Production process of thermosensitive raw material adaptive sterile feed for egg breeding hens

Abstract

The invention relates to the technical field of feed production, and discloses a thermosensitive raw material adaptive sterile feed production process, which comprises: taking 1000 parts by weight of bulk raw materials, spraying 8-12 parts by weight of a non-corrosive hypertonic sensitization liquid, and mixing to obtain a sensitization mixture with a wet surface; feeding the sensitization mixture into a conditioner, and introducing steam to carry out damp and hot conditioning, so as to obtain a high-temperature sterilized wet material; granulating the high-temperature sterilized wet material, and cooling the prepared granules to 20-30 DEG C to obtain a cooled base material; and adding 20-30 parts by weight of a reaction type buffer premix into the cooled base material, and uniformly mixing to obtain the thermosensitive raw material adaptive sterile feed for egg breeding hens. According to the method, sensitization low-temperature conditioning is matched with post-addition of the irradiation premix, so that the contradiction between activity retention of thermosensitive raw materials and microbial control of sterile feed for egg breeding hens is solved, and secondary pollution of finished products is effectively prevented.

Description

Technical Field

[0001] This invention relates to the field of feed production technology, specifically to a process for producing aseptic feed for laying hens that is compatible with heat-sensitive raw materials. Background Technology

[0002] As the source of the poultry industry chain, the health of laying hens directly affects the quality of their offspring chicks. To cut off the vertical transmission of pathogens such as Salmonella, the breeding end has extremely high biosecurity requirements. Using sterile feed is a key measure to control pathogen input and ensure the production performance of breeding hens. Feed formulations typically include heat-sensitive ingredients such as vitamins and enzymes to meet the high metabolic and reproductive demands of laying hens.

[0003] Existing aseptic feed production processes mainly rely on high-temperature, high-pressure, moist heat conditioning or extrusion technology to kill microorganisms. In traditional processes, heat-sensitive raw materials are usually mixed with bulk raw materials such as corn and soybean meal, and then undergo a long-term high-temperature heat treatment process together in order to achieve commercial aseptic standards.

[0004] However, this overall heat treatment method has significant drawbacks. Increasing the treatment intensity to achieve complete sterilization can lead to significant degradation and ineffectiveness of heat-sensitive raw materials, resulting in nutritional deficiencies. Conversely, lowering the temperature to protect nutrients makes it difficult to completely kill heat-resistant pathogens. Furthermore, aseptic feed prepared using traditional processes lacks a long-lasting antibacterial buffer mechanism after cooling, making it highly susceptible to moisture absorption and secondary mold contamination during storage. The direct addition of acidifiers can also negatively impact palatability, making it difficult to balance sterilization effectiveness, nutritional activity, and storage stability.

[0005] Therefore, this invention proposes a process for producing aseptic feed for layer chickens that is compatible with heat-sensitive raw materials, in order to overcome the shortcomings of existing technologies. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a production process for aseptic feed for laying hens adapted to heat-sensitive raw materials. This process solves the problems in existing aseptic feed production, such as the inactivation of heat-sensitive nutrients due to high-temperature heat treatment, the difficulty in completely killing heat-resistant pathogens due to low-temperature processes, and the susceptibility to secondary contamination during the storage of finished feed.

[0007] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a process for producing aseptic feed for heat-sensitive breeding hens, using the following technical solution: A process for producing heat-sensitive raw material-adapted aseptic feed for laying hens includes the following steps: taking 1000 parts by weight of bulk raw materials, spraying in 8-12 parts by weight of a non-corrosive, high-permeability sensitizing liquid, mixing to obtain a surface-wetted sensitized mixture; feeding the sensitized mixture into a conditioner, introducing steam for wet heat conditioning to obtain a high-temperature sterilized wet feed; granulating the high-temperature sterilized wet feed, and cooling the resulting granules to 20-30°C to obtain a cooled base material; adding 20-30 parts by weight of a reactive buffer premix to the cooled base material, mixing evenly to obtain the heat-sensitive raw material-adapted aseptic feed for laying hens.

[0008] By adopting the above technical solution, this invention implements a graded and synergistic sterilization strategy for bulk raw materials and heat-sensitive core materials, and establishes an acid-base buffer system in the finished product. The specific effects and principles are as follows: Staged sterilization and heat-sensitive protection mechanism: This process employs different sterilization paths based on the varying heat resistance properties of the raw materials. For the majority of bulk raw materials (corn and soybean meal), a "chemical sensitization + moist heat conditioning" treatment method is used. The non-corrosive, high-permeability sensitizing solution reduces the heat resistance of bacteria carried by the raw materials, allowing for sterilization effects equivalent to traditional high temperatures (above 100℃) under relatively mild conditioning conditions (e.g., below 95℃), thus minimizing the damage to the protein and starch quality of the bulk raw materials caused by high temperatures. For the core ingredients of the heat-sensitive premix (vitamins and enzymes), the front-end moist heat conditioning and granulation processes are bypassed; instead, "cobalt-60 irradiation cold sterilization" is used, and the ingredients are added later in the cooling stage. This combined process addresses the microbial load problem of bulk raw materials through front-end heat treatment and avoids the thermal degradation of heat-sensitive components through back-end cold sterilization and post-addition processes, ultimately producing an overall sterile feed with complete nutrient retention.

[0009] Mold prevention and homeostasis maintenance of the reactive buffer system: The non-corrosive, high-osmotic sensitizing solution introduced in the process is acidic, while the reactive buffer premix added later contains sodium bicarbonate. In the dry state of feed storage, due to the oil film coating isolation technology used in the premix, the acidic and alkaline components do not react and synergistically inhibit mold growth. When the feed enters the poultry's digestive tract or is in a high-humidity environment, the oil film ruptures, the acid and alkaline components undergo a neutralization reaction, adjusting the pH value and releasing carbon dioxide, thus providing buffering and antibacterial effects.

[0010] Preferably, the conditioning temperature of the wet heat conditioning is 88-95℃, and the conditioning time is 120-180 seconds.

[0011] By adopting the above technical solution, and with the help of the sensitizing solution, the conditioning temperature is controlled below 95℃, which is sufficient to kill the sensitized Salmonella and Escherichia coli. At the same time, it avoids excessive starch gelatinization and Maillard reaction caused by high temperature, thus maintaining the palatability and digestibility of the feed.

[0012] Preferably, the non-corrosive hypertonic sensitizing solution is made from raw materials comprising the following parts by weight: deionized water: 22-30 parts; sodium formate: 18-25 parts; lactic acid with a mass fraction of 80%: 28-35 parts; glyceryl monolaurate: 5-8 parts; 1,2-propanediol: 10-20 parts.

[0013] By employing the above technical solution, the synergistic effect of each component disrupts the bacterial structure: sodium formate and lactic acid form a high-osmotic-pressure organic acid salt system, leading to bacterial cell dehydration; glyceryl monolaurate, as a surfactant, penetrates the phospholipid layer of the bacterial cell membrane, altering cell membrane permeability; and 1,2-propanediol promotes the penetration and spreading of the above-mentioned active ingredients on the surface of the raw materials. These physicochemical effects collectively reduce the mechanical strength and heat resistance of the bacterial cell wall, creating conditions for subsequent low-temperature conditioning and sterilization.

[0014] Preferably, the non-corrosive hypertonic sensitizing solution is prepared by the following method: deionized water is heated to 45-55°C, and sodium formate is added to dissolve it to obtain an organic salt aqueous solution; while maintaining the temperature, lactic acid is added dropwise to the organic salt aqueous solution and stirred to obtain an acidic buffer system solution; glyceryl monolaurate is dissolved in 1,2-propanediol heated to 40-50°C to obtain an organic phase solution; the organic phase solution is injected into the acidic buffer system solution, and sheared and mixed at 350-500 rpm for 20-30 minutes until a homogeneous transparent liquid is formed, thus obtaining the non-corrosive hypertonic sensitizing solution.

[0015] By adopting the above technical solution and using a phase separation dissolution followed by shear emulsification process, the problem of low solubility and easy precipitation of monolaurate glyceryl ester in acidic salt solution is solved, and a homogeneous and stable transparent liquid is obtained, ensuring that the nozzle will not be blocked during the spraying process and that it is evenly distributed on the surface of the feed.

