Feed for mandarin fish containing Chinese herbal medicine papyrus and preparation method thereof

Abstract

This invention belongs to the field of fish farming, and particularly relates to a mandarin fish feed containing the traditional Chinese medicine *Phyllanthus chinensis*, comprising the following raw materials in parts by weight: 30-45 parts fish meal, 15-25 parts soybean meal, 5-15 parts peanut meal, 10-18 parts wheat flour, 3-6 parts fish oil, 2-4 parts soybean oil, 1-3 parts soybean lecithin, 0.5-1.5 parts compound vitamins, 0.5-1.5 parts compound minerals, 1-2 parts calcium dihydrogen phosphate, and 8-12 parts traditional Chinese medicine additives; the traditional Chinese medicine additives are made from the following raw materials in parts by weight: 40-60 parts *Phyllanthus chinensis*, 10-20 parts *Astragalus membranaceus*, 10-15 parts *Isatis indigotica*, 5-10 parts honeysuckle, 5-10 parts licorice, and 2-5 parts allicin. This invention also discloses its preparation method. This invention activates the immune system of mandarin fish by adding traditional Chinese medicine additives to the feed, significantly increases serum lysozyme activity, and reduces malondialdehyde content, thereby enhancing the fish's resistance to common pathogens such as Aeromonas hydrophila and reducing morbidity and mortality during the breeding process.

Description

Technical Field

[0001] This invention relates to the field of fish farming, and in particular to a mandarin fish feed containing the traditional Chinese medicine *Phyllanthus praecox* and its preparation method. Background Technology

[0002] Mandarin fish (Siniperca chuatsi) is an important and valuable freshwater economic fish in my country, highly favored by the market for its tender flesh, delicious taste, and rich nutrition. In recent years, with the continuous growth in consumer demand for mandarin fish, its aquaculture scale has been expanding, and high-density intensive aquaculture has become the mainstream of the industry. However, under high-density aquaculture conditions, problems such as frequent disease outbreaks, low survival rates, and high risks of drug residues in mandarin fish have become increasingly prominent. Particularly noteworthy is that mandarin fish are typical carnivorous fish with extremely poor adaptability to artificial formulated feeds. Traditional aquaculture has long relied on feeding live bait (such as mud carp and loach), which not only leads to high aquaculture costs and huge resource consumption, but also makes live bait highly susceptible to carrying pathogenic microorganisms such as Aeromonas hydrophila, becoming an important medium for cross-infection of diseases, further exacerbating the difficulty of disease control during the aquaculture process.

[0003] To address these issues, the industry has gradually begun developing specialized artificial feeds for mandarin fish, adding functional ingredients such as immune enhancers, probiotics, and traditional Chinese medicine to improve fish health. Among these, traditional Chinese medicine has become a research hotspot in the field of aquatic feed additives due to its advantages such as natural origin, low toxicity, no residue in animals, and low likelihood of inducing drug resistance in pathogens. Modern pharmacological studies have shown that the active ingredients in traditional Chinese medicine, such as polysaccharides, flavonoids, alkaloids, and saponins, can improve the non-specific immune function of aquatic animals by activating macrophages, promoting cytokine secretion, and enhancing complement system activity. Simultaneously, some traditional Chinese medicine components can improve the intestinal microecological environment, promote digestive enzyme secretion, improve feed conversion rate, and have certain antibacterial and bacteriostatic effects, which can, to some extent, replace antibiotics for disease prevention in aquaculture.

[0004] Lemna minor L. is an aquatic plant belonging to the genus Lemna in the family Lemnaceae. It is widely distributed in freshwater areas of my country, with abundant resources and low harvesting costs. Its dry matter is not only rich in protein, vitamins and trace elements, but also rich in flavonoids, phenolic acids, polysaccharides and natural vitamin E, carotenoids and other bioactive substances. Modern pharmacological studies have confirmed that it has the effects of clearing heat and detoxifying, diuresis and swelling reduction, antibacterial and anti-inflammatory and antioxidant effects.

