 0.9 Comparative Example 2 5.7 1.8

[0133] As shown in Table 1, the elongation at break of the coating layer in Examples 1-4 is ≤3%, and the elastic modulus is in the range of 0.1-1MPa, which meets the performance indicators of the coating layer required by the present invention.

[0134] Experiment Example 2

[0135] 1. Laboratory animals

[0136] Healthy channel catfish were selected as experimental subjects, with a total of 10 fish and an average weight of 50±5g.

[0137] 2. Group settings

[0138] Ten spotted catfish were divided into four groups of two fish each, with two bathtubs per group. The specific groupings were as follows:

[0139] Example 1 group: Feeding experiments were conducted using the feed prepared in Example 1.

[0140] Example 2 group: Feeding experiments were conducted using the feed prepared in Example 2.

[0141] Example 3 group: Feeding experiment was conducted using the feed prepared in Example 3.

[0142] Example 4 group: Feeding experiments were conducted using the feed prepared in Example 4.

[0143] Comparative Example 2: Feeding experiments were conducted using the feed prepared in Comparative Example 2.

[0144] 3. Experimental Procedure

[0145] A. Experimental Preparation

[0146] Eight aquariums, each measuring 30cm long, 20cm wide, and 25cm high, were selected as experimental containers. Before use, the aquariums were thoroughly cleaned with water and then soaked in a 0.1% potassium permanganate solution for 30 minutes for disinfection. Afterward, they were rinsed several times with clean water to ensure no disinfectant residue remained. Each aquarium was filled with tap water that had been aerated for at least 24 hours, with the water level maintained at approximately 20cm. A filtration system and an air pump were also provided to maintain stable water quality and sufficient dissolved oxygen.

[0147] B. Placement of the fish

[0148] Place one spotted catfish in each tank and allow the fish to acclimatize to the environment for 24 hours. During this acclimatization period, do not feed the fish and closely observe their activity and health to ensure no abnormalities occur.

[0149] C. Feeding Operation

[0150] Each fish should be fed 30 pellets of feed, and the feeding process should be completed within 5 minutes.

[0151] D. Dissection and sampling procedures

[0152] Once the designated dissection time (15 minutes) is reached, quickly remove the fish from the aquarium, use a sterilized scalpel and forceps to cut along the midline of the fish's abdomen, completely remove the stomach, and then pour the gastric juices into a petri dish.

[0153] 4. Fluorescence observation

[0154] The culture dishes containing gastric fluid were placed under a UV lamp (365nm) for observation, and the fluorescence phenomena of each group were recorded.

[0155] The specific observations for Experiment Example 2 are shown in Table 2.

[0156] Table 2

[0157] Group Observation results Example 1 Group Obvious fluorescence was observed. Example 2 group Obvious fluorescence was observed. Example 3 Group Obvious fluorescence was observed. Example 4 group Obvious fluorescence was observed. Comparative Example 2 No fluorescence

[0158] Table 2 shows that in Examples 1-4, the gastric juice of the fish exhibited significant fluorescence 15 minutes after feeding. This indicates that at this time, most of the feed coating layer had been destroyed by the digestive peristalsis of the fish's stomach, causing the feed particles to break and releasing water-soluble vitamins. In contrast, no fluorescence was observed in Comparative Example 2, suggesting that its coating layer failed to break effectively in the fish's stomach, resulting in the delayed release of water-soluble vitamins. This result contrasts sharply with Examples 1-4, demonstrating that the brittle and hydrophobic coating layer of the present invention can rapidly break in response to physical pressure after feeding in channel catfish, thereby ensuring the effective release of water-soluble vitamins.

[0159] Experimental Example 3

[0160] The feeds prepared in Examples 1-4 and Comparative Examples 1-2 were selected as experimental materials. Six experimental groups were set up, corresponding to the feeds in Examples 1-4 and Comparative Examples 1-2, respectively, and two parallel groups were set up for each group.

[0161] Experimental Preparation: Twelve aquariums, each 30cm long, 20cm wide, and 25cm high, were selected as the main experimental containers. Three aquariums were used for each group of feed. Before use, the aquariums were thoroughly cleaned with water and then soaked in a 0.1% potassium permanganate solution for 30 minutes for disinfection. Afterward, they were rinsed several times with clean water to ensure no disinfectant residue remained. Each aquarium was filled with tap water that had been aerated for at least 24 hours, and the water level was maintained at approximately 20cm.

[0162] Experimental steps: Accurately weigh each group of feed and put them into the corresponding fish tank. Put 100g of feed into each fish tank and ensure that the feed is completely submerged in water.

