Feed additive for heat stress resistance of laying hens and preparation and application thereof

Abstract

The present application provides a kind of laying hen anti-heat stress feed additive and its preparation and application, to solve the problem of relieving heat stress state of laying hen, so as to achieve the effect of improving the egg production of laying hen and egg quality, enhance the immunity of laying hen, improve the benefit of poultry breeding.The laying hen anti-heat stress feed additive is made of the following raw materials by weight: 3-5 parts of Anemarrhena, 2-3 parts of licorice, 1-2 parts of coix seed, 1-2 parts of dodder seed, 1-2 parts of dandelion, 1-2 parts of ophiopogon.The laying hen anti-heat stress feed additive provided by the present application can improve the feed egg ratio of laying hen, has a positive effect on maintaining egg production rate, and to some extent can improve egg quality, at the same time, through anti-inflammatory, anti-stress, immune enhancement and other effects, it can relieve the damage of reproductive system of laying hen caused by heat stress, improve the production performance of heat stress laying hen, reduce the cost of breeding, adapt to the needs of large-scale breeding of laying hen.

Description

Technical Field

[0001] This invention relates to the field of feed additive technology, specifically to a heat stress-resistant feed additive for laying hens and its preparation and application. Background Technology

[0002] With global economic development and population growth, the demand for meat and eggs is constantly increasing. Eggs, as an important part of the human diet, require increased production to meet market demand. However, heat stress is a common problem in egg-laying hen farming. Chicken heat stress, also known as chicken heatstroke, is an overheating condition caused by a rapid rise in the chicken's internal temperature due to external environmental factors, leading to physiological dysfunction. Chickens lack sweat glands and have a relatively high internal body temperature. Their bodies are covered in feathers, and they primarily regulate their body temperature through their respiratory system. If the external temperature and humidity are too high, water intake is insufficient, and especially ventilation is poor, chickens have difficulty dissipating heat, easily leading to heat stress. This results in decreased egg production, slowed growth, and weakened immunity, and in severe cases, even death.

[0003] Currently, nutritional regulation and appropriate drug intervention are commonly used and simple effective means to regulate heat stress in livestock and poultry. Reasonable and rich feed nutrition can effectively eliminate or reduce heat stress response in laying hens, while appropriate drug intervention can also help improve or eliminate egg drop syndrome and heat stress response in chickens. However, most of the commonly used drugs are Western medicines (such as antibiotics), which have problems such as drug residues and increased drug resistance.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the background technology of this disclosure and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] This invention provides a heat stress-resistant feed additive for laying hens, its preparation and application, aiming to solve the problem of alleviating heat stress in laying hens, thereby increasing egg production and quality, enhancing the immunity of laying hens, and improving the efficiency of poultry farming.

[0006] Traditional Chinese medicine theory holds that high temperatures can cause heat-related illnesses, also known as heat stress syndrome. This syndrome is primarily characterized by excess heat in the Qi level, which quickly develops into heat in the Ying and Xue levels. If the intensity of the heat stressor continues to increase, it can lead to exhaustion and death. Therefore, the principle of prevention and treatment should be "treating heat with cold," using traditional Chinese medicine that clears heat and detoxifies, replenishes Qi and nourishes Yin to enhance the chicken's adaptability to high temperatures, regulate the body's immune function, and alleviate the chicken's heat stress response.

[0007] Based on traditional Chinese veterinary medicine theory and combined with extensive experience, the inventors propose the following technical solution:

[0008] Design a heat stress-resistant feed additive for laying hens, made from the following ingredients in parts by weight: 3-5 parts Anemarrhena asphodeloides, 2-3 parts Glycyrrhiza uralensis, 1-2 parts Coix lacryma-jobi, 1-2 parts Cuscuta chinensis, 1-2 parts Taraxacum mongolicum, and 1-2 parts Ophiopogon japonicus.

[0009] A method for preparing the aforementioned heat stress-resistant feed additive for laying hens is provided, comprising the following steps:

[0010] (1) Material preparation: Prepare each raw material according to the weight ratio stated above;

[0011] (2) Extraction: Mix all raw materials, soak in water for 50 min to 70 min, and extract by decoction 1 to 3 times;

[0012] (3) Drying: Combine the decoctions from each decoction, concentrate them, and then spray dry them to obtain the final product.