[0005] Therefore, developing a traditional Chinese medicine additive and its special feed for mandarin fish with *Phyllanthus chinensis* as the core functional component, specifically designed for the digestive physiology and feeding habits of mandarin fish, capable of simultaneously promoting growth, enhancing immunity, improving antioxidant capacity, and meeting the requirements of green and healthy aquaculture, is of great industrial value and practical significance for promoting the transformation of mandarin fish farming from live bait dependence to compound feed farming, reducing antibiotic use, and ensuring the quality and safety of aquatic products. Summary of the Invention

[0006] The purpose of this invention is to provide a mandarin fish feed containing the traditional Chinese medicine *Phyllanthus praecox* and its preparation method, so as to solve the technical problems mentioned in the background art. To achieve the above objectives, the present invention adopts the following technical solution: A mandarin fish feed containing the traditional Chinese medicine *Phyllanthus parasiticus* comprises the following raw materials in parts by weight: 30-45 parts fish meal, 15-25 parts soybean meal, 5-15 parts peanut meal, 10-18 parts wheat flour, 3-6 parts fish oil, 2-4 parts soybean oil, 1-3 parts soybean lecithin, 0.5-1.5 parts compound vitamins, 0.5-1.5 parts compound minerals, 1-2 parts calcium dihydrogen phosphate, and 8-12 parts traditional Chinese medicine additives; wherein the traditional Chinese medicine additives are made from the following raw materials in parts by weight: 40-60 parts *Phyllanthus parasiticus*, 10-20 parts *Astragalus membranaceus*, 10-15 parts *Isatis indigotica*, 5-10 parts honeysuckle, 5-10 parts licorice, and 2-5 parts allicin.

[0007] Furthermore, the aforementioned multivitamin includes vitamin A, vitamin D3, vitamin C, vitamin E, vitamin K3, vitamin B1, vitamin B2, vitamin B6, vitamin B12, niacin, calcium pantothenate, folic acid, and biotin.

[0008] Furthermore, the composite minerals include ferrous sulfate, copper sulfate, zinc sulfate, manganese sulfate, sodium selenite, potassium iodide, and cobalt chloride.

[0009] Furthermore, the preparation method of the herbal additive includes the following steps: S1: Wash fresh water hyacinth, dry it until the moisture content is ≤10%, and crush it through a 60-80 mesh sieve to obtain water hyacinth powder; S2: Dry Astragalus membranaceus, Isatis indigotica, Lonicera japonica, and Glycyrrhiza uralensis separately until the moisture content is ≤10%, then pulverize them and pass them through a 60-80 mesh sieve. Mix them evenly to obtain a mixed medicinal powder. S3: Mix the pampas grass powder, mixed medicinal powder and allicin evenly to obtain the Chinese herbal medicine additive.

[0010] A method for preparing mandarin fish feed containing the traditional Chinese medicine *Phyllanthus urinaria* includes the following steps: S1: Grind fish meal, soybean meal, peanut meal, and flour through a 60-80 mesh sieve; add the herbal additives, soybean meal, and peanut meal into a premixer and mix for 5-10 minutes to obtain the premixed carrier material; S2: Add the premixed carrier material, fish meal, flour, and calcium dihydrogen phosphate into a mixer and mix for 5-8 minutes. Then add compound vitamins and compound minerals and continue mixing for 3-5 minutes to obtain powdered base material. S3: Premix fish oil, soybean oil, and soybean lecithin evenly, then spray evenly onto the surface of the powdered base material, and continue mixing for 3-5 minutes to obtain a complete mixture. S4: Feed the complete mixture into the conditioner, introduce saturated steam for conditioning, control the material moisture content to reach 18%-22%, and the discharge temperature to reach 85-95℃; S5: Feed the conditioned material into the ring die pellet mill and pelletize it at 80-90℃; S6: Feed the pelleted feed into a counter-current cooler, cool it to room temperature with cold air and dry it until the moisture content is ≤10%, and you will get mandarin fish feed containing the Chinese herbal medicine puping.

[0011] Furthermore, in S5, the saturated steam temperature is 90-100℃, and the conditioning time is 3-5 minutes.

[0012] Furthermore, in S6, the granulation particle size is 4-5 mm.

