Application of luteolin in regulating lipid metabolism disorder and inflammatory response in ketotic dairy cows

Abstract

This invention discloses the application of luteolin in regulating lipid metabolism disorders and inflammatory responses in ketotic dairy cows, elucidating the application of luteolin as a flavonoid compound in improving lipid metabolism and inflammatory responses in ketotic dairy cows. This invention found that luteolin intervention significantly reduced the levels of β-hydroxybutyrate, NEFA, and pro-inflammatory factors in ketotic dairy cows, while increasing the levels of glucose, insulin, and the anti-inflammatory factor IL-10, thereby regulating lipid metabolism disorders and inflammatory responses caused by negative energy balance in ketotic dairy cows. Furthermore, analysis of dairy cow milk components revealed that luteolin intervention significantly reduced milk fat percentage and somatic cell count in ketotic dairy cows, while significantly increasing milk protein and milk yield, contributing to improved production efficiency and milk quality.

Description

Technical Field

[0001] This invention relates to the field of animal husbandry and veterinary medicine technology, specifically the application of luteolin in regulating lipid metabolism disorders and inflammatory responses in ketotic dairy cows, with the aim of improving the production performance of ketotic dairy cows. Background Technology

[0002] Ketosis in dairy cows is a common herd disease, particularly prevalent in the peripartum period. It typically occurs within one month postpartum (most commonly within three weeks). Ketosis is a metabolic disorder caused by insufficient energy supply and high energy demands during lactation, leading to a negative energy balance (NEB) in the cow. The energy balance in dairy cows is influenced by energy intake, maintenance needs, and lactation requirements. Although feed intake increases along with milk production in early lactation, high-producing cows at this stage may still not consume enough feed to meet their energy needs, further causing endocrine and metabolic changes, mobilizing fat and skeletal muscle protein, resulting in excessive fat mobilization. During the peripartum period, dairy cows have low insulin levels and reduced glucose utilization by tissues, necessitating the breakdown of fat as an energy source. Triglycerides (TG) stored in fat are hydrolyzed into non-esterified fatty acids (NEFA) and glycerol. Part of the NEFA enters mammary epithelial cells for milk fat synthesis, while the rest enters liver cells as an energy source. Ketosis in dairy cows commonly presents with inflammatory damage and oxidative stress, associated with elevated levels of pro-inflammatory factors such as interleukin-6 (IL-6), interleukin-1beta (IL-1β), and tumor necrosis factor-alpha (TNF-α) in the blood. Furthermore, ketosis reduces immunity, increases the risk of mastitis and endometritis, prolongs the postpartum estrus interval, severely impairs reproductive performance, and causes significant economic losses to farms.

[0003] Luteolin (LUT) belongs to the flavonoid polyphenol family and is a 3′,4′,5,7-tetrahydroxy flavonoid widely distributed in flowers, herbs, vegetables, and spices. It is absorbed from the intestine in free or glycosylated form and metabolized into glucuronic acid or sulfate conjugates. Luteolin has been reported to have antioxidant, antibacterial, and anti-inflammatory effects and can be used to treat gout, asthma, psoriasis, and erythema. Adipose tissue, as an important organ for metabolic control, dynamically responds to changes in nutrient deficiency and excess through adipocyte hypertrophy and proliferation. Related studies have shown that luteolin exerts its anti-obesity and anti-diabetic effects through adipose tissue, including reducing lipid peroxidation and increasing antioxidant enzyme activity; reducing adipocyte hypertrophy and mast cell infiltration into adipose tissue; improving glucose uptake and insulin sensitivity; and inhibiting adipose tissue inflammation, improving glucose and lipid metabolism disorders and alleviating inflammatory responses through various molecular mechanisms. To date, there has been little research on luteolin in ruminants. This invention uses ketogenic dairy cows as the research subject to explore its effects on lipid metabolism and inflammatory response in ketogenic dairy cows, providing new ideas and methods for the prevention and treatment of ketogenic dairy cows, which will help promote the sustainable development of animal husbandry and enrich the selection of feed additives.