[0016] Preferably, the reactive buffer premix is ​​made from raw materials comprising the following parts by weight: micronized sodium bicarbonate: 3.0-5.0 parts; defatted rice husk powder: 100 parts; soybean oil: 1.0-1.5 parts; premix core material: 20 parts.

[0017] Preferably, the reactive buffer premix is ​​prepared by the following method: defatted rice husk powder is mixed with soybean oil to obtain a carrier with an oil film on the surface; micronized sodium bicarbonate is added to the carrier with the oil film on the surface and mixed to obtain a modified buffer carrier; premix core material is added to the modified buffer carrier, and after being mixed evenly, it is sterilized by cobalt-60 irradiation.

[0018] Preferably, the particle size distribution D90 of the micronized sodium bicarbonate is less than 75 μm; and the moisture content of the defatted rice husk powder is 8%-10%.

[0019] By employing the above technical solution, microencapsulation isolation was achieved through a specific feeding sequence and mixing process: First, soybean oil forms a hydrophobic oil film on the surface of defatted rice husk powder; second, micronized sodium bicarbonate (D90 < 75 μm) is added, and the fine powder is adsorbed and embedded in the oil film layer, preventing direct contact between it and external moisture and the subsequently added core material, thus preventing moisture absorption or damage to vitamin stability during storage; finally, the core material is added and irradiated to complete the preparation. This structure allows sodium bicarbonate to remain in a "latent" state, releasing its activity only after the oil film is emulsified by the digestive liquid.

[0020] Preferably, the irradiation dose for cobalt-60 irradiation sterilization is 5-10 kGy.

[0021] By employing the above-mentioned technical solution, the penetrating power of radiation within this dosage range is utilized to directly destroy the DNA structure of microorganisms in the core material, achieving cold sterilization. This dosage control not only thoroughly kills mold spores and bacteria but also remains below the radiation degradation threshold of substances such as vitamins A and E, thus ensuring the bioactivity of core nutrients.

[0022] Preferably, the bulk raw materials are yellow corn and peeled soybean meal, and the particle size is controlled to be 1.5mm-2.5mm after crushing.

[0023] Preferably, the carrier of the premixed core material is a mixture of defatted rice bran and maifan stone powder.

[0024] By adopting the above technical solutions, particle size control of bulk raw materials helps to ensure uniform penetration of the sensitizing solution; defatted rice bran and maifan stone powder carrier have the characteristics of low moisture and chemical inertness, which are suitable for irradiation sterilization process and reduce irradiation-induced oxidation reaction.

[0025] This invention provides a process for producing aseptic feed for layer hen breeders that is adapted to heat-sensitive raw materials. It has the following beneficial effects: 1. This invention establishes a targeted aseptic assurance system through the separation of wet heat conditioning of bulk raw materials and irradiation sterilization of heat-sensitive components. The process utilizes a sensitizing solution to reduce the heat resistance of bacteria in bulk raw materials, achieving thorough low-temperature sterilization. Combined with the cold sterilization and subsequent addition of cobalt-60 to premixed feed, this avoids the destruction of heat-sensitive raw materials such as vitamins by heat treatment. This production method effectively resolves the contradiction between microbial control and the preservation of active nutrients in the production of aseptic feed for laying hens, thus improving biosafety levels.

[0026] 2. This invention pretreats bulk raw materials with a non-corrosive, high-osmotic sensitizing solution, utilizing an organic acid salt system to disrupt bacterial cell walls and induce dehydration, significantly reducing the heat resistance of pathogens such as Salmonella. This treatment allows for achieving sterility standards at relatively low conditioning temperatures during production, reducing the negative impact of high temperatures on heat-sensitive raw materials and starch gelatinization. This process ensures the sterility of laying hen feed while preserving the nutritional value and physical properties of the raw materials.

[0027] 3. This invention constructs a reactive buffer system, utilizing an oil film to encapsulate micronized sodium bicarbonate, achieving physical isolation from acidic substrates and preventing neutralization reactions during storage. Once the feed enters the digestive tract, this system releases the buffer components, utilizing the acidic environment of the substrate to inhibit mold growth and prevent secondary contamination of sterile feed. It also avoids excessive acidity that could damage the stability of heat-sensitive ingredients or irritate the intestines of laying hens, ensuring the long-term quality of the feed. Attached Figure Description

[0028] Figure 1 The figures show the test results of the physicochemical properties and corrosion performance of the present invention; wherein, Figure (a) is a comparison of pH values, Figure (b) is a comparison of the weight loss of the coupons, and Figure (c) is a comparison of the annual corrosion rates. Figure 2 The figures show the test results of the moisture absorption stability and vitamin A retention rate of the premix of the present invention; wherein, Figure (a) is a comparison of the moisture absorption weight gain rate after 48 hours, and Figure (b) is a comparison of the vitamin A retention rate. Detailed Implementation

[0029] The main raw materials and reagents used in the following examples and comparative examples have the following sources and specifications. Reagents not specifically mentioned are all commercially available analytical grade or higher grade products.

[0030] Sodium formate (CAS No. 141-53-7, feed grade, purity ≥98%), lactic acid (CAS No. 50-21-5, feed grade, 80% aqueous solution), glyceryl monolaurate (CAS No. 142-18-7, monoester content ≥90%), 1,2-propanediol (CAS No. 57-55-6, feed grade, purity ≥99.5%), sodium bicarbonate (CAS No. 144-55-8, food grade, purity ≥99%), soybean oil (CAS No. 8001-22-7, feed grade).

[0031] The defatted rice husk powder is a commercially available feed-grade carrier material with a particle size that passes through a 60-mesh sieve and a moisture content controlled at 8%-10%. The bulk raw materials are commercially available feed-grade yellow corn and dehulled soybean meal, which are pulverized to a particle size controlled at 1.5mm-2.5mm, with a weight ratio of yellow corn to dehulled soybean meal of 2:1-3:1. The core material of the premix is ​​a commercially available mixture of compound vitamins and trace elements for laying hens, containing vitamin A, vitamin D3, vitamin E, B vitamins, and trace element compounds such as copper, iron, zinc, and manganese. Its carrier is a commercially available mixture of feed-grade defatted rice bran and maifanite powder, with a weight ratio of defatted rice bran to maifanite powder of 1:1-2:1.

[0032] Preparation Example 1: This preparation example provides a method for preparing a non-corrosive hypertonic sensitizing solution, including the following steps: (1) Add 25 parts by weight of deionized water to a reaction vessel with a heating jacket, heat to 50°C, turn on the stirring (speed is 250 rpm), slowly add 22 parts by weight of sodium formate, stir at a constant temperature for 20 minutes until the solid is completely dissolved to obtain an organic salt aqueous solution. (2) Maintain the temperature at 50°C and slowly add 33 parts by weight of lactic acid (80% concentration) to the organic salt aqueous solution obtained in step (1). After the addition is complete, continue stirring for 10 minutes to obtain an acidic buffer system solution. (3) Take another container and add 6 parts by weight of glyceryl monolaurate to 14 parts by weight of 1,2-propanediol. Heat to 45°C and stir until completely dissolved to obtain an organic phase solution. (4) Slowly inject the organic phase solution obtained in step (3) into the acidic buffer system solution obtained in step (2), increase the stirring speed to 400 rpm and shear mix for 25 minutes until a homogeneous transparent liquid is formed, thus obtaining a non-corrosive hypertonic sensitizing solution.

[0033] Preparation Example 2: This preparation example provides a method for preparing a non-corrosive hypertonic sensitizing solution, including the following steps: (1) Add 30 parts by weight of deionized water to a reaction vessel with a heating jacket, heat to 45°C, turn on the stirring (speed is 200 rpm), slowly add 18 parts by weight of sodium formate, stir at constant temperature for 15 minutes until the solid is completely dissolved to obtain an organic salt aqueous solution. (2) Maintain the temperature at 45°C and slowly add 28 parts by weight of lactic acid (80% concentration) to the organic salt aqueous solution obtained in step (1). After the addition is complete, continue stirring for 10 minutes to obtain an acidic buffer system solution. (3) Take another container and add 5 parts by weight of glyceryl monolaurate to 19 parts by weight of 1,2-propanediol. Heat to 40°C and stir until completely dissolved to obtain an organic phase solution. (4) Slowly inject the organic phase solution obtained in step (3) into the acidic buffer system solution obtained in step (2), increase the stirring speed to 350 rpm and shear mix for 20 minutes until a homogeneous transparent liquid is formed, thus obtaining a non-corrosive hypertonic sensitizing solution.