[0013] The advantages of this invention compared to the prior art are as follows: 1. This invention adds traditional Chinese medicinal herbs to the feed. The active ingredients in the feed, such as flavonoids, polysaccharides and natural vitamin E, which are rich in pampas grass, work synergistically with astragalus polysaccharides, isatis root alkaloids, honeysuckle chlorogenic acid and allicin to activate the immune system of mandarin fish, significantly increase serum lysozyme activity and reduce malondialdehyde content, thereby enhancing the fish's resistance to common pathogens such as Aeromonas hydrophila and reducing the incidence and mortality of disease during the breeding process.

[0014] 2. This invention premixes traditional Chinese medicine additives with plant protein bases such as soybean meal and peanut meal, and utilizes the lightweight and porous properties of *Phyllanthus chinensis* as an adsorption carrier to ensure the uniform dispersion of traditional Chinese medicine powder in feed. Combined with subsequent low-temperature conditioning and granulation processes, it effectively protects the active ingredients in *Phyllanthus chinensis* and compound medicinal materials, making the technical solution both rational in formulation and feasible in process. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this invention clearer, preferred embodiments are described below to further illustrate the invention in detail. However, it should be noted that many details listed in the specification are merely to provide the reader with a thorough understanding of one or more aspects of the invention, and these aspects can be achieved even without these specific details.

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the present invention will be further described in detail below with reference to preferred embodiments. However, it should be noted that many details listed in the specification are merely to provide the reader with a thorough understanding of one or more aspects of the invention, and these aspects of the invention can be achieved even without these specific details.

[0017] A mandarin fish feed containing the traditional Chinese medicine *Phyllanthus parasiticus* comprises the following raw materials in parts by weight: 30-45 parts fish meal, 15-25 parts soybean meal, 5-15 parts peanut meal, 10-18 parts wheat flour, 3-6 parts fish oil, 2-4 parts soybean oil, 1-3 parts soybean lecithin, 0.5-1.5 parts compound vitamins, 0.5-1.5 parts compound minerals, 1-2 parts calcium dihydrogen phosphate, and 8-12 parts traditional Chinese medicine additives; wherein the traditional Chinese medicine additives are made from the following raw materials in parts by weight: 40-60 parts *Phyllanthus parasiticus*, 10-20 parts *Astragalus membranaceus*, 10-15 parts *Isatis indigotica*, 5-10 parts honeysuckle, 5-10 parts licorice, and 2-5 parts allicin.

[0018] The compound vitamin contains the following ingredients per kilogram: Vitamin A 5000 IU, Vitamin D3 2000 IU, Vitamin C 200 mg, Vitamin E 100 mg, Vitamin K3 20 mg, Vitamin B1 30 mg, Vitamin B2 50 mg, Vitamin B6 40 mg, Vitamin B12 0.1 mg, Niacin 100 mg, Calcium Pantothenate 60 mg, Folic Acid 10 mg, and Biotin 2 mg.

[0019] The compound mineral contains the following components per kilogram: 200 mg ferrous sulfate, 30 mg copper sulfate, 150 mg zinc sulfate, 50 mg manganese sulfate, 0.5 mg sodium selenite, 1.5 mg potassium iodide, and 1 mg cobalt chloride.

[0020] The preparation method of the herbal additive includes the following steps: S1: Wash fresh water hyacinth, dry it until the moisture content is ≤10%, and crush it through a 60-80 mesh sieve to obtain water hyacinth powder; S2: Dry Astragalus membranaceus, Isatis indigotica, Lonicera japonica, and Glycyrrhiza uralensis separately until the moisture content is ≤10%, then pulverize them and pass them through a 60-80 mesh sieve. Mix them evenly to obtain a mixed medicinal powder. S3: Mix the pampas grass powder, mixed medicinal powder and allicin evenly to obtain the Chinese herbal medicine additive.

