Feed capable of reducing heat stress in summer and preparation method thereof

Abstract

The invention discloses a feed capable of reducing heat stress in summer and a preparation method of the feed. The feed comprises corn flour, chicken blood powder, a compound bitter agent, modified silicon dioxide and lactobacillus plantarum. When the feed is exposed in the air for a long time, deliquescence and deterioration occur, putrefying bacteria breed, secreted protease hydrolyzes D-alanyl-D-alanine on modified silicon dioxide, o-nitrophenol is released and acts on a signal response layer of the compound bitterness agent, protease binding sites are exposed, amido bonds of bacterial protease sensitive hydrogel are cut, and then the feed is subjected to enzymatic hydrolysis. After hydrolysis, an exposed ethyl cellulose film is plasticized by residual o-nitrophenol, brittle rupture is realized, denatonium benzoate is released, and poultry is prevented from eating deteriorated feed by mistake. Lactobacillus plantarum can produce acid at an early stage, inhibit denatonium benzoate from being mistakenly released at an early stage, create selective advantages for acid corrosion resistance, and ensure maximization of enzyme digestion efficiency due to feed deterioration, biogenic amine accumulation, pH rise and hydrogel swelling at a later stage.

Description

Technical Field

[0001] The invention belongs to the technical field of animal breeding, and in particular relates to a feed capable of reducing summer heat stress and a preparation method thereof. Background Art

[0002] Chicken blood meal is a high-concentration, highly digestible, high-quality protein source and heme iron source. When added to feed to reduce heat stress in poultry, it can help maintain the protein nutritional status and blood oxygen carrying capacity of poultry when the poultry's feed intake is severely reduced, support energy metabolism, immune function and stress resistance, thereby reducing the negative effects of heat stress and maintaining production performance and health.

[0003] However, due to high temperatures in summer and reduced poultry feed intake, large amounts of leftover feed accumulate in troughs. Exposure to moisture in the air and poultry saliva causes the feed to deliquesce and deteriorate. Furthermore, the high protein and moisture content of chicken blood meal creates favorable conditions for spoilage bacteria, which multiply and accelerate feed deterioration. Heat-stressed poultry experience endocrine and metabolic imbalances and severely suppress their immune function. When poultry consume spoiled feed that is not promptly cleaned, various mycotoxins, bacterial toxins, and harmful substances such as aldehydes, ketones, and peroxides, which are bred in the spoiled feed, enter their bodies, further exacerbating heat stress symptoms and dramatically increasing mortality rates. Summary of the Invention

[0004] (1) Technical problems to be solved The purpose of the present invention is to provide a feed capable of reducing summer heat stress and a preparation method thereof, thereby preventing poultry from accidentally eating spoiled feed and reducing their mortality rate.

[0005] (2) Technical solution To achieve the above object, on the one hand, the present invention provides a feed capable of reducing summer heat stress, comprising the following components in parts by weight: 50-80 parts of corn flour, 8-13 parts of chicken blood powder, 0.5-1 part of a composite bittering agent, 0.3-0.8 parts of modified silicon dioxide, and 0.15-0.2 parts of Lactobacillus plantarum; The composite bittering agent has a multilayer structure, which includes a core layer, an isolation layer, and a signal response layer from the inside to the outside. The core layer is denatonium benzoate and vitamin E liposomes, the isolation layer is an ethyl cellulose film, and the signal response layer is a bacterial protease-sensitive hydrogel. The modified silica carries D-alanyl-D-alanine and o-nitrophenol.

[0006] Furthermore, the preparation method of the composite bittering agent comprises the following steps: S11. Dissolve lecithin, cholesterol, and tocopherol succinate in anhydrous ethanol, rotary evaporate to form a film, allow to solidify under nitrogen, add a NaCl solution containing denatonium benzoate, vortex, sonicate in an ice bath, add trehalose, cool, and freeze-dry to obtain a first mixture; S12. The ethyl cellulose and anhydrous ethanol were mixed, magnetically stirred, filtered, and the first mixture was placed in a fluidized bed coater and evenly sprayed with the ethyl cellulose solution to obtain a second mixture; S13. Acrylamide and N-acryloylsuccinimide are mixed in a molar ratio of 95:5 and dissolved in deionized water. N,N'-methylenebisacrylamide and propyl gallate are added in sequence with stirring. Ammonium persulfate and N,N,N',N'-tetramethylethylenediamine are added to initiate polymerization. The mixture is cured at low temperature and purified. Deionized water is added and magnetic stirring is performed to obtain a bacterial protease-sensitive hydrogel solution. The second mixture is placed in a fluidized bed coater and the bacterial protease-sensitive hydrogel solution is evenly sprayed to obtain a composite bittering agent.

