Phytosterol nutrition bar for regulating and controlling energy metabolism imbalance of dairy cows in perinatal period and preparation method of phytosterol nutrition bar

Abstract

The invention provides a phytosterol nutrition bar for regulating and controlling energy metabolism imbalance of dairy cows in the perinatal period and a preparation method thereof, and belongs to the technical field of dairy cow feed additives. The nutrition bar is prepared from the following raw materials: phytosterol, vitamin E, ferroferric oxide, calcium carbonate, chenodeoxycholic acid, hydroxypropyl methyl cellulose, calcium stearate, microcrystalline cellulose, maltodextrin, hydrogenated palm oil, conjugated linoleic acid glyceride and molecular distilled monoglyceride. The phytosterol nutrition bar disclosed by the invention is comprehensive in nutrition function, strong in synergism, good in formability and stability, high in bioavailability, capable of reducing the incidence rate of energy metabolism imbalance diseases, and convenient to operate.

Description

Technical Field

[0001] This invention relates to the field of dairy cow feed additives, and in particular to a plant sterol nutritional bar for regulating energy metabolism imbalance in periparturient dairy cows and its preparation method. Background Technology

[0002] Peripartum dairy cows face the dual physiological pressures of calving and lactation. The contradiction between insufficient dry matter intake and a surge in energy demand leads to a common negative energy balance, and hypocholesterolemia is prevalent within one week postpartum, subsequently triggering metabolic diseases such as ketosis and fatty liver. Clinical data shows that the incidence of ketosis in peripartum dairy cows is as high as 20%-50%, and the incidence of fatty liver is also persistently high. These diseases not only lead to decreased milk production and poor milk quality but also affect the reproductive performance of dairy cows, increasing the risk of secondary diseases such as mastitis and abomasal displacement, causing huge economic losses to the dairy industry.

[0003] Cholesterol is a key component in the synthesis of very low-density lipoprotein (VLDL) in the liver, which is the main carrier of triglycerides excreted by the liver. Insufficient cholesterol synthesis in the liver of dairy cows during the peripartum period leads to triglyceride accumulation and exacerbates metabolic disorders. Phytosterols, as natural isomers of cholesterol, have a chemical structure highly similar to cholesterol. They can be effectively absorbed by dairy cows and positively regulate endogenous cholesterol metabolism, significantly reducing the incidence of ketosis and fatty liver, while also alleviating liver damage and improving energy metabolism indicators.

[0004] Current applications of phytosterols mainly involve adding them in trace amounts to the diet for their anti-inflammatory and antioxidant effects. However, feeding them to dairy cows during the peripartum period presents challenges such as cumbersome operation, inconvenient dosage control, and low bioavailability. Some formulations require complex coating processes, which increase production costs and may affect absorption. There is an urgent need for a phytosterol formulation that combines energy metabolism regulation and nutritional supplementation functions and is easy to use. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a phytosterol nutritional bar for regulating the energy metabolism imbalance of dairy cows during the peripartum period, solving the problems of inconvenient application forms and limited functions of existing phytosterols, and achieving the dual effects of regulating energy metabolism and supplementing nutrition in dairy cows during the peripartum period.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A phytosterol nutritional bar for regulating energy metabolism imbalance in peripartum dairy cows comprises the following raw materials in parts by weight: 30-35 parts phytosterols, 1-2 parts vitamin E, 20-25 parts iron tetroxide, 2-3 parts calcium carbonate, 1-2 parts chenodeoxycholic acid, 3-5 parts hydroxypropyl methylcellulose, 1-2 parts calcium stearate, 1-2 parts microcrystalline cellulose, 4-5 parts maltodextrin, 12-15 parts hydrogenated palm oil, 3-5 parts conjugated linoleic acid glycerides, and 0.075-0.08 parts molecularly distilled monoglycerides.

[0008] Preferably, the hydrogenated palm oil is hydrogenated palm oil with a melting point of 42°C; in a specific embodiment of the present invention, the hydrogenated palm oil is food-grade or industrial-grade 42°C daily chemical detergent additive palm oil purchased from Shandong Junfeng Chemical Co., Ltd.