[0021] A method for preparing mandarin fish feed containing the traditional Chinese medicine *Phyllanthus urinaria* includes the following steps: S1: Grind fish meal, soybean meal, peanut meal, and flour through a 60-80 mesh sieve; add the herbal additives, soybean meal, and peanut meal into a premixer and mix for 5-10 minutes to obtain the premixed carrier material; S2: Add the premixed carrier material, fish meal, flour, and calcium dihydrogen phosphate into a mixer and mix for 5-8 minutes. Then add compound vitamins and compound minerals and continue mixing for 3-5 minutes to obtain powdered base material. S3: Premix fish oil, soybean oil, and soybean lecithin evenly, then spray evenly onto the surface of the powdered base material, and continue mixing for 3-5 minutes to obtain a complete mixture. S4: Feed the complete mixture into the conditioner, introduce saturated steam at a temperature of 90-100℃, condition for 3-5 minutes, control the material moisture content to reach 18%-22%, and the discharge temperature to reach 85-95℃; S5: Feed the conditioned material into a ring die pellet mill and granulate it at 80-90℃ to achieve a particle size of 4-5mm. S6: Feed the pelleted feed into a counter-current cooler, cool it to room temperature with cold air and dry it until the moisture content is ≤10%, and you will get mandarin fish feed containing the Chinese herbal medicine puping.

[0022] The following description uses more specific examples.

[0023] Example 1 A mandarin fish feed containing the traditional Chinese medicine *Phyllanthus parasiticus* comprises the following raw materials in parts by weight: 38 parts fish meal, 25 parts soybean meal, 8 parts peanut meal, 14 parts wheat flour, 4 parts fish oil, 2 parts soybean oil, 3 parts soybean lecithin, 1 part compound vitamins, 1 part compound minerals, 1.5 parts calcium dihydrogen phosphate, and 12 parts traditional Chinese medicine additives; the traditional Chinese medicine additives are made from the following raw materials in parts by weight: 50 parts *Phyllanthus parasiticus*, 20 parts astragalus, 10 parts isatis root, 8 parts honeysuckle, 8 parts licorice, and 5 parts allicin.

[0024] The preparation method of the herbal additive includes the following steps: S1: Wash fresh water hyacinth, dry it until the moisture content is ≤10%, and crush it through an 80-mesh sieve to obtain water hyacinth powder; S2: Dry Astragalus membranaceus, Isatis indigotica, Lonicera japonica, and Glycyrrhiza uralensis separately until the moisture content is ≤10%, then pulverize them through an 80-mesh sieve and mix them evenly to obtain a mixed medicinal powder; S3: Mix the pampas grass powder, mixed medicinal powder and allicin evenly to obtain the Chinese herbal medicine additive.

[0025] A method for preparing mandarin fish feed containing the traditional Chinese medicine *Phyllanthus urinaria* includes the following steps: S1: Grind fish meal, soybean meal, peanut meal, and flour through a 60-mesh sieve; add the herbal additives, soybean meal, and peanut meal into a premixer and mix for 10 minutes to obtain the premixed carrier material; S2: Add the premixed carrier material, fish meal, flour, and calcium dihydrogen phosphate into a mixer and mix for 8 minutes. Then add compound vitamins and compound minerals and continue mixing for 5 minutes to obtain powdered base material. S3: Premix fish oil, soybean oil and soybean lecithin evenly, then spray evenly onto the surface of the powdered base material, and continue mixing for 4 minutes to obtain a complete mixture; S4: Feed the complete mixture into the conditioner, introduce saturated steam at 100℃, condition for 3 minutes, control the material moisture content to reach 18%, and the discharge temperature to reach 90℃. S5: The conditioned material is fed into a ring die pellet mill and pelletized at 90°C to a particle size of 4mm. S6: Feed the pelleted feed into a counter-current cooler, cool it to room temperature with cold air and dry it until the moisture content is ≤10%, and you will get mandarin fish feed containing the Chinese herbal medicine puping.

[0026] Example 2 A mandarin fish feed containing the traditional Chinese medicine *Phyllanthus praecox* comprises the following raw materials in parts by weight: 30 parts fish meal, 25 parts soybean meal, 15 parts peanut meal, 18 parts wheat flour, 3 parts fish oil, 4 parts soybean oil, 2 parts soybean lecithin, 0.5 parts compound vitamins, 1 part compound minerals, 2 parts calcium dihydrogen phosphate, and 8 parts traditional Chinese medicine additives; the traditional Chinese medicine additives are made from the following raw materials in parts by weight: 60 parts *Phyllanthus praecox*, 15 parts Astragalus membranaceus, 15 parts Isatis indigotica, 5 parts honeysuckle, 5 parts licorice, and 3 parts allicin.