[0007] Furthermore, the thickness of the ethyl cellulose film is 18-22 μm, and the thickness of the bacterial protease-sensitive hydrogel layer is 45-55 μm.

[0008] Furthermore, the preparation method of the modified silicon dioxide comprises the following steps: S21. The mesoporous silica was immersed in a mixed solution of 3-aminopropyltriethoxysilane and ethanol, refluxed, washed and dried to obtain a first compound; S22. D-alanyl-D-alanine is dissolved in N,N-dimethylformamide, and 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide and N-hydroxysuccinimide are added to obtain a second compound; S23. The second compound and the first compound were mixed in a mass ratio of 1:5, shaken, washed with ethanol, and dried in vacuo to obtain a third compound; S24. Place the third compound in a saturated ethanol solution of o-nitrophenol, evacuate the solution, soak the solution at normal pressure, add a stearic acid ethanol solution, stir the solution, wash the solution with deionized water, and dry the solution in vacuum to obtain modified silica.

[0009] Furthermore, the Lactobacillus plantarum is a mixture of Lactobacillus plantarum powder and maltodextrin in a mass ratio of 1:1, and the viable count of Lactobacillus plantarum is ≥10¹¹ CFU / g.

[0010] On the other hand, based on the same inventive concept, the present invention also provides a method for preparing a feed capable of reducing summer heat stress, which is applied to the feed capable of reducing summer heat stress and comprises the following steps: S1 dry material mixing: corn flour, chicken blood powder added to the twin-shaft mixer, mixed evenly, added bentonite, premix and stirred to mix evenly; S2. Wet material preparation: Dissolve sodium propionate in water with stirring, add soybean oil, and emulsify at high speed; S3. Granulation: The wet material is added to the dry material and mixed evenly, placed in a ring die pelletizer, and cut into pellets with a diameter of 3 to 5 mm; S4. Spraying: Place the feed in a three-channel intelligent spray tower and spray compound bittering agent, modified silicon dioxide, and plant lactobacillus in sequence. The binder is hydroxypropyl methylcellulose. After fluidized bed drying, the feed is obtained to reduce summer heat stress.

[0011] Furthermore, the premix is ​​a mixture of complex vitamins, minerals and enzyme preparations.

[0012] Furthermore, the temperature during the entire spraying process is lower than 40°C.

[0013] Corn flour and chicken blood meal are the main raw materials for preparing feed that can reduce heat stress in poultry in summer. They are exposed to air for a long time and become deliquescent and deteriorate after coming into contact with moisture in the air and poultry saliva. In particular, chicken blood meal has high protein and moisture content and is easily corrupted in a hot and humid environment, releasing amine-like odorous substances and breeding pathogens. The high protein and high moisture content of chicken blood meal is a "culture medium" for spoilage bacteria, causing them to multiply in large numbers and further accelerating feed deterioration.

[0014] The composite bittering agent has a complex structure, with a core layer composed of denatonium benzoate-vitamin E liposomes. Denatonium benzoate is a bittering agent that effectively prevents poultry from accidentally ingesting spoiled feed. Vitamin E, a potent fat-soluble antioxidant, inhibits mold growth in feed and quenches free radicals in the lipid bilayer, preventing phospholipid oxidative degradation, thereby maintaining the structural integrity of the liposome and preventing denatonium benzoate leakage. Vitamin E also protects the chemical stability of denatonium benzoate, preventing its oxidative inactivation. The surface of the denatonium benzoate-vitamin E liposomes is coated with an acid- and alkali-resistant ethyl cellulose film, which physically isolates the core layer of the denatonium benzoate-vitamin E liposomes and synergizes with the liposome bilayer to prevent denatonium benzoate leakage. The outermost layer is a bacterial protease-sensitive hydrogel, which serves as a signal-responsive layer. It contains numerous amide bonds and is cleaved only by proteases secreted by spoilage bacteria (such as Bacillus subtilis) in spoiled feed, which are not found in the poultry digestive tract. However, the amide bonds in the hydrogel are less sensitive to bacterial proteases, and the subtilisin secreted by Bacillus subtilis cannot directly cut the amide bonds and release the nuclear layer material.

