Intelligent device combined selenium-rich egg chicken precise breeding method

Abstract

This invention relates to the fields of agricultural biotechnology and precision animal breeding, specifically a method for precision breeding of selenium-enriched laying hens using intelligent equipment. It includes intelligent environmental control, dynamic feeding of selenium-enriched antibiotic-free diets, and high-temperature aerobic fermentation of selenium-containing chicken manure. The method maintains suitable temperature, humidity, and ammonia concentration in the chicken house through intelligent control, dynamically feeds a diet containing selenium-enriched microcapsule probiotics according to the egg production curve, and converts the excreted selenium-containing chicken manure, after adjusting the carbon-nitrogen ratio, into humic acid organic fertilizer through inoculation with a compound fermentation agent. Its core is the enrichment of selenium through Bacillus fermentation and cross-linking with sodium alginate to produce selenium-enriched microcapsule probiotic powder, achieving safe and stable delivery of organic selenium. This invention solves the problems of traditional inorganic selenium easily causing oxidative stress in laying hens and antibiotic dependence damaging the intestinal flora. While improving the bioconversion rate of selenium and ensuring the health of laying hens, it effectively avoids environmental pollution caused by direct discharge of selenium-enriched chicken manure, achieving resource recycling.

Description

Technical Field

[0001] This invention relates to the fields of agricultural biotechnology and precision animal breeding, specifically a method for precision breeding of selenium-enriched laying hens using intelligent equipment. Background Technology

[0002] The existing selenium-enriched egg production and laying hen farming systems face the following technical challenges: Traditional processes often involve directly adding inorganic selenium to the diet; however, the absorption of inorganic selenium in the poultry gut is primarily through passive diffusion, resulting in low conversion rates and a safety threshold limited to a specific concentration range. Excessive accumulation can trigger oxidative stress and liver and kidney damage, leading to selenium poisoning in laying hens; conventional high-density farming environments can easily induce immune stress in laying hens, causing damage to the intestinal barrier. Traditional methods rely excessively on antibiotics, resulting in antibiotic residues in eggs and disrupting the gut microbiota, further reducing the bioavailability of trace elements; the lack of dynamic nutritional regulation based on animal physiological stages and environmental stress states leads to significant selenium excretion; and the direct discharge of high-concentration selenium-enriched chicken manure without scientific carbon-nitrogen ratio adjustment and microbial degradation will cause eutrophication of soil and water bodies and heavy metal pollution. Summary of the Invention

[0003] The purpose of this invention is to provide a method for precise breeding of selenium-enriched laying hens using intelligent devices. This method aims to solve the problems of low conversion rates and stress in laying hens caused by direct addition of inorganic selenium in existing technologies, the overuse of antibiotics in conventional farming which disrupts the gut microbiota, and the lack of dynamic nutritional regulation leading to direct discharge of selenium-enriched chicken manure that pollutes the environment. Specifically, the technical solution of this invention is as follows: A method for precise breeding of selenium-enriched laying hens using smart devices, which includes: The monitoring array, consisting of temperature and humidity sensors and ammonia concentration sensors, acquires real-time environmental data inside the chicken house and transmits the environmental data to a central microprocessor. The central microprocessor sends feedback control commands to the ventilation actuator and temperature control equipment according to preset environmental thresholds to maintain the set temperature, relative humidity and ammonia concentration parameters. The selenium-enriched antibiotic-free diet fed to laying hens comprises a basal diet, compound organic acids, plant extracts, and selenium-enriched microcapsule probiotic powder attached to the surface of pelleted feed made by mixing the basal diet, the compound organic acids, and the plant extracts; the selenium-enriched antibiotic-free diet does not contain any antibiotic chemical drug components; the selenium-enriched microcapsule probiotic powder contains selenium-enriched cells of Bacillus amyloliquefaciens and Bacillus belyceae, and the effective organic selenium concentration in the selenium-enriched antibiotic-free diet is 0.25-0.35 mg / kg; The method also includes a selenium-containing chicken manure fermentation step: collecting the selenium-containing chicken manure excreted by the laying hens, adjusting the moisture content and carbon-nitrogen ratio, and then inoculating it with a compound fermentation agent for aerobic fermentation to convert it into selenium-rich humic acid organic fertilizer.

[0004] Preferably, the plant extract comprises astragalus polysaccharide and oregano essential oil, and the mass ratio of astragalus polysaccharide to oregano essential oil is 3:1.

[0005] Preferably, the selenium-enriched antibiotic-free diet is obtained through the following preparation steps: S1. Inoculate Bacillus amyloliquefaciens and Bacillus belye into liquid culture medium. Control the stirring speed of the fermenter at 150-250 rpm and the dissolved oxygen at 20-30%. Use a constant-rate feeding method to add sodium selenite solution with a concentration of 5-10 mg / mL at a feeding rate of 0.5-2.0 mL / h for fermentation. Control the total selenium concentration in the fermentation broth to gradually increase to 15-25 μg / mL. Ferment for 48-72 h to obtain the first fermentation system. Then, centrifuge the first fermentation system, collect the selenium-enriched cells, and wash them with sterile physiological saline to obtain the washed selenium-enriched cells. S2. The washed selenium-enriched bacterial cells are suspended in sterile physiological saline to obtain a selenium-enriched bacterial cell suspension. The selenium-enriched bacterial cell suspension is mixed with a 2% sodium alginate solution at a mass ratio of 1:3, and dropped into a curing bath for a cross-linking reaction for 30 minutes. After filtration and collection, and pre-freezing, the mixture is freeze-dried to obtain selenium-enriched microcapsule probiotic powder. The curing bath contains 0.1 mol / L calcium chloride and 0.5% chitosan. S3. The basal diet, the compound organic acid and the plant extract are mixed and then granulated at low temperature, with the granulation temperature controlled to be less than 65°C, to obtain pelleted feed; then the selenium-enriched microcapsule probiotic powder is dispersed in oil at the set target organic selenium concentration to obtain a suspension, and the suspension is attached to the surface of the pelleted feed by a post-spraying process to obtain the selenium-enriched antibiotic-free diet.

[0006] Preferably, the compound organic acid is a microencapsulated compound organic acid; and / or, the basal diet is a corn-soybean meal basal diet.

[0007] Preferably, the number of live bacteria in the selenium-enriched microcapsule probiotic powder is not less than 1.0 × 10⁻⁶. 10 CFU / g, and the proportion of organic selenium is not less than 85% by weight.

[0008] Preferably, the compound fermentation agent comprises thermophilic laterosporium and Bacillus subtilis, and the compound fermentation agent is prepared by the following steps: thermophilic laterosporium and Bacillus subtilis are activated and cultured at 30-37°C for 24-48 hours, and then mixed at a live cell ratio of 1:1-2:1 to obtain the compound fermentation agent.

[0009] Preferably, in the selenium-containing chicken manure fermentation step, the inoculation amount of the compound fermentation agent is 0.1-0.3% of the total weight of the fermentation substrate, and the fermentation substrate includes the selenium-containing chicken manure and materials for adjusting the carbon-nitrogen ratio.

[0010] Preferably, when the laying hens are at their peak egg production period of 25-40 weeks of age, the daily feeding frequency of the selenium-enriched antibiotic-free diet is adjusted to 4 times; and / or, when the laying hens are in the molting period or in the high-temperature stress period with an ambient temperature higher than 30°C, compound vitamins and electrolytes are added to the drinking water.

[0011] Preferably, in step S2, the mixture of the selenium-enriched bacterial suspension and the sodium alginate solution with a concentration of 2% by weight is dripped into the curing bath using a high-pressure microcapsule granulation device.

[0012] The beneficial effects of this invention are as follows: This invention constructs a microcapsule structure containing a polyelectrolyte composite wall through a cross-linking reaction of sodium alginate and calcium chloride. This physical barrier significantly reduces the degradation and inactivation of selenium-enriched bacteria by the external simulated gastric acid environment, ensuring that the selenium-enriched microcapsule probiotic powder maintains a set concentration of live bacteria after entering a specific intestinal segment, thereby achieving safe and stable delivery and colonization of organic selenium. This invention maintains suitable temperature, humidity, and ammonia concentration in the chicken house by combining an automated control system with an antibiotic-free diet containing selenium-enriched microcapsule probiotic powder of Bacillus amyloliquefaciens and Bacillus belye. This improves the bioconversion rate of selenium and effectively avoids the oxidative stress problems that are easily caused by traditional inorganic selenium. At the same time, the selenium-containing chicken manure excreted is inoculated with a compound fermentation agent and converted into humic acid organic fertilizer, avoiding environmental pollution caused by direct discharge and realizing the scientific recycling of agricultural resources. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Figure 1 This is a bar chart comparing the number of days of peak egg production in each embodiment and the comparative example of the present invention; Detailed Implementation

[0014] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Example 1: One thousand 18-week-old Hy-Line Brown laying hens were selected and pre-fed for 7 days before the trial began, which lasted for 20 weeks. S1. Preparation of Selenium-Enriched Bacterial Cells: Commercial standard strains of *Bacillus amyloliquefaciens* and *Bacillus belyssus* were used. Liquid culture media were prepared per liter of culture medium as follows: glucose 20g, peptone 15g, yeast extract 10g, dipotassium hydrogen phosphate 1.5g, magnesium sulfate 0.5g, with the remainder being deionized water. The initial pH was adjusted to 7.0. After activating *Bacillus amyloliquefaciens* and *Bacillus belyssus* separately, they were mixed at a 1:1 volume ratio and inoculated into the culture medium, with a total inoculum of 6% by volume. Fermentation was carried out at 37℃, with a stirring speed of 200 rpm and dissolved oxygen at 25%. A sodium selenite solution was fed at a constant rate of 1.2 mL / h, with a concentration of 8 mg / mL, to gradually increase the total selenium concentration in the fermentation broth to 20 μg / mL. Fermentation continued for 60 h to obtain the first fermentation system. At this point, the Bacillus in the fermentation system was in the late logarithmic growth phase, accumulating the target concentration of intracellular organic selenium and active metabolites, providing a highly active selenium-enriched bacterial source for subsequent microencapsulation. The first fermentation system was centrifuged at 6000 rpm for 10 min, and the bacterial cells were collected and washed three times with sterile physiological saline to obtain washed selenium-enriched bacterial cells. Washing effectively removed impurities and unconverted free inorganic selenium from the fermentation broth, ensuring the purity and biosafety of the subsequent microencapsulation. S2. Preparation of selenium-enriched microcapsule probiotic powder: The washed selenium-enriched bacteria were added to sterile physiological saline to prepare a bacterial suspension with a solid content of 12% by weight. This suspension state ensured the uniform dispersion of bacteria in the sodium alginate matrix and avoided the adverse effects of bacterial aggregation on the encapsulation effect. The bacterial suspension was mixed with 2% by weight sodium alginate solution at a mass ratio of 1:3 and dripped into the curing bath using a high-pressure microcapsule granulation device. The curing bath contained 0.1 mol / L calcium chloride and 0.5 wt% chitosan, and cross-linking was performed for 30 min. A fixed combination of parameters—2 wt% sodium alginate solution, a 1:3 mass ratio with the bacterial suspension, 0.1 mol / L calcium chloride in the curing bath, 0.5 wt% chitosan, and a 30 min cross-linking time—encapsulated a dense polyelectrolyte composite wall with suitable mechanical strength, resulting in a microcapsule encapsulation rate exceeding 92%. In a simulated gastric acid environment, the number of viable bacteria was more than three orders of magnitude higher than that of unencapsulated free bacteria, ensuring the stability and bioavailability of the encapsulation structure. After filtration and collection of the microcapsules, they were pre-frozen at -40°C for 8 h, followed by freeze-drying for 24 h to obtain selenium-enriched microcapsule probiotic powder. The viable bacteria count of the obtained product was 1.3 × 10⁻⁶. 10 CFU / g, with organic selenium accounting for 89.4% by weight; S3. Preparation of selenium-enriched antibiotic-free diet: The basic diet adopts a corn-soybean meal formula; based on the total weight of the basic diet, 0.30% by weight of microencapsulated compound organic acid is added. This compound organic acid is a mixture of formic acid, acetic acid, propionic acid and lactic acid in a mass ratio of 2:1:1:1 as the core material, which can synergistically regulate the pH value of different sections of the intestine and exert synergistic antibacterial and digestive-promoting effects. It is prepared and encapsulated by spray condensation method using hydrogenated palm oil as the wall material. Simultaneously, 0.08% by weight of plant extract was added. The mass ratio of astragalus polysaccharide to oregano essential oil in the plant extract was 3:1. This fixed ratio of plant extract had a corresponding synergistic effect in anti-inflammatory and antioxidant aspects. After being mixed evenly, the mixture was granulated at low temperature, with the granulation temperature controlled at 62℃, to obtain pelleted feed. The pelleted feed had a compact structure and uniform internal nutrient distribution, providing a stable physical carrier for the subsequent attachment of selenium-enriched probiotics. The selenium-enriched microcapsule probiotic powder was dispersed in soybean oil according to the required selenium content to form a suspension, which was then sprayed onto the surface of the pelleted feed. The effective organic selenium concentration in the finished diet was controlled at 0.30 mg / kg, resulting in a selenium-enriched antibiotic-free diet. S4. Feeding and Management: Place the laying hens in a smart-controlled chicken house, maintaining a temperature of 23℃, relative humidity of 55%, light duration of 16h / d, and ammonia concentration at 8ppm. The smart feeding system feeds according to the laying rate curve. The specific control logic is as follows: monitor the daily laying rate of the flock in real time. When the laying rate is below 85%, set the basic feeding amount to 110g / bird / day, divided into 3 equal feedings per day. When the laying rate reaches 85% to 90%, increase the feeding amount to 115g / bird / day, divided into 3 equal feedings per day. When the laying rate exceeds 90%, increase the feeding amount to 120g / bird / day, and during the peak laying period from 25 to 40 weeks of age, adjust the feeding from 3 times a day to 4 times a day. During molting warnings or when the ambient temperature is above 30℃, supplement the drinking water with compound vitamins and electrolytes at 0.05% by weight. S5. Selenium-enriched chicken manure fermentation treatment: Collect chicken manure daily, add straw powder to adjust the carbon-nitrogen ratio to 28:1, and adjust the moisture content to 58%; inoculate with a compound fermentation agent at 0.2% by weight of the total fermentation substrate; the compound fermentation agent is composed of thermophilic laterospora and Bacillus subtilis, mixed at a live bacteria ratio of 1.5:1; carry out aerobic fermentation for 18 days under forced ventilation and an ambient temperature higher than 30℃, with the fermentation temperature controlled at 60℃, to obtain selenium-enriched humic acid organic fertilizer.

[0015] Example 2: 1000 Hy-Line Brown laying hens aged 18 weeks were selected. The experimental conditions were the same as in Example 1, except that the parameters of each step were as follows. S1. The fermentation stirring speed was 150 rpm, the dissolved oxygen was 20%, the sodium selenite solution concentration was 5 mg / mL, the feeding rate was 0.5 mL / h, the total selenium concentration was increased to 15 μg / mL, and the fermentation was carried out for 48 h to obtain the first fermentation system; after centrifugation and washing, the washed selenium-enriched cells were obtained. S2, the solid content of the bacterial suspension was 10% by weight; the live bacteria count of the obtained selenium-enriched microcapsule probiotic powder was 1.1 × 10⁻⁶. 10 CFU / g, with an organic selenium content of 86.8% by weight; using the same fixed microencapsulation parameters as in Example 1, a high encapsulation rate was also obtained, and the survival rate of live bacteria in a simulated gastric acid environment was significantly improved; S3, with 0.25% by weight of microencapsulated compound organic acid and 0.06% by weight of plant extract, and a pelleting temperature of 60℃, yields a pelleted feed with a compact structure and uniform nutrient distribution. The effective organic selenium concentration in the finished diet is controlled at 0.25 mg / kg. S4. The temperature in the chicken house is 21℃, the relative humidity is 50%, and the ammonia concentration is controlled at 9ppm. S5. The carbon-nitrogen ratio of the chicken manure fermentation substrate is adjusted to 25:1, the moisture content is 55%, the inoculum amount of the compound fermentation agent is 0.1% by weight, the fermentation time is 15 days, and the fermentation temperature is controlled at 55℃.

[0016] Example 3: 1000 Hy-Line Brown laying hens aged 18 weeks were selected. The experimental conditions were the same as in Example 1, except that the parameters of each step were as follows. S1. The fermentation stirring speed was 250 rpm, the dissolved oxygen was 30%, the sodium selenite solution concentration was 10 mg / mL, the feeding rate was 2.0 mL / h, the total selenium concentration was increased to 25 μg / mL, and the fermentation was carried out for 72 h to obtain the first fermentation system; after centrifugation and washing, the washed selenium-enriched cells were obtained. S2, the solid content of the bacterial suspension was 13% by weight; the live bacteria count of the obtained selenium-enriched microcapsule probiotic powder was 1.2 × 10⁻⁶. 10CFU / g, with an organic selenium content of 88.1% by weight; using the same fixed microencapsulation parameters as in Example 1, a high encapsulation rate was also obtained, and the survival rate of live bacteria in a simulated gastric acid environment was significantly improved; S3, with 0.35% by weight of microencapsulated compound organic acid and 0.10% by weight of plant extract, and a pelleting temperature of 64℃, yields a pelleted feed with a compact structure and uniform nutrient distribution. The effective organic selenium concentration in the finished diet is controlled at 0.35 mg / kg. S4. The chicken house temperature is 25℃, the relative humidity is 60%, and the ammonia concentration is controlled at 9.5ppm; S5. The carbon-nitrogen ratio of the chicken manure fermentation substrate is adjusted to 30:1, the moisture content is 60%, the inoculum amount of the compound fermentation agent is 0.3% by weight, the fermentation time is 20 days, and the fermentation temperature is controlled at 65℃.

[0017] Example 4: 1000 Hy-Line Brown laying hens aged 18 weeks were selected. The experimental conditions were the same as in Example 1, except that the parameters of each step were as follows. S1. The fermentation stirring speed was 180 rpm, the dissolved oxygen was 22%, the sodium selenite solution concentration was 7 mg / mL, the feeding rate was 1.5 mL / h, the total selenium concentration was increased to 18 μg / mL, and the fermentation time was 56 h. S2, the solid content of the bacterial suspension was 11% by weight; the live bacteria count of the obtained selenium-enriched microcapsule probiotic powder was 1.2 × 10⁻⁶. 10 CFU / g, with organic selenium accounting for 87.6% by weight; S3, the amount of microencapsulated compound organic acid added is 0.28% by weight, the amount of plant extract added is 0.08% by weight, the granulation temperature is 61℃, and the effective organic selenium concentration in the finished diet is controlled at 0.28mg / kg; S4. The temperature in the chicken house is 24℃, the relative humidity is 57%, and the ammonia concentration is controlled below 8ppm. S5. The carbon-nitrogen ratio of the chicken manure fermentation substrate is adjusted to 27:1, the moisture content is 57%, the inoculum amount of the compound fermentation agent is 0.2% by weight, the fermentation time is 17 days, and the fermentation temperature is controlled at 58℃.

[0018] Comparative Example 1: The difference between this comparative example and Example 1 is that the microencapsulation process in step S2 is omitted, and the washed selenium-enriched bacteria are directly freeze-dried to obtain selenium-enriched bacterial powder, which is added to the diet at the same selenium addition amount as in Example 1. Other operating steps and process parameters are exactly the same as in Example 1.

[0019] Comparative Example 2: The difference between this comparative example and Example 1 is that the granulation temperature in step S3 is replaced by 80°C instead of 62°C, while the other operating steps and process parameters are exactly the same as in Example 1.

[0020] Comparative Example 3: The difference between this comparative example and Example 1 is that the plant extract is omitted in step S3, while the other operating steps and process parameters are exactly the same as in Example 1.

[0021] Comparative Example 4: The difference between this comparative example and Example 1 is that the feeding frequency is not adjusted according to the egg production rate curve in step S4, and the same amount of feeding is maintained 3 times a day throughout the entire experiment. Other operating steps and process parameters are exactly the same as in Example 1.

[0022] Comparative Example 5: The difference between this comparative example and Example 1 is that the ammonia concentration in the chicken house is controlled at 20 ppm in step S4, and the temperature, humidity and light conditions are exactly the same as in Example 1. Other operating steps and process parameters are exactly the same as in Example 1.

[0023] Comparative Example 6: The difference between this comparative example and Example 1 is that straw powder is not added in step S5 to adjust the carbon-nitrogen ratio, and the carbon-nitrogen ratio of the fermentation substrate is maintained at 16:1. Other operating steps and process parameters are exactly the same as in Example 1.

[0024] Performance Testing and Datasheets The viable count of microencapsulated probiotic powder was determined by plate counting; the total selenium content and organic selenium ratio in eggs were determined by high performance liquid chromatography-inductively coupled plasma mass spectrometry; the glutathione peroxidase activity in the serum of laying hens was determined by a commercial reagent kit; the number of days of peak egg production was defined as the number of consecutive days with an egg production rate of not less than 90%; the survival rate was calculated based on the number of hens at the end of the experiment; and the humus content of organic fertilizer was determined by the potassium dichromate external heating method. Table 1 Comparison of performance test data between each embodiment and the comparative example.

[0025] Combination Figure 1 Comparing the test results of Example 1 and Comparative Example 1 in Table 1, it can be seen that after omitting the microencapsulation treatment, the number of viable bacteria, the total selenium content of eggs, the proportion of organic selenium in eggs, and the activity of serum glutathione peroxidase all decreased significantly. The underlying mechanism is that unencapsulated selenium-enriched bacteria are more easily inactivated in feed storage, pelleting friction, and gastric acid environment, resulting in a decrease in the number of viable bacteria entering the intestine, a weakening of the directional release and colonization of organic selenium in the bacteria, and a decrease in the absorption of organic selenium such as selenomethionine in the intestine, which in turn leads to the deposition of selenium in eggs and a decrease in the activity of antioxidant enzymes, and a corresponding shortening of the peak egg production period. As can be seen from the comparison of the test results of Example 1 and Comparative Example 2 in Table 1, after increasing the granulation temperature to 80℃, the number of viable bacteria, the total selenium content of eggs, the proportion of organic selenium in eggs, and the activity of serum glutathione peroxidase decreased. The underlying mechanism is that the higher granulation temperature will cause local shrinkage or rupture of the microcapsule wall material, and cause some Bacillus and associated metabolites to be inactivated. The heat load of the granules before the subsequent spraying will also weaken the adhesion stability of the feed surface. Therefore, the amount of effective selenium-enriched bacteria entering the digestive tract is reduced, and the bioavailability of selenium is reduced. As can be seen from the comparison of the test results of Example 1 and Comparative Example 3 in Table 1, after omitting the plant extract, the proportion of organic selenium in eggs, serum glutathione peroxidase activity, the duration of peak egg production, and the survival rate decreased. The underlying mechanism is that astragalus polysaccharide and oregano essential oil can reduce intestinal inflammatory response and inhibit the proliferation of harmful bacteria, which helps maintain the integrity of the intestinal mucosa without the use of antibiotics. After the absence of this component, the stability of the intestinal barrier decreased, the colonization rate of selenium-enriched probiotics in the intestine was significantly reduced, and the absorption efficiency of organic selenium and the body's antioxidant level were all affected. As can be seen from the comparison of the test results of Example 1 and Comparative Example 4 in Table 1, after not adjusting the feeding frequency according to the egg production rate curve, the total selenium content of eggs, the proportion of organic selenium in eggs, and the number of days of peak egg production decreased. The underlying mechanism is that during the peak egg production period, the demand of laying hens for energy, amino acids, and trace elements increases simultaneously. The fixed feeding method cannot cover the feeding rhythm during the peak period, resulting in insufficient intake of effective organic selenium per unit time, which leads to a decrease in selenium deposition in eggs and weakens the continuous egg production capacity. As can be seen from the comparison of the test results of Example 1 and Comparative Example 5 in Table 1, after increasing the ammonia concentration in the chicken house to 20 ppm, the total selenium content of eggs, the proportion of organic selenium in eggs, serum glutathione peroxidase activity, the duration of peak egg production, and the survival rate all decreased. The underlying mechanism is that higher ammonia concentrations stimulate the respiratory and intestinal mucosa, causing an enhanced stress response, increased antioxidant consumption by the body to maintain basic homeostasis, and abnormally increased intestinal barrier permeability, resulting in a decrease in selenium absorption and utilization efficiency. Therefore, selenium deposition and production performance are adversely affected. As can be seen from the comparison of the test results of Example 1 and Comparative Example 6 in Table 1, when the carbon-nitrogen ratio of the chicken manure fermentation substrate is not adjusted, the humus content of the organic fertilizer is lower than the corresponding value of Example 1, while no statistical difference is found in the front-end breeding indicators. The underlying mechanism is that when the carbon-nitrogen ratio is low, nitrogen volatilization and local anaerobic conditions are more likely to occur during the fermentation process, the microorganisms do not fully transform the organic matter, the degree of humification is reduced, and the stability of the combination of residual selenium and humus will also decrease. Therefore, the fermentation indicators of the back-end fertilizer do not meet the set standards. As can be seen from the test results of Examples 1 to 4 in Table 1, within the scope of the present invention, adjusting the fermentation intensity, dietary organic selenium level, environmental conditions and fermentation treatment parameters can achieve the desired selenium-enriched antibiotic-free breeding effect. Among them, the indicators of Example 1 are relatively balanced, indicating that there is a matching relationship between the total selenium concentration of fermentation, microcapsule protection strength, low temperature granulation conditions, dietary organic selenium level and chicken house environmental control parameters that meet the technical requirements.

[0026] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any conventional modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention shall still fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for precise breeding of selenium-enriched laying hens using intelligent equipment, characterized in that: The method includes: The monitoring array, consisting of temperature and humidity sensors and ammonia concentration sensors, acquires real-time environmental data inside the chicken house and transmits the environmental data to a central microprocessor. The central microprocessor sends feedback control commands to the ventilation actuator and temperature control equipment according to preset environmental thresholds to maintain the set temperature, relative humidity and ammonia concentration parameters. The selenium-enriched antibiotic-free diet fed to laying hens includes a basal diet, compound organic acids, plant extracts, and selenium-enriched microcapsule probiotic powder attached to the surface of the pelleted feed made by mixing the basal diet, the compound organic acids, and the plant extracts; the selenium-enriched antibiotic-free diet does not contain any antibiotic chemical drug components. The selenium-enriched microcapsule probiotic powder contains selenium-enriched cells of Bacillus amyloliquefaciens and Bacillus belyceae, and the effective organic selenium concentration in the selenium-enriched antibiotic-free diet is 0.25-0.35 mg / kg; the method also includes a selenium-enriched chicken manure fermentation step: collecting the selenium-enriched chicken manure excreted by the laying hens, adjusting the moisture content and carbon-nitrogen ratio, and then inoculating it with a compound fermentation agent for aerobic fermentation to convert it into selenium-enriched humic acid organic fertilizer.

2. The method according to claim 1, wherein, The plant extract contains astragalus polysaccharide and oregano essential oil, and the mass ratio of astragalus polysaccharide to oregano essential oil is 3:

1.

3. The method according to claim 1 or 2, wherein, The selenium-enriched antibiotic-free diet is obtained through the following preparation steps: S1. Inoculate Bacillus amyloliquefaciens and Bacillus belye into liquid culture medium. Control the stirring speed of the fermenter at 150-250 rpm and the dissolved oxygen at 20-30%. Use a constant-rate feeding method to add sodium selenite solution with a concentration of 5-10 mg / mL at a feeding rate of 0.5-2.0 mL / h for fermentation. Control the total selenium concentration in the fermentation broth to gradually increase to 15-25 μg / mL. Ferment for 48-72 h to obtain the first fermentation system. Then, centrifuge the first fermentation system, collect the selenium-enriched cells, and wash them with sterile physiological saline to obtain the washed selenium-enriched cells. S2. The washed selenium-enriched bacterial cells are suspended in sterile physiological saline to obtain a selenium-enriched bacterial cell suspension. The selenium-enriched bacterial cell suspension is mixed with a 2% sodium alginate solution at a mass ratio of 1:3, and dropped into a curing bath for a cross-linking reaction for 30 minutes. After filtration and collection, and pre-freezing, the mixture is freeze-dried to obtain selenium-enriched microcapsule probiotic powder. The curing bath contains 0.1 mol / L calcium chloride and 0.5% chitosan. S3. The basal diet, the compound organic acid and the plant extract are mixed and then granulated at low temperature, with the granulation temperature controlled to be less than 65°C, to obtain pelleted feed; then the selenium-enriched microcapsule probiotic powder is dispersed in oil at the set target organic selenium concentration to obtain a suspension, and the suspension is attached to the surface of the pelleted feed by a post-spraying process to obtain the selenium-enriched antibiotic-free diet.

4. The method according to any one of claims 1 to 3, wherein, The compound organic acid is a microencapsulated compound organic acid; and / or, the basal diet is a corn-soybean meal basal diet.

5. The method according to claim 1, wherein, The selenium-enriched microcapsule probiotic powder contains no less than 1.0 × 10⁻⁶ live bacteria. 10 CFU / g, and the proportion of organic selenium is not less than 85% by weight.

6. The method according to claim 1, wherein, The compound fermentation agent contains thermophilic laterosporium and Bacillus subtilis. The compound fermentation agent is prepared by the following steps: thermophilic laterosporium and Bacillus subtilis are activated and cultured at 30-37℃ for 24-48 hours, and then mixed at a live cell ratio of 1:1-2:1 to obtain the compound fermentation agent.

7. The method according to claim 1, wherein, In the selenium-containing chicken manure fermentation step, the inoculation amount of the compound fermentation agent is 0.1-0.3% of the total weight of the fermentation substrate, and the fermentation substrate includes the selenium-containing chicken manure and materials used to adjust the carbon-nitrogen ratio.

8. The method according to claim 1, wherein, When the laying hens are at their peak egg production period of 25-40 weeks of age, the daily feeding frequency of the selenium-enriched antibiotic-free diet should be adjusted to 4 times; and / or, when the laying hens are in molting period or in a period of high temperature stress with an ambient temperature higher than 30°C, compound vitamins and electrolytes should be added to the drinking water.

9. The method according to claim 3, wherein, In step S2, the mixture of the selenium-enriched bacterial suspension and the sodium alginate solution with a concentration of 2% by weight is dripped into the curing bath using a high-pressure microcapsule granulation device.

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