[0163] Fluorescence observation:

[0164] After soaking the feed for 15 minutes, take 100ml of water sample from each tank and observe the water sample under an ultraviolet lamp (365nm). Record the fluorescence phenomenon of each group.

[0165] The specific data for Experiment Example 3 are shown in Table 3.

[0166] Table 3

[0167] Group Observation results Example 1 Group No fluorescence Example 2 group No fluorescence Example 3 Group No fluorescence Example 4 group No fluorescence Comparative Example 1 Fluorescence phenomenon occurs Comparative Example 2 No fluorescence

[0168] As shown in Table 3, Comparative Example 1, due to the lack of coating treatment, exhibited fluorescence after soaking in water for 15 minutes. This indicates that water-soluble vitamins rapidly dissolved in the water without protection, leading to nutrient loss. Conversely, no fluorescence was observed in the feeds of Examples 1-4 and Comparative Example 2 after soaking in water for the same period, demonstrating that the coating layer in these feeds effectively prevented the premature release and loss of water-soluble vitamins.

[0169] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A premix that promotes liver health in channel catfish, characterized in that, It comprises the following components: water-soluble vitamins, fat-soluble vitamins, minerals and functional additives, wherein the surface of the water-soluble vitamins is coated with a brittle and hydrophobic coating layer, and the elongation at break of the coating layer is ≤3%, and the elastic modulus of the coating layer is 0.1-1 MPa; The coating layer is a gelatin-based composite film, and polydimethylsiloxane is dispersed in the coating layer; The coating layer is formed by coating with a coating liquid containing gelatin, tannic acid, nano silica and polydimethylsiloxane emulsion; The mass ratio of gelatin, tannic acid and nano silica is (65-75):(20-30):(3-8), the solid content of the polydimethylsiloxane emulsion is 25%-40%, and the amount of polydimethylsiloxane emulsion added accounts for 5%-10% of the mass of gelatin. The pelleting method used in the process of making the premix into complete compound feed is as follows: Feed ingredients and premixed feed are added to a mixer in proportion and mixed evenly at 8-10 rpm. The mixed material is then transferred to a fluidized bed and sprayed with gum arabic solution at a rate of 2-3 mL / min. Granulation and drying are then performed to obtain the target feed. The fluidized bed is configured with the following parameters: atomization pressure of 0.1-0.15 MPa and fluidizing gas velocity of 0.5-0.8 m / s.

2. The premix for promoting liver health in channel catfish according to claim 1, characterized in that: The water-soluble vitamins comprise the following components in parts by weight: vitamin B1 0.05-0.2 parts, vitamin B2 0.1-0.5 parts, vitamin B6 0.01-0.05 parts, vitamin B12 0.01-0.05 parts, nicotinamide 0.3-1.0 parts, calcium pantothenate 0.2-0.8 parts, vitamin C 1.0-3.0 parts, folic acid 0.05-0.2 parts, and biotin 0.01-0.05 parts.

3. The premix for promoting liver health in channel catfish according to claim 1, characterized in that, The fat-soluble vitamins comprise the following components in parts by weight: vitamin A 0.5-2.0 parts, vitamin D3 0.1-0.5 parts, vitamin E 0.5-2.0 parts, and vitamin K3 0.05-0.2 parts.

4. The premix for promoting liver health in channel catfish according to claim 1, characterized in that, The minerals comprise the following components in parts by weight: 5-15 parts calcium dihydrogen phosphate, 0.5-2.0 parts sodium chloride, 1.0-3.0 parts potassium chloride, 0.5-1.5 parts magnesium sulfate, 0.1-0.5 parts ferrous sulfate, 0.05-0.2 parts zinc sulfate, 0.01-0.05 parts copper sulfate, 0.05-0.2 parts manganese sulfate, 0.005-0.02 parts calcium iodate, 0.005-0.01 parts cobalt sulfate, 0.001-0.005 parts sodium selenite, and 5-15 parts zeolite powder.

5. The premix for promoting liver health in channel catfish according to claim 1, characterized in that: The functional additive comprises the following components in parts by weight: 1.2-2.0 parts of bile acids and 0.6-1.0 parts of glutathione.

6. The method for preparing the premix for promoting liver health in channel catfish according to any one of claims 1-5, characterized in that, The steps are as follows: A coating layer is applied to the surface of water-soluble vitamins to obtain coated water-soluble vitamins; then the coated water-soluble vitamins, fat-soluble vitamins, minerals and functional additives are thoroughly mixed to obtain a premix.