[0034] Preparation Example 3: This preparation example provides a method for preparing a non-corrosive hypertonic sensitizing solution, including the following steps: (1) Add 22 parts by weight of deionized water to a reaction vessel with a heating jacket, heat to 55°C, turn on the stirring (300 rpm), slowly add 25 parts by weight of sodium formate, stir at a constant temperature for 30 minutes until the solid is completely dissolved to obtain an organic salt aqueous solution. (2) Maintain the temperature at 55°C and slowly add 35 parts by weight of lactic acid (80% concentration) to the organic salt aqueous solution obtained in step (1). After the addition is complete, continue stirring for 15 minutes to obtain an acidic buffer system solution. (3) Take another container and add 8 parts by weight of glyceryl monolaurate to 10 parts by weight of 1,2-propanediol. Heat to 50°C and stir until completely dissolved to obtain an organic phase solution. (4) Slowly inject the organic phase solution obtained in step (3) into the acidic buffer system solution obtained in step (2), increase the stirring speed to 500 rpm and shear mix for 30 minutes until a homogeneous transparent liquid is formed, thus obtaining a non-corrosive hypertonic sensitizing solution.

[0035] Preparation Example 4: This preparation example provides a method for preparing a non-corrosive hypertonic sensitizing solution, including the following steps: (1) Add 24 parts by weight of deionized water to a reaction vessel with a heating jacket, heat to 50°C, turn on the stirring (speed is 250 rpm), slowly add 20 parts by weight of sodium formate, stir at constant temperature for 20 minutes until the solid is completely dissolved to obtain an organic salt aqueous solution. (2) Maintain a temperature of 50°C and slowly add 30 parts by weight of lactic acid (80% concentration) to the organic salt aqueous solution obtained in step (1). After the addition is complete, continue stirring for 10 minutes to obtain an acidic buffer system solution. (3) Take another container and add 6 parts by weight of glyceryl monolaurate to 20 parts by weight of 1,2-propanediol. Heat to 45°C and stir until completely dissolved to obtain an organic phase solution. (4) Slowly inject the organic phase solution obtained in step (3) into the acidic buffer system solution obtained in step (2), increase the stirring speed to 450 rpm and shear mix for 25 minutes until a homogeneous transparent liquid is formed, thus obtaining a non-corrosive hypertonic sensitizing solution.

[0036] Preparation Example 5: This preparation example provides a method for preparing a reactive buffer premix, including the following steps: (1) Sodium bicarbonate raw material is fed into an air jet mill for pulverization and classification, and powder with particle size distribution D90 less than 75μm is collected to obtain micronized sodium bicarbonate. (2) Put 100 parts by weight of defatted rice husk powder into a horizontal ribbon mixer, start stirring, spray in 1.2 parts by weight of soybean oil, mix for 4 minutes, and obtain a carrier with an oil film on the surface. (3) 4.0 parts by weight of the micronized sodium bicarbonate obtained in step (1) are sieved into the carrier with the surface coated with oil film obtained in step (2), and the mixture is continued for 6 minutes to obtain the modified buffer carrier. (4) Add 20 parts by weight of premixed core material to the modified buffer carrier obtained in step (3), mix evenly, and then sterilize by cobalt-60 irradiation with an irradiation dose of 8 kGy to obtain reactive buffer premix.

[0037] Preparation Example 6: This preparation example provides a method for preparing a reactive buffer premix, including the following steps: (1) Sodium bicarbonate raw material is fed into an air jet mill for pulverization and classification, and powder with particle size distribution D90 less than 75μm is collected to obtain micronized sodium bicarbonate. (2) Put 100 parts by weight of defatted rice husk powder into a horizontal ribbon mixer, start stirring, spray in 1.5 parts by weight of soybean oil, mix for 5 minutes, and obtain a carrier with an oil film on the surface. (3) 5.0 parts by weight of the micronized sodium bicarbonate obtained in step (1) are sieved into the carrier with the surface coated with oil film obtained in step (2), and the mixture is continued for 8 minutes to obtain the modified buffer carrier. (4) Add 20 parts by weight of premixed core material to the modified buffer carrier obtained in step (3), mix evenly, and then sterilize by cobalt-60 irradiation with an irradiation dose of 10 kGy to obtain reactive buffer premix.

[0038] Preparation Example 7: This preparation example provides a method for preparing a reactive buffer premix, including the following steps: (1) Sodium bicarbonate raw material is fed into an air jet mill for pulverization and classification, and powder with particle size distribution D90 less than 75μm is collected to obtain micronized sodium bicarbonate. (2) Put 100 parts by weight of defatted rice husk powder into a horizontal ribbon mixer, start stirring, spray in 1.0 part by weight of soybean oil, mix for 3 minutes, and obtain a carrier with an oil film on the surface. (3) Sift 3.0 parts by weight of the micronized sodium bicarbonate obtained in step (1) into the carrier with the surface coated with oil film obtained in step (2), and continue mixing for 5 minutes to obtain the modified buffer carrier. (4) Add 20 parts by weight of premixed core material to the modified buffer carrier obtained in step (3), mix evenly, and then sterilize by cobalt-60 irradiation with an irradiation dose of 5 kGy to obtain reactive buffer premix.

[0039] Example 1: This example provides a process for producing aseptic feed for heat-sensitive breeding hens, including the following steps: (1) Take 1000 parts by weight of bulk raw materials and put them into a twin-shaft paddle mixer. Spray in 10 parts by weight of the non-corrosive hypertonic sensitizing liquid obtained in Preparation Example 1 and mix for 180 seconds to obtain a surface-wetted sensitizing mixture. (2) The sensitized mixture obtained in step (1) is fed into a conditioner and steam is introduced for wet heat conditioning. The conditioning temperature is 90°C and the conditioning time is 150 seconds to obtain high-temperature sterilized wet material. (3) The high-temperature sterilized wet material obtained in step (2) is fed into a ring die pellet mill for pressing and pelletizing, and the resulting pellets are fed into a counter-current cooler to cool to 25°C to obtain a cooled base material. (4) The cooled base material obtained in step (3) is transported to a closed drum mixer, and 25 parts by weight of the reactive buffer premix obtained in Preparation Example 5 are added. The mixture is mixed at low speed for 120 seconds to obtain heat-sensitive raw material-adapted aseptic feed for laying hens.

[0040] Example 2: This example provides a process for producing aseptic feed for heat-sensitive breeding hens, including the following steps: (1) Take 1000 parts by weight of bulk raw materials and put them into a twin-shaft paddle mixer. Spray in 8 parts by weight of the non-corrosive hypertonic sensitizing liquid obtained in Preparation Example 2 and mix for 150 seconds to obtain a surface-wetted sensitizing mixture. (2) The sensitized mixture obtained in step (1) is fed into a conditioner and steam is introduced for wet heat conditioning. The conditioning temperature is 88°C and the conditioning time is 180 seconds to obtain high-temperature sterilized wet material. (3) The high-temperature sterilized wet material obtained in step (2) is fed into a ring die pellet mill for pressing and pelletizing, and the resulting pellets are fed into a counter-current cooler to cool to 20°C to obtain a cooled base material. (4) The cooled base material obtained in step (3) is transported to a closed drum mixer, and 30 parts by weight of the reactive buffer premix obtained in Preparation Example 6 are added. The mixture is mixed at low speed for 150 seconds to obtain heat-sensitive raw material-adapted aseptic feed for laying hens.

[0041] Example 3: This example provides a process for producing aseptic feed for heat-sensitive breeding hens, including the following steps: (1) Take 1000 parts by weight of bulk raw materials and put them into a twin-shaft paddle mixer. Spray in 12 parts by weight of the non-corrosive hypertonic sensitizing liquid obtained in Preparation Example 3 and mix for 200 seconds to obtain a surface-wetted sensitizing mixture. (2) The sensitized mixture obtained in step (1) is fed into a conditioner and steam is introduced for wet heat conditioning. The conditioning temperature is 95°C and the conditioning time is 120 seconds to obtain high-temperature sterilized wet material. (3) The high-temperature sterilized wet material obtained in step (2) is fed into a ring die pellet mill for pressing and pelletizing, and the resulting pellets are fed into a counter-current cooler to cool to 30°C to obtain a cooled base material. (4) The cooled base material obtained in step (3) is transported to a closed drum mixer, and 20 parts by weight of the reactive buffer premix obtained in Preparation Example 7 are added. The mixture is mixed at low speed for 100 seconds to obtain heat-sensitive raw material-adapted aseptic feed for laying hens.

