Preparation method and application of day lily extract for promoting lactation of sows

Abstract

The invention belongs to the technical field of feed additives and preparation thereof, and discloses a preparation method and application of a hemerocallis citrina baroni extract for promoting lactation of sows, and the preparation method comprises the following steps: S1, selecting a hemerocallis citrina baroni raw material; s2, mixing the day lily with ethanol or pure water with the volume fraction of 80-95% according to the material-liquid ratio of (1: 5)-(1: 10), and performing reflux extraction; s3, combining the extracting solutions, filtering to remove impurities, and concentrating into thick paste; and S4, carrying out spray drying or vacuum drying treatment on the concentrated solution, and crushing the dried material to obtain daylily extract powder. The extracts are obtained from different parts of the day lily through a water extraction or alcohol extraction process, are rich in flavonoid and hydroxy fatty acid active ingredients, can significantly improve the lactation performance of sows and the weight of weaned piglets, and realize feed additive and industrial popularization and application in the field of animal husbandry.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of feed additives and its preparation, in particular to a preparation method of day lily extract for promoting lactation of sows and application thereof. BACKGROUND

[0002] As the core female parent in modern intensive pig production system, the health status of sows is directly related to reproductive performance, lactation ability, and survival rate and growth rate of piglets. Since the immune function and digestive system of newborn piglets are not fully developed, they are highly dependent on the quantity and quality of milk. Therefore, improving the lactation performance of sows is a key measure to ensure the healthy development of piglets, increase the weaning litter weight, and improve the breeding efficiency.

[0003] For a long time, in order to improve the lactation level of sows, some breeders try to add antibiotics or hormone substances in feed, although the lactation status is improved to some extent, but such substances have the risk of drug residues, which does not comply with the current national policy direction of "ban on antibiotics" and advocating green and healthy breeding. It is urgent to develop safe, efficient and natural alternative feed additives.

[0004] Day lily is a traditional Chinese medicinal and edible plant. Modern research shows that day lily is rich in flavonoids, polyphenols and hydroxy fatty acids and other plant active ingredients, and has certain physiological regulation potential. However, existing research mainly focuses on its medicinal and edible functions and human health care effects, and the functional evaluation of day lily extract in livestock nutrition is still limited, especially the application of day lily extract in lactating sows lacks systematic research. At the same time, there is no unified extraction process of effective components of day lily and standardized feeding technology route.

[0005] Therefore, it is urgent to develop a functional extract of day lily with clear source, stable process and definite effect, to clarify its preparation method, functional component composition and application effect in lactating sows, so as to realize its feed additive and industrialization popularization and application in the field of animal husbandry. SUMMARY

[0006] The present application aims to provide a preparation method of day lily extract for promoting lactation of sows and application thereof. The extract is obtained from different parts of day lily by water extraction or alcohol extraction process, rich in flavonoids and hydroxy fatty acid active ingredients, which can significantly improve the lactation performance of sows and the weaning litter weight of piglets, and has good application effect and industrialization prospect.

[0007] In order to achieve the above purpose, the present application provides the following technical scheme:

[0008] A preparation method of day lily extract for promoting lactation of sows, comprising the following steps:

[0009] S1, raw material pretreatment: select fresh or dried day lily raw materials, remove impurities and cut into pieces for standby;

[0010] S2, extraction: the treated day lily is mixed with 80% to 95% ethanol or pure water according to the ratio of 1:5 to 1:10, and refluxed for multiple times under the preset temperature condition;

[0011]

[0012] S3, filtration and concentration: the extraction liquid is combined, filtered to remove impurities, and concentrated to a thick paste under reduced pressure;

[0013] S4, drying: the thick paste of the concentrated liquid is treated by spray drying or vacuum drying, and the dried material is crushed to obtain a day lily extract powder.

[0014] Further, in S1, the day lily raw material includes day lily flowers, stems, leaves or roots.

[0015] Further, in S2, the reflux extraction multiple times under the preset temperature condition includes reflux extraction for 0.5 to 2 hours at 80 to 100 ℃, and extraction for 1 to 3 times.

[0016] Further, in S2, the volume fraction of ethanol is 90%.

[0017] Further, in S4, the day lily extract powder contains flavonoids and hydroxyl fatty acid active ingredients.

