Compound nutrient feed suitable for growth and development of Yili horses in alpine regions

Abstract

This invention relates to the field of animal feed technology and discloses a compound nutritional feed suitable for the growth and development of Ili horses in high-altitude and cold regions. The feed comprises 88-92 parts roughage and 8-12 parts solid-dispersed microspheres. The solid-dispersed microspheres are made of hydrogenated palm oil, calcium propionate, anhydrous citric acid, and lysophosphatidylcholine, and have a lipid crystalline network structure. In an aqueous environment, the lysophosphatidylcholine within the microspheres establishes hydration channels, promoting water penetration and triggering an in-situ acid-base metathesis reaction between calcium propionate and anhydrous citric acid. The resulting liquid free propionic acid causes a sharp drop in the local melting point of the microspheres, leading to the disintegration of the macroscopic structure. This invention can simultaneously release free propionic acid and hydrogenated palm oil, providing energy through gluconeogenesis and intestinal enzymatic hydrolysis, respectively, achieving a dual-effect synergistic energy supply from carbohydrates and lipids. This meets the energy metabolism needs of Ili horses in high-altitude and cold environments and exhibits good long-term storage stability.

Description

Technical Field

[0001] This invention relates to the field of animal feed technology, specifically to a compound nutritional feed suitable for the growth and development of Ili horses in high-altitude and cold regions. Background Technology

[0002] The Ili horse is mainly distributed in high-altitude and cold regions. Its growth, development, and daily activities require a significant amount of energy to maintain body temperature and basal metabolism. Current horse feed typically consists mainly of conventional hay and grains, supplemented with ordinary oils or energy additives. However, the energy release pattern of traditional feed in the digestive tract is relatively simple, making it difficult to meet the dual energy needs of horses in low-temperature environments, which require both immediate carbohydrates and long-lasting high-calorie lipids.

[0003] To improve energy efficiency, existing technologies include the direct addition of short-chain fatty acids and oils to feed. However, free short-chain fatty acids are volatile and prone to deterioration and degradation during feed processing and external storage. Meanwhile, conventional oils are susceptible to oxidative rancidity upon prolonged exposure to air, reducing the feed's shelf life. Currently available coated compound formulations mostly employ simple physical mixing or conventional surface coatings. These formulations lack a stable internal physical barrier structure, making the internal ingredients susceptible to moisture absorption or premature reaction due to environmental humidity, resulting in poor external storage stability. Furthermore, these conventional additives lack a targeted structural disintegration mechanism after entering the horse's digestive tract, often dissolving disorderly under the influence of digestive juices, failing to achieve the simultaneous release of carbohydrate precursors and lipid energy. This limits the digestibility and absorption of feed in horses, hindering its synergistic energy supply and making it difficult to fully meet the physiological and growth requirements of Ili horses in high-altitude, cold regions. Summary of the Invention

[0004] The technical problem solved by this invention is that the Yili horse in the high-altitude and cold region has a high energy demand during its growth and development. The release and conversion rate of energy substances in conventional feed is limited, making it difficult to quickly provide high-density energy. In addition, the liquid energy supplements directly added to the feed are easy to volatilize and oxidize, and the conventional solid fat has a long degradation and absorption cycle, resulting in a lag in the energy supply of the animal body.

[0005] To address the above problems, the present invention provides the following technical solution:

[0006] A compound nutritional feed suitable for the growth and development of Ili horses in high-altitude and cold regions comprises the following components in parts by weight:

[0007] 88-92 parts roughage;

[0008] 8-12 parts of solid dispersed microspheres;

[0009] The solid dispersion microspheres are made from raw materials comprising the following parts by weight:

[0010] 60-70 parts hydrogenated palm oil;

[0011] 15-20 parts of calcium propionate;

[0012] Anhydrous citric acid 10.3-13.7 parts;

[0013] 3-5 parts of lysophosphatidylcholine;

[0014] The solid dispersed microspheres have a lipid crystallization network structure, in which calcium propionate and anhydrous citric acid are doped.

[0015] By employing the above technical solution, and using hydrogenated palm oil as the continuous phase to construct a lipid crystallization network structure, calcium propionate, anhydrous citric acid, and lysophosphatidylcholine are embedded internally, forming a physical isolation system. Therefore, the feed achieves chemical stability under anhydrous storage conditions. After horses consume the feed, the solid dispersed microspheres enter the aqueous environment of the digestive tract fluid, undergoing in-situ reactions and structural disintegration. The specific mechanism includes the following steps:

[0016] Step 1: Water penetration and dissolution. Water from the digestive fluid penetrates the lipid crystal network on the surface of the solid dispersion microspheres and enters the interior of the microspheres, where calcium propionate and anhydrous citric acid dissolve in the aqueous phase.

[0017] Step two, in-situ acid-base reaction. The dissolved calcium propionate reacts with anhydrous citric acid in the aqueous microenvironment inside the microspheres. The calcium ions in the calcium propionate combine with the citrate ions to form calcium citrate, while releasing liquid free propionic acid.

[0018] Step 3: Product phase transition and skeletal disintegration. The free propionic acid generated in the reaction is liquid at body temperature. As a low molecular weight organic solvent, free propionic acid plasticizes and dissolves the lipid crystal network of hydrogenated palm oil, lowers the melting point of local lipids, and destroys the structural integrity of the solid dispersion microspheres, leading to the structural disintegration of the solid dispersion microspheres.

[0019] Step four: Nutrient release and absorption. Upon disintegration, the microspheres release free propionic acid, hydrogenated palm oil, and lysophosphatidylcholine. Free propionic acid is absorbed by the digestive tract epithelium and enters the liver, where it is converted into glucose via gluconeogenesis, providing metabolic energy. Hydrogenated palm oil, emulsified by lysophosphatidylcholine, disperses into microdroplets, increasing the contact area with digestive enzymes, improving fat degradation, and providing high-density heat energy. Together, these components meet the energy needs of Ili horses in high-altitude, cold regions for maintaining body temperature and growth.

[0020] Preferably, the solid dispersion microspheres are made from raw materials comprising the following parts by weight:

[0021] 65 parts hydrogenated palm oil, 17.5 parts calcium propionate, 12 parts anhydrous citric acid, and 4 parts lysophosphatidylcholine;

[0022] Compound nutritional feed contains the following components in parts by weight:

[0023] 90 parts roughage and 10 parts solid dispersion microspheres.

[0024] By adopting the above technical solution, the mass ratio of matrix to reactant is limited so that the amount of free propionic acid generated inside the microsphere reaches the threshold that triggers the complete disintegration of the lipid crystallization network, while avoiding excessive acid production that could cause intestinal pH imbalance and maintaining the digestive safety of the feed.

[0025] Preferably, the iodine value of hydrogenated palm oil is less than or equal to 5 g I2 / 100 g;

[0026] The hydrophilic-lipophilic balance value of lysophosphatidylcholine is 8 to 12.

[0027] By adopting the above technical solution, the content of unsaturated double bonds is limited by using hydrogenated palm oil with low iodine value, which improves the antioxidant performance and mechanical strength of the lipid crystal network at room temperature; the lysophosphatidylcholine with a hydrophilic-lipophilic balance value of 8 to 12 takes into account both water solubility and lipid solubility, and reduces the oil-water interfacial tension after microsphere disintegration, thus promoting the emulsification and dispersion of hydrogenated palm oil in digestive fluid.

[0028] Preferably, the roughage is composed of oat hay and alfalfa hay mixed in a 1:1 mass ratio, and the cut length of both oat hay and alfalfa hay is 3cm to 5cm.

[0029] By adopting the above technical solution, the ratio of oat hay to alfalfa hay provides a balanced crude protein and crude fiber; the 3cm to 5cm chopped length matches the chewing characteristics of Ili horses, promotes the chewing process and stimulates saliva secretion, buffers gastrointestinal acidity, and improves the cecal fermentation environment.