[0027] The preparation method of the herbal additive includes the following steps: S1: Wash fresh water hyacinth, dry it until the moisture content is ≤10%, and crush it through a 60-mesh sieve to obtain water hyacinth powder; S2: Dry Astragalus membranaceus, Isatis indigotica, Lonicera japonica, and Glycyrrhiza uralensis separately until the moisture content is ≤10%, then pulverize them through a 60-mesh sieve and mix them evenly to obtain a mixed medicinal powder; S3: Mix the pampas grass powder, mixed medicinal powder and allicin evenly to obtain the Chinese herbal medicine additive.

[0028] A method for preparing mandarin fish feed containing the traditional Chinese medicine *Phyllanthus urinaria* includes the following steps: S1: Grind fish meal, soybean meal, peanut meal, and flour through an 80-mesh sieve; add the herbal additives, soybean meal, and peanut meal into a premixer and mix for 8 minutes to obtain the premixed carrier material; S2: Add the premixed carrier material, fish meal, flour, and calcium dihydrogen phosphate into a mixer and mix for 6 minutes. Then add compound vitamins and compound minerals and continue mixing for 4 minutes to obtain powdered base material. S3: Premix fish oil, soybean oil and soybean lecithin evenly, then spray evenly onto the surface of the powdered base material, and continue mixing for 3 minutes to obtain a complete mixture; S4: Feed the complete mixture into the conditioner, introduce saturated steam at 95℃, condition for 5 minutes, control the material moisture content to reach 20%, and the discharge temperature to reach 95℃. S5: The conditioned material is fed into a ring die pellet mill and pelletized at 85°C to a particle size of 4mm. S6: Feed the pelleted feed into a counter-current cooler, cool it to room temperature with cold air and dry it until the moisture content is ≤10%, and you will get mandarin fish feed containing the Chinese herbal medicine puping.

[0029] Example 3 A mandarin fish feed containing the traditional Chinese medicine *Phyllanthus urinaria* comprises the following raw materials in parts by weight: 45 parts fish meal, 15 parts soybean meal, 10 parts peanut meal, 10 parts wheat flour, 6 parts fish oil, 3 parts soybean oil, 1 part soybean lecithin, 1.5 parts compound vitamins, 1.5 parts compound minerals, 1 part calcium dihydrogen phosphate, and 10 parts traditional Chinese medicine additives; the traditional Chinese medicine additives are made from the following raw materials in parts by weight: 55 parts *Phyllanthus urinaria*, 10 parts Astragalus membranaceus, 12 parts Isatis indigotica, 10 parts honeysuckle, 10 parts licorice, and 2 parts allicin.

[0030] The preparation method of the herbal additive includes the following steps: S1: Wash fresh water hyacinth, dry it until the moisture content is ≤10%, and crush it through an 80-mesh sieve to obtain water hyacinth powder; S2: Dry Astragalus membranaceus, Isatis indigotica, Lonicera japonica, and Glycyrrhiza uralensis separately until the moisture content is ≤10%, then pulverize them through an 80-mesh sieve and mix them evenly to obtain a mixed medicinal powder; S3: Mix the pampas grass powder, mixed medicinal powder and allicin evenly to obtain the Chinese herbal medicine additive.