[0015] D-alanyl-D-alanine and o-nitrophenol are loaded on the modified silica. When the feed deteriorates, Bacillus subtilis grows and the secreted subtilisin hydrolyzes the covalent bond between D-alanyl-D-alanine and o-nitrophenol, releasing o-nitrophenol, which penetrates into the bacterial protease-sensitive hydrogel layer of the composite bittering agent. The nitro group (-NO2) of o-nitrophenol carries a partial negative charge, neutralizing the negative charge of N-acryloylsuccinimide (NAS), thereby weakening the electrostatic repulsion between subtilisin and o-nitrophenol. The most important thing is that o-nitrophenol forms a face-to-face π-π stacking with the succinimide ring of NAS, thereby locking the active ester group (-COO-NHS) of NAS in a highly reactive conformation, exposing the protease binding site. NAS covalently binds to subtilisin, inducing conformational changes in the protease, so that the originally partially obscured "Ala-Ala-Pro-Phe" cleavage sequence is fully exposed from the hydrogel network, allowing subtilisin to smoothly cleave the amide bond between Ala-Pro. The hydrogel disintegrates, and the exposed ethyl cellulose film is plasticized by the residual o-nitrophenol, increasing its brittleness, causing it to mechanically rupture and release denatonium benzoate and vitamin E.

[0016] Lactobacillus plantarum initially produces lactic acid, inhibiting non-acid-resistant bacteria (such as E. coli) and creating a selective advantage for acid-resistant spoilage bacteria. These bacteria then convert amino acids into biogenic amines using amino acid decarboxylases. As biogenic amines accumulate, the pH rises, causing the bacterial protease-sensitive hydrogel to swell, ensuring maximum enzymatic cleavage efficiency. Furthermore, the early acid production by Lactobacillus plantarum causes the hydrogel to shrink, preventing the erroneous release of denatonium benzoate and vitamin E due to bacterial interference. Later, after poultry stop eating, the feed is exposed to air for a long time and deteriorates, allowing spoilage bacteria to proliferate and accumulate biogenic amines, a sign of irreversible, advanced spoilage. This is when denatonium benzoate and vitamin E are correctly released.

[0017] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. Denatonium benzoate is released after the feed deteriorates, preventing poultry from eating deteriorated feed and reducing the mortality rate of poultry. Vitamin E can inhibit the growth of mold in the feed, prevent the leakage of denatonium benzoate, protect the chemical stability of denatonium benzoate, avoid its oxidative inactivation, and enable denatonium benzoate to play an effective role.

[0018] 2. The bacterial protease-sensitive hydrogel works synergistically with modified silica to release denatonium benzoate only when the feed is deteriorating, preventing denatonium benzoate from affecting the use of normal feed.

[0019] 3. Lactobacillus plantarum initially produces lactic acid to prevent the early erroneous release of denatonium benzoate and vitamin E. Later, as biogenic amines accumulate, the pH rises and the hydrogel swells, ensuring maximum enzymatic cleavage efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The present invention is a flow chart of the feed preparation process for reducing summer heat stress. DETAILED DESCRIPTION

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0022] Electronic balance (Sartorius, Germany), electric blast constant temperature dryer (Shanghai Formosa Laboratory Equipment), pH meter (Shanghai Precision Scientific Instruments), rotary evaporator (Shanghai Darlo Scientific Instruments), pulverizer (Shandong Tianfang Machinery), magnetic stirrer (Shanghai Meiyingpu), fluidized bed coating machine (Changzhou Lima), twin-shaft mixer (Hengfu Machinery), ring die granulator (Shandong Shuanghe); Lactobacillus plantarum was purchased from Guangzhou Huihe Biotechnology Co., Ltd., and chemicals and reagents were purchased from Sigma-Aldrich.