[0009] Preferably, the plant sterol nutrition bar for regulating energy metabolism imbalance in periparturient dairy cows has a cylindrical structure with a diameter of 3cm, a height of 8±0.2cm, a weight of 80±2g, and a moisture content of ≤4wt%. The cylindrical structure, which is the size of a feed, facilitates quantitative feeding. The moisture content of ≤4wt% ensures that the product has moderate hardness and avoids mold problems caused by excessive moisture content, thus extending the shelf life.

[0010] The raw materials of the present invention are classified into the following categories:

[0011] (1) Core functional ingredients: phytosterols and vitamin E. Phytosterols (purity ≥95%, main components are β-sitosterol, stigmasterol and campesterol), as cholesterol isomers, can be effectively absorbed into the blood of dairy cows, increasing the levels of β-sitosterol, stigmasterol, campesterol and cholesterol in the blood, promoting the assembly and secretion of very low density lipoprotein in the liver, accelerating lipid turnover, and reducing the incidence of ketosis and fatty liver; vitamin E has enhanced antioxidant capacity, can reduce the damage of oxidative stress to the liver, and further optimize the metabolic regulation effect.

[0012] (2) Nutritional supplement ingredients: iron oxide and calcium carbonate. Iron oxide helps stabilize the structure of the nutritional bar after molding through reasonable density design; calcium carbonate supplements calcium, maintains the health of dairy cow bones and neuromuscular function, and improves the absorption and utilization rate of calcium.

[0013] (3) Synergistic ingredient: chenodeoxycholic acid. Chenodeoxycholic acid can enhance the abundance of intestinal phytosterol metabolism-sensitive bacteria, synergistically regulate lipid metabolism with phytosterols, promote cholesterol conversion and utilization, and enhance the energy metabolism regulation effect.

[0014] (4) Molding auxiliary materials: hydroxypropyl methylcellulose, calcium stearate, microcrystalline cellulose, maltodextrin, 42° hydrogenated palm oil and conjugated linoleic acid glycerides. Hydroxypropyl methylcellulose (HPMC) and calcium stearate work together as binders and lubricants to improve the molding properties and demolding effect of the mixture; microcrystalline cellulose enhances the structural stability of the product and prevents breakage during storage and transportation; maltodextrin improves the viscosity and mixing uniformity of raw materials and has excellent adsorption properties for sterols, thus improving the molding effect; 42° hydrogenated palm oil and conjugated linoleic acid glycerides can both slow down the release rate of phytosterols in the rumen and improve bioavailability, and optimize the dispersibility and stability of fat-soluble nutrients in the product.

[0015] Another objective of this invention is to provide a method for preparing phytosterol nutritional bars that regulate energy metabolism imbalance in peripartum dairy cows, comprising the following steps:

[0016] (1) Raw material pretreatment: Phytosterol, iron oxide and calcium carbonate are passed through an 80-mesh sieve and then dried. Sieving can remove large-diameter impurities and ensure that the raw material particles are uniform and fine, avoiding large particles from affecting the mixing effect and molding quality. Vacuum drying prevents moisture absorption and clumping during subsequent storage and processing, ensuring product stability. In this process, sieving and vacuum drying are combined to take into account the uniformity, dryness and activity retention of the raw materials, laying the foundation for subsequent mixing and molding.

[0017] (2) Targeted encapsulation and emulsification of functional components: Hydrogenated palm oil and conjugated linoleic acid glycerides are mixed in proportion and heated to melt. Molecularly distilled monoglycerides are added and mixed and sheared to obtain molten oil. Vitamin E is dispersed into the molten oil ester by homogenization to obtain an encapsulated oil phase system. This improves the stability and targeted release effect of fat-soluble functional components.