[0031] A method for preparing mandarin fish feed containing the traditional Chinese medicine *Phyllanthus urinaria* includes the following steps: S1: Grind fish meal, soybean meal, peanut meal, and flour through an 80-mesh sieve; add the herbal additives, soybean meal, and peanut meal into a premixer and mix for 5 minutes to obtain the premixed carrier material; S2: Add the premixed carrier material, fish meal, flour, and calcium dihydrogen phosphate into a mixer and mix for 5 minutes. Then add compound vitamins and compound minerals and continue mixing for 3 minutes to obtain powdered base material. S3: Premix fish oil, soybean oil and soybean lecithin evenly, then spray evenly onto the surface of the powdered base material, and continue mixing for 5 minutes to obtain a complete mixture; S4: Feed the complete mixture into the conditioner, introduce saturated steam at 90℃, condition for 4 minutes, control the material moisture content to reach 22%, and the discharge temperature to reach 85℃. S5: Feed the conditioned material into a ring die pellet mill and pelletize it at 90°C to a particle size of 5mm. S6: Feed the pelleted feed into a counter-current cooler, cool it to room temperature with cold air and dry it until the moisture content is ≤10%, and you will get mandarin fish feed containing the Chinese herbal medicine puping.

[0032] Example 4 A mandarin fish feed containing the traditional Chinese medicine *Phyllanthus parasiticus* comprises the following raw materials in parts by weight: 40 parts fish meal, 20 parts soybean meal, 12 parts peanut meal, 15 parts wheat flour, 5 parts fish oil, 4 parts soybean oil, 3 parts soybean lecithin, 1.2 parts compound vitamins, 1.2 parts compound minerals, 2 parts calcium dihydrogen phosphate, and 10 parts traditional Chinese medicine additives; the traditional Chinese medicine additives are made from the following raw materials in parts by weight: 40 parts *Phyllanthus parasiticus*, 18 parts Astragalus membranaceus, 10 parts Isatis indigotica, 5 parts honeysuckle, 8 parts licorice, and 3 parts allicin.

[0033] The preparation method of the herbal additive includes the following steps: S1: Wash fresh water hyacinth, dry it until the moisture content is ≤10%, and crush it through an 80-mesh sieve to obtain water hyacinth powder; S2: Dry Astragalus membranaceus, Isatis indigotica, Lonicera japonica, and Glycyrrhiza uralensis separately until the moisture content is ≤10%, then pulverize them through an 80-mesh sieve and mix them evenly to obtain a mixed medicinal powder; S3: Mix the pampas grass powder, mixed medicinal powder and allicin evenly to obtain the Chinese herbal medicine additive.

[0034] A method for preparing mandarin fish feed containing the traditional Chinese medicine *Phyllanthus urinaria* includes the following steps: S1: Grind fish meal, soybean meal, peanut meal, and flour through a 60-mesh sieve; add the herbal additives, soybean meal, and peanut meal into a premixer and mix for 10 minutes to obtain the premixed carrier material; S2: Add the premixed carrier material, fish meal, flour, and calcium dihydrogen phosphate into a mixer and mix for 6 minutes. Then add compound vitamins and compound minerals and continue mixing for 3 minutes to obtain powdered base material. S3: Premix fish oil, soybean oil and soybean lecithin evenly, then spray evenly onto the surface of the powdered base material, and continue mixing for 5 minutes to obtain a complete mixture; S4: Feed the complete mixture into the conditioner, introduce saturated steam at 95℃, condition for 4.5 minutes, control the material moisture content to reach 18%, and the discharge temperature to reach 85℃. S5: Feed the conditioned material into the ring die pellet mill and granulate it at 80℃ to a particle size of 5mm. S6: Feed the pelleted feed into a counter-current cooler, cool it to room temperature with cold air and dry it until the moisture content is ≤10%, and you will get mandarin fish feed containing the Chinese herbal medicine puping.

[0035] Comparative Example 1 It is basically the same as Example 3, except that the mandarin fish feed does not contain any Chinese herbal medicine additives.

[0036] Aquaculture experiment Three hundred healthy mandarin fish with an initial weight of approximately 100g were selected and randomly divided into 5 groups, corresponding to Examples 1-4 and Comparative Example 1, with 3 replicates per group and 30 fish per replicate. They were raised in an indoor recirculating aquaculture system for 60 days at a water temperature of 26±1℃ and dissolved oxygen >6mg / L. They were fed twice daily (8:00 and 16:00) at an amount of 3%-5% of the fish's body weight, adjusted according to their feeding behavior.