[0042] Example 4: This example provides a process for producing aseptic feed for heat-sensitive breeding hens, including the following steps: (1) Take 1000 parts by weight of bulk raw materials and put them into a twin-shaft paddle mixer. Spray in 10 parts by weight of the non-corrosive hypertonic sensitizing liquid obtained in Preparation Example 4 and mix for 180 seconds to obtain a surface-wetted sensitizing mixture. (2) The sensitized mixture obtained in step (1) is fed into a conditioner and steam is introduced for wet heat conditioning. The conditioning temperature is 92°C and the conditioning time is 140 seconds to obtain high-temperature sterilized wet material. (3) The high-temperature sterilized wet material obtained in step (2) is fed into a ring die pellet mill for pressing and pelletizing, and the resulting pellets are fed into a counter-current cooler to cool to 25°C to obtain a cooled base material. (4) The cooled base material obtained in step (3) is transported to a closed drum mixer, and 25 parts by weight of the reactive buffer premix obtained in Preparation Example 5 are added. The mixture is mixed at low speed for 120 seconds to obtain heat-sensitive raw material-adapted aseptic feed for laying hens.

[0043] Comparative Example 1: Compared with Example 1, the difference is that in the preparation of the non-corrosive hypertonic sensitizing solution (i.e. in Preparation Example 1), step (3) does not add glyceryl monolaurate, but instead uses an equal part by weight of 1,2-propanediol, and the rest are the same.

[0044] Comparative Example 2: Compared with Example 1, the difference is that the non-corrosive hypertonic sensitizing solution used was prepared (i.e., in Preparation Example 1), sodium formate was not added in step (1), and the amount of deionized water was directly increased to 47 parts by weight, while the rest were the same.

[0045] Comparative Example 3: Compared with Example 1, the difference is that the operation of spraying soybean oil in step (2) was omitted when preparing the reactive buffer premix (i.e., in Preparation Example 5). Specifically, 100 parts by weight of defatted rice husk powder, 4.0 parts by weight of micronized sodium bicarbonate obtained in step (1), and 20 parts by weight of premix core material were directly and simultaneously put into a horizontal ribbon mixer and mixed for 10 minutes to obtain a mixture without oil film coating. Then, it was sterilized by cobalt-60 irradiation. All other aspects were the same.

[0046] Comparative Example 4: Compared with Example 1, the difference is that the process feeding sequence and flow were changed, and step (4) was canceled. The specific operation is as follows: In step (1), 1000 parts by weight of bulk raw materials, 10 parts by weight of non-corrosive hypertonic sensitizing liquid and 25 parts by weight of reactive buffer premix (obtained in Preparation Example 5) were put into a twin-shaft paddle mixer for mixing; then the conditioning in step (2) and the granulation and cooling in step (3) were carried out according to the parameters of the original Example 1; the cooled base material obtained after cooling to 25°C in step (3) is the final heat-sensitive raw material adapted aseptic feed for laying hens, and the rest are the same.

[0047] Comparative Example 5: Compared with Example 1, the difference is that in step (1), instead of spraying non-corrosive hypertonic sensitizing liquid, an equal weight of deionized water is sprayed; in step (2), in order to achieve the same sterilization effect, the conditioning temperature is increased to 95°C and the conditioning time is maintained for 150 seconds; the rest are the same.

[0048] Test Example 1: 1. Experimental Materials and Grouping: Test strain: Salmonella Typhimurium, strain number CMCC(B)50115.

[0049] Stainless steel hanging plate: made of 304 stainless steel, with a size of 50mm×25mm×2mm. The surface is polished with 2000-grit sandpaper, degreased with acetone, and dried for later use.

[0050] Experimental groups: There are a total of 6 groups.

[0051] Experimental groups 1-4: Non-corrosive hypertonic sensitizing solutions prepared in Preparation Examples 1, 2, 3, and 4 were used, respectively. Control group A (blank control): 0.85% sterile physiological saline was used. Control group B (positive control): 5% (w / w) formic acid aqueous solution was used.

[0052] 2. Experimental steps: (1) Under aseptic conditions, lyophilized Salmonella typhimurium powder was resuscitated and inoculated into nutrient broth and cultured at 37°C for 18 hours. The bacterial cells were collected by centrifugation, washed twice with sterile physiological saline and resuspended, and the bacterial concentration was adjusted to approximately 1.0 × 10⁻⁶. 8The bacterial suspension for the test is obtained by measuring CFU / mL.

[0053] (2) Take about 50 mL of each group of test liquids and measure the pH value using a pH meter at 25℃. Take the average value of three parallel measurements.

[0054] (3) Take the treated 304 stainless steel hanging sheet, place it in a desiccator for 24 hours to balance, and then accurately weigh the initial weight using an electronic balance (recorded as ). The tablets were completely immersed in wide-mouthed bottles containing the test liquids for each group, with three parallel samples per group. The bottles were sealed. They were placed in a 50℃ constant temperature water bath shaker (60 rpm) for 168 hours. After soaking, the tablets were removed, rinsed with running water, and surface corrosion products were removed with a soft brush. They were then ultrasonically cleaned with anhydrous ethanol to dehydrate, dried with cold air, and placed in a desiccator for equilibration for 24 hours. The endpoint weight was then recorded (recorded as...). ), and observe and record the surface morphology of the hanging plates. Calculate the weight loss of the hanging plates. : The annual corrosion rate was then calculated using the following formula. : Calculate the annual corrosion rate (mm / a), where The surface area of ​​the hanging piece (cm²) 2 ); Soaking time (h); For the density of the material, 304 stainless steel is taken as 7.93 g / cm³. 3 ; 87600 is the unit conversion factor ( ), used to convert corrosion depth from centimeters / hour to millimeters / year.

[0055] (4) Place thin-walled test tubes containing 4.5 mL of the test liquid for each experimental group in a water bath, heat and keep the temperature constant to 85.0℃ (accuracy ±0.1℃). Quickly inject 0.5 mL of the bacterial suspension prepared in step (1) into the test tube, mix quickly and start timing. Experimental groups 1-4 and control group B take 0.1 mL of sample solution at 0s, 10s, 20s, 30s and 40s respectively when heated; control group A takes 0.1 mL of sample solution at 0s, 30s, 60s, 90s, 120s and 150s respectively. Immediately inject the taken sample solution into a test tube containing 4.9 mL of 4℃ pre-cooled physiological saline to stop the heating effect, and perform a 10-fold serial dilution. Spread the bacterial solution of appropriate dilution on Salmonella chromogenic medium plates, incubate at 37℃ for 24 hours and calculate the number of surviving colonies. Based on heating time The x-axis represents the logarithm of the number of surviving bacteria. A linear regression was performed on the ordinate, and the fitted regression equation is as follows: .in, For time The number of viable colonies at that time (CFU / mL); The heating treatment time is in seconds. The slope of the regression line; This is the intercept. And based on the slope... Calculate the D value at this temperature (i.e., the time required for the bacterial count to decrease by one logarithmic order): .

[0056] 3. Experimental data (see Table 1): Table 1: Physicochemical properties, corrosion rate, and D-value determination results of each group of sensitizing solutions

[0057] 4. Conclusion: Table 1 and Figure 1 Data shows that Salmonella typhimurium in physiological saline (control group A) environment... The value was 172.5 seconds, indicating that the strain exhibited high thermal stability at 85℃ without external intervention, and conventional short-term conditioning was insufficient to completely kill it. Experimental groups 1 to 4... The values ​​ranged from 16.1 seconds to 25.4 seconds. Compared with control group A, the D values ​​of each experimental group were significantly lower. Among them, experimental group 3 (high lactic acid / sodium formate concentration) had a pH of 3.23 and the lowest measured D value (16.1 seconds), indicating the highest sterilization efficiency. Compared with the data of control group B (5% formic acid, pH 2.08), its D value was 29.1 seconds, which was higher than that of experimental groups 1, 3, and 4. Although the pH value of control group B was lower, its heat sensitization effect was weaker than that of the experimental groups. This indicates that the efficient sensitization effect of the experimental groups did not depend entirely on the low pH value. The monolaurate glycerol and organic acid salt system had a synergistic effect in disrupting cell membrane permeability, promoting the intracellular penetration of organic acid molecules. The corrosion test results showed that the weight loss of the control group B was 0.0625g, the annual corrosion rate reached 0.1864mm / a, and pitting corrosion appeared on the surface, which is considered severe corrosion. The annual corrosion rate of experimental groups 1-4 was controlled between 0.0033-0.0066 mm / a, with no pitting corrosion on the surface, meeting the superior corrosion resistance standard for metallic materials. The experimental results confirm that the sensitizing solution system of this invention reduces bacterial heat resistance while avoiding corrosion of equipment by strong acids.