[0004] Therefore, this invention used 5 healthy dairy cows and 20 ketogenic dairy cows with similar body condition and parity as research subjects. They were divided into a healthy control group, a ketogenic control group, and low, medium, and high-dose luteolin treatment groups. Milk protein, milk fat, lactose, and somatic cell count were measured using a milk component analyzer; the levels of β-hydroxybutyrate, acetoacetic acid, and acetone were measured using a fully automated blood analyzer; and the levels of serum lipid metabolism-related indicators such as NEFA, TG, and TC, and inflammatory factors such as IL-1β, TNF-α, and IL-10 were measured using ELISA and biochemical reagent kits. This provides a theoretical basis for the application of luteolin as a feed additive in dairy farming to improve the production performance, lipid metabolism disorders, and inflammatory responses in ketogenic dairy cows. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides an application of luteolin in regulating lipid metabolism disorders and inflammatory responses in ketotic dairy cows, which has the advantages of effectively improving lipid metabolism disorders and alleviating inflammatory responses in ketotic dairy cows.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the present invention provides the following technical solution: The application of luteolin in regulating lipid metabolism disorder and inflammatory response in ketotic dairy cows, comprising the following steps: Main reagent: Luteolin (98% purity) S1. Grouping: Five healthy dairy cows with similar body condition and parity were selected as the healthy control group using a blood ketone meter, and 20 dairy cows with ketosis (blood β-hydroxybutyrate BHBA concentration > 1.2 mmol / L) were selected and randomly divided into 4 groups: ketosis control group, low-dose luteolin group [5 g / (cow·d)], medium-dose luteolin group [10 g / (cow·d)], and high-dose luteolin group [15 g / (cow·d)]. The experimental period was 8 days. S2. Effects of luteolin on the production performance of dairy cows with ketosis. Milk samples were collected from the healthy control group (n=5), the ketosis control group (n=5), the luteolin [5 g / (cow·d)] group (n=5), the luteolin [10 g / (cow·d)] group (n=5), and the luteolin [15 g / (cow·d)] group (n=5) at the first milking on days 0, 3, 5, and 8 of the experiment. The samples were preserved and transported to the testing site at 4°C within 12 hours. The daily milk yield was determined in conjunction with the farm records. The milk fat percentage, milk protein percentage, blood urea nitrogen, and somatic cell count were measured using a milk composition and somatic cell analysis system. S3. Effects of luteolin on glucose and lipid metabolism in ketotic dairy cows Blood samples of 20 mL were collected from the tail vein of the healthy control group (n=5), the ketosis control group (n=5), the luteolin [5 g / (cow·d)] group (n=5), the luteolin [10 g / (cow·d)] group (n=5), and the luteolin [15 g / (cow·d)] group (n=5) before morning feeding on days 0, 3, 5, and 8 of the experiment. The serum was separated by centrifugation at 3,500×g for 15 min at 4 ℃ and stored at -20 ℃ for subsequent testing. S4. Effects of luteolin on lipid metabolism disorders in ketotic dairy cows Blood samples of 20 mL were collected from the tail vein of the healthy control group (n=5), the ketosis control group (n=5), the luteolin (5 g / cow / d) group (n=5), the luteolin [5 g / (cow·d)] group (n=5), the luteolin [10 g / (cow·d)] group (n=5), and the luteolin [15 g / (cow·d)] group (n=5) before morning feeding on days 0, 3, 5, and 8 of the experiment. The serum was separated by centrifugation at 3,500×g for 15 min at 4 ℃ and stored at -20 ℃ for subsequent testing. S5. Effects of luteolin on inflammatory response in dairy cows with ketosis. On days 0, 3, 5, and 8 of the experiment, before morning feeding, 20 mL of blood samples were collected from the tail vein of the healthy control group (n=5), the ketosis control group (n=5), the luteolin [5 g / (cow·d)] group (n=5), the luteolin [10 g / (cow·d)] group (n=5), and the luteolin [15 g / (cow·d)] group (n=5). The samples were centrifuged at 3,500×g for 15 min at 4 ℃, and the serum was separated and stored at -20 ℃ for subsequent testing. Preferably, according to step S2, the experimental method is as follows: One preservative capsule (containing 20 mg of bromonitrobenzene glycol) is pre-placed in a sampling bottle (50 mL). Milk samples are collected from each cow: healthy control group (n=5), ketosis control group (n=5), luteolin [5 g / (cow·d)] group (n=5), luteolin [10 g / (cow·d)] group (n=5), and luteolin [15 g / (cow·d)] group (n=5). 40 mL of milk is collected from each cow. Milking is done in a 6:4 ratio (morning:evening) for two shifts. After collection, the samples are shaken until the preservative is completely dissolved. The samples are transported to the laboratory at 4°C within two days. For cows participating in the DHI assay, the ear tag number, parity, calving date, sampling date, number of days of lactation, and daily milk yield are recorded.

[0009] Preferably, according to step S3, the experimental method is as follows: serum samples were extracted from healthy control group (n=5), ketosis control group (n=5), luteolin [5 g / (cow·d)] group (n=5), luteolin [10 g / (cow·d)] group (n=5), and luteolin [15 g / (cow·d)] group (n=5) according to the instructions of BHBA, ACAC, Glu biochemical reagent kits, etc., and the effects of different doses of luteolin on the regulation of glucose and lipid metabolism in ketosis dairy cows were detected.

[0010] Preferably, according to step S4, the experimental method is as follows: serum samples were extracted from healthy control group (n=5), ketosis control group (n=5), luteolin [5 g / (cow·d)] group (n=5), luteolin [10 g / (cow·d)] group (n=5), and luteolin [15 g / (cow·d)] group (n=5) according to the instructions of TG, TC, NEFA, HDL-C and LDL-C ELISA kits, and the effects of different doses of luteolin on lipid metabolism disorder in ketosis dairy cows were detected.

[0011] Preferably, according to step S5, the experimental method is as follows: serum samples were extracted from healthy control group (n=5), ketosis control group (n=5), luteolin [5 g / (cow·d)] group (n=5), luteolin [10 g / (cow·d)] group (n=5), and luteolin [15 g / (cow·d)] group (n=5) according to the instructions of the TL-6, IL-8, IL-10, IL-1β and TNF-α ELISA detection kits, and the effects of different doses of luteolin on the inflammatory response of ketosis dairy cows were detected.

[0012] (III) Beneficial Effects

[0013] Compared with the prior art, the present invention provides an application of luteolin in regulating lipid metabolism disorder and inflammatory response in ketotic dairy cows, which has the following beneficial effects: 1. Analysis of dairy cow milk components revealed that luteolin intervention significantly reduced milk fat percentage and somatic cell count in ketotic dairy cows, while significantly increasing milk protein and milk yield, thus helping to improve production efficiency and milk quality. This invention reveals that luteolin can effectively improve lipid metabolism disorders and alleviate inflammatory responses in ketotic dairy cows, and can be used as a feed additive or veterinary preparation, providing a theoretical basis for the prevention and treatment of ketosis, and has good application prospects. Attached Figure Description

[0014] Figure 1 The structural formula of luteolin; Figure 2 The effects of different doses of luteolin on the production performance of dairy cows with ketosis; Figure 3 The effects of different doses of luteolin on the regulation of glucose and lipid metabolism in dairy cows with ketosis; Figure 4 The effects of different doses of luteolin on the regulation of lipid metabolism in ketotic dairy cows; Figure 5 To investigate the effects of different doses of luteolin on the regulation of inflammatory response in dairy cows with ketosis. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0016] Please see Figure 1-5 This invention provides the application of luteolin in regulating lipid metabolism disorder and inflammatory response in ketotic dairy cows, comprising the following steps: Main reagent: Luteolin (98% purity) Modeling method: Five healthy dairy cows with similar body condition and parity were selected as the healthy control group using a blood ketone meter, and 20 dairy cows with ketosis (BHBA content higher than 1.2 mmol / L) were randomly divided into four groups: ketosis control group, low-dose luteolin group [5 g / (cow·d)], medium-dose luteolin group [10 g / (cow·d)], and high-dose luteolin group [15 g / (cow·d)]. The experimental period was one week.

[0017] Example 1: Effects of luteolin on the production performance of dairy cows with ketosis Ketosis has a comprehensive, profound, and significant impact on dairy cow productivity, causing substantial economic losses. It not only leads to a temporary decrease in milk production but also has a cascading effect on the entire lactation cycle, reproductive efficiency, and herd turnover. In ketotic cows, milk production decreases, milk fat and protein percentages fluctuate, somatic cell counts increase, and reproductive performance is affected by delayed ovulation and non-pregnancy, or various complications such as metritis and mastitis may develop. Therefore, it is crucial to monitor various indicators in dairy cows in advance. This study investigates the impact of luteolin on the productivity of ketotic cows by analyzing various indicators using a milk component analyzer.

[0018] Main instruments: Milk component and somatic cell analysis system (FOSS CombiFoss FT+), digital display water bath (QTF-303B), centrifuge, etc. Main reagents: Luteolin (98% purity), etc. Animal groups: healthy control group (n=5), ketosis control group (n=5), luteolin [5 g / (cow·d)] group (n=5), luteolin [10 g / (cow·d)] group (n=5), luteolin [15 g / (cow·d)] group (n=5), luteolin was administered by gavage.

[0019] Sample collection: Milk samples were collected from the healthy control group (n=5), ketosis control group (n=5), luteolin [5 g / (cow·d)] group (n=5), luteolin [10 g / (cow·d)] group (n=5), and luteolin [15 g / (cow·d)] group (n=5) at the first milking on days 0, 3, 5, and 8 of the experiment. The samples were preserved and transported to the testing facility at 4°C within 12 hours. The daily milk yield was determined in conjunction with the farm records. Milk fat percentage, milk protein percentage, blood urea nitrogen, and somatic cell count were measured using a milk composition and somatic cell analysis system.

[0020] Experimental Methods: One preservative capsule (containing 20 mg of bromonitrile glycol) was placed in each 50 mL sampling bottle. Milk samples were collected from each cow: healthy control group (n=5), ketosis control group (n=5), luteolin [5 g / (cow·d)] group (n=5), luteolin [10 g / (cow·d)] group (n=5), and luteolin [15 g / (cow·d)] group (n=5). 40 mL of milk was collected from each cow. Milking was carried out in a 6:4 ratio (morning:evening) for two shifts. After collection, the samples were shaken until the preservative was completely dissolved. The samples were transported to the laboratory at 4℃ within 2 days. For cows participating in the DHI assay, the ear tag number, parity, calving date, sampling date, number of days of lactation, and daily milk yield were recorded.

[0021] The testing method was carried out in accordance with the "Technical Specification for Determination of Production Performance of Holstein Cattle in China" (NY / T 1450—2007). The samples were preheated at 42 ℃ for 15 to 20 minutes, shaken well, and then loaded onto the instrument. The instrument read out the indicators such as milk fat percentage, milk protein percentage, urea nitrogen, and somatic cell count in one go.

[0022] Figure 2 To investigate the effects of different doses of luteolin on the production performance of ketotic dairy cows, compared with ketotic dairy cows, medium and high doses of luteolin significantly increased milk yield in ketotic dairy cows during the experimental period. Meanwhile, low, medium and high doses of luteolin significantly reduced milk fat percentage and fat-to-protein ratio starting from day three, significantly increased milk protein content on day eight, and significantly reduced somatic cell count in ketotic dairy cows on day five, thus improving milk quality and enhancing the production performance of ketotic dairy cows.

[0023] Example 2: Effects of luteolin on glucose and lipid metabolism in ketotic dairy cows To investigate the role of luteolin in the regulation of glucose and lipid metabolism in ketotic dairy cows, blood was collected from the tail vein at 0, 3, 5, and 8 days before morning feeding. 20 mL of blood was collected and the serum was separated by centrifugation at 3,500 × g for 15 min at 4°C. The serum was then stored at -20°C. The levels of β-hydroxybutyrate, acetone, acetoacetic acid, glucose, and insulin in the collected serum were measured using a biochemical kit to reveal the regulatory role of luteolin in glucose and lipid metabolism in ketotic dairy cows.

[0024] Main instruments: MR-96A microplate reader (Mindray Medical, China), centrifuge, etc.

[0025] Main reagents: luteolin (98% purity), BHBA, ACAC, Glu biochemical reagent kit, etc.

[0026] Animal groups: healthy control group (n=5), ketosis control group (n=5), luteolin [5 g / (cow·d)] group (n=5), luteolin [10 g / (cow·d)] group (n=5), luteolin [15 g / (cow·d)] group (n=5), luteolin was administered by gavage.

[0027] Sample collection: On days 0, 3, 5, and 8 of the experiment, before morning feeding, 20 mL of tail vein blood samples were collected from the healthy control group (n=5), the ketosis control group (n=5), the luteolin [5 g / (cow·d)] group (n=5), the luteolin [10 g / (cow·d)] group (n=5), and the luteolin [15 g / (cow·d)] group (n=5). The samples were centrifuged at low temperature, and the supernatant was collected and stored at -20°C for subsequent testing.

[0028] Experimental methods: Serum samples were extracted from healthy control group (n=5), ketosis control group (n=5), luteolin [5 g / (cow·d)] group (n=5), luteolin [10 g / (cow·d)] group (n=5), and luteolin [15 g / (cow·d)] group (n=5) according to the instructions of BHBA, ACAC, and Glu biochemical reagent kits. The effects of different doses of luteolin on the regulation of glucose and lipid metabolism in ketosis dairy cows were detected.

[0029] Figure 3 To investigate the effects of different doses of luteolin on glucose and lipid metabolism regulation in ketotic dairy cows, compared with ketotic cows, low, medium, and high doses of luteolin significantly reduced β-hydroxybutyrate levels starting from day 5 of the experiment. However, compared with healthy controls and ketotic cows, low, medium, and high doses of luteolin did not significantly change the levels of acetoacetic acid and acetone. Meanwhile, low, medium, and high doses of luteolin significantly increased glucose levels on day 8 of the experiment, and high-dose luteolin significantly increased insulin levels on day 5 of the experiment. In conclusion, luteolin can effectively alleviate glucose and lipid metabolism disorders in ketotic dairy cows.

[0030] Example 3: Effects of luteolin on lipid metabolism disorder in ketotic dairy cows The concentration of NEFA in the blood is now used as an early warning indicator of negative energy balance. Due to negative energy balance, peripheral adipose tissue is mobilized in large quantities, causing the body's stored energy TG to be broken down into NEFA and glycerol to provide energy for other tissues. When the TG content decreases, the synthesis of very low-density lipoprotein (VLDL) is inhibited, and its secreted product, very low-density lipoprotein cholesterol (LDL-C), also decreases. Cholesterol exists in the blood in the form of lipoproteins and is transported to extrahepatic tissues via LDL-C. Therefore, by collecting blood and serum to detect lipid metabolism-related indicators such as TG, TC, NEFA, and LDL-C, this study explores the regulatory effect of luteolin on lipid metabolism in ketotic dairy cows.

[0031] Main instruments: MR-96A microplate reader (Mindray Medical, China), centrifuge, etc.

[0032] Main reagents: luteolin (98% purity), TG, TC, NEFA, HDL-C and LDL-C ELISA detection kits, etc.

[0033] Animal groups: healthy control group (n=5), ketosis control group (n=5), luteolin [5 g / (cow·d)] group (n=5), luteolin [10 g / (cow·d)] group (n=5), luteolin [15 g / (cow·d)] group (n=5), luteolin was administered by gavage.

[0034] Sample collection: On days 0, 3, 5, and 8 of the experiment, before morning feeding, 20 mL of tail vein blood samples were collected from the healthy control group (n=5), the ketosis control group (n=5), the luteolin [5 g / (cow·d)] group (n=5), the luteolin [10 g / (cow·d)] group (n=5), and the luteolin [15 g / (cow·d)] group (n=5). The samples were centrifuged at low temperature, and the supernatant was collected and stored at -20°C for subsequent testing.

[0035] Experimental methods: Serum samples were extracted from healthy control group (n=5), ketosis control group (n=5), luteolin [5 g / (cow·d)] group (n=5), luteolin [10 g / (cow·d)] group (n=5), luteolin [15 g / (cow·d)] group (n=5), and luteolin (15 g / cow / d) group (n=5) according to the instructions of TG, TC, NEFA, HDL-C and LDL-C ELISA kits. The effects of different doses of luteolin on lipid metabolism disorder in ketosis dairy cows were detected.

[0036] Figure 4To investigate the effects of different doses of luteolin on lipid metabolism regulation in ketotic dairy cows, compared with healthy dairy cows, ketotic dairy cows showed significantly increased NEFA levels and significantly decreased TG, TC, and LDL-C levels. After feeding with luteolin, low, medium, and high doses all significantly reduced NEFA levels on the third day of the experiment. High doses of luteolin significantly increased TG levels on the fifth day of feeding and significantly increased TC and LDL-C levels on the eighth day of the experiment, indicating that luteolin plays a certain regulatory role in lipid metabolism in ketotic dairy cows.

[0037] Example 4: Effect of luteolin on inflammatory response in dairy cows with ketosis During the inflammatory response, the immune system is activated and releases a large number of immune cells and cytokines to the affected area. These cells and factors work together to fight infection and initiate the healing process. In the study of ketotic dairy cows, the liver showed a severe inflammatory response, mainly manifested as the large production of inflammatory mediators, impaired hepatocyte function, and decreased liver function, such as elevated levels of TNF-α and decreased levels of the anti-inflammatory cytokine IL-10. Therefore, the levels of pro-inflammatory factors IL-6, IL-8, IL-1β, TNF-α, and anti-inflammatory factor IL-10 in serum were detected using an ELISA kit to elucidate the regulatory role of luteolin in the inflammatory response of ketotic dairy cows.

[0038] Main instruments: MR-96A microplate reader (Mindray Medical, China), centrifuge, etc.

[0039] Main reagents: Luteolin (98% purity), IL-6, IL-8, IL-10, IL-1β and TNF-α ELISA detection kit.

[0040] Animal groups: healthy control group (n=5), ketosis control group (n=5), luteolin (5 g / cow / d) group (n=5), luteolin [5 g / (cow·d)] group (n=5), luteolin [10 g / (cow·d)] group (n=5), luteolin [15 g / (cow·d)] group (n=5), luteolin was administered by gavage.

[0041] Sample collection: On days 0, 3, 5, and 8 of the experiment, before morning feeding, 20 mL of tail vein blood samples were collected from the healthy control group (n=5), the ketosis control group (n=5), the luteolin [5 g / (cow·d)] group (n=5), the luteolin [10 g / (cow·d)] group (n=5), and the luteolin [15 g / (cow·d)] group (n=5). The samples were centrifuged at low temperature, and the supernatant was collected and stored at -20°C for subsequent testing.

[0042] Experimental methods: Serum samples were extracted from healthy control group (n=5), ketosis control group (n=5), luteolin [5 g / (cow·d)] group (n=5), luteolin [10 g / (cow·d)] group (n=5), and luteolin [15 g / (cow·d)] group (n=5) according to the instructions of the TL-6, IL-8, IL-10, IL-1β and TNF-α ELISA kits, and the effects of different doses of luteolin on the inflammatory response of ketosis dairy cows were detected.

[0043] Figure 5 To investigate the effects of different doses of luteolin on the regulation of inflammatory responses in ketotic dairy cows, compared with healthy dairy cows, ketotic dairy cows had significantly higher levels of pro-inflammatory factors and lower levels of anti-inflammatory factors. After feeding low, medium and high doses of luteolin, it was found that high doses of luteolin significantly increased the content of the anti-inflammatory factor IL-10 on day 5 of the experiment, and decreased the content of pro-inflammatory factors IL-1β, IL-6, IL-8 and TNF-α on day 8 of the experiment, thus alleviating the inflammatory response in ketotic dairy cows.

[0044] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. The application of luteolin in the preparation of feed additives or veterinary formulations for regulating lipid metabolism disorders and inflammatory responses in dairy cows with ketosis, characterized in that, The luteolin was applied to dairy cows with ketosis at a dosage of 5–15 g / (cow·d), preferably 15 g / (cow·d); its application and efficacy verification included the following steps: Main reagent: Luteolin (98% purity) S1. Grouping: Five healthy dairy cows with similar body condition and parity were selected as the healthy control group using a blood ketone meter, and 20 dairy cows with ketosis (blood β-hydroxybutyrate BHBA concentration > 1.2 mmol / L) were selected and randomly divided into 4 groups: ketosis control group, low-dose luteolin group [5 g / (cow·d)], medium-dose luteolin group [10 g / (cow·d)], and high-dose luteolin group [15 g / (cow·d)]. The experimental period was 8 days. S2. Effects of luteolin on the production performance of dairy cows with ketosis. Milk samples were collected from the healthy control group (n=5), the ketosis control group (n=5), the luteolin [5 g / (cow·d)] group (n=5), the luteolin [10 g / (cow·d)] group (n=5), and the luteolin [15 g / (cow·d)] group (n=5) at the first milking on days 0, 3, 5, and 8 of the experiment. The samples were preserved and transported to the testing site at 4°C within 12 hours. The daily milk yield was determined in conjunction with the farm records. The milk fat percentage, milk protein percentage, blood urea nitrogen, and somatic cell count were measured using a milk composition and somatic cell analysis system. S3. Effects of luteolin on glucose and lipid metabolism in ketotic dairy cows Blood samples of 20 mL were collected from the tail vein of healthy control group (n=5), ketosis control group (n=5), luteolin [5 g / (cow·d)] group (n=5), luteolin [10 g / (cow·d)] group (n=5), and luteolin [15 g / (cow·d)] group (n=5) before morning feeding on days 0, 3, 5, and 8 of the experiment. The serum was separated by centrifugation at 3,500×g for 15 min at 4 ℃ and stored at -20 ℃ for subsequent testing. S4. Effects of luteolin on lipid metabolism disorders in ketotic dairy cows Blood samples of 20 mL were collected from the tail vein of healthy control group (n=5), ketosis control group (n=5), luteolin [5 g / (cow·d)] group (n=5), luteolin [10 g / (cow·d)] group (n=5), and luteolin [15 g / (cow·d)] group (n=5) before morning feeding on days 0, 3, 5, and 8 of the experiment. The serum was separated by centrifugation at 3,500×g for 15 min at 4 ℃ and stored at -20 ℃ for subsequent testing. S5. Effects of luteolin on inflammatory response in dairy cows with ketosis. On days 0, 3, 5, and 8 of the experiment, before morning feeding, 20 mL of blood samples were collected from the tail vein of the healthy control group (n=5), the ketosis control group (n=5), the luteolin (5 g / cow / d) group (n=5), the luteolin (10 g / cow / d) group (n=5), and the luteolin (15 g / cow / d) group (n=5). The samples were centrifuged at low temperature, and the supernatant was collected and stored at -20°C for subsequent testing.

2. The application of luteolin according to claim 1 in regulating lipid metabolism disorder and inflammatory response in ketotic dairy cows, characterized in that: According to step S2, the experimental method is as follows: One preservative capsule (containing 20 mg of bromonitrobenzene glycol) is pre-placed in each sampling bottle (50 mL). Milk samples are collected from each cow: healthy control group (n=5), ketosis control group (n=5), luteolin [5 g / (cow·d)] group (n=5), luteolin [10 g / (cow·d)] group (n=5), and luteolin [15 g / (cow·d)] group (n=5). 40 mL of milk is collected from each cow and mixed according to a 6:4 ratio of milk volume from morning and evening milking. After collection, the samples are shaken until the preservative is completely dissolved. The samples are transported to the laboratory at 4℃ within 2 days. For cows participating in the DHI assay, the ear tag number, parity, calving date, sampling date, number of days of lactation, and daily milk production are recorded.

3. The application of luteolin according to claim 1 in regulating lipid metabolism disorder and inflammatory response in ketotic dairy cows, characterized in that: According to step S3, the experimental method was as follows: serum samples were extracted from the healthy control group (n=5), the ketosis control group (n=5), the luteolin [5 g / (cow·d)] group (n=5), the luteolin [10 g / (cow·d)] group (n=5), and the luteolin [15 g / (cow·d)] group (n=5) according to the instructions of BHBA, ACAC, and Glu biochemical reagent kits, and the effects of different doses of luteolin on the regulation of glucose and lipid metabolism in ketosis dairy cows were detected.

4. The application of luteolin according to claim 1 in regulating lipid metabolism disorder and inflammatory response in ketotic dairy cows, characterized in that: According to step S4, the experimental method was as follows: following the instructions of the TG, TC, NEFA, HDL-C and LDL-C ELISA kits, serum samples were extracted from the healthy control group (n=5), the ketosis control group (n=5), the luteolin (5 g / cow / d) group (n=5), the luteolin [5 g / (cow·d)] group (n=5), the luteolin [10 g / (cow·d)] group (n=5), and the luteolin [15 g / (cow·d)] group (n=5). The effects of different doses of luteolin on the regulation of lipid metabolism disorder in ketosis dairy cows were detected.

5. The application of luteolin according to claim 1 in regulating lipid metabolism disorder and inflammatory response in ketotic dairy cows, characterized in that: According to step S5, the experimental method was as follows: following the instructions of the TL-6, IL-8, IL-10, IL-1β and TNF-α ELISA detection kits, serum was extracted from the healthy control group (n=5), the ketosis control group (n=5), the luteolin [5 g / (cow·d)] group (n=5), the luteolin [10 g / (cow·d)] group (n=5), and the luteolin [15 g / (cow·d)] group (n=5) to detect the effect of different doses of luteolin on the inflammatory response of ketosis dairy cows.

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