[0023] Example 1 This embodiment discloses a feed capable of reducing summer heat stress, comprising the following components in parts by weight: 50 parts of corn flour, 8 parts of chicken blood powder, 0.5 parts of a composite bittering agent, 0.3 parts of modified silicon dioxide, and 0.15 parts of plant lactobacillus; The composite bittering agent has a multilayer structure, which includes a core layer, an isolation layer, and a signal response layer from the inside to the outside. The core layer is denatonium benzoate and vitamin E liposomes, the isolation layer is an ethyl cellulose film, and the signal response layer is a bacterial protease-sensitive hydrogel. The modified silica carries D-alanyl-D-alanine and o-nitrophenol.

[0024] The preparation method of the composite bittering agent comprises the following steps: S11. Dissolve lecithin, cholesterol, and tocopherol succinate in anhydrous ethanol, rotary evaporate to form a film, allow to solidify under nitrogen, add a NaCl solution containing denatonium benzoate, vortex, sonicate in an ice bath, add trehalose, cool, and freeze-dry to obtain a first mixture; S12. The ethyl cellulose and anhydrous ethanol were mixed, magnetically stirred, filtered, and the first mixture was placed in a fluidized bed coater and evenly sprayed with the ethyl cellulose solution to obtain a second mixture; S13. Acrylamide and N-acryloylsuccinimide are mixed in a molar ratio of 95:5 and dissolved in deionized water. N,N'-methylenebisacrylamide and propyl gallate are added in sequence with stirring. Ammonium persulfate and N,N,N',N'-tetramethylethylenediamine are added to initiate polymerization. The mixture is cured at low temperature and purified. Deionized water is added and magnetic stirring is performed to obtain a bacterial protease-sensitive hydrogel solution. The second mixture is placed in a fluidized bed coater and the bacterial protease-sensitive hydrogel solution is evenly sprayed to obtain a composite bittering agent.

[0025] The thickness of the ethyl cellulose film is 18 μm, and the thickness of the bacterial protease sensitive hydrogel layer is 45 μm.

[0026] The preparation method of the modified silicon dioxide comprises the following steps: S21. The mesoporous silica was immersed in a mixed solution of 3-aminopropyltriethoxysilane and ethanol, refluxed, washed and dried to obtain a first compound; S22. D-alanyl-D-alanine is dissolved in N,N-dimethylformamide, and 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide and N-hydroxysuccinimide are added to obtain a second compound; S23. The second compound and the first compound were mixed in a mass ratio of 1:5, shaken, washed with ethanol, and dried in vacuo to obtain a third compound; S24. Place the third compound in a saturated ethanol solution of o-nitrophenol, evacuate the solution, soak the solution at normal pressure, add a stearic acid ethanol solution, stir the solution, wash the solution with deionized water, and dry the solution in vacuum to obtain modified silica.

[0027] The plant lactobacillus is a mixture of plant lactobacillus powder and maltodextrin in a mass ratio of 1:1, and the number of viable bacteria of the plant lactobacillus is ≥1011 CFU / g.

[0028] The method for preparing a feed capable of reducing summer heat stress comprises the following steps: S1 dry material mixing: corn flour, chicken blood powder added to the twin-shaft mixer, mixed evenly, added bentonite, premix and stirred to mix evenly; S2. Wet material preparation: Dissolve sodium propionate in water with stirring, add soybean oil, and emulsify at high speed; S3. Granulation: The wet material is added to the dry material and mixed evenly, placed in a ring die pelletizer, and cut into pellets with a diameter of 3 to 5 mm; S4. Spraying: Place the feed in a three-channel intelligent spray tower and spray compound bittering agent, modified silicon dioxide, and plant lactobacillus in sequence. The binder is hydroxypropyl methylcellulose. After fluidized bed drying, the feed is obtained to reduce summer heat stress.

[0029] The premix is ​​a mixture of complex vitamins, minerals and enzyme preparations.

[0030] The temperature during the entire spraying process is lower than 40°C.

[0031] It should be noted that, as shown in Figure 1, which is a flow chart of the preparation process of the present invention, since Lactobacillus plantarum is not resistant to high temperatures, the present invention first prepares dry materials and wet materials separately, mixes and granulates them, and then sprays the composite bittering agent, modified silica and Lactobacillus plantarum. The spraying temperature cannot exceed 40°C in order to prevent the destruction of the composite bittering agent and modified silica structures, and to prevent the inactivation of Lactobacillus plantarum by high temperature.