[0037] Measurement indicators: Growth performance: initial body weight, final body weight, weight gain rate, feed conversion ratio Immune indicators: serum lysozyme activity, superoxide dismutase (SOD) activity, and malondialdehyde (MDA) content. Challenge experiment: After 60 days of rearing, 10 fish were randomly selected from each replicate and injected intraperitoneally with Aeromonas hydrophila (1×10⁻⁶). 6 CFU / tail), record the mortality rate within 7 days.

[0038] The test results are shown in Table 1.

[0039] Table 1 Results of the breeding experiment As can be seen from Table 1, the four examples with added traditional Chinese medicine additives showed improvements in six indicators compared to the control group: weight gain rate, feed conversion ratio, lysozyme activity, SOD activity, MDA content, and survival rate after viral challenge.

[0040] The weight gain rates of Examples 1-4 ranged from 246.9% to 274.4%, all higher than the control group's 242.8%. Example 3 achieved a weight gain rate of 274.4 ± 11.3%, a 13.0% increase compared to the control group. This indicates that adding this traditional Chinese medicine additive to the feed can promote the growth of mandarin fish. The feed conversion ratios of the four examples ranged from 1.38 to 1.50, all lower than the control group's 1.60, representing a decrease of 6.3% to 13.8%. This suggests that the traditional Chinese medicine additive can improve feed conversion efficiency and reduce feed consumption per unit of weight gain. Its mechanism may be related to the active ingredients in *Phyllanthus urinaria* promoting intestinal health and increasing digestive enzyme activity.

[0041] From the perspective of immune indicators, the lysozyme activity of the four examples ranged from 71.4 to 81.5 U / mL, which was 28.6% to 46.8% higher than that of the control group (55.5 U / mL). This indicates that the herbal additive can activate the non-specific immune system of mandarin fish, significantly increase serum lysozyme activity, and enhance the body's defense against pathogens.

[0042] The survival rates of the four embodiments ranged from 70.1% to 76.4%, which was 13.9 to 20.2 percentage points higher than the 56.2% of the control group. This indicates that the addition of traditional Chinese medicine additives to the feed significantly enhanced the resistance of mandarin fish to Aeromonas hydrophila and greatly improved the survival rate after infection.

[0043] The SOD activity of the four embodiments ranged from 139.1 to 153.5 U / mL, which was 10.3% to 21.8% higher than that of the control group (126.1 U / mL). This indicates that the herbal additive can increase the level of superoxide dismutase in mandarin fish and enhance the body's ability to scavenge free radicals.

[0044] From the perspective of antioxidant indicators, the MDA content of the four examples ranged from 5.19 to 6.72 nmol / mL, all lower than the 7.39 nmol / mL of the control group. This indicates that the feed of this application can inhibit lipid peroxidation in mandarin fish, reduce malondialdehyde accumulation, and thus alleviate the damage of oxidative stress to fish tissues. Notably, Examples 2 and 3 showed the largest reduction in MDA, at 27.0% and 29.8% respectively, and the proportion of *Phyllanthus urinaria* in these two examples was the highest. This suggests that *Phyllanthus urinaria*, as the core component of this herbal additive, is likely the main contributor to the reduction in MDA due to its rich natural antioxidant components. Examples 1 and 4 showed relatively smaller reductions in MDA, at 16.1% and 9.1% respectively, but still showed a trend of reduction compared to the control group. This indicates that even when the proportion of *Phyllanthus urinaria* or the total amount of the additive is at a low level, this herbal additive can still exert an antioxidant effect to a certain extent.

[0045] A comprehensive comparison of the four examples with the control group shows that the introduction of this traditional Chinese medicine additive into the basal feed resulted in a systematic improvement in the growth performance, immune indicators, and antioxidant levels of mandarin fish. Weight gain increased by 1.7%-13.0%, feed conversion ratio decreased by 6.3%-13.8%, lysozyme activity increased by 28.6%-46.8%, survival rate after viral challenge increased by 13.9-20.2 percentage points, SOD activity increased by 10.3%-21.8%, and MDA decreased by 9.1%-29.8%.

[0046] The results showed that the synergistic combination of *Phyllanthus praecox*, *Astragalus membranaceus*, *Isatis indigotica*, *Lonicera japonica*, *Glycyrrhiza uralensis*, and allicin could simultaneously promote growth, enhance immunity, and provide antioxidant protection in mandarin fish, thereby improving growth performance and disease resistance.