[0058] Test Example 2: 1. Experimental Materials and Grouping: Experimental Groups: This experiment consisted of 4 groups, with samples taken from the production processes of Preparation Examples 5, 6, and 7 and Comparative Example 3, respectively.

[0059] Experimental Group A: Taken from Preparation Example 5. Experimental Group B: Taken from Preparation Example 6. Experimental Group C: Taken from Preparation Example 7. Control Group: Taken from Comparative Example 3.

[0060] Sample collection: During the preparation process of each group above, two sampling operations were performed: Pre-irradiation sample: After the mixing step is completed and before irradiation, 50g of intermediate sample is randomly selected, sealed and stored in the dark for the determination of initial vitamin A content.

[0061] Irradiated samples: After completing the cobalt-60 irradiation sterilization step, 50g of finished product samples were randomly selected to determine the vitamin A content and moisture absorption weight gain rate after irradiation.

[0062] 2. Experimental steps: (1) Determination of moisture absorption weight gain rate: Place a clean weighing bottle in a 105℃ oven to dry until constant weight, and weigh it (record the weight as follows). Accurately weigh approximately 5.00g of each group of "irradiated samples" and spread it evenly at the bottom of the weighing bottle. Determine the initial total weight of the "bottle + sample" (recorded as ). Place the weighing bottle open in a constant temperature and humidity chamber, set the temperature to 30℃ and the relative humidity to 90%RH, and let it stand for 48 hours. Remove the weighing bottle and immediately seal it tightly. Place it in a desiccator to cool to 25℃, then weigh the "bottle + sample" total weight at the endpoint (recorded as ). According to the formula Calculate the moisture absorption weight gain rate of the three parallel samples respectively. , , The arithmetic mean of the three values ​​is taken as the final moisture absorption weight gain rate of the sample group.

[0063] (2) Determination of Vitamin A content and retention rate: Accurately weigh vitamin A acetate standard (purity ≥99.0%, chromatographic grade), and dilute it stepwise with methanol to prepare a concentration ( ). A series of standard working solutions with concentrations of 2.0, 5.0, 10.0, 20.0, and 50.0 IU / mL were prepared. The solutions were injected and analyzed under chromatographic conditions, and the corresponding peak areas (A) were recorded. The concentration of vitamin A was used as the reference. Using the x-axis as the horizontal axis and the peak area A as the y-axis, linear regression was performed using the least squares method to obtain the standard curve equation: .

[0064] Note: In this linear regression analysis, the correlation coefficient was calculated. Used to evaluate the goodness of fit of the standard curve, i.e., the reliability of the linear relationship between the detector response signal and the concentration of the analyte. This experiment requires... The value should be greater than 0.999 to ensure the accuracy of quantitative analysis. The regression equation actually measured in this experiment and used for subsequent calculations is: Its correlation coefficient This is the common foundation for quantitative analysis in this field.

[0065] Accurately weigh 2.0g of each of the "pre-irradiation sample" and "post-irradiation sample" from each group (accurate to 0.0001g, denoted as ). The solution was placed in a saponification flask. 30 mL of anhydrous ethanol, 5 mL of 50% potassium hydroxide solution, and 0.2 g of ascorbic acid were added. Under nitrogen protection, the mixture was refluxed in a water bath at 80°C for 30 minutes. After cooling, the mixture was extracted several times with diethyl ether. The extracts were combined, washed with water until neutral, dried over anhydrous sodium sulfate, and then evaporated to dryness by rotary evaporation. The residue was dissolved in methanol and transferred to a 50 mL volumetric flask, and the volume was made up to 100 mL. After passing through a 0.45 μm filter membrane, 20 μL of the sample is injected for analysis.

[0066] For the "pre-irradiation sample", record its chromatographic peak area as follows: For the "irradiated sample", record its chromatographic peak area as... .

[0067] Chromatographic conditions: C18 reversed-phase column (4.6 mm × 250 mm, 5 μm); mobile phase: methanol / water (98:2, v / v); flow rate: 1.0 mL / min; detection wavelength: 325 nm; column temperature: 25 °C.

[0068] Results calculation: Using the same standard curve equation and the same calculation formula, the vitamin A content (IU / g) before and after irradiation was calculated respectively.

[0069] VA content before irradiation ( Calculation of the measured peak area: Substituting into the regression equation, the concentration of the sample solution is obtained. .

[0070] ; VA content after irradiation ( Calculation of the measured peak area: Substituting into the regression equation, the concentration of the sample solution is obtained. .

[0071] ; Retention rate calculation: ; 3. Experimental data (see Table 2): Table 2: Results of moisture absorption weight gain and vitamin A irradiation retention rate determination for each group of premixes

[0072] 4. Conclusion: Table 2 and Figure 2Data shows that after 48 hours of exposure to high temperature and humidity (30℃, 90%RH), the moisture absorption weight gain rate of the control group samples was 13.42%, and significant clumping was observed. In contrast, the moisture absorption weight gain rates of experimental groups A, B, and C were 2.15%, 1.83%, and 2.67%, respectively, and the samples remained in a loose powder state. The control group used a direct mixing process of solid powders, with sodium bicarbonate micropowder and defatted rice husk powder directly exposed to high humidity air, exhibiting high hygroscopicity. The experimental groups introduced soybean oil during the preparation process, forming an oil film coating on the carrier and sodium bicarbonate surface. This hydrophobic layer reduced the contact between the material and moisture, lowering the moisture absorption rate. Regarding vitamin A stability, after irradiation with 8 kGy, the vitamin A content of the control group (without the oil film) decreased from 185,880 IU / g to 118,591 IU / g, with a retention rate of 63.8%, indicating significant loss. Experimental group A, under the same irradiation dose (8 kGy), maintained a vitamin A retention rate of 92.2%. Although the irradiation dose in experimental group B was increased to 10 kGy, the vitamin A retention rate remained at 91.3% due to the increased oil film content of 1.5%. These results indicate that under the same irradiation sterilization conditions, the oil film coating process can improve the vitamin A retention rate. This is because the oil layer physically isolates oxygen and moisture, reducing the reaction medium for vitamin A oxidation and degradation; simultaneously, as an organic phase, the oil consumes some of the free radicals generated during the irradiation process, thus protecting the core material.

[0073] Test Example 3: 1. Experimental Materials and Grouping: Test strains: Salmonella Typhimurium CMCC(B)50115 and Escherichia coli ATCC 25922.

[0074] Basic carrier: The bulk raw materials (commercially available feed-grade yellow corn and peeled soybean meal) were used as the contamination carrier. Testing showed that the total background bacterial count of this batch of raw materials was <10. 3 CFU / g, and Salmonella was not detected.

[0075] Experimental Groups: Positive control group: Bulk raw materials that underwent only artificial contamination treatment, without any subsequent granulation or heat treatment, used to determine the initial bacterial content. Example groups 1-4: Feed products prepared using contaminated bulk raw materials according to the complete process described in Examples 1 to 4. Comparative examples 1, 2, and 5: Feed products prepared using contaminated bulk raw materials according to the process described in Comparative Examples 1, 2, and 5, respectively.

[0076] 2. Experimental steps: (1) Activated Salmonella typhimurium and Escherichia coli were inoculated into TSB broth and cultured at 37°C until the logarithmic growth phase. The bacterial cells were collected by centrifugation, resuspended in sterile physiological saline and mixed to prepare a high-concentration compound bacterial suspension. The bacterial suspension was sprayed evenly into the base carrier (bulk raw material) by atomization and mixed in a V-type mixer for 30 minutes to obtain the contaminated bulk raw material.