[0032] It should be noted that the composite bittering agent added to the feed prepared by the present invention is safe and reliable and can be ingested by poultry in normal feed. Since D-alanyl-D-alanine in the modified silica is a D-configuration amino acid, poultry proteases can only hydrolyze L-configuration amino acids. In addition, the bacterial protease-sensitive hydrogel of the composite bittering agent shrinks in the gastric acid environment and can only recognize bacterial proteases, while poultry digestive enzymes cannot act. Even in the neutral environment of the intestine, the bacterial protease-sensitive hydrogel swells, and the exposed ethyl cellulose film is acid and alkali resistant, ensuring that denatonium benzoate is not released in the poultry body and is ultimately excreted intact.

[0033] Example 2 This example is based on Example 1, but differs from Example 1 in that the feed in this example includes the following components in parts by weight: 65 parts corn flour, 10 parts chicken blood powder, 0.7 parts composite bittering agent, 0.5 parts modified silicon dioxide, and 0.17 parts Lactobacillus plantarum. Other components and preparation methods are the same as those in Example 1.

[0034] Example 3 This example is based on Example 1, but differs from Example 1 in that the feed in this example includes the following components in parts by weight: 80 parts corn flour, 13 parts chicken blood powder, 1 part composite bittering agent, 0.8 parts modified silicon dioxide, and 0.2 parts Lactobacillus plantarum. Other components and preparation methods are the same as those in Example 1.

[0035] Example 4 This embodiment is based on Example 1, but differs from Example 1 in that the thickness of the ethyl cellulose film in this embodiment is 22 μm, and the thickness of the bacterial protease-sensitive hydrogel layer is 55 μm. Other components and preparation methods are the same as those in Example 1.

[0036] Comparative Example 1 This example is based on Example 1, but differs from Example 1 in that vitamin E is not added to the composite bittering agent in this comparative example.

[0037] The preparation method of the composite bittering agent comprises the following steps: S11. Ethyl cellulose and anhydrous ethanol were mixed, magnetically stirred, filtered, and denatonium benzoate was placed in a fluidized bed coater and evenly sprayed with the ethyl cellulose solution to obtain a first mixture; S12. Acrylamide and N-acryloylsuccinimide are mixed in a molar ratio of 95:5 and dissolved in deionized water. N,N'-methylenebisacrylamide and propyl gallate are added in sequence with stirring. Ammonium persulfate and N,N,N',N'-tetramethylethylenediamine are added to initiate polymerization. The mixture is cured at low temperature and purified. Deionized water is added and magnetic stirring is performed to obtain a bacterial protease-sensitive hydrogel solution. The first mixture is placed in a fluidized bed coater and the bacterial protease-sensitive hydrogel solution is evenly sprayed to obtain a composite bittering agent.

[0038] Other components and preparation methods are the same as those in Example 1.

[0039] Comparative Example 2 This example is based on Example 1, but is different from Example 1 in that the composite bittering agent in this comparative example does not have an ethyl cellulose film as an isolation layer.

[0040] The preparation method of the composite bittering agent comprises the following steps: S11. Dissolve lecithin, cholesterol, and tocopherol succinate in anhydrous ethanol, rotary evaporate to form a film, allow to solidify under nitrogen, add a NaCl solution containing denatonium benzoate, vortex, sonicate in an ice bath, add trehalose, cool, and freeze-dry to obtain a first mixture; S12. Acrylamide and N-acryloylsuccinimide are mixed in a molar ratio of 95:5 and dissolved in deionized water. N,N'-methylenebisacrylamide and propyl gallate are added in sequence with stirring. Ammonium persulfate and N,N,N',N'-tetramethylethylenediamine are added to initiate polymerization. The mixture is cured at low temperature and purified. Deionized water is added and magnetic stirring is performed to obtain a bacterial protease-sensitive hydrogel solution. The first mixture is placed in a fluidized bed coater and the bacterial protease-sensitive hydrogel solution is evenly sprayed to obtain a composite bittering agent.

[0041] Other components and preparation methods are the same as those in Example 1.

[0042] Comparative Example 3 This example is based on Example 1, but is different from Example 1 in that the composite bittering agent in this comparative example does not have a signal response layer of bacterial protease-sensitive hydrogel.