[0047] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A mandarin fish feed containing the traditional Chinese medicine *Phyllanthus urinaria*, characterized in that, The ingredients include the following parts by weight: 30-45 parts fish meal, 15-25 parts soybean meal, 5-15 parts peanut meal, 10-18 parts wheat flour, 3-6 parts fish oil, 2-4 parts soybean oil, 1-3 parts soybean lecithin, 0.5-1.5 parts compound vitamins, 0.5-1.5 parts compound minerals, 1-2 parts calcium dihydrogen phosphate, and 8-12 parts traditional Chinese medicine additives; the traditional Chinese medicine additives are made from the following parts by weight: 40-60 parts of *Pueraria lobata*, 10-20 parts of *Astragalus membranaceus*, 10-15 parts of *Isatis indigotica*, 5-10 parts of honeysuckle, 5-10 parts of licorice, and 2-5 parts of allicin.

2. The mandarin fish feed containing the traditional Chinese medicine *Phyllanthus praecox* according to claim 1, characterized in that: The multivitamin includes vitamin A, vitamin D3, vitamin C, vitamin E, vitamin K3, vitamin B1, vitamin B2, vitamin B6, vitamin B12, niacin, calcium pantothenate, folic acid, and biotin.

3. The mandarin fish feed containing the traditional Chinese medicine *Phyllanthus praecox* according to claim 1, characterized in that: The composite minerals include ferrous sulfate, copper sulfate, zinc sulfate, manganese sulfate, sodium selenite, potassium iodide, and cobalt chloride.

4. The mandarin fish feed containing the traditional Chinese medicine *Phyllanthus praecox* according to claim 1, characterized in that: The preparation method of the herbal additive includes the following steps: S1: Wash fresh water hyacinth, dry it until the moisture content is ≤10%, and crush it through a 60-80 mesh sieve to obtain water hyacinth powder; S2: Dry Astragalus membranaceus, Isatis indigotica, Lonicera japonica, and Glycyrrhiza uralensis separately until the moisture content is ≤10%, then pulverize them and pass them through a 60-80 mesh sieve. Mix them evenly to obtain a mixed medicinal powder. S3: Mix the pampas grass powder, mixed medicinal powder and allicin evenly to obtain the Chinese herbal medicine additive.

5. The method for preparing mandarin fish feed containing the traditional Chinese medicine *Phyllanthus urticaria* according to any one of claims 1-4, characterized in that, Includes the following steps: S1: Grind fish meal, soybean meal, peanut meal, and flour through a 60-80 mesh sieve; add the herbal additives, soybean meal, and peanut meal into a premixer and mix for 5-10 minutes to obtain the premixed carrier material; S2: Add the premixed carrier material, fish meal, flour, and calcium dihydrogen phosphate into a mixer and mix for 5-8 minutes. Then add compound vitamins and compound minerals and continue mixing for 3-5 minutes to obtain powdered base material. S3: Premix fish oil, soybean oil, and soybean lecithin evenly, then spray evenly onto the surface of the powdered base material, and continue mixing for 3-5 minutes to obtain a complete mixture. S4: Feed the complete mixture into the conditioner, introduce saturated steam for conditioning, control the material moisture content to reach 18%-22%, and the discharge temperature to reach 85-95℃; S5: Feed the conditioned material into the ring die pellet mill and pelletize it at 80-90℃; S6: The pelleted feed is fed into a counter-current cooler, cooled to room temperature by cold air and dried to a moisture content of ≤10%, thus obtaining the mandarin fish feed containing the Chinese herbal medicine *Phyllanthus praecox*.

6. The method for preparing mandarin fish feed containing the traditional Chinese medicine *Phyllanthus urticaria* according to claim 5, characterized in that: In S5, the saturated steam temperature is 90-100℃, and the conditioning time is 3-5 minutes.

7. The method for preparing mandarin fish feed containing the traditional Chinese medicine *Phyllanthus urinaria* according to claim 5, characterized in that: In S6, the granulation particle size is 4-5mm.

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