[0013] According to one aspect of this disclosure, in step (2), the amount of water added is 8 to 10 times the total weight of the medicinal materials.

[0014] A method for preventing heat stress in laying hens is provided, wherein the heat stress-preventing feed additive for laying hens is added to the basic daily diet of laying hens, mixed evenly, and then fed to laying hens normally.

[0015] According to another aspect of this disclosure, when the temperature is ≥32°C, the heat stress-resistant feed additive for laying hens is added to the basal diet of laying hens at a weight percentage of 0.2% to 0.3%.

[0016] According to another aspect of this disclosure, when laying hens experience heat stress, the heat stress-resistant feed additive for laying hens is added to the basal diet of the laying hens at a weight percentage of 0.45% to 0.55%.

[0017] Anemarrhena asphodeloides has the effects of clearing heat and purging fire, nourishing yin and moistening dryness. It can greatly clear heat in the qi level and also generate fluids to replenish yin. Ophiopogon japonicus nourishes yin, benefits the stomach and generates fluids, and replenishes the yin fluids consumed by heat syndrome. Anemarrhena asphodeloides combined with Ophiopogon japonicus and licorice enhances the sweetness of the prescription and makes the overall effect of nourishing yin and moistening dryness even stronger. Taraxacum mongolicum combined with Coix lacryma-jobi can clear heat and detoxify, while also strengthening the spleen and stopping diarrhea. Cuscuta chinensis tonifies the liver and kidneys, generates fluids and quenches thirst, prevents excessive heat clearing from damaging the body's vital energy, and can also enhance the production performance of laying hens. The combination of these herbs allows the yin-nourishing effect of Anemarrhena asphodeloides to reach the five internal organs and replenish yin fluids throughout the body. In addition, Anemarrhena asphodeloides, dandelion, and Coix lacryma-jobi also have anti-inflammatory, antiviral, and immune-enhancing effects. After combination, the above herbs can regulate the production function of laying hens, improve their tolerance to heat stress, and improve egg quality.

[0018] Numerous studies have shown that changes in animal productivity during heat stress are closely related to changes in blood metabolites and negative energy balance. However, research on alleviating heat stress in laying hens is limited to the detection of certain physiological indicators in the blood, and these indicators lack a holistic and systematic approach, which is insufficient to explain the overall physiological changes in heat-stressed laying hens. Therefore, metabolomics, by studying endogenous metabolic differences and the relationship between endogenous metabolites and overall metabolism, can better reflect the physiological health of an organism.

[0019] One or more technical solutions provided in the embodiments of this application have at least one of the following technical effects:

[0020] 1. This application uses metabolomics technology to verify that the prepared heat stress-resistant feed additive for laying hens can improve the heat stress state of laying hens, enhance their immunity, and help maintain the endocrine physiological balance of laying hens under heat stress.

[0021] 2. The heat stress-resistant feed additive for laying hens proposed in this application can improve the decrease in feed intake caused by heat stress in laying hens, increase the feed conversion ratio of laying hens, play a positive role in maintaining the laying rate, and improve egg quality to a certain extent.

[0022] 3. The heat stress-resistant feed additive for laying hens proposed in this application can alleviate the damage to the reproductive system of laying hens caused by heat stress through anti-inflammatory, anti-stress, and immune-enhancing effects, improve the production performance of heat-stressed laying hens, reduce breeding costs, and meet the needs of large-scale laying hen farming.

[0023] 4. Compared with antibiotics and other Western medicines, the additives in this application are characterized by low cost, low toxicity, no drug residues, and no drug resistance. In particular, the absence of drug residues in traditional Chinese medicine products makes them especially suitable for laying hens during the egg-laying period, solving the problem of drug residues in eggs caused by antibiotic use during this period and ensuring food safety for humans. Furthermore, traditional Chinese medicine additives are inexpensive, have no side effects, and offer advantages such as enhancing animal constitution and reducing the likelihood of drug resistance. Heat stress falls under the category of kidney deficiency in traditional Chinese veterinary medicine. Traditional Chinese medicine can exert its anti-heat stress effects through clearing heat and detoxifying, tonifying deficiency and strengthening the body, and calming the mind and relieving convulsions. It has wide applications in laying hen farming. Moreover, specific traditional Chinese medicine compound preparations contain rich nutrients and have a certain anti-heat stress effect, offering a broader range of physiological regulatory functions compared to single chemical additives. Attached Figure Description

[0024] Figure 1 This is a PCA score diagram showing the protection of heat-stressed laying hens by heat-stress-resistant feed additives in one embodiment of this application.