[0077] (2) Divide the above-mentioned contaminated raw materials into 8 equal portions.

[0078] Positive control group: One sample was taken directly for microbial testing without further processing.

[0079] Examples 1-4 and Comparative Examples 1, 2, and 5: The remaining 7 samples from Examples 1-4 and Comparative Examples 1, 2, and 5 replaced the common bulk raw materials in their respective preparation examples, were processed according to their respective described process steps, and the final products were collected. The positive control group was not further processed and was directly sampled.

[0080] (3) Determination of Salmonella and Escherichia coli residues: Under aseptic conditions, weigh 25g of each group of samples and put them into a homogenizing bag containing 225mL of sterile buffered peptone water. Homogenize for 2 minutes to prepare a 1:10 test solution and perform a 10-fold serial dilution.

[0081] Salmonella detection: Spread 0.1 mL of the appropriately diluted sample solution onto an XLD selective agar plate and incubate at 37°C for 24 hours. Count the number of black central colonies and calculate the colony forming units (CFU / g) per gram of sample. Record this value as “Salmonella Residue” in Table 3.

[0082] Escherichia coli detection: Pour 1.0 mL of the appropriately diluted sample solution onto a crystal violet neutral bile salt agar plate and incubate at 36°C for 24 hours. Count the number of colonies in the purple-red precipitate and calculate the colony forming units (CFU / g) per gram of sample. Record this value as “E. coli residue” in Table 3.

[0083] Each sample group was measured in parallel 5 times, and the arithmetic mean was taken. If no colonies grew on the plate, it was recorded as "not detected" and the calculation was performed according to the lowest detection limit (<10 CFU / g).

[0084] (4) Log Reduction Value Calculation: Based on the residual data obtained in step (3), calculate the Log Reduction Value (LRV). LRV represents the logarithmic order of the reduction in microbial numbers and is used to evaluate the efficiency of the sterilization process. The calculation formula is as follows: ; in, The residual amount of the corresponding bacterial species measured in the positive control group (i.e., the initial bacterial contamination amount, CFU / g). The residual amount (CFU / g) of the corresponding bacterial species was measured in each example group or comparative example group. The calculated values ​​are recorded as "Log kill value of Salmonella" and "Log kill value of Escherichia coli" in Table 3.

[0085] 3. Experimental data (see Table 3): Table 3: Results of Microbial Residue and Logarithmic Kill Value in Feed Products of Each Group

[0086] 4. Conclusion: Table 3 shows that the initial bacterial load was extremely high (Salmonella 5.2 × 10⁻⁶). 6 Under the test conditions of CFU / g, the sterilization effects of different treatment processes varied significantly. In Comparative Example 5, the Salmonella residue in the finished product was 4.6 × 10⁻⁶. 4 The CFU / g and the logarithmic kill value were only 2.05. This data indicates that, within the normal conditioning time in industrial production, relying solely on heat at 95℃ is insufficient to reduce the high-load pathogenic bacteria to a safe level; the lag in heat transfer within the particles allows some bacteria to survive. The Salmonella residue in Comparative Example 1 (sensitization solution without glyceryl monolaurate) was 3.1 × 10⁻⁶. 3 CFU / g (log kill value 3.22), the residual amount of Comparative Example 2 (sensitizing solution without sodium formate) was 9.5 × 10⁻⁶. 2 CFU / g (log kill value 3.74). Compared with Comparative Example 5, the bactericidal effect of these two groups was improved, but still did not reach the "not detected" standard. This indicates that the absence of either glyceryl monolaurate or organic acid salts weakens the synergistic efficacy of the sensitizing solution. Data from Comparative Example 1 confirms that without glyceryl monolaurate to disrupt cell membrane permeability, organic acids cannot efficiently enter the bacterial cell; data from Comparative Example 2 suggests that the lack of sodium formate leads to insufficient osmotic pressure and buffering capacity, and the bacterial heat resistance is not adequately inhibited. In the finished products of Examples 1, 3, and 4, Salmonella and Escherichia coli were not detected (<10 CFU / g), and the log kill value exceeded 5.71, meeting the commercial sterility requirements. Although a trace amount of Salmonella was detected in Example 2 (20 CFU / g), its log kill value was still as high as 5.41, far superior to the comparative examples. In summary, this invention uses glyceryl monolaurate to disrupt the bacterial cell membrane and organic acid salts to construct a hyperosmolar buffer system, putting pathogenic bacteria in a heat-sensitized state. Under these conditions, the bacteria become significantly more sensitive to heat treatment at 85°C, thus achieving efficient killing of heat-resistant Salmonella and Escherichia coli in feed without using high temperatures (>100°C).

[0087] Test Example 4: 1. Experimental Materials and Grouping: Sample to be tested: Example Groups 1-4: Final feed products prepared from Examples 1 to 4. Comparative Example Groups 1-5: Final feed products prepared from Comparative Examples 1 to 5.

[0088] Standards and reagents: Vitamin A acetate standard (purity ≥99.0%); phytase standard (5000 U / g, derived from Escherichia coli); sodium phytate (substrate, purity ≥98%); ammonium vanadate colorimetric reagent; all other reagents were of analytical grade.

[0089] 2. Experimental steps: (1) Sample pretreatment: In order to ensure that the target components can be fully extracted in subsequent chemical analysis, the finished feed pellets of each group were crushed by a laboratory grinder and passed through a 40-mesh sieve and mixed evenly. Three parallel samples (approximately 50g each) were randomly selected from each group, sealed and stored in the dark for testing.

[0090] (2) Weigh approximately 5g (accurate to 0.0001g) of the above-mentioned pulverized sample, place it in a saponification bottle, add 50mL of ethanol and 10mL of 50% potassium hydroxide solution, and saponify by reflux in an 85℃ water bath for 30 minutes. After cooling, extract three times with n-hexane, combine the extracts, wash with water until neutral, dry with anhydrous sodium sulfate, and then evaporate to dryness by rotary evaporation. Dissolve the residue in methanol and make up to 50mL, filter through a 0.45μm filter membrane to obtain the test solution. The determination of vitamin A content and the establishment of the standard curve were strictly performed according to the chromatographic conditions (C18 column, methanol / water mobile phase, 325nm detection) and regression equation () under the "Determination of Vitamin A Content and Retention Rate" section in Test Example 2. The determination was performed. The measured peak area was substituted into the regression equation to calculate the sample concentration, which was then converted to the actual content in the sample. Finally, the vitamin A retention rate was calculated using the following formula: .in, The content of vitamin A (IU / g) in each gram of finished feed product was actually measured by high performance liquid chromatography. This is to calculate the theoretical amount of vitamin A added per gram of finished feed (IU / g) based on the feed formulation ratio and the initial vitamin A content in the premix.

[0091] (3) Weigh 2.0 g of the above-mentioned pulverized sample, place it in an Erlenmeyer flask, add 50 mL of acetate-sodium acetate buffer (pH 5.5), shake and extract for 30 minutes, filter and collect the supernatant. Take the supernatant and react it with sodium phytate substrate solution at 37℃ for 30 minutes, add ammonium vanadate solution to terminate the reaction, and measure the absorbance at a wavelength of 415 nm. Determination and calculation of phytase activity: Accurately weigh the phytase standard, dilute it with buffer to prepare a series of standard solutions of 0, 0.2, 0.4, 0.6, 0.8, and 1.0 U / mL, develop the color and measure the absorbance in the same way as above. Plot a standard curve with enzyme activity (U / mL) as the abscissa and absorbance as the ordinate to obtain the regression equation. Substitute the absorbance of the sample to be tested into the regression equation to calculate the enzyme activity of the sample solution, and then calculate the actual enzyme activity in the sample. Finally, calculate the phytase activity retention rate according to the following formula: .in, The phytase activity (U / g) per gram of finished feed product was actually measured by colorimetric method. The theoretical activity (U / g) of phytase per gram of finished feed is calculated based on the feed formulation ratio and the initial labeled activity of phytase in the premix.