[0018] (3) High homogeneity mixing of multiphase system: microcrystalline cellulose, calcium stearate, maltodextrin and hydroxypropyl methylcellulose are premixed according to the ratio to obtain a solid carrier; pretreated phytosterols, iron oxide, calcium carbonate and chenodeoxycholic acid are added to the solid carrier, and then the embedded oil phase system is added, sheared and emulsified to obtain a mixture.

[0019] (4) Controllable pressure gradient pressing molding: The mixture is filled into a mold and pressed into shape;

[0020] (5) Segmented low-temperature air drying and quality curing: Demold the product after pressing and drying it until the product moisture content is ≤4wt%, and then carry out crystal stabilization treatment to obtain the plant sterol nutritional bar that regulates the energy metabolism imbalance of dairy cows during the peripartum period.

[0021] Preferably, the drying process in step (1) is carried out under a negative pressure of 0.08-0.1MPa and a temperature of 30-40℃ for 3-4 hours, with the water activity of the raw material controlled to be ≤0.3, and then cooled to 25±1℃.

[0022] Preferably, the temperature of heating to the melting point in step (2) is 55-65°C; the shearing speed is 1200-1300 rpm, and the shearing time is 5-8 min.

[0023] Preferably, the rotation speed of the shear emulsification in step (3) is 2000-2500 rpm, the shearing time is 20-25 min, and nitrogen gas is introduced for protection during shear emulsification to ensure that the components are fully integrated, avoid uneven local concentration and oxidation of components, and keep the oxygen content of the mixed system at about 0.4%.

[0024] Preferably, the pressing method in step (4) is as follows: first, pre-press with 5 tons of pressure for 30-35 seconds to release the air, then maintain pressure with 10 tons of pressure for 2-3 minutes, and finally stabilize with 8 tons of pressure for 1-1.5 minutes.

[0025] Preferably, the air-drying method in step (5) is as follows: air-dry for 2-2.5 hours at 20-25℃ and 40-45% relative humidity to remove free surface moisture; then continue air-drying for 1.5-2 hours at 28-30℃ and 30-35% relative humidity.

[0026] Preferably, the crystal stabilization treatment in step (5) is performed by placing the crystal in a dark environment at 20-25°C for 5-6 hours to stabilize the crystal form of the components, thereby avoiding damage to active ingredients such as phytosterols by high-temperature drying and ensuring stable product quality.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. Comprehensive and synergistic nutritional functions: It integrates the core role of phytosterols in metabolic regulation, the calcium supplementation effect of calcium carbonate, the metabolic assistance effect of vitamin E, and the synergistic effect of chenodeoxycholic acid in lipid metabolism, addressing the energy metabolism imbalance, nutritional deficiencies, and health protection needs of dairy cows during the peripartum period from multiple dimensions, and achieving one-stop nutritional supply.

[0029] 2. Excellent Formability and Stability: Utilizing a multiphase system and controllable pressure gradient molding process, the nutrient bars exhibit a dense structure and stable molding. Compressive strength tests show that the nutrient bars did not crack or crumble at the edges under approximately 0.09 tons of pressure, indicating that the product is not easily broken and is suitable for transportation and large-scale application. After segmented low-temperature air drying, the initial moisture content of the finished product was 3.3 wt%. After storage at 25℃ and 60% relative humidity for 30 days, the moisture content only increased to 3.5 wt%, without any moisture absorption, softening, or mold growth, demonstrating excellent structural and storage stability.

[0030] 3. High bioavailability: Precise pretreatment of raw materials, targeted encapsulation and emulsification of functional components, and highly homogenized mixing process of multiphase system ensure uniform dispersion of each component; composite oil ester carrier slows down the release rate of phytosterols and increases their retention time in the rumen; quantitative feeding program matches the key time window of metabolic regulation, ensuring efficient absorption and utilization of nutrients and reducing the incidence of energy metabolism imbalance diseases.

[0031] 4. Easy to operate: The molded nutrition bars make it easy to accurately control the feeding dosage, eliminating the need for complicated feeding operations, reducing labor intensity, and making them suitable for large-scale dairy farming scenarios; all raw materials used are feed-grade safe ingredients with a scientific and reasonable ratio, without harmful additives, and have no adverse effects on the safety of dairy cows and dairy products. Attached Figure Description

[0032] Figure 1 Image of the phytosterol nutrient bar prepared in Example 1. Detailed Implementation

[0033] The present invention will be further described below with reference to the embodiments.

[0034] Example 1

[0035] A plant sterol nutritional bar for regulating energy metabolism imbalance in peripartum dairy cows is composed of the following raw materials in parts by weight: 30 parts plant sterol (95% purity, containing 65% β-sitosterol, 20% stigmasterol, and 10% campesterol), 20 parts iron oxide, 2 parts calcium carbonate, 1 part microcrystalline cellulose, 1 part calcium stearate, 4 parts maltodextrin, 3 parts hydroxypropyl methylcellulose, 1 part vitamin E, 1 part chenodeoxycholic acid, 12 parts 42° hydrogenated palm oil, 3 parts conjugated linoleic acid glycerides, and 0.075 parts molecularly distilled monoglycerides.

[0036] The preparation method of the plant sterol nutritional bar for regulating energy metabolism imbalance in peripartum dairy cows includes the following steps:

[0037] (1) Raw material pretreatment: Phytosterol, iron oxide and calcium carbonate were passed through an 80-mesh sieve. The sieved raw materials were placed in a vacuum drying oven and dried for 3.5 hours under a negative pressure of 0.08 MPa and a temperature of 35°C. After cooling to 25°C, the water activity of the raw materials was measured to be 0.28. The raw materials were then cooled to 25°C for later use.

[0038] (2) Targeted encapsulation and emulsification of functional components: 42° hydrogenated palm oil and conjugated linoleic acid glycerides were mixed and heated to 0°C to melt. Molecularly distilled monoglycerides were added and sheared at 1200 rpm for 5 minutes to obtain molten oil. Vitamin E was dispersed into the molten oil ester by homogenization to obtain an encapsulated oil phase system.

[0039] (3) High homogeneity mixing of multiphase system: Microcrystalline cellulose, calcium stearate, maltodextrin and hydroxypropyl methylcellulose were mixed and premixed in a double helix conical mixer at 80 r / min for 10 minutes to obtain a solid support; pretreated phytosterols, iron oxide, calcium carbonate and vitamin E were added to the solid support, and then an embedded oil phase system was added. The mixture was then transferred to a high-speed shear emulsifier and sheared at 2500 rpm for 20 minutes while nitrogen protection was introduced. The oxygen content of the mixture was measured to be 0.4%.

[0040] (4) Controllable pressure gradient pressing molding: The mixture is filled into a customized cylindrical mold (inner diameter 3cm) in batches. First, it is pre-pressed with 5 tons of pressure for 30 seconds to release the air, then pressed with 10 tons of pressure for 2 minutes, and finally pressed with 8 tons of pressure for 1 minute.

[0041] (5) Segmented low-temperature air drying and quality curing: Demold the pressed product and place it in a constant temperature and humidity drying room. Air dry for 2 hours at 25℃ and 40% relative humidity. Adjust the parameters to 30℃ and 30% relative humidity and continue air drying for 1.5 hours. The moisture content of the finished product is 3.3wt%. Place the product in a 20℃, light-proof environment and let it stand for 6 hours to obtain the finished product. The structure is intact and without cracks. The nutrient bar has a cylindrical structure with a diameter of 3cm, a height of 8±0.2cm, and a single bar weight of 81g. Figure 1 .

[0042] Comparative Example 1

[0043] The difference from Example 1 is that hydroxypropyl methylcellulose is not added.

[0044] The preparation method is the same as in Example 1.

[0045] In Comparative Example 1, step (3) of the mixed system had an oxygen content of 0.45%.

[0046] Comparative Example 1: The final product had a moisture content of 3.6 wt% and a single piece weight of 79.5 g. It had insufficient structural density, was prone to chipping at the edges, and was susceptible to cracking under stress.

