Granular crushed concentrated feed for poultry and preparation method of granular crushed concentrated feed

Abstract

The invention discloses a granular crushed concentrated feed for poultry and a preparation method thereof, and belongs to the technical field of feed processing, and the preparation process comprises the following steps: crushing and uniformly mixing the raw materials, feeding the uniformly mixed materials into a granulator, tempering by steam, granulating after tempering, carrying out vacuum freeze drying on the granules, and carrying out ultrasonic treatment to obtain the granular crushed concentrated feed for poultry. Then the granules are fed into a granule crusher to be crushed, and finally, the granules are screened through a double-layer vibrating screen to obtain middle-size-fraction granules; through the preparation process, the porosity of the feed can be increased, the palatability of the feed can be improved, the hardness of the feed can be improved, and by combining a vacuum freeze-drying and ultrasonic post-crushing process, a ring die granulator for granulating and a screening process in a specific particle size range, the uniformity of the material particle size can be improved, the particle size difference of particles can be eliminated, and the grading of the feed can be reduced; it is guaranteed that each chicken can intake enough calcium sources, and the laying rate of laying hens and the egg quality are improved.

Description

Technical Field

[0001] This invention relates to the field of feed processing technology, specifically to a process for preparing pelleted and concentrated feed for poultry. Background Technology

[0002] Currently, during the formulation of poultry concentrates, the large differences in the physical properties of traditional powdered concentrates make them prone to separation due to vibration and gravity during transportation and feeding. Furthermore, parameters such as mixing time and blade design of the mixer may not be able to uniformly mix materials with different physical properties. This leads to the gradual separation of materials with different densities and particle sizes in the feed trough: heavier components such as stone powder sink to the bottom, while lighter particles float to the top, resulting in malnutrition in poultry, insufficient calcium intake, and indigestion. In addition, the poor palatability and digestibility of traditional poultry concentrates affect the absorption rate of minerals such as calcium and phosphorus, resulting in low egg production rate, low egg weight, low eggshell strength, and low thickness.

[0003] Therefore, there is an urgent need for a process to prepare pelleted concentrate that can eliminate particle size differences in poultry pelleted concentrate, improve feed palatability and digestibility, and increase poultry egg production rate and egg quality. Summary of the Invention

[0004] To address the aforementioned deficiencies in the prior art, this invention provides a method for preparing poultry pelleted concentrate. By freeze-drying and ultrasonically treating the pellets after pelleting, the porosity of the feed is increased, palatability is improved, and feed hardness is reduced. Appropriate pellet hardness stimulates the secretion of gastric acid and protease digestive juices, increasing the digestibility and absorption of minerals such as calcium and phosphorus, promoting gizzard development in laying hens, thereby increasing feed intake and improving egg quality. High-porosity feed allows for more thorough contact with digestive enzymes, resulting in more complete digestion and a lower feed conversion ratio. Crushing the pellets after vacuum freeze-drying and ultrasonic processing makes the physical morphology of the pelleted concentrate more uniform. Combined with ring die pelleting and screening within a specific particle size range, the uniformity of particle size is further improved, eliminating particle size differences. This reduces feed grading, prevents uneven nutrition caused by heavy components settling at the bottom of the feed trough, ensures that each chicken ingests sufficient calcium, and improves egg production and eggshell strength.

[0005] To achieve the above technical effects, the following technical solution is adopted: A method for preparing pelleted concentrate for poultry includes the following steps: Step S1: Weigh each raw material and crush it, then mix the crushed materials thoroughly. Step S2: The uniformly mixed material is fed into a granulator and conditioned by steam. After conditioning, it is granulated. The conditioning temperature is 80-90℃ and the granulation temperature is 80-90℃. Step S3: The granules prepared in step S2 are subjected to vacuum freeze-drying and ultrasonic treatment, and then the granules are fed into a granulator for crushing. Step S4: The material crushed in step S3 is screened through a double-layer vibrating screen, where the upper screen has a mesh size of 6 mesh and the lower screen has a mesh size of 10 mesh, and intermediate-sized pellet feed with a mesh size between 6 mesh and 10 mesh is obtained after screening.

[0006] Furthermore, in step S3, the freezing temperature of the vacuum freeze-drying is -50 to -40°C, the freezing time is 3 to 5 hours, the heating and drying temperature is -20 to 10°C, and the drying time is 10 to 18 hours. Furthermore, in step S3, the vacuum degree of vacuum freeze drying reaches 30-40 Pa within 1 hour, and the heating rate is 3-5 °C / min; Furthermore, in step S3, the ultrasonic vibration frequency is 20–30 kHz; the ultrasonic amplitude is 20–30 μm; and the ultrasonic vibration time is 20–30 min. Furthermore, the mixing time in step S1 is 5–20 min; Furthermore, in step S2, the conditioning temperature is 80℃ and the steam pressure is 0.3~0.5 MPa; Furthermore, the granulation temperature in step S2 is 85°C. Furthermore, in step S2, a ring die pellet mill is used for pelleting, and the diameter of the membrane pores of the ring die pellet mill is 3-5 mm. Furthermore, in step S4, the oversized particles separated by the upper screen are returned to the crusher for further crushing, while the overly fine powder separated by the lower screen is returned to the pellet mill for re-granulation, resulting in a finished crushed granular material with uniform particle size.

[0007] The present invention also provides a pelleted concentrate for poultry prepared by the above-described preparation method.

[0008] The beneficial effects of this invention are as follows: This invention discloses a method for preparing poultry pelleted concentrate. By freeze-drying and ultrasonically treating the pellets after pelleting, the porosity of the feed can be increased, palatability improved, and feed hardness reduced. Moderate pellet hardness stimulates the secretion of gastric acid and protease digestive juices, increasing the digestibility and absorption of minerals such as calcium and phosphorus, promoting gizzard development in laying hens, thereby increasing feed intake and improving eggshell quality. High-porosity feed allows for more thorough contact with digestive enzymes, resulting in more complete digestion and a lower feed conversion ratio. Crushing the pellets after vacuum freeze-drying and ultrasonic processing makes the pelleted concentrate more uniform in physical form. This is further enhanced by combining pelleting with a ring die pellet mill and specific... The particle size range screening process can further improve the uniformity of material particle size and eliminate particle size differences. It can reduce feed grading and avoid uneven nutrition caused by heavy components settling at the bottom of the feed trough. The high porosity and uniform particle size of the prepared feed are very suitable for laying hens to peck at. It is not easy for them to choke, and it does not require a long time to peck at large particles. It increases their appetite and ensures the stability of daily nutrient intake, thereby ensuring that each hen can ingest sufficient calcium, improving the laying rate and egg quality. In other words, the preparation process of this invention can significantly improve the feed intake, laying rate and egg quality of laying hens, reduce the feed conversion ratio, and thus improve the utilization rate of laying hen feed. It has important application value. Detailed Implementation

[0009] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0010] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0011] Example 1: Step S1: Take corn alcohol residue, fermented sugar residue, chili meal, soybean meal (43%, 46%), and hydrolyzed feather meal and put them into a pulverizer for pulverization. The pulverizer screen has a mesh size of 12 to obtain powder raw materials. Then, weigh each powder raw material according to the weight in Table 1 and put it into a horizontal ribbon mixer for mixing. The mixing time is 8 minutes. The power of the horizontal ribbon mixer is 35KW and the speed is 30rpm.

[0012] Table 1. Ingredients for preparing pelleted concentrate for poultry

[0013] Step S2: The mixed raw materials prepared in step S1 are fed into a ring die granulator. They are conditioned by steam at a temperature of 80°C for 1 minute and a steam pressure of 0.5 MPa. After conditioning, they are fed into the granulation chamber and granulated at 85°C. The membrane pore diameter of the ring die granulator is 4 mm. Step S3: The pellets prepared in step S2 are fed into a freeze dryer at a freezing temperature of -50℃ for 3 hours. Then, a low-temperature vacuum is applied, with the preset vacuum level reaching 30 Pa within 1 hour. Once the preset vacuum level is reached, heating is turned on at a heating plate heating rate of 3℃ / min, a drying temperature of 10℃, and a drying time of 18 hours. When the drying temperature reaches 10℃, an ultrasonic vibration device is activated at a frequency of 30kHz, an amplitude of 30μm, and a duration of 25 minutes. After ultrasonic vibration is completed, the ultrasonic vibration is turned off, and sublimation drying continues. After freeze-drying, the pellets are fed into a pellet crusher for crushing to obtain feed pellets with a particle size of approximately 2.5 mm. Step S4: The crushed material is screened through a double-layer vibrating screen, where the upper screen has a mesh size of 6 mesh and the lower screen has a mesh size of 10 mesh. After screening, intermediate-sized feed pellets SK1, which are between 6 mesh and 10 mesh, are obtained.

[0014] Example 2 Step S1: Take corn alcohol residue, fermented sugar residue, chili meal, soybean meal (43%, 46%), and hydrolyzed feather meal and put them into a pulverizer for pulverization. The pulverizer screen has a mesh size of 12 to obtain powder raw materials. Then, weigh each powder raw material according to the weight in Table 1 of Example 1 and put it into a horizontal ribbon mixer for mixing. The mixing time is 5 minutes. The power of the horizontal ribbon mixer is 40KW and the speed is 30rpm.

[0015] Step S2: The mixed raw materials prepared in step S1 are fed into a ring die granulator. They are conditioned by steam at a temperature of 80°C for 1 minute and a steam pressure of 0.3 MPa. After conditioning, they are fed into the granulation chamber and granulated at 85°C. The membrane pore diameter of the ring die granulator is 4 mm. Step S3: The pellets prepared in step S2 are fed into a freeze dryer at a freezing temperature of -40℃ for 5 hours. Then, a low-temperature vacuum is applied, with the preset vacuum level reaching 30 Pa within 1 hour. Once the preset vacuum level is reached, heating is turned on at a heating plate heating rate of 4℃ / min, a drying temperature of 5℃, and a drying time of 14 hours. When the drying temperature reaches 10℃, the ultrasonic vibration device is turned on at a frequency of 20kHz, an amplitude of 20μm, and a duration of 30 minutes. After ultrasonic vibration is completed, the ultrasonic vibration is turned off, and sublimation drying continues. After freeze-drying, the pellets are fed into a pellet crusher for crushing to obtain feed pellets with a particle size of approximately 2.5 mm. Step S4: The crushed material is screened through a double-layer vibrating screen, where the upper screen has a mesh size of 6 mesh and the lower screen has a mesh size of 10 mesh. After screening, intermediate-sized feed pellets SK2, which are between 6 mesh and 10 mesh, are obtained.

[0016] Comparative Example 1 Step S3 does not involve vacuum freeze-drying or ultrasonic processing; other processes and parameters are the same as in Example 1. Pellet feed DK1 is prepared using the following specific process: Step S1: Take corn alcohol residue, fermented sugar residue, chili meal, soybean meal (43%, 46%), and hydrolyzed feather meal and put them into a pulverizer for pulverization. The pulverizer screen has a mesh size of 12 to obtain powder raw materials. Then, weigh each powder raw material according to the weight in Table 1 of Example 1 and put it into a horizontal ribbon mixer for mixing. The mixing time is 8 minutes. The power of the horizontal ribbon mixer is 35KW and the speed is 30rpm. Step S2: The mixed raw materials prepared in step S1 are fed into a ring die granulator. They are conditioned by steam at a temperature of 80°C for 1 minute and a steam pressure of 0.5 MPa. After conditioning, they are fed into the granulation chamber and granulated at 85°C. The membrane pore diameter of the ring die granulator is 4 mm. Step S3: The pellets prepared in step S2 are fed into a pellet crusher for crushing to obtain feed pellets with a particle size of approximately 2.5 mm. Step S4: The crushed material is screened through a double-layer vibrating screen, where the upper screen has a mesh size of 6 mesh and the lower screen has a mesh size of 10 mesh, and intermediate-sized feed pellets DK1 with a mesh size between 6 mesh and 10 mesh are obtained after screening.

[0017] Comparative Example 2 Step S3 does not involve vacuum freeze-drying; other processes and parameters are the same as in Example 1, yielding pelleted feed DK2. The specific process is as follows: Step S1: Take corn alcohol residue, fermented sugar residue, chili meal, soybean meal (43%, 46%), and hydrolyzed feather meal and put them into a pulverizer for pulverization. The pulverizer screen has a mesh size of 12 to obtain powder raw materials. Then, weigh each powder raw material according to the weight in Table 1 of Example 1 and put it into a horizontal ribbon mixer for mixing. The mixing time is 8 minutes. The power of the horizontal ribbon mixer is 35KW and the speed is 30rpm. Step S2: The mixed raw materials prepared in step S1 are fed into a ring die granulator. They are conditioned by steam at a temperature of 80°C for 1 minute and a steam pressure of 0.5 MPa. After conditioning, they are fed into the granulation chamber and granulated at 85°C. The membrane pore diameter of the ring die granulator is 4 mm. Step S3: The pellets prepared in step S2 are fed into an ultrasonic vibration device with an ultrasonic vibration frequency of 30kHz, an ultrasonic amplitude of 30μm, and an ultrasonic vibration time of 25min. After ultrasonication, the pellets are fed into a pellet crusher for crushing to obtain feed pellets with a particle size of approximately 2.5mm. Step S4: The crushed material is screened through a double-layer vibrating screen, where the upper screen has a mesh size of 6 mesh and the lower screen has a mesh size of 10 mesh. After screening, intermediate-sized feed pellets DK2, which are between 6 mesh and 10 mesh, are obtained.

[0018] Comparative Example 3 Step S3 does not involve ultrasonic processing; other processes and parameters are the same as in Example 1, resulting in pelleted feed DK3. The specific process is as follows: Step S1: Take corn alcohol residue, fermented sugar residue, chili meal, soybean meal (43%, 46%), and hydrolyzed feather meal and put them into a pulverizer for pulverization. The pulverizer screen has a mesh size of 12 to obtain powder raw materials. Then, weigh each powder raw material according to the weight in Table 1 of Example 1 and put it into a horizontal ribbon mixer for mixing. The mixing time is 8 minutes. The power of the horizontal ribbon mixer is 35KW and the speed is 30rpm. Step S2: The mixed raw materials prepared in step S1 are fed into a ring die granulator. They are conditioned by steam at a temperature of 80°C for 1 minute and a steam pressure of 0.5 MPa. After conditioning, they are fed into the granulation chamber and granulated at 85°C. The membrane pore diameter of the ring die granulator is 4 mm. Step S3: The pellets prepared in step S2 are fed into a freeze dryer at a freezing temperature of -50℃ for 3 hours. Then, a low-temperature vacuum is applied, with the vacuum level set to reach 30 Pa within 1 hour. Once the vacuum level reaches the set value, heating is turned on at a heating plate heating rate of 3℃ / min, a drying temperature of 10℃, and a drying time of 18 hours. After freeze-drying, the pellets are fed into a pellet crusher for crushing to obtain feed pellets with a particle size of approximately 2.5 mm. Step S4: The crushed material is screened through a double-layer vibrating screen, where the upper screen has a mesh size of 6 mesh and the lower screen has a mesh size of 10 mesh, and intermediate-sized feed pellets DK3 with a mesh size between 6 mesh and 10 mesh are obtained after screening.

[0019] Comparative Example 4 Step S4 is omitted. Other processes and parameters are the same as in Example 1, resulting in pelleted feed DK4. The specific process is as follows: Step S1: Take corn alcohol residue, fermented sugar residue, chili meal, soybean meal (43%, 46%), and hydrolyzed feather meal and put them into a pulverizer for pulverization. The pulverizer screen has a mesh size of 12 to obtain powder raw materials. Then, weigh each powder raw material according to the weight in Table 1 of Example 1 and put it into a horizontal ribbon mixer for mixing. The mixing time is 8 minutes. The power of the horizontal ribbon mixer is 35KW and the speed is 30rpm.

[0020] Step S2: The mixed raw materials prepared in step S1 are fed into a ring die granulator. They are conditioned by steam at a temperature of 80°C for 1 minute and a steam pressure of 0.5 MPa. After conditioning, they are fed into the granulation chamber and granulated at 85°C. The membrane pore diameter of the ring die granulator is 4 mm. Step S3: The pellets prepared in step S2 are fed into a freeze dryer at a freezing temperature of -50℃ for 3 hours. Then, a low-temperature vacuum is applied, with the preset vacuum level reaching 30 Pa within 1 hour. Once the preset vacuum level is reached, heating is turned on at a heating plate heating rate of 3℃ / min, a drying temperature of 10℃, and a drying time of 18 hours. When the drying temperature reaches 10℃, an ultrasonic vibration device is activated at a frequency of 30kHz, an amplitude of 30μm, and a duration of 25 minutes. After ultrasonic vibration is completed, the ultrasonic vibration is turned off, and sublimation drying continues. After freeze-drying, the pellets are fed into a pellet crusher for crushing to obtain feed pellets DK4 with a particle size of 2.5 mm. Comparative Example 5 Without the vacuum freeze-drying, ultrasonication, and crushing processes in step S3, pellet feed DK5 is obtained. The specific process is as follows: Step S1: Take corn alcohol residue, fermented sugar residue, chili meal, soybean meal (43%, 46%), and hydrolyzed feather meal and put them into a pulverizer for pulverization. The pulverizer screen has a mesh size of 12 to obtain powder raw materials. Then, weigh each powder raw material according to the weight in Table 1 of Example 1 and put it into a horizontal ribbon mixer for mixing. The mixing time is 8 minutes. The power of the horizontal ribbon mixer is 35KW and the speed is 30rpm.

[0021] Step S2: The mixed raw materials prepared in step S1 are fed into a ring die granulator. They are conditioned by steam at a temperature of 80°C for 1 minute and a steam pressure of 0.5 MPa. After conditioning, they are fed into the granulation chamber and granulated at 85°C. The membrane pore diameter of the ring die granulator is 2.5 mm. Step S3: The pelleted feed pellets are sieved through a double-layer vibrating screen, where the upper screen has a mesh size of 6 mesh and the lower screen has a mesh size of 10 mesh. After sieving, intermediate-sized feed pellets DK5, which are between 6 mesh and 10 mesh, are obtained.

[0022] Comparative Example 6 Step S3 does not involve crushing; the specific process is as follows: Step S1: Take corn alcohol residue, fermented sugar residue, chili meal, soybean meal (43%, 46%), and hydrolyzed feather meal and put them into a pulverizer for pulverization. The pulverizer screen has a mesh size of 12 to obtain powder raw materials. Then, weigh each powder raw material according to the weight in Table 1 of Example 1 and put it into a horizontal ribbon mixer for mixing. The mixing time is 8 minutes. The power of the horizontal ribbon mixer is 35KW and the speed is 30rpm. Step S2: The mixed raw materials prepared in step S1 are fed into a ring die granulator. They are conditioned by steam at a temperature of 80°C for 1 minute and a steam pressure of 0.5 MPa. After conditioning, they are fed into the granulation chamber and granulated at 85°C. The membrane pore diameter of the ring die granulator is 2.5 mm. Step S3: The granules prepared in step S2 are fed into a freeze dryer at a freezing temperature of -50℃ for 3 hours. Then, a low-temperature vacuum is applied, with the preset vacuum level reaching 30 Pa within 1 hour. Once the preset vacuum level is reached, heating is started at a heating plate temperature rise rate of 3℃ / min, a drying temperature of 10℃, and a drying time of 18 hours. When the drying temperature reaches 10℃, the ultrasonic vibration device is activated at a frequency of 30kHz, an amplitude of 30μm, and a duration of 25 minutes. After ultrasonication is completed, the ultrasonic vibration is turned off, and sublimation drying continues. Step S4: The material prepared in step S3 is screened through a double-layer vibrating screen, wherein the upper screen has a mesh size of 6 mesh and the lower screen has a mesh size of 10 mesh, and intermediate-sized feed pellets DK6 with a mesh size between 6 mesh and 10 mesh are obtained after screening.

[0023] Comparative Example 7 Steps S3 and S4 are omitted. The specific process is as follows: Step S1: Take corn alcohol residue, fermented sugar residue, chili meal, soybean meal (43%, 46%), and hydrolyzed feather meal and put them into a pulverizer for pulverization. The pulverizer screen has a mesh size of 12 to obtain powder raw materials. Then, weigh each powder raw material according to the weight in Table 1 of Example 1 and put it into a horizontal ribbon mixer for mixing. The mixing time is 8 minutes. The power of the horizontal ribbon mixer is 35KW and the speed is 30rpm. Step S2: The mixed raw materials prepared in step S1 are fed into a ring die pellet mill. They are conditioned by steam at a temperature of 80°C for 1 minute and a steam pressure of 0.5 MPa. After conditioning, they are fed into the pelleting chamber and pelleted at 85°C. The diameter of the membrane pores of the ring die pellet mill is 2.5 mm. After pelleting, feed pellets DK7 are obtained.

[0024] Test case Test treatment 1350 healthy 25-week-old Hy-Line Brown laying hens with similar weight and production performance were randomly divided into 9 treatment groups, with 5 replicates per group and 30 hens per treatment group. The experiment lasted for 10 weeks, including a 2-week pre-trial period and an 8-week formal trial period. 30 wt% of the pelleted concentrate prepared in Examples 1-2 and Comparative Examples 1-7 were mixed with 70 wt% corn to form a complete diet. The feeding period was 8 weeks, with free access to feed. Specifically, Example 1 was fed a complete diet prepared by mixing 30 wt% of feed pellets SK1 prepared in Example 1 with 70 wt% corn; Example 2 was fed a complete diet prepared by mixing 30 wt% of feed pellets SK2 prepared in Example 2 with 70 wt% corn; and Examples 3-9 were fed a complete diet prepared by mixing 30 wt% of feed pellets prepared in Comparative Examples 1-7 with 70 wt% corn. The specific feeding details for each experimental group are shown in Table 2.

[0025] Table 2 shows the specific total diet feeding details for each experimental group.

[0026] Trial Management The experiment was conducted in a closed chicken house. Environmental parameters within the chicken house were regulated by an automatic control system: temperature was maintained within a suitable range of (18-22)℃; relative humidity was controlled at (55-65)%. A constant light regime was adopted, with 16 hours of light per day and a light intensity of 15-20 lux (lx). A continuous longitudinal ventilation system was used, with ventilation volume adjusted according to the season and temperature to ensure fresh air and ammonia concentration below 10 ppm. Treatment groups were randomly assigned within the chicken house to eliminate potential environmental differences due to location. Free access to feed was provided. Chickens were fed twice daily at set times, ensuring the feed troughs were always full. All chickens had free access to clean, fresh tap water via nipple drinkers.

[0027] Test Records Feed intake record: During the trial period, clean the feed troughs once a day and record the amount of feed fed and the amount of leftover feed, and calculate the feed intake; count the number of qualified eggs (excluding broken eggs and soft-shelled eggs) in the laying boxes and on the ground at a fixed time every day. Accurately record the number of laying hens in stock on that day.

[0028] Daily egg production (grams / hen / day) = (Total egg weight ÷ Number of laying hens) Egg production rate (%) = (Total eggs produced that day ÷ Number of laying hens) × 100% Average egg weight: Using an electronic balance with an accuracy of 0.1 grams, a fixed proportion of eggs are weighed daily to calculate: Average egg weight (grams) = Total egg weight ÷ Total number of eggs.

[0029] Feed-to-egg ratio = Total feed consumption ÷ Total egg weight.

[0030] Eggshell strength: Use an eggshell strength tester. Place the egg horizontally on the instrument and apply pressure to the equator (widest part) of the egg with the probe until the shell cracks. The instrument automatically records the maximum pressure value.

[0031] Eggshell thickness: Eggshell thickness was measured at the blunt end, middle, and tip of the eggshell using a micrometer (accurate to 0.001 mm). The average value was then taken.

[0032] Haugh units: First, weigh the fresh egg (W). Then, break the egg and pour it onto a flat glass plate, measuring the height of the concentrated albumen (H). Finally, calculate using the following formula: Haugh unit = 100 × log(H + 7.57 - 1.7 × W^0.37) H = height of concentrated albumen (mm), W = weight of egg (g).

[0033] The feed intake and egg production performance of Hy-Line Brown chickens in experimental groups 1-9 are shown in Table 3. Table 3 shows the feed intake and egg production performance of Hy-Line Brown hens in experimental groups 1-9.