[0092] 3. Experimental data (see Table 4): Table 4: Results of the determination of the retention rate of heat-sensitive nutrients in the finished feed products of each group

[0093] 4. Conclusion: Table 4 reveals the impact of different processing routes on the stability of heat-sensitive nutrients. Comparative Example 4 showed the lowest vitamin A retention rate (46.3%) and phytase activity retention rate (38.7%) among all test groups. This group's process altered the feeding sequence, directly mixing the premix containing heat-sensitive components with bulk raw materials before 90°C humid heat conditioning. The data confirmed that in the high-temperature, high-humidity conditioning environment, vitamin A underwent oxidative isomerization, and the enzyme protein denatured and became inactive, resulting in a loss of more than half of the nutritional value. This result verifies that placing heat-sensitive components pre-processed in the conditioning step is the main reason for the decline in feed quality. Examples 1 to 4 all showed vitamin A retention rates above 93.8% and phytase activity retention rates above 91.9%. Compared to Comparative Example 4, the retention rates increased by approximately 40% to 50%. These examples employed a post-addition process, adding the heat-sensitive premix via a drum mixer after the high-temperature conditioning and cooling processes. This spatial-temporal separation strategy avoided direct contact between nutrients and high-temperature steam, ensuring the high nutritional value of the finished product. The vitamin A retention rate of Comparative Example 3 was 87.6%, lower than the 94.2% of Example 1. The premix carrier of Comparative Example 3 was not coated with an oil film. Although this group also used a post-addition process, the lack of oil film protection and the high hygroscopicity of sodium bicarbonate led to fluctuations in the microenvironment pH and increased water activity during mixing, accelerating vitamin degradation. This indicates that oil film coating technology contributes to maintaining the chemical stability of the premix during processing and storage. The nutrient retention rates of Comparative Example 5 (91.5% and 89.8%) were close to those of the Example group, consistent with its post-addition process. However, a comprehensive evaluation based on the data from Test Example 3 is necessary: ​​while Comparative Example 5 retained nutrients, its Salmonella kill log was only 2.05 (far lower than the >5.71 of the Example), failing to achieve commercial sterility. If Comparative Example 5 attempts to achieve sterility by increasing the conditioning temperature, it will inevitably destroy heat-sensitive nutrients such as lysine in the bulk raw materials. In summary, Examples 1-4 achieved low-temperature (88-95℃) conditioning and sterilization using a non-corrosive, high-permeability sensitizing solution, and combined this with a post-addition process to achieve heat-sensitive nutrient protection. This combined process maximizes the preservation of the feed's nutritional value without sacrificing microbial safety, solving the technical challenge of balancing sterilization and nutrient preservation in traditional high-temperature pelleting processes.

[0094] Test Example 5: 1. Experimental Materials and Grouping Sample to be tested: Example Groups 1-4: Final feed products prepared from Examples 1 to 4. Comparative Example Group 4: Final feed products prepared from Comparative Example 4.

[0095] Reagents and instruments: pepsin (activity > 250 U / mg), trypsin (activity > 250 U / mg); standard hydrochloric acid titration solution (1.000 mol / L); particle hardness tester (range 0-20 kg); rotary box pulverization rate tester (equipped with rotary box and standard sieve).

[0096] 2. Experimental steps: (1) Take samples from each group and randomly measure the radial compressive strength of 20 particles using a particle hardness tester. Record the average value to obtain the particle hardness (kg / cm). 2 Take another 500g sample (denoted as ). The sample was placed in the rotary box of a rotary box pulverization rate tester, with the rotation speed set to 50 rpm and the rotation time set to 10 minutes. The sample was then removed and sieved through a standard sieve with a 2.5 mm aperture. The weight of the whole particles on the sieve was measured (recorded as ). Calculate the powdering rate (PDI) using the following formula: .

[0097] (2) Crush the sample and pass it through a 60-mesh sieve. Weigh 1g of the sample (recorded as 1g). Place the sample in a 50 mL centrifuge tube, add 25 mL of distilled water, and incubate at 37°C in a water bath with shaking at 100 rpm for 30 minutes. Then centrifuge at 3000 rpm for 15 minutes. Discard the supernatant and weigh the wet weight of the precipitated gel (recorded as...). Calculate the water absorption index (WAI) using the following formula: This index is used to characterize the hydrophilicity of the internal matrix of particles and the abundance of pore structure.

[0098] (3) In vitro simulated digestion was performed using a two-step method on a monogastric animal. 1.000 g of the pulverized sample (denoted as ) was accurately weighed. The sample was placed in an Erlenmeyer flask, and 25 mL of simulated gastric juice (containing pepsin, pH 2.0) preheated to 37°C was added. Digestion was carried out at 37°C with shaking for 4 hours. The pH was adjusted to 6.8, and 25 mL of simulated intestinal juice (containing trypsin) was added. Digestion continued for 4 hours. After digestion, the residue was filtered and collected, then dried at 105°C to constant weight. The dry weight of the residue was measured (recorded as...). Calculate in vitro dry matter digestibility (IVDMD) using the following formula: .

[0099] (4) Determine the acid-holding capacity (ABC value) to assess the buffering capacity of the finished product in an acidic environment. Weigh 10.0 g of the pulverized sample, disperse it in 100 mL of distilled water, and stir magnetically until homogeneous. Titrate with 1.000 mol / L hydrochloric acid solution until the pH of the suspension stabilizes at 3.0, and record the volume of hydrochloric acid consumed. (Unit: mL). Calculate the acid-binding power using the following formula: .in, The concentration of hydrochloric acid is 1.000 mol / L. The sample weight is 10.0g.

[0100] 3. Experimental data (see Table 5): Table 5: Physical properties and in vitro digestibility test data of each group of feed products

[0101] 4. Conclusion: Table 5 provides data that verifies the effectiveness of the process of this invention from two dimensions: physical structural stability and chemical buffering performance. Regarding physical properties, the particle hardness of Examples 1-4 ranges from 6.5 to 7.1 kg / cm². 2 Between these values, the powdering density (PDI) remained at a high level of 96.8% to 98.2%. In contrast, the particle hardness of Comparative Example 4 decreased significantly to 4.3 kg / cm². 2 The pulverization rate was only 89.5%. Comparative Example 4 used a mixing-before-granulation process, which caused the acidic sensitizing solution and sodium bicarbonate to undergo a premature neutralization reaction in the high-temperature and high-humidity environment of the conditioner. The resulting carbon dioxide gas escaped before granulation, causing penetrating cracks inside the granules and disrupting the starch binding network, resulting in a loose structure in the finished product. Differences in water absorption index (WAI) data confirmed the existence of the microporous structure. The WAI value of the Example group (mean 3.44 g / g) was significantly higher than that of Comparative Example 4 (2.15 g / g). This invention, through a spatiotemporal separation process, allows the acidic sensitizing solution to act solely on the bulk raw materials during the conditioning stage. The organic acid performs mild chemical etching and modification on the starch granules, constructing abundant micropores in the granule matrix, thereby improving the specific surface area and water-holding capacity of the granules. Comparative Example 4, due to premature acid-base neutralization, lost the modifying effect of the acid on the raw materials, resulting in a lower WAI value. In vitro dry matter digestibility (IVDMD) and acid-holding capacity (ABC value) showed a positive correlation. The IVDMD of the Example Groups reached 85.9%-87.1%, significantly better than that of Comparative Example 4 (76.4%). The key reason lies in the significant difference in acid-holding capacity: the ABC values ​​of the Example Groups remained at 672-694 mmol / kg, while those of Comparative Example 4 were only 145 mmol / kg. This indicates that the buffer in Comparative Example 4 was essentially depleted during processing. The Example Groups benefited from post-addition and oil film coating technology, retaining the alkaline reserves of sodium bicarbonate in the finished product. During in vitro digestion, the retained sodium bicarbonate neutralized in situ with the organic acids pre-infiltrated into the particles, optimizing the pH environment of the simulated digestion solution and improving enzymatic hydrolysis efficiency.

[0102] Test Example 6: 1. Experimental materials and grouping of experimental subjects: Hy-Line Brown parent chickens of 300 days old, with similar weight and good health were selected as experimental animals.

[0103] Experimental Groups: Example Group 1: Feeded with the feed prepared in Example 1. Comparative Example Group 1: Feeded with the feed prepared in Comparative Example 1. Comparative Example Group 4: Feeded with the feed prepared in Comparative Example 4. Comparative Example Group 5: Feeded with the feed prepared in Comparative Example 5.