[0043] The preparation method of the composite bittering agent comprises the following steps: S11. Dissolve lecithin, cholesterol, and tocopherol succinate in anhydrous ethanol, rotary evaporate to form a film, allow to solidify under nitrogen, add a NaCl solution containing denatonium benzoate, vortex, sonicate in an ice bath, add trehalose, cool, and freeze-dry to obtain a first mixture; S12. Ethyl cellulose and anhydrous ethanol are mixed, magnetically stirred, and filtered. The first mixture is placed in a fluidized bed coater and evenly sprayed with the ethyl cellulose solution to obtain a composite bittering agent.

[0044] Other components and preparation methods are the same as those in Example 1.

[0045] Comparative Example 4 This example is based on Example 1, but differs from Example 1 in that the D-alanyl-D-alanine in the modified silica is replaced with L-alanyl-L-alanine.

[0046] Other components and preparation methods are the same as those in Example 1.

[0047] Comparative Example 5 This example is based on Example 1, but differs from Example 1 in that the spraying temperature in the feed preparation that can reduce summer heat stress is set to 50°C.

[0048] Other components and preparation methods are the same as those in Example 1.

[0049] Comparative Example 6 This example is based on Example 1, but different from Example 1 in that no composite bittering agent is added. Other components and preparation methods are the same as those in Example 1.

[0050] Comparative Example 7 This example is based on Example 1, but differs from Example 1 in that modified silicon dioxide is not added. Other components and preparation methods are the same as those in Example 1.

[0051] Comparative Example 8 This example is based on Example 1, but different from Example 1 in that Lactobacillus plantarum is not added. Other components and preparation methods are the same as those in Example 1.

[0052] Test verification: The prepared feed was placed in a poultry bionic digestive system and a natural feeding trough, respectively. The ambient temperature was 28-35°C and the humidity was 40-60% (this temperature causes heat stress in poultry and is the most suitable temperature for the reproduction of spoilage bacteria). The concentration of denatonium benzoate was detected by HPLC, and the release time of denatonium benzoate was recorded.

[0053]

[0054] As shown in Table 1, in the trough, Example 4, with its thicker ethylcellulose film and bacterial protease-sensitive hydrogel layer compared to Example 1, released less denatonium benzoate and released later. Comparative Examples 1, 2, and 3, respectively, lacked the vitamin E liposomes, ethylcellulose film, and bacterial protease-sensitive hydrogel layer compared to Example 1. These instances resulted in a higher concentration of denatonium benzoate and an earlier release time. Comparative Example 3, which replaced D-alanyl-D-alanine with L-alanyl-L-alanine compared to Example 1, did not significantly affect the trough. However, in the poultry biomimetic digestive system, digestive enzymes hydrolyzed L-alanyl-L-alanine, releasing o-nitrophenol, which reacted with the compound bitterant, releasing denatonium benzoate. The spraying temperature in Comparative Example 4 exceeded the tolerance temperature of Lactobacillus plantarum and disrupted the structure of the composite bittering agent and modified silica, resulting in a large release of denatonium benzoate in both the mixed bacterial culture medium and the poultry biomimetic digestive system. This release was extremely early, causing the release of denatonium benzoate before the feed spoiled, affecting poultry consumption. Compared to Example 1, which did not add modified silica, Comparative Example 6 showed minimal denatonium benzoate release, demonstrating that modified silica plays a significant role in the release of denatonium benzoate. When D-alanyl-D-alanine on the modified silica is hydrolyzed by subtilisin, o-nitrophenol is released. This release of o-nitrophenol acts on the bacterial protease-sensitive hydrogel of the composite bittering agent, exposing protease binding sites and facilitating cleavage of amide bonds. This hydrogel then hydrolyzes, causing the ethylcellulose film to rupture brittlely and releasing denatonium benzoate. Comparative Example 7, which did not add Lactobacillus plantarum, showed earlier release of denatonium benzoate compared to Example 1. Data from the poultry biomimetic digestive system show that the structure of the compound bittering agent is complete and strong, and it will not be affected by the internal environment of the poultry to release denatonium benzoate.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions and improvements made by any technician familiar with the field within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A feed capable of reducing summer heat stress, characterized in that: The invention comprises the following components in parts by weight: 50-80 parts of corn flour, 8-13 parts of chicken blood powder, 0.5-1 part of compound bittering agent, 0.3-0.8 part of modified silicon dioxide, and 0.15-0.2 part of plant lactobacillus; The composite bittering agent has a multilayer structure, which includes a core layer, an isolation layer, and a signal response layer from the inside to the outside. The core layer is denatonium benzoate and vitamin E liposomes, the isolation layer is an ethyl cellulose film, and the signal response layer is a bacterial protease-sensitive hydrogel. The modified silica carries D-alanyl-D-alanine and o-nitrophenol.