[0030] Preferably, the water content inside the solid dispersion microspheres is less than or equal to 0.15% by mass, and the initial content of free propionic acid in the solid dispersion microspheres is less than or equal to 0.2 mg / g.

[0031] By adopting the above technical solution, the water content and initial free propionic acid content inside the microspheres are limited, the aqueous medium conditions for the reaction between calcium propionate and anhydrous citric acid during storage are cut off, the solid dispersed microspheres are prevented from disintegrating and degrading in the in vitro environment, and the stability period of the compound nutrient feed is extended.

[0032] Preferably, the method for preparing solid dispersed microspheres includes:

[0033] Calcium propionate and anhydrous citric acid were weighed according to the formula, and subjected to micronization and fluidized bed drying and dehydration treatment. Then, they were dry mixed at room temperature to obtain a dry powder phase.

[0034] Hydrogenated palm oil was heated and melted according to the formula, and lysophosphatidylcholine was added and mixed at a constant temperature to establish a hot melt circulation loop and obtain a hot melt liquid phase.

[0035] The dry powder phase and the hot melt phase are simultaneously and continuously pumped into a high-shear emulsifier for mixing to form a solid-liquid suspension micro-slurry;

[0036] The solid-liquid suspension microslurry is pumped into the top of a spray condenser for centrifugal atomization, and then undergoes rapid cooling phase change and solidification under the action of cold air, and the solid dispersed microspheres are collected.

[0037] By adopting the above technical solutions, micronization increases the specific surface area of ​​the dry powder phase, drying and dehydration removes free water from the inside and surface of the raw materials, preventing side reactions during processing; the dry powder phase and the hot melt liquid phase are pumped into a high-shear emulsifier to achieve uniform dispersion of solid particles in liquid lipids; spray condensation granulation technology cools the atomized droplets in the air and causes a liquid-solid phase change, forming dense solid dispersion microspheres, thus completing the encapsulation of active ingredients.

[0038] Preferably, during the preparation of the dry powder phase, the particle size D90 of the pulverized particles after micronization is controlled to be less than or equal to 38μm; then hot air at a temperature of 80-85℃ is introduced for drying and dehydration treatment for 60-90 minutes, and the moisture content of the powder is controlled to be 0.05%-0.15%.

[0039] By adopting the above technical solutions, the particle size parameters of the pulverized particles are controlled to ensure that the solid particles do not become clogged when passing through the high-shear equipment and atomizer, thereby reducing the settling velocity of the particles in the hot melt lipids; the hot air drying and dehydration process removes the water attached to the raw materials and reduces the water activity of the internal system of the solid dispersion microspheres.

[0040] Preferably, during the process of preparing the hot melt liquid phase, the system temperature is maintained at 75-80℃, the stirrer is turned on and the speed is controlled at 300-500 rpm, and the mixture is kept at a constant temperature for 20-30 minutes, and the water mass fraction of the liquid phase system is controlled to be less than or equal to 0.1%.

[0041] By adopting the above technical solution, the temperature is maintained at 75-80℃ to ensure the fluidity of the liquid system and to prevent the thermal degradation of lysophosphatidylcholine; constant temperature stirring dissolves lysophosphatidylcholine in the liquid lipids, thus establishing a homogeneous system.

[0042] Preferably, during the process of forming solid-liquid suspension microslurry, the high-shear emulsifier preheats the chamber temperature to 75-80℃, sets the rotation speed to 2800-3200rpm, and controls the feed flow rate so that the average residence time of the material in the chamber is 1.5-3.0s.

[0043] By adopting the above technical solution, the shear force generated by the high rotation speed breaks the hard agglomeration of solid particles, suspending them in the continuous lipid phase; the preheating chamber and the control of short residence time prevent the material from locally agglomerating or accumulating heat in the mixing chamber, thus maintaining the physical stability of the suspended microslurry.

[0044] Preferably, during the centrifugal atomization and rapid cooling phase change solidification process, the centrifugal atomization disc speed is set to 10,000-15,000 rpm, cold air at a temperature of 0-5℃ is blown into the bottom of the condensation tower, and the droplets have a free fall time of 3-5 seconds inside the tower.

[0045] By employing the above technical solution, centrifugal speed disperses the solid-liquid suspension microslurry into droplets; cold air at 0-5℃ comes into countercurrent contact with the droplets, causing lipid molecules to crystallize and solidify during free fall. The quenching process restricts the migration of solid particles within the droplets, ensuring that calcium propionate and anhydrous citric acid are uniformly distributed in the final lipid crystallization network.

[0046] This invention provides a compound nutritional feed suitable for the growth and development of Ili horses in high-altitude and cold regions. It has the following beneficial effects:

[0047] 1. This invention utilizes lysophosphatidylcholine to establish hydration channels in an aqueous environment, promoting an in-situ acid-base metathesis reaction between calcium propionate embedded in hydrogenated palm oil and anhydrous citric acid. The resulting liquid free propionic acid disrupts the lipid crystallization network, leading to the disintegration of the microsphere structure. This process allows the feed to simultaneously release free propionic acid and hydrogenated palm oil after entering the horse's digestive tract, providing carbohydrate and lipid energy through gluconeogenesis and intestinal enzymatic hydrolysis, respectively, thus meeting the energy metabolism needs of Ili horses in high-altitude and cold regions.

[0048] 2. This invention eliminates the medium conditions for premature reaction of internal raw materials by controlling the moisture content inside the solid dispersed microspheres to be less than or equal to 0.15% by controlling the moisture content inside the ...

[0049] 3. In this invention, oat hay and alfalfa hay are mixed at a mass ratio of 1:1 and chopped to 3-5 cm as a roughage carrier. The ratio and length of the hay provide the fiber substrate required for microbial fermentation in the cecal intestine of horses, and promote the uniform mixing of solid dispersed microspheres with the food during chewing and gastrointestinal transport. This facilitates the smooth entry of the microspheres into the later part of the digestive tract for targeted disintegration and release, thereby improving the overall digestibility and absorption rate of nutrients. Attached Figure Description

[0050] Figure 1The graph shows the dynamic changes of the physicochemical properties of the solid microspheres of the present invention in a simulated intestinal fluid aqueous incubation system.

[0051] Figure 2 This is a line graph showing the macroscopic self-disintegration transmittance monitoring of the solid microspheres of the present invention in an aqueous system at 38℃;

[0052] Figure 3 The bar chart shows the fiber degradation rate and total VFA yield of each group of feed samples after 48 hours of in vitro fermentation according to the present invention.

[0053] Figure 4 This is a line graph showing the lipid degradation of each group of samples in the in vitro simulated intestinal fluid digestion system of the present invention;

[0054] Figure 5 This is a dynamic response curve of postprandial blood glucose in experimental animals after feeding each group of feed according to the present invention. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings, preparation examples, embodiments, comparative examples, and test examples. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] To clarify the correspondence between the technical solution and specific embodiments of the present invention, it is hereby stated that: the proportion of each raw material in the present invention is expressed in parts by weight, while in the following preparation examples and embodiments, the specific amount of each raw material is measured in kg. The two are numerically equivalent, i.e., 1 kg is equivalent to 1 part by weight.

[0057] 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.

[0058] Hydrogenated palm oil, CAS number 68514-74-9, has an iodine value less than or equal to 5gI2 / 100g and a melting point range of 58℃ to 62℃.

[0059] Lysophosphatidylcholine, CAS No. 9008-30-4, is in powder form with a hydrophilic-lipophilic balance value of 8 to 12.

[0060] Calcium propionate (CAS No. 4075-81-4), anhydrous citric acid (CAS No. 77-92-9), monoglycerides (CAS No. 123-94-4), soybean oil, and conventional roughage (oat hay and alfalfa hay) are all commercially available products in this field.