[0034] Table 3 shows that in experimental groups 1-2, which used 30 wt% of feed pellets prepared in Examples 1-2 plus 70 wt% corn as a total diet, the feed intake, egg production, egg production rate, average egg weight, eggshell strength and thickness, and Haugh unit were significantly higher than in experimental groups 3-9, while the feed conversion ratio was lower. The Haugh unit was greater than 85, meeting the standard for premium eggs. The above experimental data verify that the present invention, through freeze-drying and ultrasonic treatment of the pelleted feed after pelleting, can increase the porosity of the feed, improve its palatability, and improve its hardness, thereby stimulating the secretion of gastric acid and protease digestive juices, and improving the digestibility and absorption rate of minerals such as calcium and phosphorus, thus increasing the feed intake and egg production of laying hens. The high porosity of the feed allows for more thorough contact with digestive enzymes, improving feed digestibility. Vacuum freeze-drying followed by ultrasonic crushing of the pellets results in a more uniform physical morphology of the concentrated pellets. Combined with ring die pelleting and screening within a specific particle size range, this further enhances particle size uniformity, eliminates particle size differences, reduces feed grading, and prevents uneven nutrition caused by heavy components settling at the bottom of the feed trough. This ensures each chicken receives sufficient calcium, increasing egg production and quality, and consequently significantly improving egg production, average egg weight, eggshell strength, eggshell thickness, and Haugh unit.

[0035] Therefore, those skilled in the art will recognize that although embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Therefore, the scope of the present invention should be understood and recognized as covering all such other variations or modifications.

Claims

1. A method for preparing pelleted and concentrated feed for poultry, characterized in that, Includes the following steps: Step S1: Weigh each raw material and crush it, then mix the crushed materials thoroughly. Step S2: The uniformly mixed material is fed into a granulator and conditioned by steam. After conditioning, it is granulated. The conditioning temperature is 80-90℃ and the granulation temperature is 80-90℃. Step S3: The granules prepared in step S2 are subjected to vacuum freeze-drying and ultrasonic treatment, and then the granules are fed into a granulator for crushing. Step S4: The material crushed in step S3 is screened through a double-layer vibrating screen, where the upper screen has a mesh size of 6 mesh and the lower screen has a mesh size of 10 mesh, and intermediate-sized pellet feed with a mesh size between 6 mesh and 10 mesh is obtained after screening.

2. The method for preparing poultry pelleted concentrate as described in claim 1, characterized in that, In step S3, the freezing temperature for vacuum freeze drying is -50 to -40°C, the freezing time is 3 to 5 hours, the heating and drying temperature is -20 to 10°C, and the drying time is 10 to 18 hours.

3. The method for preparing poultry pelleted concentrate as described in claim 1, characterized in that, In step S3, the vacuum degree of vacuum freeze drying is 30-40 Pa within 1 hour, and the heating rate is 3-5 °C / min.

4. The method for preparing poultry pelleted concentrate as described in claim 1, characterized in that, In step S3, the ultrasonic vibration frequency is 20–30 kHz; the ultrasonic amplitude is 20–30 μm; and the ultrasonic vibration time is 20–30 min.

5. The method for preparing poultry pelleted concentrate as described in claim 1, characterized in that, The mixing time in step S1 is 5 to 20 minutes.

6. The method for preparing poultry pelleted concentrate as described in claim 1, characterized in that, In step S2, the conditioning temperature is 80℃ and the steam pressure is 0.3~0.5 MPa.

7. The method for preparing poultry pelleted concentrate as described in claim 1, characterized in that, The granulation temperature in step S2 is 85℃.

8. The method for preparing poultry pelleted concentrate as described in claim 1, characterized in that, In step S2, a ring die granulator is used for granulation. The diameter of the membrane pores in the ring die granulator is 3-5 mm.

9. The method for preparing poultry pelleted concentrate as described in claim 1, characterized in that, In step S4, the oversized particles separated by the upper screen are returned to the crusher for further crushing, while the overly fine powder separated by the lower screen is returned to the granulator for regranulation.

10. A poultry pelleted concentrate prepared by the preparation method described in claims 1-9.

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