[0025] Figure 2This is an OPLS-DA score diagram showing the protection of heat-stressed laying hens by the anti-heat-stress feed additive in one embodiment of this application.

[0026] Figure 3 This is a metabolic pathway enrichment diagram of the protective effect of heat stress-resistant feed additives on heat-stressed laying hens in one embodiment of this application. Detailed Implementation

[0027] To better understand the technical solution of this application, the above technical solution will be described in detail below with reference to specific implementation methods.

[0028] Unless otherwise specified, the pesticide and adjuvant raw materials involved in the following examples are all commercially available conventional raw materials; unless otherwise specified, the preparation methods, application methods and testing methods involved are all conventional methods.

[0029] The following examples of heat stress-resistant feed additives for laying hens include the following preparation steps:

[0030] (1) Prepare each raw material according to the following weight ratio: Anemarrhena asphodeloides 3-5 parts, Glycyrrhiza uralensis 2-3 parts, Coix lacryma-jobi 1-2 parts, Cuscuta chinensis 1-2 parts, Taraxacum mongolicum 1-2 parts, Ophiopogon japonicus 1-2 parts;

[0031] The above drug combinations are all derived from a catalog of 117 natural plant feed ingredients.

[0032] (2) Mix all the raw medicinal materials evenly, add 8 to 10 times the amount of water of the total amount of medicinal materials, soak for 1 hour, then decoct and extract 1 to 3 times, combine the decoctions, concentrate and set aside.

[0033] (3) The concentrated liquid is spray-dried to obtain feed extract powder.

[0034] The following examples of heat stress-resistant feed additives for laying hens include the following usage methods:

[0035] (1) When the temperature exceeds 32°C, preventive administration can be given by adding heat stress-resistant feed additives to the basic diet of laying hens at a weight percentage of 0.2% to 0.3% to prevent heat stress in laying hens.

[0036] (2) When laying hens are in a state of heat stress, adding heat stress-resistant feed additives to the basic diet of laying hens at a weight percentage of 0.45% to 0.55% can alleviate the heat stress of laying hens.

[0037] Example 1: A heat stress-resistant feed additive for laying hens, made from the following raw materials in parts by weight:

[0038] Anemarrhena asphodeloides 5 parts, Glycyrrhiza uralensis 3 parts, Coix lacryma-jobi 1 part, Cuscuta chinensis 2 parts, Taraxacum mongolicum 2 parts, Ophiopogon japonicus 1 part.

[0039] Example 2: A heat stress-resistant feed additive for laying hens, made from the following raw materials in parts by weight:

[0040] Anemarrhena asphodeloides 4 parts, Glycyrrhiza uralensis 3 parts, Coix lacryma-jobi 2 parts, Cuscuta chinensis 2 parts, Taraxacum mongolicum 1 part, Ophiopogon japonicus 2 parts.

[0041] Example 3: A heat stress-resistant feed additive for laying hens, made from the following raw materials in parts by weight:

[0042] Anemarrhena asphodeloides 5 parts, Glycyrrhiza uralensis 3 parts, Coix lacryma-jobi 1 part, Cuscuta chinensis 2 parts, Taraxacum mongolicum 2 parts, Ophiopogon japonicus 1 part.

[0043] Example 4: A heat stress-resistant feed additive for laying hens, made from the following raw materials in parts by weight:

[0044] Anemarrhena asphodeloides 4 parts, Glycyrrhiza uralensis 2 parts, Coix lacryma-jobi 2 parts, Cuscuta chinensis 1 part, Taraxacum mongolicum 1 part, Ophiopogon japonicus 1 part.

[0045] Example 5:

[0046] 1. Experimental Methods

[0047] 1.1 Experimental Animals

[0048] Three hundred 51-week-old Hy-Line Brown laying hens were randomly divided into experimental and control groups, for a total of five groups, with three replicates in each group and 20 laying hens in each replicate.

[0049] 1.2 Experimental Protocol: All laying hens were housed in three-tiered tiered cages, with four hens per cage. Four groups of feed additives with the same basic formula were used as experimental feeds. The control group was fed a basal diet without the addition of the heat stress-resistant feed additive. Experimental group 1 was fed the heat stress-resistant feed additive of Example 1 of this invention at a weight percentage of 0.25%. Experimental group 2 was fed the heat stress-resistant feed additive of Example 2 of this invention at a weight percentage of 0.25%. Experimental group 3 was fed the heat stress-resistant feed additive of Example 3 of this invention at a weight percentage of 0.25%. Experimental group 4 was fed the heat stress-resistant feed additive of Example 4 of this invention at a weight percentage of 0.25%.

[0050] 1.3 Feeding and Management: After 7 days of acclimatization feeding, the formal trial began and lasted for 21 days. During the trial, the chickens were fed twice daily, and all experimental chickens had free access to water and feed. On day 14, the rearing temperature in each group was adjusted to 31℃~33℃, and the humidity was maintained at 60%~70%.

[0051] 1.4 Results and Analysis: The heat stress-resistant feed additives for laying hens in each group were able to alleviate the decrease in feed intake caused by heat stress, increase the rate of high-quality eggs produced by heat-stressed laying hens, and alleviate oxidative damage caused by heat stress. Furthermore, metabolomics studies revealed that the heat stress-resistant feed additives for laying hens in each group could improve plasma metabolite levels and influence metabolic pathways, thereby alleviating the heat stress state in laying hens.

[0052] The specific experimental results are as follows:

[0053] (1) The heat stress-resistant feed additive for laying hens in this application can alleviate the decrease in feed intake of laying hens caused by heat stress (as shown in Table 1).

[0054] Table 1. Effects of heat stress-resistant feed additives on average daily feed intake in laying hens.

[0055] .

[0056] Note: * indicates a significant difference compared to the control group (P<0.05) within the same column. The same applies below.

[0057] (2) The heat stress-resistant feed additive for laying hens in this application can improve the rate of high-quality eggs produced by heat-stressed laying hens (as shown in Table 2).

[0058] Table 2. Effects of heat stress-resistant feed additives on the average daily high-quality egg production rate in laying hens.

[0059] .

[0060] (3) The heat stress-resistant feed additive for laying hens in this application can alleviate the oxidative damage to laying hens caused by heat stress (as shown in Tables 3 and 4).

[0061] Table 3. Effects of heat stress-resistant feed additives on serum SOD and GSH levels in heat-stressed laying hens.

[0062] .

[0063] Table 4. Effects of heat stress-resistant feed additives on MDA and CAT levels in liver tissue of heat-stressed laying hens.

[0064] .

[0065] When animals are subjected to heat stress, the activities of catalase (CAT), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) in their bodies are affected, thereby impacting the body's antioxidant system, altering the levels of free radicals, and causing oxidative stress. In other words, heat stress disrupts the balance between the animal's oxidative and antioxidant systems, leading to damage to tissue cells and biomolecules such as proteins and nucleic acids.

[0066] Superoxide dismutase (SOD) is the primary substance for scavenging free radicals in living organisms, effectively preventing free radical damage to animal cells. Enhanced SOD activity strengthens the body's antioxidant function. Glycoside hydrogen sulfoxide (GSH) is the most important antioxidant sulfhydryl substance in cells, playing a crucial role in antioxidation, protein sulfhydryl groups, and amino acid membrane transport. Higher levels in the body indicate higher antioxidant levels. Catalytic oxygenase (CAT) is the most important H2O2 scavenging enzyme in the reactive oxygen species scavenging system of animal cells, playing a vital role in the antioxidant system. Malondialdehyde (MDA) is the final oxidation product of lipid peroxidation caused by free radicals in animals. Its level reflects the degree of damage caused by free radical attack; therefore, lower MDA levels are better.

[0067] Experiments have shown that heat stress-resistant feed additives for laying hens can increase the activity of SOD and CAT and the content of GSH in laying hens, and reduce the content of MDA, indicating that they can enhance the antioxidant capacity of laying hens and thus alleviate the negative effects of heat stress.

[0068] (4) The heat stress-resistant feed additive for laying hens of this application can significantly improve the plasma metabolite levels of heat-stressed laying hens.

[0069] Plasma samples from laying hens in each group were collected, processed, and analyzed by liquid chromatography-mass spectrometry (LC-MS). The obtained data were then subjected to PCA analysis. The results are shown below. Figure 1 As shown in the figure, the samples from the control group and the four experimental groups were all within the 95% confidence interval, and there was a clear separation between the control group and the experimental groups, indicating that there were differences in plasma metabolites between the control group and the four experimental groups.

[0070] To further remove noise signals irrelevant to the model classification and obtain more reliable differential metabolite information, an OPLS-DA model was constructed based on the PCA model. The results are shown below. Figure 2 As shown in the figure, the samples from each group were well separated on the OPLS-DA coordinate axis, indicating that feeding heat stress-resistant feed additives to laying hens can improve their heat stress status.

[0071] (5) The heat stress-resistant feed additive for laying hens in this application alleviates the heat stress state of laying hens by affecting their metabolic pathways.

[0072] Based on the constructed OPLS-DA model diagram, VIP values ​​were calculated to screen for differential heat stress metabolism, identifying metabolites with VIP > 1. A T-test was performed on the screened metabolites to identify differentially expressed components among the groups (P < 0.05). The screened components were identified based on fragment information and corresponding mass numbers obtained from mass spectrometry, and database searches were performed using HMDB, KEGG, METLIN, Massbank, and Chemspider. The identification results and changes in related components are shown in Table 5. Table 5 shows that compared with the control group, a total of 14 differentially expressed compounds were detected. After administration, 7 of these metabolites showed significant differences compared with the control group (P < 0.05), indicating that the four experimental groups could improve the heat stress status of laying hens to some extent.

[0073] Table 5. VIP and P values ​​of differentially expressed compounds

[0074] .

[0075] Based on the identified differential metabolites in laying hen plasma, we further explored the metabolic pathways by which heat stress-resistant feed additives for laying hens were used to combat heat stress. KEGG pathway analysis and visualization were performed on potential biomarkers in laying hen plasma. The results are shown below. Figure 3 As shown in Table 6, a P < 0.05 indicates a significant impact on this pathway. The results indicate that heat stress-resistant feed additives for laying hens have a significant impact on the biosynthesis of aminoacyl-tRNA, cysteine ​​and methionine metabolism, glycine, serine and threonine metabolism, glycerophospholipid metabolism, arginine and proline metabolism, linoleic acid metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, tyrosine metabolism, and thiamine metabolism pathway in heat-stressed laying hens.

[0076] Amino acids are fundamental building blocks of organisms. They undergo aerobic metabolism through the tricarboxylic acid cycle, providing energy and playing a vital role in the body. Experimental results show that heat stress-resistant feed additives for laying hens affect multiple amino acid metabolic pathways in heat-stressed hens, indicating that intervention with these additives can regulate various amino acid metabolisms in heat-stressed hens, thereby adjusting the overall condition of the hens.

[0077] Table 6. Metabolic pathways affected by heat stress-resistant feed additives in laying hens.

[0078] .

[0079] The present application has been described in detail above with reference to the embodiments; however, those skilled in the art will understand that, without departing from the inventive concept, the specific parameters in the above embodiments can be changed, or the relevant materials and method steps can be equivalently substituted, thereby forming multiple specific embodiments, all of which are common variations of the present application, and will not be described in detail here.

Claims

1. A heat stress-resistant feed additive for laying hens, characterized in that, It is made from the following ingredients in parts by weight: Anemarrhena asphodeloides 3-5 parts, Glycyrrhiza uralensis 2-3 parts, Coix lacryma-jobi 1-2 parts, Cuscuta chinensis 1-2 parts, Taraxacum mongolicum 1-2 parts, and Ophiopogon japonicus 1-2 parts.

2. The preparation method of the heat stress-resistant feed additive for laying hens according to claim 1, comprising the following steps: (1) Material preparation: Prepare each raw material according to the weight ratio stated above; (2) Extraction: Mix all raw materials, soak in water for 50 min to 70 min, and extract by decoction 1 to 3 times; (3) Drying: Combine the decoctions from each decoction, concentrate them, and then spray dry them to obtain the final product.

3. The preparation method according to claim 2, characterized in that, In step (2), the amount of water added is 8 to 10 times the total weight of the medicinal materials.

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