[0061] Preparation Examples 1-3:

[0062] Preparation Example 1:

[0063] This preparation example provides a method for preparing solid dispersed microspheres, including the following steps:

[0064] (1) 15 kg of calcium propionate and 10.3 kg of anhydrous citric acid were fed into an air jet mill for micronization treatment, and the particle size distribution after pulverization was controlled to be D90 less than or equal to 38 μm. The pulverized mixed powder was fed into a fluidized bed dryer and dried and dehydrated for 60 min with hot air at 80 °C, and the moisture content was controlled to be 0.15%. Subsequently, the dried powder was dry-mixed at room temperature in a zero-gravity mixer for 15 min, and then sealed and transferred to a dry powder silo for later use as a dry powder phase.

[0065] (2) Add 60 kg of hydrogenated palm oil to a batching reactor with a heating jacket, raise the temperature and maintain the temperature inside the reactor at 75°C. Turn on the stirrer and control the speed at 300 rpm, add 3 kg of lysophosphatidylcholine, mix at a constant temperature for 20 min, control the water content of the liquid phase system to be less than or equal to 0.1%, and establish a 75°C circulation loop in the pipeline through a heat-insulated gear pump as a hot melt liquid phase for later use.

[0066] (3) Start the inline high-shear emulsifier, preheat the chamber to 75°C, and set the speed to 2800 rpm. Through the feeder and metering pump, the above dry powder phase and hot melt phase are pumped into the high-shear chamber synchronously and continuously. The feed flow rate is controlled so that the average residence time of the material in the chamber is 1.5s, forming a solid-liquid suspension micro slurry and pumping it out continuously.

[0067] (4) The micro-slurry is directly pumped into the centrifugal atomizing plate at the top of the spray condenser, and the speed of the atomizing plate is set to 10,000 rpm. Cold air at 0°C is blown into the bottom of the condenser. The microdroplets fall freely in the tower for 3 seconds, undergo a rapid cooling phase change and solidify into microspheres. The solid dispersed microspheres are collected.

[0068] Preparation Example 2:

[0069] This preparation example provides a method for preparing solid dispersed microspheres, including the following steps:

[0070] (1) 17.5 kg of calcium propionate and 12 kg of anhydrous citric acid were fed into an air jet mill for micronization treatment, and the particle size distribution after pulverization was controlled to be D90 less than or equal to 38 μm. The pulverized mixed powder was fed into a fluidized bed dryer and dried and dehydrated for 75 min with hot air at 82 °C, and the moisture content was controlled to be 0.10%. Subsequently, the dried powder was dry-mixed at room temperature in a zero-gravity mixer for 18 min, and then sealed and transferred to a dry powder silo for later use as a dry powder phase.

[0071] (2) Add 65 kg of hydrogenated palm oil to a batching reactor with a heating jacket, raise the temperature and maintain the temperature inside the reactor at 77°C. Turn on the stirrer and control the speed at 400 rpm, add 4 kg of lysophosphatidylcholine, mix at a constant temperature for 25 min, control the water content of the liquid phase system to be less than or equal to 0.1%, and establish a 77°C circulation loop in the pipeline through a heat-insulated gear pump as a hot melt liquid phase for later use.

[0072] (3) Start the inline high-shear emulsifier, preheat the chamber to 77°C, and set the speed to 3000 rpm. Through the feeder and metering pump, the above dry powder phase and hot melt phase are pumped into the high-shear chamber synchronously and continuously. The feed flow rate is controlled so that the average residence time of the material in the chamber is 2.0 s, forming a solid-liquid suspension micro slurry, which is then continuously pumped out.

[0073] (4) The micro-slurry is directly pumped into the centrifugal atomizing plate at the top of the spray condenser, and the speed of the atomizing plate is set to 12,000 rpm. Cold air at a temperature of 2°C is blown into the bottom of the condenser. The microdroplets fall freely in the tower for 4 seconds, undergo a rapid cooling phase change and solidify into microspheres. The solid dispersed microspheres are collected.

[0074] Preparation Example 3:

[0075] This preparation example provides a method for preparing solid dispersed microspheres, including the following steps:

[0076] (1) 20 kg of calcium propionate and 13.7 kg of anhydrous citric acid were fed into an air jet mill for micronization treatment, and the particle size distribution after pulverization was controlled to be D90 less than or equal to 38 μm. The pulverized mixed powder was fed into a fluidized bed dryer and dried and dehydrated for 90 min with hot air at 85 °C, and the moisture content was controlled to be 0.05%. Subsequently, the dried powder was dry-mixed at room temperature in a zero-gravity mixer for 20 min, and then sealed and transferred to a dry powder silo for later use as a dry powder phase.

[0077] (2) Add 70 kg of hydrogenated palm oil to a batching reactor with a heating jacket, raise the temperature and maintain the temperature inside the reactor at 80°C. Turn on the stirrer and control the speed at 500 rpm, add 5 kg of lysophosphatidylcholine, mix at a constant temperature for 30 min, control the water content of the liquid phase system to be less than or equal to 0.1%, and establish an 80°C circulation loop in the pipeline through a heat-insulated gear pump as a hot melt liquid phase for later use.

[0078] (3) Start the inline high-shear emulsifier, preheat the chamber to 80°C, and set the speed to 3200 rpm. Through the feeder and metering pump, the above dry powder phase and hot melt phase are pumped into the high-shear chamber synchronously and continuously. The feed flow rate is controlled so that the average residence time of the material in the chamber is 3.0 s, forming a solid-liquid suspension micro slurry and pumping it out continuously.

[0079] (4) The micro-slurry is directly pumped into the centrifugal atomizing plate at the top of the spray condenser, and the speed of the atomizing plate is set to 15,000 rpm. Cold air at 5°C is blown into the bottom of the condenser. The microdroplets fall freely in the tower for 5 seconds, undergo a rapid cooling phase change and solidify into microspheres. The solid dispersed microspheres are collected.

[0080] Examples 1-3:

[0081] Example 1:

[0082] This embodiment provides a method for preparing a compound nutritional feed, including the following steps:

[0083] Weigh 8 kg of the solid dispersed microspheres obtained in Preparation Example 1 and 92 kg of roughage (roughage is a uniform mixture of oat hay and alfalfa hay chopped to 3 cm to 5 cm in mass ratio of 1:1). Put the solid dispersed microspheres and roughage into a twin-shaft paddle mixer and mix for 5 minutes at room temperature and pressure to ensure uniform mixing.

[0084] Example 2:

[0085] This embodiment provides a method for preparing a compound nutritional feed, including the following steps:

[0086] Weigh 10 kg of the solid dispersed microspheres obtained in Preparation Example 2 and 90 kg of roughage (roughage is a uniform mixture of oat hay and alfalfa hay chopped to 3 cm to 5 cm in mass ratio of 1:1). Put the solid dispersed microspheres and roughage into a twin-shaft paddle mixer and mix for 8 minutes at room temperature and pressure to ensure uniform mixing.

[0087] Example 3:

[0088] This embodiment provides a method for preparing a compound nutritional feed, including the following steps:

[0089] Weigh 12 kg of the solid dispersed microspheres obtained in Preparation Example 3 and 88 kg of roughage (roughage is made by uniformly mixing oat hay and alfalfa hay chopped to 3 cm to 5 cm in a mass ratio of 1:1). Put the solid dispersed microspheres and roughage into a twin-shaft paddle mixer and mix for 10 min at room temperature and pressure to ensure uniform mixing.

[0090] Comparative Examples 1-5:

[0091] Comparative Example 1:

[0092] Compared with Example 2, the difference is that: instead of adding solid dispersed microspheres, soybean oil and calcium propionate powder with the same energy and mass equivalent as in Example 2 are directly added to 90 kg of roughage. The soybean oil is evenly sprayed on the surface of the roughage, and the calcium propionate powder is directly physically stirred and mixed. The rest are the same.