[0104] Experimental design: A single-factor completely randomized design was adopted, with a total of 4 treatment groups, 4 replicates (plots) in each treatment group, 40 chickens in each replicate, and a total of 640 chickens.

[0105] 2. Experimental steps: (1) A 7-day pre-feeding period was conducted before the experiment, during which the chicken house was thoroughly cleaned and disinfected, and all chickens were vaccinated and dewormed. The experiment lasted for a total of 56 days (8 weeks). All experimental chickens were housed in the same fully enclosed tiered layer house, using a three-tiered cage system with 4 chickens per cage. The lighting program, temperature and humidity control, and daily management were strictly carried out in accordance with the Hy-Line Brown parent stock management manual. Chickens had free access to feed and water.

[0106] (2) Production data recording: The number of eggs laid, the number of broken eggs and the number of dead chickens are recorded daily, using "repetition" (i.e., 40 chickens per plot) as the statistical unit. The amount of feed consumed is calculated once a week.

[0107] (3) Reproductive performance determination: In the 4th and 8th weeks of the experiment, semen was collected from multiple healthy roosters and mixed evenly (to eliminate the influence of individual differences in roosters on the fertilization rate), and artificial insemination was performed on the experimental chickens. Starting from the day after insemination, hatching eggs were collected for 5 consecutive days for incubation, and the number of fertilized eggs was checked by candling and recorded.

[0108] (4) Calculation of indicators: Egg production rate (%) = (Total number of eggs produced during the trial period / Total number of surviving hens per day during the trial period) × 100%; Feed conversion ratio (FCR) = Total feed consumption during the trial period (kg) / Total egg production weight during the trial period (kg); Mortality rate (%) = (Number of chickens that died and were culled during the trial period / Initial number of chickens in the trial) × 100%; Fertilization rate of hatching eggs (%) = (Number of fertilized eggs / Number of eggs put into incubation) × 100%.

[0109] 3. Experimental data (see Table 6): Table 6: Test results of production and reproductive performance of laying hens in each group

[0110] 4. Conclusion: Table 6 shows the production performance data reflecting the practical application effects of feed microstructure, nutrient retention rate, and microbial safety in animal husbandry. All indicators of Example 1 are superior to those of the comparative examples. The egg production rate is 96.4%, the feed conversion ratio is 2.03, and the mortality rate is 0.63%. These results verify the comprehensive effectiveness of the process of this invention: First, as shown in Test Example 5, Example 1 has a high water absorption index and microporous structure, and retains the acid-binding power of sodium bicarbonate, which improves the digestibility and absorption rate of the feed in the chicken's digestive tract, resulting in a lower feed conversion ratio. Second, as shown in Test Example 3, Example 1 achieves commercial sterility through a non-corrosive hypertonic sensitizing solution, cutting off the oral transmission route of pathogens such as Salmonella, resulting in an extremely low mortality rate. Comparative Example 4 has the lowest egg production rate (88.7%) and fertilization rate (86.5%) among all groups. This group used premixed feed pre-addition and high-temperature conditioning processes. Based on the data from Test Example 4, this process resulted in a significant loss of heat-sensitive vitamin A and phytase. Vitamin A is a key nutrient for maintaining the integrity of reproductive epithelial cells, and its deficiency directly leads to a decrease in fertilization rate; phytase inactivation affects phosphorus utilization and eggshell quality, thereby reducing egg production performance. The mortality rate of Comparative Example 5 was as high as 4.38%, significantly higher than that of Example 1. Although Comparative Example 5 retained its nutritional components through a post-addition process (its egg production rate and fertilization rate were not significantly different from the Example group), the lack of sensitization treatment meant that its 95°C high-temperature conditioning failed to completely kill heat-resistant pathogens (see data from Test Example 3). Residual pathogens such as Salmonella caused latent infections or subclinical symptoms in the flock, increasing the mortality rate. This demonstrates that relying solely on physical high-temperature sterilization is insufficient to simultaneously ensure nutritional protection and biosafety, while the chemical sensitization-assisted low-temperature sterilization scheme of this invention effectively solves this problem. The mortality rate of Comparative Example 1 was 1.88%, higher than that of Example 1. Comparative Example 1 did not add GML (glyceryl monolaurate) to the sensitization solution. This indicates that without the synergistic effect of GML, the lethal effect of a single acidic sensitizing solution on Gram-positive bacteria and some acid-resistant bacteria is weakened, leading to a decline in feed hygiene quality and consequently affecting the survival rate of the flock.

Claims

1. A process for producing aseptic feed for heat-sensitive breeding hens, characterized in that, Includes the following steps: Take 1000 parts by weight of bulk raw materials, spray in 8-12 parts by weight of non-corrosive hypertonic sensitizing liquid, mix, and obtain a surface-wetted sensitizing mixture; The sensitized mixture is fed into a conditioner and steam is introduced for wet heat conditioning to obtain a high-temperature sterilized wet mixture. The high-temperature sterilized wet material is granulated, and the resulting granules are cooled to 20-30°C to obtain a cooled base material. Add 20-30 parts by weight of reactive buffer premix to the cooling base material and mix evenly to obtain heat-sensitive raw material-adapted aseptic feed for laying hens.

2. The process for producing heat-sensitive raw material-adapted aseptic feed for laying hens according to claim 1, characterized in that, The conditioning temperature for the wet heat conditioning is 88-95℃, and the conditioning time is 120-180 seconds.

3. The production process of heat-sensitive raw material-adapted aseptic feed for laying hens according to claim 1, characterized in that, The non-corrosive hypertonic sensitizing solution is made from raw materials comprising the following parts by weight: Deionized water: 22-30 parts; Sodium formate: 18-25 parts; Lactic acid with a mass fraction of 80%: 28-35 parts; Glyceryl monolaurate: 5-8 parts; 1,2-Propanediol: 10-20 parts.

4. The process for producing aseptic feed for heat-sensitive breeding hens according to claim 3, characterized in that, The non-corrosive hypertonic sensitizing solution is prepared by the following method: Deionized water is heated to 45-55℃, and sodium formate is added to dissolve it to obtain an aqueous solution of organic salts. While maintaining the temperature, lactic acid was added dropwise to the aqueous solution of the organic salt, and the mixture was stirred to obtain an acidic buffer system solution; Glyceryl monolaurate was dissolved in 1,2-propanediol heated to 40-50℃ to obtain an organic phase solution; The organic phase solution is injected into the acidic buffer system solution and sheared and mixed at 350-500 rpm for 20-30 minutes until a homogeneous transparent liquid is formed, thus obtaining the non-corrosive hypertonic sensitizing solution.

5. The process for producing aseptic feed for heat-sensitive breeding hens according to claim 1, characterized in that, The reactive buffer premix is ​​made from raw materials comprising the following parts by weight: Micronized sodium bicarbonate: 3.0-5.0 parts; Defatted rice husk powder: 100 parts; Soybean oil: 1.0-1.5 parts; Premixed feed core material: 20 parts.

6. The production process of heat-sensitive raw material-adapted aseptic feed for laying hens according to claim 5, characterized in that, The reactive buffer premix is ​​prepared by the following method: Defatted rice husk powder is mixed with soybean oil to obtain a carrier with an oil film on its surface; Micronized sodium bicarbonate was added to the carrier with the oil film on its surface and mixed to obtain a modified buffer carrier. The premixed core material was added to the modified buffer carrier, and after being mixed evenly, it was sterilized by cobalt-60 irradiation.

7. The process for producing aseptic feed for heat-sensitive raw materials adapted to laying hens according to claim 6, characterized in that, The irradiation dose for cobalt-60 irradiation sterilization is 5-10 kGy.

8. The process for producing aseptic feed for heat-sensitive raw materials adapted to laying hens according to claim 5, characterized in that, The particle size distribution D90 of the micronized sodium bicarbonate is less than 75 μm; the moisture content of the defatted rice husk powder is 8%-10%.

9. The production process of heat-sensitive raw material-adapted aseptic feed for laying hens according to claim 1, characterized in that, The main raw materials are yellow corn and peeled soybean meal, and the particle size is controlled to be 1.5mm-2.5mm after crushing.

10. The process for producing aseptic feed for heat-sensitive breeding hens according to claim 5, characterized in that, The carrier of the premixed core material is a mixture of defatted rice bran and maifan stone powder.

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