2. A feed capable of reducing summer heat stress according to claim 1, characterized in that: The preparation method of the composite bittering agent comprises the following steps: S11. Dissolve lecithin, cholesterol, and tocopherol succinate in anhydrous ethanol, rotary evaporate to form a film, allow to solidify under nitrogen, add a NaCl solution containing denatonium benzoate, vortex, sonicate in an ice bath, add trehalose, cool, and freeze-dry to obtain a first mixture; S12. The ethyl cellulose and anhydrous ethanol were mixed, magnetically stirred, filtered, and the first mixture was placed in a fluidized bed coater and evenly sprayed with the ethyl cellulose solution to obtain a second mixture; S13. Acrylamide and N-acryloylsuccinimide are mixed in a molar ratio of 95:5 and dissolved in deionized water. N,N'-methylenebisacrylamide and propyl gallate are added in sequence with stirring. Ammonium persulfate and N,N,N',N'-tetramethylethylenediamine are added to initiate polymerization. The mixture is cured at low temperature and purified. Deionized water is added and magnetic stirring is performed to obtain a bacterial protease-sensitive hydrogel solution. The second mixture is placed in a fluidized bed coater and the bacterial protease-sensitive hydrogel solution is evenly sprayed to obtain a composite bittering agent.

3. A feed capable of reducing summer heat stress according to claim 2, characterized in that: The thickness of the ethyl cellulose film is 18-22 μm, and the thickness of the bacterial protease sensitive hydrogel layer is 45-55 μm.

4. A feed capable of reducing summer heat stress according to claim 1, characterized in that: The preparation method of the modified silicon dioxide comprises the following steps: S21. The mesoporous silica was immersed in a mixed solution of 3-aminopropyltriethoxysilane and ethanol, refluxed, washed and dried to obtain a first compound; S22. D-alanyl-D-alanine is dissolved in N,N-dimethylformamide, and 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide and N-hydroxysuccinimide are added to obtain a second compound; S23. The second compound and the first compound were mixed in a mass ratio of 1:5, shaken, washed with ethanol, and dried in vacuo to obtain a third compound; S24. Place the third compound in a saturated ethanol solution of o-nitrophenol, evacuate the solution, soak the solution at normal pressure, add a stearic acid ethanol solution, stir the solution, wash the solution with deionized water, and dry the solution in vacuum to obtain modified silica.

5. A feed capable of reducing summer heat stress according to claim 1, characterized in that: The plant lactobacillus is a mixture of plant lactobacillus powder and maltodextrin in a mass ratio of 1:1, and the number of viable bacteria of the plant lactobacillus is ≥1011 CFU / g.

6. A method for preparing a feed capable of reducing summer heat stress, which is used to prepare a feed capable of reducing summer heat stress according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: S1 dry material mixing: corn flour, chicken blood powder added to the twin-shaft mixer, mixed evenly, added bentonite, premix and stirred to mix evenly; S2. Wet material preparation: Dissolve sodium propionate in water with stirring, add soybean oil, and emulsify at high speed; S3. Granulation: The wet material is added to the dry material and mixed evenly, placed in a ring die pelletizer, and cut into pellets with a diameter of 3 to 5 mm; S4. Spraying: Place the feed in a three-channel intelligent spray tower and spray compound bittering agent, modified silicon dioxide, and plant lactobacillus in sequence. The binder is hydroxypropyl methylcellulose. After fluidized bed drying, the feed is obtained to reduce summer heat stress.

7. The method for preparing a feed capable of reducing summer heat stress according to claim 6, characterized in that: The premix is ​​a mixture of complex vitamins, minerals and enzyme preparations.

8. The method for preparing a feed capable of reducing summer heat stress according to claim 6, characterized in that: The temperature during the entire spraying process is lower than 40°C.

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