[0093] Comparative Example 2:

[0094] Compared with Example 2, the difference is that anhydrous citric acid was removed from the solid dispersed microspheres used in the preparation process, while the other components and process parameters are the same.

[0095] Comparative Example 3:

[0096] Compared with Example 2, the difference is that the solid dispersed microspheres used in this example have lysophosphatidylcholine and other components replaced with monoglycerides during the preparation process, while the other components and process parameters are the same.

[0097] Comparative Example 4:

[0098] Compared with Example 2, the difference is that instead of the hot-melt, pipeline high-shear and spray-cooling phase change granulation process, equal amounts of hydrogenated palm oil powder, lysophosphatidylcholine powder, calcium propionate powder and anhydrous citric acid powder are directly mixed at room temperature to obtain a mixed powder, which is then used as an additive to mix with roughage. All other aspects are the same.

[0099] Comparative Example 5:

[0100] Compared with Example 2, the difference is that the solid dispersed microspheres used in the preparation process omit the fluidized bed hot air drying and dehydration treatment step of calcium propionate and anhydrous citric acid, and directly use the normal aqueous micronized mixture into the subsequent high-shear mixing process of the hot melt liquid phase. The other components and process parameters are the same.

[0101] Test Example 1-5:

[0102] Detailed experimental description and data analysis for Test Example 1:

[0103] (1) Take 5 g of each of the dried microspheres prepared in Preparation Example 1, Preparation Example 2, Preparation Example 3 and Comparative Example 5, place them in centrifuge tubes, add 50 mL of n-hexane and vortex to dissolve them completely. Add 50 mL of deionized water to the solution for liquid-liquid extraction, and centrifuge at 4000 rpm for 10 min. Take the lower aqueous phase solution, filter it through a 0.22 μm aqueous microporous membrane, and inject it into a gas chromatograph to determine the initial content of free propionic acid in the system.

[0104] (2) Artificial intestinal fluid was prepared using phosphate buffered saline, the initial pH was adjusted to 6.85, and it was placed in a constant temperature water bath system and kept at 38°C.

[0105] 3) Weigh 10g of the microsphere samples from Preparation Example 2, Comparative Example 2 and Comparative Example 5 respectively, and put them into a constant temperature reactor containing 200mL of the above simulated intestinal fluid. Turn on the mechanical stirring and keep the speed constant at 200rpm.

[0106] (4) At the time points of 0 min, 5 min, 10 min, 15 min, 20 min, 30 min, 45 min and 60 min during the incubation process, the real-time pH value of the reaction system was directly read and recorded using an insertion online pH meter.

[0107] (5) While recording the pH value, at the corresponding time point, 1 mL of suspension was taken from the reaction system, centrifuged at high speed to obtain the supernatant, and filtered through a 0.22 μm filter membrane. The mass concentration of free propionic acid in the filtrate was determined by gas chromatography, and the real-time release rate of free propionic acid was calculated in combination with the amount of reactants added.

[0108] Table 1. Initial content of free propionic acid in dried solid microspheres

[0109] Sample type Free propionic acid content (mg / g) Preparation Example 1 0.14 Preparation Example 2 0.09 Preparation Example 3 0.17 Comparative Example 5 46.82

[0110] Table 2. Dynamic changes in pH and free propionic acid release rate during simulated intestinal fluid incubation.

[0111] Time point pH value of the preparation system in Example 2 Preparation Example 2: Propionic acid release rate (%) pH value of Comparative Example 2 system Comparative Example 2: Propionic acid release rate (%) pH value of Comparative Example 5 system Comparative Example 5: Propionic acid release rate (%) 0min 6.85 0.03 6.85 0.01 6.84 14.36 5min 6.42 11.27 6.83 0.15 6.51 22.84 10min 5.86 28.54 6.85 0.38 6.32 29.15 15min 5.21 47.91 6.86 0.52 6.27 34.62 20min 4.68 69.18 6.84 0.81 6.18 38.07 30min 4.35 84.62 6.85 1.14 6.13 42.19 45min 4.22 92.73 6.86 1.47 6.12 45.31 60min 4.18 95.81 6.84 1.83 6.10 46.58

[0112] in conclusion:

[0113] Based on the data in Tables 1 and 2, combined with Figure 1 The dynamic change curves of the physicochemical properties of solid microspheres in a simulated intestinal fluid aqueous incubation system show that the solid dispersed microspheres of the present invention achieve thermodynamic locking of the reaction system during the preparation and drying storage stages, and can rapidly dissociate and release free propionic acid in situ after entering the aqueous environment.

[0114] The test results in Table 1 show that the free propionic acid content in the dried microspheres of Preparation Examples 1 to 3 was at an extremely low level. This confirms that under strict control of environmental moisture and with a non-polar high-melting-point lipid as the encapsulating continuous phase, the calcium propionate and anhydrous citric acid coexisting inside the microspheres cannot ionize due to the lack of a polar solvent medium, and the metathesis reaction between ions is completely suppressed. In Comparative Example 5, because the fluidized bed drying and dehydration step was omitted, the bound water and free water remaining in the powder system triggered a pre-neutralization reaction, resulting in an extremely high concentration of free propionic acid detected in the dried granulated product, thus losing the conditions for triggering the reaction in the intestine.

[0115] Table 2 shows the dynamic monitoring data and Figure 1 The change curve corresponds synchronously. Figure 1This is a dual Y-axis line graph. The horizontal axis represents the incubation time (min), the left Y-axis represents the pH value of the reaction system, and the right Y-axis represents the release rate of free propionic acid (%). In the graph, the solid lines with hollow circles and the solid lines with asterisks represent the pH value and release rate changes of Preparation Example 2, respectively; the dashed lines with hollow squares and the dashed lines with crosses represent the pH value and release rate changes of Comparative Example 2, which lacks anhydrous citric acid, respectively; and the dotted lines with hollow triangles and the dotted lines with hollow rhombuses represent the pH value and release rate changes of Comparative Example 5, which did not undergo the drying and dehydration process, respectively.

[0116] When the microspheres of Preparation Example 2 were placed in artificial simulated intestinal fluid at 38°C, water molecules established hydration channels through the hydrophilic groups of surfactants on the surface of the microspheres and penetrated into the interior of the nonpolar lipid network. Figure 1 The in-situ dissociation and acid production process of the microspheres (Preparation Example 2) of this invention under aqueous phase osmosis was visually demonstrated. The pH value dropped sharply within the first 20 minutes, from neutral to 4.68; simultaneously, the release rate of free propionic acid increased non-linearly exponentially, reaching 69.18%. This indicates that the solid-phase acid-base pair rapidly undergoes a proton exchange reaction under aqueous phase osmosis. After 45 minutes, the release rate reached 92.73% and gradually approached equilibrium, indicating that the reaction proceeded completely.

[0117] Comparative examples, due to missing components or process errors, failed to exhibit normal hydration-triggered dissociation kinetics. Comparative Example 2, lacking anhydrous citric acid as an acidic trigger in its formulation, could not undergo in-situ acid production; the system pH remained at the initial level, and the propionic acid release rate fluctuated near the baseline, exhibiting only extremely slow physical dissolution of the microsphere surface. Comparative Example 5, however, showed an abnormally high initial release rate followed by weak subsequent growth, likely due to the depletion of its active ingredient during processing. These physicochemical characterization results clearly confirm the feasibility of the anhydrous isolation encapsulation and hydration-permeation dissociation mechanism under macroscopic conditions.

[0118] Detailed experimental description and data analysis for Test Example 2:

[0119] (1) Take 2g of each of the dried microspheres prepared in Preparation Example 2, Comparative Example 2, and Comparative Example 3 as pre-trigger samples. Separately, weigh 5g of each of the above three groups of microsphere samples and put them into centrifuge tubes containing 100mL of simulated intestinal fluid with a pH of 6.85. Place them in a constant temperature shaker at 38℃ and shake at 150rpm for 30min for pre-incubation. After incubation, immediately separate the lower precipitate by centrifugation at 8000rpm at 4℃ and freeze-dry it at -40℃ for 24h using a vacuum freeze dryer to obtain the post-trigger samples.

[0120] (2) Differential scanning calorimetry (DSC) was used to perform thermodynamic tests on each group of samples before and after triggering. 3.0 mg to 5.0 mg of sample were accurately weighed and placed in an aluminum crucible and sealed. Under a nitrogen protective atmosphere, the temperature was scanned from 20 °C to 90 °C at a heating rate of 10 °C / min. The endothermic curve of the sample was recorded, and the endothermic peak temperature (characterizing the melting point Tm) and the enthalpy of fusion (ΔH) were extracted.

[0121] (3) The macroscopic disintegration process of the microspheres was monitored using a UV-Vis spectrophotometer. The instrument's test wavelength was set to 600 nm, and the transmittance was adjusted to 100% using pure simulated intestinal fluid as a reference solution.

[0122] (4) Add 50 mL of simulated intestinal fluid to a cuvette (or flow cell) with magnetic stirring and a temperature-controlled water jacket, maintain the temperature at 38°C, and set the stirring speed to 300 rpm.

[0123] (5) Accurately add 0.5 g of the dried microspheres of Preparation Example 2, Comparative Example 2, and Comparative Example 3 to the system respectively. Starting from the time of addition, measure the transmittance of the system at time points of 0 min, 10 min, 20 min, 30 min, 45 min, and 60 min. Microsphere disintegration will cause the internal lipids and particles to be released and suspended in the aqueous phase, the turbidity of the system will increase, and the transmittance will decrease accordingly.

[0124] Table 3. Changes in DSC thermodynamic parameters of solid microspheres before and after hydration triggering

[0125] Sample type Tm (°C) before triggering ΔH (J / g) before triggering Tm (°C) after triggering ΔH (J / g) after triggering Preparation Example 2 59.13 143.6 36.27 82.4 Comparative Example 2 59.78 146.2 59.41 144.5 Comparative Example 3 58.62 141.8 51.35 119.7

[0126] Table 4. Dynamic changes in transmittance (%) during the microsphere disintegration process in simulated intestinal fluid at 38℃

[0127] Time point Preparation Example 2 Transmittance Comparative Example 2: Light Transmittance Comparative Example 3 Light Transmittance 0min 98.42 99.05 98.71 10min 78.15 98.24 91.36 20min 41.36 97.51 82.58 30min 19.82 96.83 73.14 45min 14.27 95.42 64.82 60min 11.59 94.76 58.15

[0128] in conclusion:

[0129] Based on the data in Tables 3 and 4, combined with Figure 2 The dynamic change curve of transmittance and the translational characteristics of endothermic peak of solid microspheres in an aqueous system at 38℃ were obtained. The free propionic acid generated by in-situ dissociation destroyed the lattice arrangement of the continuous phase lipids, which triggered a sharp drop in phase transition temperature and caused the microspheres to undergo self-disintegration of macrostructure under animal body temperature conditions.

[0130] Table 3 shows the DSC thermodynamic test data, indicating that the endothermic peak temperature of each group of microspheres before triggering was between 58℃ and 60℃, exhibiting typical characteristics of high-melting-point stearin. The high enthalpy of fusion indicates that the hydrogenated palm oil in the system presents a highly ordered polycrystalline network structure. After simulated intestinal fluid hydration triggering, the endothermic peak temperature of the microspheres in Example 2 shifted significantly to the left, decreasing from 59.13℃ to 36.27℃, while the enthalpy of fusion decreased to 82.4 J / g. This confirms that after the aqueous phase infiltration triggers the internal acid-base metathesis reaction, the generated liquid free propionic acid is incorporated in situ as a small molecule impurity into the crystalline network of the high-melting-point lipid. Following the freezing point depression law, the regularity of the crystal arrangement of the continuous phase lipid is disrupted, and the intermolecular van der Waals forces weaken, causing the overall melting point to drop below 38℃. In Comparative Example 2, due to the lack of anhydrous citric acid, no chemical reaction occurred within the system to release free propionic acid. Its Tm after triggering was 59.41℃, with no substantial temperature shift, and the crystal structure remained stable. In Comparative Example 3, because lysophosphatidylcholine was replaced with conventional monoglycerides, the establishment of hydration osmotic channels was hindered. The rate and quantity of water molecules entering the microspheres were insufficient to support a complete metathesis reaction, limiting acid production. Its Tm after triggering dropped to 51.35℃, failing to exceed the body temperature threshold of 38℃.

[0131] Table 4 transmittance monitoring data and Figure 2 The dynamic change curve confirms the macroscopic self-disintegration effect brought about by the microscopic melting point collapse. Figure 2 The graph shows the macroscopic self-disintegration transmittance monitoring, with the horizontal axis representing the test time (min) and the vertical axis representing the transmittance of the reaction system (%). This graph visually reflects the macroscopic morphological stability of each group of microspheres under constant temperature aqueous phase stirring at 38℃. Different line types and symbols distinguish the test groups: solid lines with hollow circles represent the transmittance change of Preparation Example 2; dashed lines with hollow squares represent the transmittance change of Comparative Example 2 lacking anhydrous citric acid; and dotted lines with hollow triangles represent the transmittance change of Comparative Example 3 where the emulsifier was replaced with monoglyceride.

[0132] The transmittance of Preparation Example 2, indicated by the solid line with hollow circles, exhibits a typical S-shaped sharp decrease. Between 10 and 30 minutes, the transmittance rapidly dropped from 78.15% to 19.82%, confirming complete structural disintegration and the formation of a suspension. This is because the melting point of its components decreased to 36.27°C, below the ambient temperature (38°C), causing the solid lipid matrix to transform into a semi-fluid state. The microspheres lost their structural framework and rapidly disintegrated under mechanical stirring, releasing a large amount of encapsulated material and lipid droplets into the aqueous phase. After 45 minutes, the transmittance stabilized at around 14%, indicating complete disintegration.

[0133] The curve of Comparative Example 2, shown by the dashed line with hollow squares, remained basically horizontal and did not disintegrate. At 60 min, the transmittance was still as high as 94.76%, indicating that the microspheres maintained a hard solid particle configuration under the encapsulation of high-melting-point lipids and did not undergo structural rupture.

[0134] Comparative Example 3, shown by the dotted line with hollow triangles, only exhibits a slow decrease in transmittance, with a sluggish rate of decrease. At 60 minutes, the transmittance is 58.15%, indicating that only localized surface dissolution occurs, and effective structural disintegration and complete structural collapse cannot be achieved.

[0135] Detailed experimental description and data analysis for Test Example 3:

[0136] (1) Take the fermentation broth from the posterior intestinal tract (or rumen) of a healthy donor animal with a permanent digestive tract fistula. Filter the collected contents through four layers of gauze, and place the filtrate in an insulated container filled with carbon dioxide gas, maintaining the temperature at 39°C until use.

[0137] (2) Prepare an anaerobic fermentation medium containing trace element solution, macro element solution, bicarbonate buffer and resazurite indicator, and add sodium sulfide as a reducing agent to remove dissolved oxygen from the system. Mix the filtered digestive tract fermentation broth with the above medium at a volume ratio of 1:4 to prepare a mixed inoculum. The entire process is carried out under continuous carbon dioxide purging.

[0138] (3) Accurately weigh 0.5g of the compound nutrient feed samples of Examples 1, 2, 3, Comparative Example 1 and Comparative Example 4 after being crushed through a 1mm standard sieve, and put them into 100mL glass fermentation bottles. Set up 3 parallel replicates for each sample, and set up a blank control group without feed.

[0139] (4) Inject 50 mL of the above mixed inoculum into each fermentation flask containing the sample, purge the air from the top of the flask with high-purity carbon dioxide gas, seal with butyl rubber stopper and tighten with aluminum cap.

[0140] (5) Transfer the sealed fermentation bottle into a constant temperature anaerobic shaker at 39°C, set the rotation speed to 120 rpm, and ferment continuously for 48 hours.

[0141] (6) After fermentation is complete, remove the fermentation bottle and immediately immerse it in ice water for 5 minutes to stop microbial activity. Open the fermentation bottle and measure the pH value of the system.

[0142] (7) Transfer all the suspension and residue in the fermentation flask to centrifuge tubes and centrifuge at 10,000 rpm for 15 minutes at 4°C. Take the supernatant and add metaphosphoric acid solution for acidification. After filtering through a 0.22 μm filter membrane, inject it into a gas chromatograph (GC) to determine the total concentration of volatile fatty acids (VFA) in the fermentation broth.

[0143] (8) Collect the solid residue at the bottom of the centrifuge tube, wash it repeatedly with distilled water until neutral, and bake it in a 65°C forced-air drying oven until constant weight. The Van Soest fiber analysis method was used to determine the mass of neutral detergent fiber (NDF) and acid detergent fiber (ADF) in the residue using a fiber analyzer. Combined with the initial fiber content of the sample before fermentation, the apparent degradation rate of NDF and ADF was calculated.

[0144] Table 5. Fiber degradation rate and total VFA yield of feed samples in each group after 48 hours of in vitro fermentation.

[0145] Sample type NDF degradation rate (%) ADF degradation rate (%) Total VFA production (mmol / L) Example 1 56.42 41.27 84.15 Example 2 55.89 40.91 87.32 Example 3 54.76 39.84 91.06 Comparative Example 1 38.15 26.53 59.48 Comparative Example 4 51.22 37.65 76.91

[0146] in conclusion:

[0147] Based on the data in Table 5, combined with Figure 3 The bar chart shows the fiber degradation rate and total VFA production of each group of feed samples after 48 hours of in vitro fermentation. The solid dispersed microspheres used in this invention can effectively avoid the physical encapsulation of the roughage surface by liquid oil, ensuring the adhesion and digestion of fiber components by hindgut microorganisms and degradation enzymes. Figure 3 This is a side-by-side bar chart with dual Y-axis. The horizontal axis represents feed samples from different treatment groups (Examples 1 to 3, Comparative Example 1, and Comparative Example 4). The left vertical axis represents fiber degradation rate (%), corresponding to dark gray bars (representing neutral detergent fiber NDF degradation rate) and medium gray bars (representing acid detergent fiber ADF degradation rate); the right vertical axis represents total volatile fatty acid production (mmol / L), corresponding to light gray bars (representing total VFA production). Specific test values ​​are labeled at the top of each bar.

[0148] Table 5 Test Results and Figure 3The results clearly demonstrate that the Example Group significantly outperformed Comparative Example 1, which directly added liquid oil, in terms of NDF degradation rate (above 54%), ADF degradation rate (above 39%), and microbial fermentation acid production capacity (above 84 mmol / L). After 48 hours of fermentation, the neutral detergent fiber (NDF) degradation rate of the compound nutrient feeds in Examples 1, 2, and 3 remained between 54.76% and 56.42%, and the acid detergent fiber (ADF) degradation rate between 39.84% and 41.27%. In Comparative Example 1, the addition of liquid soybean oil caused a sharp drop in fiber degradation rate, with an NDF degradation rate of only 38.15% and an ADF degradation rate decreasing to 26.53%. Simultaneously, the total VFA production dropped from over 84 mmol / L in Example 1 to 59.48 mmol / L. This indicates that the solid-dispersed microsphere form used in this invention successfully prevented the physical encapsulation of free oil on the surface of the feed fiber, maintaining normal substrate fermentation degradation rate and microbial activity.

[0149] In this scheme, the outer continuous phase of the solid-dispersed microspheres is a high-melting-point hydrogenated lipid, which maintains a rigid solid particle configuration during room-temperature processing and mixing. When these solid microspheres are physically stirred with roughage such as oat hay and alfalfa hay, they only form a random dispersion between particles and do not spread on the rough plant fiber surface. The porous structure and hydrophilic surface of the fiber are preserved. After entering the aqueous environment of the digestive tract, although the microspheres undergo hydration triggering and melting point collapse at 38°C, the feed has already been infiltrated and dispersed in the digestive fluid. The lipid droplets released by in-situ disintegration are emulsified by the surfactants in the digestive tract and cannot re-aggregate and cover the surface of the suspended fiber particles. This spatial isolation mechanism ensures that intestinal cellulose-degrading bacteria and water-soluble polysaccharide-degrading enzymes can smoothly enter the fiber gaps and maintain a normal substrate hydrolysis rate. The fermentation data of the example are close to the digestibility of conventional roughage without added fat.

[0150] Comparative Example 1: Liquid soybean oil was directly sprayed onto the surface of roughage. Under mechanical stirring, the low surface tension liquid oil spontaneously penetrated and spread along the surface pores of the hay fibers, forming a continuous and dense hydrophobic oil film. This lipid barrier altered the surface wettability of the feed particles, blocking the penetration of water from the fermentation broth into the fiber interior, resulting in a severe steric hindrance effect. Microbial cells and cellulase could not contact the cellulose and hemicellulose polymer chains, and the enzymatic cleavage sites were physically masked, leading to the stagnation of fiber digestion and a significant reduction in the concentration of volatile fatty acids (VFAs) in the final fermentation product. Comparative Example 4: A room-temperature physical dry-mixed powder was used. Some lipids may have undergone uneven dissolution or micro-agglomeration during the mixing process or intestinal fluid. Its fiber degradation rate was slightly lower than that of the Example group, indicating the necessity of microsphere granulation technology in maintaining the physical independence of the system. The test results verified that this invention, while providing high-density energy, solves the technical defect of conventional oil additives that inhibit the digestion of roughage fiber.

[0151] Detailed experimental description and data analysis for Test Example 4:

[0152] (1) Preparation of a basic buffer solution for simulating intestinal digestion. Accurately weigh appropriate amounts of tris(hydroxymethyl)aminomethane (Tris), sodium chloride, and calcium chloride, dissolve them in deionized water, and prepare a basic buffer solution system containing 50 mM Tris, 150 mM sodium chloride, and 5 mM calcium chloride. Use 0.1 M hydrochloric acid or sodium hydroxide solution to precisely adjust the pH of the buffer solution to 7.0, and preheat it in a 38°C constant temperature water bath.

[0153] (2) Weigh the mixture of porcine bile salts and porcine pancreatic lipase powder, and dissolve them in the preheated basic buffer solution. After stirring until completely dissolved, filter to remove insoluble impurities, and obtain an in vitro simulated intestinal digestion system with a working concentration of 10 mM bile salts and 2000 U / mL pancreatic lipase.

[0154] (3) Weigh 2g of each of the compound nutrient feed samples of Example 1, Example 2, Example 3, Comparative Example 2 and Comparative Example 3 after crushing and grinding. Put the samples into their respective independent constant temperature reaction vessels.

[0155] (4) Add 100 mL of the prepared simulated intestinal fluid digestion system to each reaction vessel. The reaction system is placed in a constant temperature water bath with magnetic stirring. The water bath temperature is strictly controlled at 38℃, the stirring speed is set to 150 rpm, and the reaction timer is started.

[0156] (5) At time points of 30 min, 60 min, 120 min and 240 min of reaction, 2 mL of digestion mixture sample was taken from each reaction vessel. The sample was immediately transferred to a centrifuge tube pre-filled with 0.2 mL of 1 M hydrochloric acid. The pH value was lowered by acidification to inactivate pancreatic lipase and terminate the enzymatic hydrolysis reaction.

[0157] (6) Add 5 mL of a mixture of n-hexane and isopropanol in a volume ratio of 3:2 to the centrifuge tube, and vortex vigorously for 5 minutes to fully extract the free fatty acids and undigested neutral lipids into the organic phase. Centrifuge at 5000 rpm for 10 minutes to promote phase separation.

[0158] (7) The upper organic phase was aspirated and the solvent was dried using nitrogen. The residue was then subjected to methyl esterification derivatization and injected into a gas chromatograph (GC) to quantitatively determine the total amount of free fatty acids released in the system. The apparent lipid hydrolysis rate at each time point was calculated by combining the initial total lipid content in the sample and the theoretical amount of fatty acid generated.

[0159] Table 6. Dynamic lipid hydrolysis rate (%) of each group of samples in the in vitro simulated intestinal fluid digestion system

[0160] Time point Example 1 Example 2 Example 3 Comparative Example 2 Comparative Example 3 30min 21.36 24.11 22.75 1.52 4.31 60min 52.81 55.37 51.64 3.14 9.77 120min 74.52 79.16 76.83 7.85 18.25 240min 88.19 92.48 90.05 14.62 29.34

[0161] in conclusion:

[0162] Based on the data in Table 6, combined with Figure 4 The in vitro simulation of lipid dynamic hydrolysis rate changes in the intestinal system demonstrates that the in-situ acid-base triggering system can overcome the digestive steric hindrance of high-melting-point lipids under animal body temperature conditions, enabling the efficient release and utilization of long-chain fatty acids. Figure 4 This is a line graph showing lipid degradation in various samples within an in vitro simulated intestinal digestion system. The horizontal axis represents digestion reaction time (min), and the vertical axis represents the dynamic lipid hydrolysis rate (%). This graph visually demonstrates the effect of the in-situ acid-base triggering system on improving the digestibility of high-melting-point lipids.

[0163] Table 6 Test Data and Figure 4 The curves show that Examples 1, 2, and 3 exhibit extremely high lipid degradation efficiency in a simulated intestinal digestion system. Figure 4 In the diagram, the solid line with a hollow circle represents Example 1, the solid line with a hollow square represents Example 2, and the solid line with a hollow upward triangle represents Example 3. The curves for these three examples show an exponential and rapid increase over time. Within the first 60 minutes, the hydrolysis rate rapidly climbed to the range of 51.64% to 55.37%. At 240 minutes, the hydrolysis rate exceeded 88% in all three examples, with Example 2 reaching 92.48%. This indicates that after the microspheres self-disintegrate, the internal high-melting-point lipid matrix transforms into tiny lipid droplets suspended in the aqueous phase, resulting in efficient release and enzymatic hydrolysis of the lipids. The significant increase in specific surface area provides ample attachment sites for bile salt molecules and pancreatic lipase within the system, enabling the enzymatic substrate binding reaction to proceed continuously and efficiently. The chemical digestion process of high-melting-point fats is essentially equivalent to the degradation rate of conventional liquid oils.

[0164] The melting point of conventional high-melting-point lipids is much higher than the animal's body temperature (38°C). In the digestive tract, untriggered high-melting-point fatty acid chains are arranged in a highly ordered lattice structure, maintaining a rigid, large-particle morphology. The emulsifying effect of bile salts and the enzymatic cleavage of water-soluble lipases can only occur at the gas-liquid-solid interface of these solid particles and cannot penetrate deep into the lipid interior. The data in Comparative Examples 2 and 3 in Table 6, and... Figure 4 The two sets of curves, which remained at a low and flat level in the medium to long term, confirmed that high-melting-point solid lipids that did not undergo macroscopic disintegration were difficult to be effectively degraded by lipases and had significant digestive steric hindrance.

[0165] Figure 4In the diagram, the dashed line with a hollow rhombus represents Comparative Example 2, which lacks anhydrous citric acid. Since no anhydrous citric acid was added to the formulation of Comparative Example 2, the microspheres could not generate free propionic acid in the aqueous environment to induce a lowering of the freezing point. This system maintained a high-melting-point solid particle configuration throughout the 240-minute incubation process. Test data showed that its hydrolysis reaction was extremely slow, with a hydrolysis rate of only 7.85% at 120 minutes and only 14.62% at the reaction endpoint of 240 minutes, both below 30%. Enzymatic degradation was limited to physical dissolution of the outer surface of the microparticles, and a large amount of lipids encapsulated in the core were discharged from the system with the fermentation residue, losing its nutritional conversion value as a feed energy additive. The dashed line with a hollow downward-pointing triangle represents Comparative Example 3, where the emulsifier was replaced with monoglycerides. Comparative Example 3 used conventional monoglycerides instead of lysophosphatidylcholine. Conventional emulsifiers could not form effective and efficient hydration channels on the surface of the microspheres, significantly limiting the rate at which the aqueous phase entered the interior of the microspheres. The internal acid-base metathesis reaction failed to provide a sufficient concentration of free propionic acid to completely disintegrate the crystalline network of hydrogenated lipids. The interruption of the phase transition process resulted in only surface softening of the microspheres, failing to achieve macroscopic self-disintegration. The curve also remained low and flat, with a final lipid hydrolysis rate of 29.34% at 240 min, below 30%, slightly higher than Comparative Example 2, but far below the design requirements of the Example group. The test results confirm the irreplaceable role of the in-situ dissociation acid production mechanism and the construction of special hydration channels in ensuring the intestinal digestibility and absorption of high-melting-point lipids.

[0166] Detailed experimental description and data analysis for Test Example 5:

[0167] (1) Healthy growing pigs with similar body weights were selected as a monogastric metabolic model. Before the experiment, the pigs underwent jugular vein cannulation and recovered for 14 days. All pigs were fasted for 12 hours before the experiment, and were given plenty of water during the period.

[0168] (2) The experimental pigs were randomly assigned to different treatment groups, corresponding to the compound nutrient diets of Example 1, Example 2, Example 3, Comparative Example 1 and Comparative Example 2, respectively. Five replicates were set up for each group.

[0169] (3) Based on the weight of the experimental pigs, feed each group of feed once according to the uniform feeding amount standard. Record the time when feeding is completed as 0 minutes.

[0170] (4) At 0, 45, 90, 180 and 300 minutes after feeding, 5 mL of blood samples were collected via jugular vein cannulation. The collected blood samples were injected into vacuum blood collection tubes without anticoagulants.

[0171] (5) Allow the vacuum blood collection tube to stand at room temperature for 30 minutes to allow the blood to coagulate naturally. Then, centrifuge at 3000 rpm for 15 minutes at 4°C to separate and extract the upper serum sample. Store the aliquoted serum sample in a freezer at -80°C.

[0172] (6) The glucose concentration in serum samples at each time point was determined using the glucose oxidase method and a fully automated biochemical analyzer. Based on the blood glucose concentration data at each time point, the area under the blood glucose curve (AUC) from 0 to 180 minutes was calculated using the trapezoidal rule.

[0173] (7) The concentration of non-esterified fatty acids (NEFA) in serum was measured 300 minutes after eating using a colorimetric method and a non-esterified fatty acid assay kit.

[0174] Table 7. Blood metabolic parameters and area under the blood glucose curve after feeding in experimental animals

[0175] Sample type 0-minute blood glucose (mmol / L) 45-minute blood glucose (mmol / L) 90-minute blood glucose (mmol / L) 180-minute blood glucose (mmol / L) Blood glucose AUC Serum NEFA (μmol / L) at 300 min Example 1 4.12 5.86 5.91 4.93 1632.4 428.6 Example 2 4.08 6.02 5.88 5.01 1675.8 445.2 Example 3 4.15 5.94 6.05 5.12 1689.1 458.7 Comparative Example 1 4.09 4.45 4.72 4.31 1345.6 382.4 Comparative Example 2 4.11 4.51 4.63 4.22 1312.9 154.3

[0176] in conclusion:

[0177] Based on the data in Table 7, combined with Figure 5 The dynamic response curves of postprandial blood glucose in experimental animals after feeding each group of feed showed that the compound nutritional feeds of Examples 1 to 3 constructed a dual-effect energy supply pathway in the animals, which combines fast-acting carbohydrates and long-acting lipids. Figure 5 This is a line graph showing the dynamic changes in serum blood glucose concentration from 0 to 180 minutes after feeding each group of compound nutrient diets in a monogastric animal metabolic model. The horizontal axis represents the time after feeding (min), and the vertical axis represents the serum glucose concentration (mmol / L). In the graph, the solid line with a hollow circle represents Example 1, the solid line with a hollow square represents Example 2, the solid line with a hollow upward triangle represents Example 3, the dashed line with a hollow rhombus represents Comparative Example 1 (directly sprayed liquid oil), and the dashed line with a hollow downward triangle represents Comparative Example 2 (without anhydrous citric acid). Figure 5 This visually demonstrates the rapid energy supply characteristics of the in-situ acid-base triggering system in this solution.

[0178] The data in Table 7 and Figure 5The curves show that the animals in the example group exhibited a significant blood glucose peak within 45 to 90 minutes after feeding, with blood glucose concentration rising from a baseline of approximately 4.12 mmol / L to a range of 5.86 mmol / L to 6.05 mmol / L. The calculated area under the blood glucose curve (AUC) exceeded 1600. This rapid blood glucose response indicates that the free propionic acid produced by microsphere disintegration is quickly absorbed and enters the liver via the portal vein, directly participating in the gluconeogenesis pathway to convert into glucose, thus compensating for the delayed energy supply caused by the long fermentation time of conventional roughage. 300 minutes after feeding, the serum non-esterified fatty acid (NEFA) concentration in the example group remained between 428.6 μmol / L and 458.7 μmol / L. The lipid droplets released by microsphere disintegration are digested in the intestine, and long-chain fatty acids continuously enter the bloodstream via the lymphatic system, providing a long-lasting energy metabolism substrate.

[0179] Conversely, the blood glucose curves of both comparative groups showed a generally low and flat trend, failing to achieve a rapid rise in blood glucose. Comparative Example 1, where liquid soybean oil was directly sprayed onto the feed, saw the liquid lipids physically encapsulate the fiber, inhibiting the fermentation of the substrate by intestinal microorganisms and reducing the production of endogenous volatile fatty acids. The blood glucose peak of the animals in Comparative Example 1 90 minutes after feeding was only 4.72 mmol / L, and the blood glucose AUC dropped to 1345.6.

[0180] In Comparative Example 2, without the addition of anhydrous citric acid, the microspheres could not dissociate in situ in vivo to produce free propionic acid, thus disrupting the rapid gluconeogenesis energy supply pathway based on propionic acid. The blood glucose concentration in the animals 45 minutes after feeding was only 4.51 mmol / L. The high-melting-point lipids in Comparative Example 2 failed to undergo phase transition disintegration in the animal's digestive tract, and lipases could not effectively degrade the large solid lipid particles. The hindered fat digestion led to a reduced release rate of free fatty acids, with the serum NEFA concentration dropping to 154.3 μmol / L at 300 minutes. The data from both comparative examples confirm that the lack of an acidic trigger or the presence of free lipids encapsulating fibers both result in an energy intake vacuum period in the animals at the beginning of feeding, validating the necessity of the acid-base triggering system within the microspheres for achieving rapid energy supply from free propionic acid and long-term energy supply from high-melting-point lipids.

Claims

1. A compound nutritional feed suitable for the growth and development of Ili horses in high-altitude and cold regions, characterized in that, The compound nutritional feed comprises the following components in parts by weight: 88-92 parts roughage; 8-12 parts of solid dispersed microspheres; The solid dispersed microspheres are made from raw materials comprising the following parts by weight: 60-70 parts hydrogenated palm oil; 15-20 parts of calcium propionate; Anhydrous citric acid 10.3-13.7 parts; 3-5 parts of lysophosphatidylcholine; The solid dispersed microspheres have a lipid crystallization network structure, and the calcium propionate and the anhydrous citric acid are doped into the lipid crystallization network structure.

2. The compound nutritional feed for the growth and development of Ili horses in high-altitude and cold regions according to claim 1, characterized in that, The solid dispersion microspheres are made from raw materials comprising the following parts by weight: 65 parts hydrogenated palm oil, 17.5 parts calcium propionate, 12 parts anhydrous citric acid, and 4 parts lysophosphatidylcholine; The compound nutritional feed comprises the following components in parts by weight: 90 parts roughage and 10 parts solid dispersion microspheres.

3. The compound nutritional feed suitable for the growth and development of Ili horses in high-altitude and cold regions according to claim 1, characterized in that, The iodine value of the hydrogenated palm oil is less than or equal to 5 gI2 / 100g; The hydrophilic-lipophilic balance value of the lysophosphatidylcholine is 8 to 12.

4. The compound nutritional feed for the growth and development of Ili horses in high-altitude and cold regions according to claim 1, characterized in that, The roughage consists of oat hay and alfalfa hay mixed in a 1:1 mass ratio, and the oat hay and alfalfa hay are both cut to a length of 3cm to 5cm.

5. The compound nutritional feed for the growth and development of Ili horses in high-altitude and cold regions according to claim 1, characterized in that, The water content inside the solid dispersed microspheres is less than or equal to 0.15% by mass, and the initial content of free propionic acid in the solid dispersed microspheres is less than or equal to 0.2 mg / g.

6. The compound nutritional feed for the growth and development of Ili horses in high-altitude and cold regions according to claim 5, characterized in that, The method for preparing the solid dispersed microspheres includes: Calcium propionate and anhydrous citric acid were weighed according to the formula, and subjected to micronization and fluidized bed drying and dehydration treatment. Then, they were dry mixed at room temperature to obtain a dry powder phase. Hydrogenated palm oil was heated and melted according to the formula, and lysophosphatidylcholine was added and mixed at a constant temperature to establish a hot melt circulation loop and obtain a hot melt liquid phase. The dry powder phase and the hot melt liquid phase are simultaneously and continuously pumped into a high-shear emulsifier for mixing to form a solid-liquid suspension micro slurry; The solid-liquid suspension microslurry is pumped into the top of a spray condenser tower for centrifugal atomization and then undergoes rapid cooling phase change and solidification under the action of cold air, and the solid dispersed microspheres are collected.

7. The compound nutritional feed for the growth and development of Ili horses in high-altitude and cold regions according to claim 6, characterized in that, In the process of preparing the dry powder phase, the particle size D90 of the pulverized particles after micronization is controlled to be less than or equal to 38 μm; Then, hot air at a temperature of 80-85℃ is introduced for drying and dehydration for 60-90 minutes, controlling the moisture content of the powder to be 0.05%-0.15%.

8. The compound nutritional feed for the growth and development of Ili horses in high-altitude and cold regions according to claim 6, characterized in that, During the preparation of the hot melt liquid phase, the system temperature is maintained at 75-80℃, the stirrer is turned on and the speed is controlled at 300-500 rpm, and the mixture is kept at a constant temperature for 20-30 minutes, while controlling the water mass fraction of the liquid phase system to be less than or equal to 0.1%.

9. The compound nutritional feed for the growth and development of Ili horses in high-altitude and cold regions according to claim 6, characterized in that, During the formation of the solid-liquid suspension microslurry, the high-shear emulsifier preheats the chamber temperature to 75-80℃, sets the rotation speed to 2800-3200rpm, and controls the feed flow rate so that the average residence time of the material in the chamber is 1.5-3.0s.

10. The compound nutritional feed for the growth and development of Ili horses in high-altitude and cold regions according to claim 6, characterized in that, During the centrifugal atomization and rapid cooling phase change solidification process, the centrifugal atomization disk speed is set to 10,000-15,000 rpm, cold air at a temperature of 0-5℃ is blown into the bottom of the condensation tower, and the droplets fall freely in the tower for 3-5 seconds.

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