[0047] Through in vitro simulation of the digestive tract environment, the sustained-release time of the product in Comparative Example 1 was 1 day, which is much shorter than the 3-day continuous release time of the product in Example 1. The nutrients are released rapidly in the rumen, and the effective retention time is greatly shortened.

[0048] Comparative Example 2

[0049] The difference from Example 1 is that chenodeoxycholic acid is not added.

[0050] The preparation method is the same as in Example 1.

[0051] In Comparative Example 2, step (3) of the mixed system had an oxygen content of 0.42%.

[0052] Comparative Example 2: The final product had a moisture content of 3.4 wt%; the weight of a single piece was 79.5 g, the structure was intact, and there was no breakage.

[0053] Comparative Example 3

[0054] The difference from Example 1 is that no phytosterols and chenodeoxycholic acid are added.

[0055] The preparation method is the same as in Example 1.

[0056] In Comparative Example 3, step (3) of the mixed system had an oxygen content of 0.43%.

[0057] Comparative Example 3: The final product had a moisture content of 3.5 wt%; the weight of a single piece was 78 g, the structure was intact, and there was no breakage.

[0058] Comparative Example 4

[0059] The raw material composition is the same as in Example 1.

[0060] The difference between the preparation method and Example 1 is that in Comparative Example 4, step (4) pressing and molding stage: the mixture is filled into a customized cylindrical mold in batches and pressed and molded with a single constant pressure. The molding is completed directly with a constant pressure of 8 tons for 3 minutes without pre-pressurization, degassing and segmented pressure gradient control.

[0061] In Comparative Example 4, step (3) of the mixed system had an oxygen content of 0.4%;

[0062] The final product of Comparative Example 4 had a moisture content of 3.4 wt% and a single piece weight of 80 g. It had an intact appearance and structure, but its compressive strength was lower than that of the product in Example 1.

[0063] Performance verification and experimental data:

[0064] To verify the beneficial effects of the present invention and confirm the effectiveness of the actual feeding dosage, dosage calculation and in vitro sustained-release performance determination were carried out on the nutrition bars prepared in Example 1 and Comparative Examples 1-4.

[0065] Experiment 1: Determination of In Vitro Sustained-Release Performance

[0066] First, prepare the in vitro rumen fluid according to Table 1.

[0067] Table 1. Formulation and preparation parameters of in vitro simulated rumen fluid

[0068]

[0069] Ten L of simulated rumen fluid was used to add three nutrient sticks to each group, and the cumulative release rate of phytosterols in each group was measured at different time points. The simulated solution was made by mixing buffer and fresh rumen fluid at a ratio of 2:1 and incubating at 39℃ with shaking. Samples were taken at 12h, 24h, 36h, 48h, 60h, and 72h, and the results of the cumulative release rate of phytosterols in vitro are shown in Table 2.

[0070] Table 2. Cumulative in vitro release rate (%) of phytosterols in each example and comparative example

[0071]

[0072] Results Analysis: As shown in Table 2, Example 1 exhibited stable release with a good linear relationship, meeting the requirement of 3-day long-acting sustained release; Comparative Example 1 had a loose structure and disintegrated too quickly, releasing completely within 36 hours, failing to maintain the 3-day therapeutic effect; Comparative Example 2 had the same process as Example 1, with good sustained-release performance; Comparative Example 3 did not contain phytosterols, and release data were not collected; Comparative Example 4 showed significant burst release in the early stage, but release was hindered in the later stage due to pore blockage, resulting in low utilization rate. The phytosterol release rate fluctuated greatly within 72 hours, and the release uniformity was lower than that of Example 1, making it difficult to achieve stable daily dose release. Example 1 alone achieved uniform release of phytosterols within 72 hours using a gradient compression process combined with an HPMC / calcium stearate / microcrystalline cellulose composite binder system, with a release rate of approximately 33% every 24 hours. Comparative Example 1 verified the crucial role of hydroxypropyl methylcellulose as a skeleton material in sustained release; the absence of this component would lead to excessively rapid product disintegration. Comparative Example 4 demonstrated that the gradient compression process is superior to the constant pressure process, as the constant pressure process tends to result in an overly rigid outer shell and an overly loose inner shell, leading to problems such as rapid initial release and incomplete release in the later stages.