[0018] The application of the extract prepared by the above-mentioned method for preparing a day lily extract for promoting lactation in sows is applied to promote lactation in sows, and the extract is added to the basic daily ration of sows at an addition amount of 200 to 1600 g / t.

[0019] The beneficial effects of the technical solution are:

[0020] 1. The extraction process is simple and efficient, and the active ingredients of the product are stable, which can realize standardized and large-scale preparation;

[0021] 2. Through actual feeding verification, the day lily extract prepared by the present application can significantly improve the lactation of sows, the average daily lactation during lactation is increased by more than 10%, the growth of piglets is promoted, and the average weight at weaning at 21 days is significantly improved;

[0022] 3. The day lily extract is natural and has no drug residues, which meets the requirements of modern green breeding, can be used as a substitute for antibiotic lactation-promoting products, reduces the risk of disease, and improves the reproductive performance of sows and the operating efficiency of the pig farm;

[0023] ​In conclusion, the application provides a natural and efficient plant-derived lactation promoting feed additive, which solves the problems of insufficient lactation and low weaning weight in the existing breeding process, and has good practical value and promotion prospect. DETAILED DESCRIPTION

[0024] The application will be further described in detail below in combination with embodiments:

[0025] The daylily extract used in the embodiment is prepared from dried daylily flowers, and the main effective components are flavonoids and hydroxy fatty acid compounds.

[0026] The preparation method of the daylily extract for promoting lactation of sows adopts an alcohol extraction method, and includes the following steps:

[0027] S1, raw material pretreatment:

[0028] Dry daylily flowers are selected, impurities are removed, and then the daylily flowers are cut into pieces for use;

[0029] S2, extraction:

[0030] First extraction: the treated daylily flowers are added with 90% ethanol according to a solid-liquid ratio of 1:8, and are reflux extracted at 85°C for 2 hours; after the extraction is completed, the filtrate is collected after filtration;

[0031] Second extraction: the obtained filter residue is added with 90% ethanol again according to a solid-liquid ratio of 1:5, and is reflux extracted at the same temperature for 1 hour; after filtration, the two filtrates are combined;

[0032] S3, filtration and concentration: the extraction liquids are combined, impurities are removed after filtration, and then the extraction liquids are concentrated into thick paste by a reduced pressure method;

[0033] S4, drying: the obtained thick paste-shaped concentrated liquid is vacuum dried at 60°C, and the dried product is crushed to obtain daylily extract powder.

[0034] Feeding effect of the daylily extract:

[0035] The prepared daylily extract is uniformly mixed in the basic diet of sows at an additive amount of 600 g / t, and is continuously fed from the 85th day of the late pregnancy to the 21st day of the lactation period when the piglets are weaned. The results show that the daylily extract can significantly improve the lactation of sows and the growth performance of piglets, and the litter weight and average weight of 21-day-old piglets are increased by more than 10% compared with the control group.

[0036] Animal feeding test of the daylily extract:

[0037] 1. Test animals and grouping

[0038] Thirty 85-day pregnant sows of similar parity and expected delivery date were randomly divided into two groups, control group and lily extract group (basal diet + 600 mg / kg lily extract).

[0039] 2. Feeding management and feeding method

[0040] Sows were transferred to the delivery house with leaky floor at 78 days of pregnancy, one sow per pen, and adapted for 7 days. From 85 days of pregnancy to weaning day (21 days of age), sows were fed as follows: 5 kg / d from 85 days of pregnancy to 2 days before delivery, 4 kg / d on the day of delivery, and an average of 7.5 kg / d postpartum, fed twice a day (08:00 and 16:00), with free access to water throughout the process.

[0041] All sows were fed the same basal diet, and the test group was added with 600 g / t lily extract, while the control group was not added with any additives.

[0042] Piglets were uniformly implemented tail docking, tooth cutting, iron supplementation, and immunization operations according to the standard procedures. From 7 days of age, piglets were supplemented with sow starter feed, fed twice a day, free access to feed and water, the starter feed was purchased from the same manufacturer, and the environmental temperature was controlled at 26±1 ℃, with a night fluctuation of not more than 2 ℃.

[0043] 3. Determination method of each index

[0044] (1) Determination of lactation performance and piglet growth performance

[0045] Piglets were weighed on the day of birth and the day of weaning, and the birth weight and weaning weight of piglets were calculated, as well as the weaning litter weight, average daily gain, and lactation performance (weaning litter weight - birth litter weight).

[0046] (2) Collection and determination of colostrum

[0047] Within 24 hours after delivery, colostrum was collected from sows, 9 sows were randomly selected from each group, and milk samples were collected from the teats of the front, middle, and back of the sow's udder, then mixed, and the udder was washed with clean warm wet hair before sampling, 40 ml of colostrum was collected from each sow, mixed evenly, and divided into 20 ml and 20 ml.

[0048] Milk routine determination: The milk samples were thawed in a constant temperature water bath at 35°C, and the milk was diluted 5 times with physiological saline before being determined for the contents of lactose, milk fat, milk protein, and dry matter in milk using a Foss MilkoScan FT 120 milk component analyzer.

[0049] Reproductive hormone determination: The milk samples were thawed in a constant temperature water bath at 35°C, and the serum was collected by centrifugation at 3000 rpm for 10 min, and the contents of prolactin (PRL), insulin-like growth factor-1 (IGF-1), and estradiol (E2) in the sow serum and colostrum were detected using an Elisa kit, and the determination procedure was referred to the kit instruction.

[0050] (3) Collection and determination of sow and piglet serum

[0051] a. Collection of serum

[0052] Sows: On the day of delivery, 9 sows were randomly selected from each group at 7:00 in the morning for collection of fasting blood samples from the auricular marginal vein. The blood collection site on the back of the ear was cleaned and disinfected using an alcohol cotton ball, 10 mL of blood was collected in a blood collection tube, and the blood was placed at room temperature for 30 min, and then centrifuged at 3000 rpm for 10 min, the supernatant was aspirated and divided into 2 mL centrifuge tubes, and stored in a-80°C refrigerator for determination.

[0053] Piglets: On the day of weaning (21 days of lactation), 1 male and 1 female piglet were selected from each of the above 9 sows for collection of fasting blood samples from the anterior vena cava, 10 mL of blood was collected in a blood collection tube, and the blood was placed at room temperature for 30 min, and then centrifuged at 3000 rpm for 10 min, the supernatant was aspirated and divided into 2 mL centrifuge tubes, and stored in a-80°C refrigerator for determination.

[0054] Umbilical cord blood: On the day of delivery, umbilical cord blood samples were collected from the newborn piglets born from the above 9 sows (about 5 mL was collected from each litter and placed in two vacuum blood collection tubes), and the samples were placed in vacuum blood collection tubes. The samples were placed at room temperature for 30 min, and then centrifuged at 3000 r / min for 10 min, the supernatant was aspirated and divided into 2 mL centrifuge tubes, and stored in a-80°C ultra-low temperature refrigerator for frozen preservation for subsequent detection and analysis.

[0055] b. Index detection

[0056] Physiological and biochemical indicators: The physiological and biochemical indicators of sows and piglets were measured, including total protein (TP), albumin (ALB), total cholesterol (TCH / T-CHO), triglyceride (TG), urea nitrogen (BUN), glucose (GLU), and other indicators, which were determined by automatic blood biochemical analyzer.

[0057] Antioxidant indicators: The antioxidant indicators of piglet serum and colostrum were measured, including malondialdehyde (MDA), total antioxidant capacity (T-AOC), total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-PX), and other indicators, which were determined by Nanjing Jiancheng Biological Technology Co., Ltd. reagent kit and MB 530 enzyme marker, strictly according to the instructions of the reagent kit and the operation process of the enzyme marker.

[0058]

[0059] Immune indicators: The immune indicators were determined by competitive method to detect the content of immunoglobulin A (IgA), immunoglobulin G (IgG), and immunoglobulin M (IgM) in the umbilical cord blood and colostrum of sows and piglets. The enzyme-linked immunosorbent assay (ELISA) kit was purchased from Shanghai Enzyme-linked Biological Technology Co., Ltd., and the specific determination process was referred to the kit instructions, and determined by MB 530 enzyme marker.

[0060] The determination of sow serum reproductive hormone indicators was the same as 3. (2).

[0061] 4. Data processing

[0062] All data were expressed as mean ± standard error, and statistical analysis was performed by SPSS 26.0 statistical software.

[0063] 5. