Use of cysteamine or salt thereof in the preparation of a feed additive for preventing and improving fatty liver of laying hens

Abstract

The application relates to the technical field of poultry feed additive preparation, in particular to application of cysteamine or a salt thereof in preparation of a feed additive for preventing and improving fatty liver of laying hens. The application provides application of cysteamine or a salt thereof in preparation of a feed additive for preventing and improving fatty liver of laying hens. The application provides a new use of cysteamine and a salt thereof in preparation of a feed additive for preventing and improving fatty liver of laying hens, and provides a new way for preventing and improving fatty liver of laying hens.

Description

Technical Field

[0001] This invention relates to the field of poultry feed additive preparation technology, specifically to the application of cysteamine or its salts in the preparation of feed additives for the prevention and improvement of fatty liver in laying hens. Background Technology

[0002] Fatty liver hemorrhagic syndrome (FLHS) is a nutritional metabolic disease caused by abnormal lipid accumulation due to disordered liver lipid metabolism in laying hens. It primarily affects caged laying hens during their peak egg-laying period. The main clinical features are an enlarged, yellow, oily, brittle liver with petechiae or ecchymoses on the surface and extensive abdominal fat deposition. Since the liver is a crucial site for lipid synthesis in poultry, the development and maturation of follicles and the formation of yolks after the onset of egg production require the liver to synthesize large amounts of lipids and transport them to the reproductive system via apolipoproteins such as very low-density lipoprotein (VLDL). Numerous factors can affect the liver itself and the lipid synthesis and transport processes, leading to disordered lipid metabolism in laying hens, abnormal fat deposition in the liver, increased weight gain, and decreased egg production, thus contributing to the occurrence of FLHS. In recent years, the continuous large-scale development of the laying hen industry, coupled with high stocking densities, limited space for laying hens, and a lack of comprehensive laying hen husbandry techniques, has resulted in an increased incidence of FLHS, causing significant economic losses for poultry farmers.

[0003] Cysteine, also known as β-mercaptoethylamine, is primarily used in production as cysteine ​​hydrochloride due to its instability. Cysteine ​​exerts its antioxidant effects mainly through two pathways: firstly, it contains a sulfhydryl group, giving it a strong antioxidant effect; secondly, it enhances the function of the body's primary antioxidant system—the glutathione system. Therefore, cysteine ​​is commonly used as an antioxidant in cosmetics and skincare, or to help improve cardiovascular health; more frequently, it is used in livestock and poultry farming to promote animal growth, enhance antioxidant capacity and immune function, maintain intestinal health, and regulate the immune system.

[0004] Currently, there are no reports on the use of cysteine ​​to improve fatty liver in laying hens. Summary of the Invention

[0005] This invention provides a novel use of cysteamine or its salts in the preparation of feed additives for the prevention and improvement of fatty liver in laying hens, offering a new approach to the prevention and improvement of fatty liver in laying hens.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides the use of cysteamine or its salts in the preparation of feed additives for the prevention and improvement of fatty liver in laying hens.

[0008] The inventors of this application conducted application tests on laying hens suffering from fatty liver disease. The results showed that cysteamine-containing salts significantly improved fatty liver in laying hens. Feeding hens with cysteamine-containing salts reduced abdominal fat content, and liver slices revealed a decrease in the area of ​​lipid droplets in the liver. It is speculated that cysteamine may prevent further fat accumulation in the liver by neutralizing excess free radicals, reducing lipid peroxidation, and protecting the integrity of hepatocyte membranes; and by regulating lipid metabolism pathways, such as promoting the oxidative decomposition of fatty acids and reducing the accumulation of triglycerides in the liver, thus helping to improve or prevent fatty liver. However, the prevention and improvement of fatty liver is complex. Besides alleviating the symptoms, the effects of cysteamine-containing salts on other aspects of the laying hen's health must be considered to avoid a temporary improvement in fatty liver followed by a decline in other health indicators. In the long run, this would also be detrimental to the health of laying hens with fatty liver, potentially significantly shortening their lifespan and affecting their egg production.

[0009] Therefore, other indicators of fatty liver laying hens still need to be measured. The inventors of this application tested the egg production of fatty liver laying hens after feeding them with feed containing cysteine ​​hydrochloride and monitored the quality of the eggs. The results showed that after feeding cysteine-containing feed for 30 days, the mortality rate of fatty liver laying hens was effectively suppressed, and the quality of the eggs was also improved. This demonstrates that feed containing cysteine ​​hydrochloride not only plays a positive role in effectively preventing and improving fatty liver, but also has no obvious side effects, and is actually beneficial to egg production in fatty liver laying hens, with their health index remaining relatively stable over a longer period. The reason for this may be that cysteine, as a precursor of sulfur-containing amino acids, participates in protein synthesis and amino acid metabolism, helping to optimize protein utilization efficiency and improve liver function and overall nutritional status. Furthermore, cysteine ​​can improve the balance of intestinal microbiota and increase the efficiency of nutrient digestion and absorption, further promoting the health and production performance of fatty liver laying hens.

[0010] Furthermore, since cysteamine reacts in air to form disulfides, it is usually formulated as a cysteamine salt. Therefore, cysteamine and cysteamine salts have essentially the same efficacy, differing only in their application methods; cysteamine requires special methods to be stabilized in feed for application, which will not be described in detail here, but only provides the possibility of using cysteamine in the prevention and improvement of fatty liver in laying hens.

[0011] In summary, the inventors of this application have discovered the use of cysteamine or its salts in the preparation of feed additives for the prevention and improvement of fatty liver in laying hens, providing a new use for cysteamine or its salts.

[0012] Preferably, the cysteamine salt is cysteamine hydrochloride or chelated cysteamine zinc.

[0013] More preferably, the cysteamine salt is cysteamine hydrochloride.

[0014] Preferably, the cysteamine or its salts prevent and improve fatty liver in laying hens by enhancing the antioxidant and anti-inflammatory capabilities of the liver and reducing the crude fat content of the liver, thus ensuring the health of the laying hen's liver.

[0015] Preferably, the dosage of cysteamine or its salt is 20-200 mg / kg.

[0016] More preferably, the dosage of cysteamine or its salt is 20–120 mg / kg.

[0017] More preferably, the dosage of cysteine ​​or its salt is 40-50 mg / kg.

[0018] This invention also provides the application of a protective cysteine ​​preparation in the preparation of an enteric-coated feed additive for the prevention and improvement of fatty liver in laying hens.

[0019] Preferably, the protective cysteamine formulation comprises cysteamine or a salt thereof and a protective material that facilitates the sustained release of cysteamine or a salt thereof in the intestine.

[0020] Because cysteamine reacts with air to form disulfides, it is typically formulated as cysteamine salts, such as cysteamine hydrochloride. However, cysteamine salts are highly susceptible to oxidation and moisture absorption, leading to rapid oxidation during processing and storage, which affects the product's effectiveness. Therefore, formulating cysteamine salts into protective cysteamine formulations is a suitable choice based on the material's characteristics. The inventors of this application have taken this a step further, aiming to maximize the targeted release of cysteamine into the intestinal tract. This reduces cysteamine loss and is more beneficial for the prevention and improvement of fatty liver in laying hens.

[0021] Preferably, the cysteamine salt is cysteamine hydrochloride or cysteamine chelate.

[0022] More preferably, the cysteamine salt is cysteamine hydrochloride.

[0023] Preferably, the cysteamine or its salt accounts for 22-29% of the total weight of the protective cysteamine formulation.

[0024] More preferably, the cysteamine or its salt accounts for 27-29% of the total weight of the protective cysteamine formulation.

[0025] More preferably, the cysteamine hydrochloride accounts for 27-29% of the total weight of the protective cysteamine formulation.

[0026] Preferably, the protective material comprises, by weight, 4-6 parts sodium alginate, 6-8 parts hydroxypropyl methylcellulose, 22-27 parts β-cyclodextrin, 13-16 parts pregelatinized starch, 4-10 parts ethyl cellulose, 3-7 parts acrylic resin IV, and 5-11 parts hydroxypropyl methylcellulose phthalate.

[0027] More preferably, by weight, the protective material comprises: 5-6 parts sodium alginate, 7-8 parts hydroxypropyl methylcellulose, 23-26 parts β-cyclodextrin, 14-15 parts pregelatinized starch, 7 parts ethyl cellulose, 5 parts acrylic resin IV, and 8 parts hydroxypropyl methylcellulose phthalate.

[0028] More preferably, by weight, the protective material comprises: 5-6 parts sodium alginate, 7-8 parts hydroxypropyl methylcellulose, 24-25 parts β-cyclodextrin, 14-15 parts pregelatinized starch, 7 parts ethyl cellulose, 5 parts acrylic resin IV, and 8 parts hydroxypropyl methylcellulose phthalate.

[0029] More preferably, the protective material comprises, by weight: 5.85 parts sodium alginate, 7.02 parts hydroxypropyl methylcellulose, 24.08 parts β-cyclodextrin, 14.62 parts pregelatinized starch, 7 parts ethyl cellulose, 5 parts acrylic resin IV, and 8 parts hydroxypropyl methylcellulose phthalate.

[0030] More preferably, the protective cysteine ​​formulation comprises, by weight: 28.38 parts cysteine ​​hydrochloride, 5.85 parts sodium alginate, 7.02 parts hydroxypropyl methylcellulose, 24.08 parts β-cyclodextrin, 14.62 parts pregelatinized starch, 7 parts ethyl cellulose, 5 parts acrylic resin IV, and 8 parts hydroxypropyl methylcellulose phthalate.

[0031] The protective material consists of three main categories: binder, powder particles, and coating solution. Sodium alginate and hydroxypropyl methylcellulose form the binder when mixed with water; while cyclodextrin, pregelatinized starch, and cysteine ​​hydrochloride are powder particles. These powder particles need to be bonded together by the binder, granulated, and then dried to remove moisture, resulting in dry particles.

[0032] The coating solution is obtained by blending ethyl cellulose, acrylic resin IV, and hydroxypropyl methylcellulose phthalate. The coating solution, after being mixed evenly, is then blended again with the above-mentioned dried particles to obtain the final protected cysteine ​​formulation.

[0033] The composition and formulation of the coating solution are particularly crucial for the intestinal release of protective cysteine ​​formulations. As the raw material for the coating formation in protective cysteine ​​formulations, the coating solution directly determines the release rate of the formulation in the intestines. Simultaneously, it is necessary to consider preventing premature release of the protective cysteine ​​formulation in the stomach, which could affect its effectiveness in preventing and improving fatty liver. Ethyl cellulose, acrylic resin IV, and hydroxypropyl methylcellulose phthalate are all effective materials that can resist the acidic environment of the stomach, preventing premature degradation or release of feed additives in the stomach. They also dissolve or permeate under suitable pH conditions in the intestines, allowing for effective release of the feed additives, achieving targeted release and / or sustained release in the intestines. This improves the bioavailability and efficacy of the feed additives while potentially reducing side effects. Therefore, the composition and formulation of the coating solution are also one of the design inventive points of this invention.

[0034] Preferably, the method for preparing the protective cysteine ​​formulation includes the following steps:

[0035] S1. A binder is obtained by mixing sodium alginate, hydroxypropyl methylcellulose, and water.

[0036] S2. A mixture of cysteine ​​or its salt, cyclodextrin, and pregelatinized starch is obtained.

[0037] S3. After wet mixing of the binder and the mixture, granulation and drying are performed to obtain dry particles;

[0038] S4. Ethyl cellulose, acrylic resin IV, hydroxypropyl methyl cellulose phthalate, and water are mixed to obtain a coating solution;

[0039] S5. The dried particles and coating solution are mixed to obtain a protective cysteine ​​preparation.

[0040] Preferably, the cysteamine salt is cysteamine hydrochloride or chelated cysteamine zinc.

[0041] More preferably, the cysteamine salt is cysteamine hydrochloride.

[0042] Preferably, the protective cysteine ​​preparation prevents and improves fatty liver in laying hens by enhancing the antioxidant and anti-inflammatory capabilities of the liver, reducing the crude fat content of the liver, and ensuring the health of the laying hen's liver.

[0043] Preferably, the dosage of the protective cysteine ​​preparation is 100–400 mg / kg.

[0044] More preferably, the dosage of the protective cysteine ​​preparation is 200–400 mg / kg.

[0045] More preferably, the dosage of the protective cysteine ​​preparation is 200-300 mg / kg.

[0046] More preferably, the dosage of the protective cysteine ​​preparation is 200 mg / kg.

[0047] Therefore, the present invention has the following beneficial effects:

[0048] (1) This invention provides a new use of cysteamine and its salts in the preparation of feed additives for the prevention and improvement of fatty liver in laying hens, providing a new approach for the prevention and improvement of fatty liver in laying hens.

[0049] (2) This invention provides the application of protective cysteine ​​preparations in the preparation of enteric-coated feed additives for the prevention and improvement of fatty liver in laying hens.

[0050] (3) The present invention provides a protective cysteamine preparation / cysteamine and its salt to prevent and improve fatty liver in laying hens by improving the antioxidant and anti-inflammatory capacity of the liver and reducing the crude fat content of the liver, thus ensuring the health of the liver.

[0051] (4) This invention provides a method for preparing a protective cysteamine preparation and gives the coating preparation materials and their proportions for a protective cysteamine preparation that is more conducive to release in the intestine, so as to achieve the purpose of intestinal localized release and / or sustained release, thereby improving the bioavailability and efficacy of cysteamine. Attached Figure Description

[0052] Figure 1 A pathological section of the liver of a laying hen. Detailed Implementation

[0053] The present invention will be further described below with reference to specific embodiments. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below are generally only some, not all, of the embodiments of the present invention. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0054]

Example

[0055] Example 1

[0056] S1. In a mixer at 20 rpm, mix 5.85 g sodium alginate, 7.02 g hydroxypropyl methylcellulose, and 90 mL water until a clear and transparent binder is obtained.

[0057] S2. Mix 28.38g cysteine ​​hydrochloride, 24.08g β-cyclodextrin, and 14.62g pregelatinized starch in a trough mixer for 30 minutes to obtain a mixture;

[0058] S3. The adhesive and mixture are wet-mixed and granulated using a 20rpm wet mixing granulator, and then dried in a vacuum drying oven at 60℃ for 4 hours to obtain dried particles.

[0059] S4. After passing 4g of ethyl cellulose, 5g of acrylic resin IV, 5g of hydroxypropyl methyl cellulose phthalate, and 30mL of water through a 100-mesh sieve, mix them in a ball mill at 100 rpm to obtain a coating solution.

[0060] S5. The dried particles and coating liquid are mixed in a multifunctional fluidized bed to obtain a protective cysteine ​​formulation, wherein the peristaltic pump speed is controlled at 80 rpm.

[0061] Examples 2-11

[0062] The embodiments in this section are basically the same as those in Embodiment 1, except that the amounts of ethyl cellulose, acrylic resin IV, and hydroxypropyl methyl cellulose phthalate are different. The amounts of ethyl cellulose, acrylic resin IV, and hydroxypropyl methyl cellulose phthalate in each embodiment are shown in Table 1.

[0063] Table 1. Coating solution ratios in Examples 1-11

[0064]

[0065] Application Example 1

[0066] This application example uses the protective cysteine ​​preparation prepared in Example 5 for subsequent application experiments. Specifically, in a laying hen farm with fatty liver, 480 Hy-Line Brown laying hens aged 180 days were randomly divided into 6 treatments, with 8 replicates per treatment and 10 laying hens per replicate. Each treatment was fed a basal diet (control group) and a basal diet plus 100 mg / kg (cysteine ​​group I), 200 mg / kg (cysteine ​​group II), 300 mg / kg (cysteine ​​group III), and 400 mg / kg (cysteine ​​group IV) of the protective cysteine ​​preparation prepared in Example 5, respectively. The feeding period was 30 days. The basal diets used in this experiment are shown in Table 2.

[0067] Table 2. Raw material composition of the diet (dry matter basis, %)

[0068]

[0069]

[0070] Note: The mass percentage of each ingredient refers to the mass percentage of the total dry matter weight of the feed, based on the total dry matter weight of the feed. The composition of the premix is ​​as follows: per kilogram of premix, the vitamins contained are: Vitamin A: 200,000–333,333 IU; Vitamin D3: 80,000–166,666 IU; dl–α–tocopherol acetate ≥670 IU; Vitamin K3: 65–166.6 mg; niacin / nicotinamide (with niacin as the main component). Total (calcium) ≥800mg; D~Calcium pantothenate ≥400mg; Vitamin B2 ≥200mg; Vitamin B6 ≥120mg; Vitamin B12 ≥0.50mg; Trace elements per kilogram of premix: Manganese: 250~5000mg; Iron: 1000~25000mg; Zinc: 1000~4000mg; Copper: 95~833.3mg; Calcium: 15.0~23.0%; Total phosphorus: 3.0~8.0%.

[0071] [Performance Testing]

[0072] 1. Enteric Coagulation Test of Protective Cysteine ​​Preparations

[0073] The sustained-release effect of cysteamine hydrochloride on the protective cysteamine formulations obtained in Examples 1-11 was determined under simulated gastric and intestinal fluids.

[0074] Liquid preparation method: Prepare artificial gastric fluid and artificial intestinal fluid as release media according to the requirements of the 2020 edition of the Chinese Veterinary Pharmacopoeia.

[0075] Artificial gastric fluid preparation procedure: Take 0.2g of protective cysteine ​​preparation (accurate to 0.0002g), place it in a dissolution vessel, and use a rotating basket. The apparatus should be in accordance with the first method (basket method) of Part I, 0931 of the 2020 edition of the Chinese Veterinary Pharmacopoeia. Add 400mL of artificial gastric fluid, set the temperature to 38℃, and the rotation speed to 100r / min. After rotating for 2 hours, use high performance liquid chromatography to determine the residue content.

[0076] Artificial intestinal fluid preparation procedure: Take 0.2g of protective cysteine ​​preparation, accurate to 0.0002g, place it in a dissolution vessel, use a rotating basket, and refer to the first method (basket method) of Part I 0931 of the 2020 edition of the Chinese Veterinary Pharmacopoeia. Add 400mL of artificial intestinal fluid, set the temperature to 38℃, the rotation speed to 100r / min, and rotate for 4 hours. Then, use high performance liquid chromatography to determine the residue content.

[0077] The test results recorded in artificial gastric fluid and artificial intestinal fluid are shown in Tables 3 and 4.

[0078] Table 3 Release rate (%) of protective cysteine ​​preparations in simulated gastric fluid

[0079] Group 0.5h 1h 1.5h 2h Example 1 <![CDATA[8.46 a ]]> <![CDATA[12.23 a ]]> <![CDATA[22.48 a ]]> <![CDATA[30.34 a ]]> Example 2 <![CDATA[8.24 a ]]> <![CDATA[13.49 a ]]> <![CDATA[20.11 a ]]> <![CDATA[27.49 a ]]> Example 3 <![CDATA[6.28 b ]]> <![CDATA[9.87 ab ]]> <![CDATA[18.65 a ]]> <![CDATA[24.28 ab ]]> Example 4 <![CDATA[5.49 bc ]]> <![CDATA[9.32 ab ]]> <![CDATA[13.49 b ]]> <![CDATA[18.63 bc ]]> Example 5 <![CDATA[2.80 c ]]> <![CDATA[3.60 c ]]> <![CDATA[4.50 c ]]> <![CDATA[10.30 d ]]> Example 6 <![CDATA[1.88 c ]]> <![CDATA[5.09 bc ]]> <![CDATA[9.10 b ]]> <![CDATA[13.87 c ]]> Example 7 <![CDATA[2.03 c ]]> <![CDATA[6.78 bc ]]> <![CDATA[9.07 b ]]> <![CDATA[12.45 cd ]]> Example 8 <![CDATA[1.49 c ]]> <![CDATA[3.76 c ]]> <![CDATA[9.06 b ]]> <![CDATA[11.98 cd ]]> Example 9 <![CDATA[3.11 c ]]> <![CDATA[5.96 bc ]]> <![CDATA[10.48 b ]]> <![CDATA[12.63 cd ]]> Example 10 <![CDATA[2.58 c ]]> <![CDATA[3.42 c ]]> <![CDATA[5.32 c ]]> <![CDATA[10.85 d ]]> Example 11 <![CDATA[2.50 c ]]> <![CDATA[3.94 c ]]> <![CDATA[5.89 c ]]> <![CDATA[9.68 d ]]>

[0080] Table 4 Release rate (%) of protective cysteine ​​preparations in artificial intestinal fluid

[0081] Group 1h 2h 3h 4h Example 1 <![CDATA[34.58 b ]]> <![CDATA[49.66 a ]]> <![CDATA[55.19 bc ]]> <![CDATA[59.34 c ]]> Example 2 <![CDATA[41.17 a ]]> <![CDATA[50.22 a ]]> <![CDATA[59.34 ab ]]> <![CDATA[63.27 c ]]> Example 3 <![CDATA[38.76 ab ]]> <![CDATA[45.88 ab ]]> <![CDATA[56.17 bc ]]> <![CDATA[66.11 bc ]]> Example 4 <![CDATA[28.37 c ]]> <![CDATA[51.23 a ]]> <![CDATA[67.25 a ]]> <![CDATA[70.14 b ]]> Example 5 <![CDATA[20.60 d ]]> <![CDATA[36.10 c ]]> <![CDATA[68.20 a ]]> <![CDATA[88.20 a ]]> Example 6 <![CDATA[21.39 d ]]> <![CDATA[40.74 b ]]> <![CDATA[58.16 b ]]> <![CDATA[71.59 b ]]> Example 7 <![CDATA[20.89 d ]]> <![CDATA[39.28b c ]]> <![CDATA[50.11 c ]]> <![CDATA[68.68 bc ]]> Example 8 <![CDATA[22.92 cd ]]> <![CDATA[35.64 c ]]> <![CDATA[65.48 a ]]> <![CDATA[71.79 b ]]> Example 9 <![CDATA[20.44 d ]]> <![CDATA[38.48 bc ]]> <![CDATA[59.24 ab ]]> <![CDATA[72.39 b ]]> Example 10 <![CDATA[23.85 cd ]]> <![CDATA[40.72 b ]]> <![CDATA[55.16 bc ]]> <![CDATA[67.47 bc ]]> Example 11 <![CDATA[22.58 cd ]]> <![CDATA[35.16 c ]]> <![CDATA[51.38 c ]]> <![CDATA[62.25 c ]]>

[0082] The above results indicate that when the ratio of ethyl cellulose: acrylic resin IV: hydroxypropyl methylcellulose phthalate is 7:5:8 (Example 5), the loss rate of cysteine ​​hydrochloride in the stomach is low and the release rate in intestinal fluid is high. However, it can also be seen from the data in Tables 2-3 that the coating solution obtained by combining ethyl cellulose, acrylic resin IV, and hydroxypropyl methylcellulose phthalate can effectively control the release of cysteine ​​hydrochloride in the intestine.

[0083] 2. Analysis of the preventive and ameliorative effects of protective cysteine ​​preparations on fatty liver in laying hens.

[0084] The following indicators were analyzed for the control group, cysteine ​​group I, cysteine ​​group II, cysteine ​​group III, and cysteine ​​group IV corresponding to Case 1. Data obtained from sections 2.1 to 2.4 were initially entered into Microsoft Excel, and then statistically analyzed using SPSS 21.0 software. One-way ANOVA analysis was performed, and Duncan's method was used for multiple comparisons. P < 0.05 was considered statistically significant. Results are expressed as mean and standard error.

[0085] 2.1 Egg production performance

[0086] The total number of eggs, egg weight, and feed intake were recorded daily in repeated units, and the egg production rate, average egg weight, average daily feed intake, and feed conversion ratio for each group were calculated weekly. The results are shown in Table 5.

[0087] Table 5. Effects of cysteamine on laying hen production performance.

[0088] project control group Cysteine ​​Group I Cysteine ​​Group II Cysteine ​​Group III Cysteine ​​IV group Egg production rate / % <![CDATA[87.04 c ]]> <![CDATA[88.23 b ]]> <![CDATA[89.54 a ]]> <![CDATA[88.01 b ]]> <![CDATA[87.67 bc ]]> Broken egg rate / % <![CDATA[3.12 a ]]> <![CDATA[1.73 bc ]]> <![CDATA[1.16 c ]]> <![CDATA[1.91 bc ]]> <![CDATA[2.51 b ]]> Dead rate / % <![CDATA[4.06 a ]]> <![CDATA[2.09 b ]]> <![CDATA[0.88 c ]]> <![CDATA[1.42 bc ]]> <![CDATA[2.11 b ]]>

[0089] As shown in Table 5, compared with the control group, cysteamine groups I, II, and III significantly increased the egg production rate of laying hens (P<0.05), while cysteamine groups I, II, III, and IV significantly reduced the egg breakage rate and mortality rate (P<0.05), with group II showing the best effect. Furthermore, the mortality rate in the cysteamine groups was significantly lower than that in the control group, demonstrating that the addition of cysteamine hydrochloride has a positive impact on the growth of laying hens.

[0090] 2.2 Egg quality

[0091] At the end of the experiment, two eggs with a weight close to the average were collected as replicates, and albumen height and Haugh units were measured using an egg quality analyzer (NABEL, DET-6000; Kyoto; Japan). The results are shown in Table 6.

[0092] Table 6. Effects of cysteine ​​on egg quality

[0093] project control group Cysteine ​​Group I Cysteine ​​Group II Cysteine ​​Group III Cysteine ​​IV group Protein height / mm <![CDATA[9.51 c ]]> <![CDATA[10.64 b ]]> <![CDATA[11.28 a ]]> <![CDATA[10.92 b ]]> <![CDATA[10.43 b ]]> Huff unit <![CDATA[99.17 c ]]> <![CDATA[102.33 b ]]> <![CDATA[104.02 a ]]> <![CDATA[103.48 b ]]> <![CDATA[101.61 b ]]>

[0094] As shown in Table 6, compared with the control group, cysteamine I, cysteamine II, cysteamine III and cysteamine IV significantly increased the albumen height and Haugh units of eggs (P<0.05), with cysteamine II showing the best effect. Moreover, the quality of eggs was significantly improved after the addition of cysteamine hydrochloride.

[0095] 2.3 Antioxidant capacity of plasma and liver

[0096] At the end of the experiment, one healthy laying hen with a weight close to the population average was selected for each replicate. Blood was collected from the carotid artery, and the supernatant was collected after centrifugation at 3500 rpm for 15 minutes. The supernatant was aliquoted into EP tubes and frozen at -20°C for plasma antioxidant index testing. After the laying hens were euthanized, liver tissue was collected, dried, pulverized, and frozen at -20°C for liver antioxidant index testing. Glutathione peroxidase (GSH-Px) activity, total superoxide dismutase (SOD) activity, catalase (CAT) activity, malondialdehyde (MDA) content, and total antioxidant capacity (T-AOC) were measured using a kit (provided by Nanjing Jiancheng Bioengineering Institute). The experimental procedures were performed according to the instructions. In addition, plasma adiponectin levels were measured using a kit (provided by Jiangsu Enzyme Immunosorbent Assay Co., Ltd.). The results are shown in Tables 7-9.

[0097] Table 7. Effects of cysteamine on antioxidant capacity of laying hen plasma.

[0098]

[0099] As shown in Table 7, compared with the control group, cysteamine I, cysteamine II, cysteamine III and cysteamine IV significantly increased the total antioxidant capacity and the activities of superoxide dismutase and glutathione peroxidase in laying hen plasma, and reduced the malondialdehyde content (P<0.05), with cysteamine II showing the best effect.

[0100] Table 8. Effects of cysteine ​​on antioxidant capacity of laying hen liver.

[0101]

[0102]

[0103] As shown in Table 8, compared with the control group, cysteamine I, cysteamine II, cysteamine III and cysteamine IV significantly increased the total antioxidant capacity and the activities of superoxide dismutase and glutathione peroxidase in the liver of laying hens, and reduced the malondialdehyde content (P<0.05), with cysteamine II showing the best effect.

[0104] Table 9. Effects of cysteamine on plasma adiponectin levels in laying hens.

[0105]

[0106] As shown in Table 9, compared with the control group, cysteamine I, cysteamine II, cysteamine III and cysteamine IV significantly increased the level of adiponectin in the plasma of laying hens (P<0.05), with cysteamine II showing the best effect.

[0107] The data in Tables 7-9 show that cysteine ​​hydrochloride significantly enhances the antioxidant capacity of the liver and plasma in laying hens. Antioxidant activity improves the liver's ability to remove toxins and waste, maintaining normal liver function, which is crucial for the recovery from fatty liver disease. Fatty liver is a common metabolic disease in poultry, usually associated with oxidative stress, excessive fat accumulation in the liver, and liver dysfunction. The antioxidant effect of cysteine ​​hydrochloride can help reduce oxidative stress and protect hepatocytes from free radical damage, potentially preventing or slowing the progression of fatty liver. This data is precisely the basis for this invention.

[0108] 2.4 Liver pathological section analysis

[0109] At the end of the experiment, six laying hens were randomly selected from each group, and liver samples of the same location (1cm × 1cm × 2cm) were collected. These samples were fixed in 40g / L paraformaldehyde for 48 hours, followed by gradient dehydration, paraffin embedding, sectioning, HE staining, and Oil Red O staining. Liver pathological scoring and histological changes were observed. The scoring criteria are shown in the table below. The results are as follows: Figure 1 As shown.

[0110] observe Figure 1It was found that, compared with the control group, cysteamine groups I, II, III, and IV reduced abdominal fat content in laying hens and all had less liver lipid droplet area, effectively alleviating liver inflammation and promoting liver health, thus improving fatty liver in laying hens. Among them, cysteamine group II showed the best improvement effect. It is speculated that cysteamine may prevent the aggravation of fat accumulation in the liver by neutralizing excess free radicals, reducing lipid peroxidation, and protecting the integrity of hepatocyte membranes; and by regulating lipid metabolism pathways, such as promoting the oxidative decomposition of fatty acids and reducing the accumulation of triglycerides in the liver, thereby helping to improve or prevent fatty liver.

Claims

1. Use of a protected cysteamine preparation for the preparation of an enteric feed additive, characterized in that, The protective cysteamine formulation includes cysteamine or a salt thereof and a protective material that helps the sustained release of cysteamine or a salt thereof in the intestine; By weight, the protective material comprises: 5-6 parts sodium alginate, 7-8 parts hydroxypropyl methylcellulose, 23-26 parts β-cyclodextrin, 14-15 parts pregelatinized starch, 7 parts ethyl cellulose, 5 parts acrylic resin IV, and 8 parts hydroxypropyl methylcellulose phthalate. The dosage of the protective cysteine ​​preparation is 200 mg / kg.

2. Use according to claim 1, wherein The cysteamine or its salts comprise 22-29% of the total weight of the protective cysteamine formulation.

3. The use according to claim 1, wherein the compound is ###0002### The preparation method of the protective cysteine ​​preparation includes the following steps: S1. A binder is obtained by mixing sodium alginate, hydroxypropyl methylcellulose, and water. S2. A mixture of cysteine ​​or its salt, β-cyclodextrin, and pregelatinized starch is obtained. S3. After wet mixing of the binder and the mixture, granulation and drying are performed to obtain dry particles; S4. Ethyl cellulose, acrylic resin IV, hydroxypropyl methyl cellulose phthalate, and water are mixed to obtain a coating solution; S5. The dried particles and coating solution are mixed to obtain a protective cysteine ​​preparation.

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