[0073] Experiment 2: In vivo rumen fistula-guided sustained-release experiment in cattle

[0074] To evaluate the in vivo sustained-release effect of the nutrient bars in the examples, the nutrient bars of Example 1, Comparative Example 2, and Comparative Example 3 were fed to dairy cows in rumen fistulas placed in nylon mesh. Three dairy cows were fed each type of nutrient bar. The remaining weight of the nutrient bars was taken out and weighed every 24 hours, and the sustained-release rate was calculated.

[0075] Table 3. Cumulative release rate of the nutrition bar in vivo (%)

[0076]

[0077] Results Analysis: The nutrient bars prepared using the technology in Example 1 showed stable release and a good linear relationship. Based on feeding 5 nutrient bars per cow per day, the total raw material components were 80.075 parts, of which 30 parts were phytosterols. With the finished weight of a single nutrient bar controlled at 80±2g, the theoretical phytosterol content per bar was approximately 30g. Therefore, the total amount of phytosterols injected into the rumen at one time was 150g, and the cumulative release rate within 72 hours reached over 95%. Thus, the average daily release was approximately: 150g ÷ 3 days = 50g / day.

[0078] Experiment 3: Feeding Experiment

[0079] Feeding trials were conducted using the nutrition bar products prepared in the examples and comparative examples:

[0080] Clinical feeding application: 27 healthy peripartum dairy cows were selected and randomly divided into experimental group A (fed with the nutrition bars of Example 1), experimental group B (fed with the nutrition bars of Comparative Example 2), and blank control group (fed with the nutrition bars of Comparative Example 3), with 9 cows in each group. Five nutrition bars were fed once on the day of calving and on the fourth day. Other feeding and management conditions were the same for the three groups. The composition and nutritional level of the basal diet are shown in Table 4.

[0081] Table 4. Composition and nutrient levels of the basal diet for the experimental dairy cows (dry matter basis)

[0082]

[0083] The clinical test results are shown in Table 5.

[0084] Table 5. Incidence of diseases caused by energy metabolism imbalance

[0085]

[0086] As shown in Table 5, the incidence of metabolic diseases in experimental group A (complete formula) was significantly lower than that in experimental group B and the blank control group. The effect of experimental group B was better than that of the blank control group but worse than that of experimental group A, which fully demonstrates that phytosterols are the core components for regulating energy metabolism, and chenodeoxycholic acid can further enhance its synergistic effect.

[0087] The effects of feeding on the level of sterols in the blood on day 7 are shown in Table 6.

[0088] Table 6. Effects of feeding on blood sterol levels on day 7.

[0089]

[0090] In Table 6, This indicates that the value was <0.05 compared to the blank control group. # indicates P<0.01 compared to the blank control group; # indicates P<0.05 compared to the experimental group B.

[0091] As shown in Table 6, the blood sterol levels on day 7 of feeding were detected using targeted metabolomics technology. The results are shown in Table 6. The levels of various sterol substances in experimental group A were significantly higher than those in the other two groups. Although the levels in experimental group B were higher than those in the blank control group, the increase was significantly lower than that in experimental group A. The blank control group had the lowest sterol content, which was consistent with the clinical disease incidence results.

[0092] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A plant sterol nutritional bar for regulating energy metabolism imbalance in peripartum dairy cows, characterized in that, The ingredients include the following parts by weight: 30-35 parts phytosterols, 1-2 parts vitamin E, 20-25 parts iron oxide, 2-3 parts calcium carbonate, 1-2 parts chenodeoxycholic acid, 3-5 parts hydroxypropyl methylcellulose, 1-2 parts calcium stearate, 1-2 parts microcrystalline cellulose, 4-5 parts maltodextrin, 12-15 parts hydrogenated palm oil, 3-5 parts conjugated linoleic acid glycerides, and 0.075-0.08 parts molecularly distilled monoglycerides.

2. The phytosterol nutritional bar for regulating energy metabolism imbalance in peripartum dairy cows according to claim 1, characterized in that, The plant sterol nutrition bar for regulating energy metabolism imbalance in periparturient dairy cows has a cylindrical structure with a diameter of 3cm, a height of 8±0.2cm, a weight of 80±2g, and a water content of ≤4wt%.

3. The method for preparing the phytosterol nutritional bar for regulating energy metabolism imbalance in peripartum dairy cows according to claim 1, characterized in that, Includes the following steps: (1) Raw material pretreatment: Phytosterol, iron oxide and calcium carbonate are passed through an 80-mesh sieve and the sieved raw materials are dried. (2) Targeted encapsulation and emulsification of functional components: Hydrogenated palm oil and conjugated linoleic acid glycerides are mixed in proportion and heated to melt. Molecularly distilled monoglycerides are added and mixed and sheared to obtain molten oil. Vitamin E is dispersed into the molten oil ester by homogenization to obtain an encapsulated oil phase system. (3) High homogeneity mixing of multiphase system: microcrystalline cellulose, calcium stearate, maltodextrin and hydroxypropyl methylcellulose are premixed according to the ratio to obtain a solid carrier; pretreated phytosterols, iron oxide, calcium carbonate and chenodeoxycholic acid are added to the solid carrier, and then the embedded oil phase system is added, sheared and emulsified to obtain a mixture. (4) Controllable pressure gradient pressing molding: The mixture is filled into a mold and pressed into shape; (5) Segmented low-temperature air drying and quality curing: Demold the product after pressing and drying it until the product moisture content is ≤4wt%, and then carry out crystal stabilization treatment to obtain the plant sterol nutritional bar that regulates the energy metabolism imbalance of dairy cows during the peripartum period.

4. The method for preparing the phytosterol nutritional bar for regulating energy metabolism imbalance in periparturient dairy cows according to claim 3, characterized in that, The drying process described in step (1) involves drying under a negative pressure of 0.08-0.1 MPa and a temperature of 30-40°C for 3-4 hours, controlling the water activity of the raw material to be ≤0.3, and then cooling to 25±1°C.

5. The method for preparing the phytosterol nutritional bar for regulating energy metabolism imbalance in peripartum dairy cows according to claim 3, characterized in that, Step (2) Heating to a melting temperature of 55-65℃; the shearing speed is 1200-1300 rpm, and the shearing time is 5-8 min.

6. The method for preparing the phytosterol nutritional bar for regulating energy metabolism imbalance in peripartum dairy cows according to claim 3, characterized in that, In step (3), the rotation speed of shear emulsification is 2000-2500 rpm, the shearing time is 20-25 min, and nitrogen gas is introduced for protection during shear emulsification.

7. The method for preparing the phytosterol nutritional bar for regulating energy metabolism imbalance in peripartum dairy cows according to claim 3, characterized in that, The pressing method described in step (4) is as follows: first, pre-press with 5 tons of pressure for 30-35 seconds to release the air, then maintain pressure with 10 tons of pressure for 2-3 minutes, and finally stabilize with 8 tons of pressure for 1-1.5 minutes.

8. The method for preparing the phytosterol nutritional bar for regulating energy metabolism imbalance in peripartum dairy cows according to claim 3, characterized in that, The air-drying method described in step (5) is as follows: air-dry for 2-2.5 hours at 20-25℃ and 40-45% relative humidity to remove free surface moisture; then continue air-drying for 1.5-2 hours at 28-30℃ and 30-35% relative humidity.

9. The method for preparing the phytosterol nutritional bar for regulating energy metabolism imbalance in peripartum dairy cows according to claim 3, characterized in that, The method for stabilizing the crystal form in step (5) is as follows: let it stand for 5-6 hours in a dark environment at 20-25℃ to complete the stabilization of the crystal form of the component.

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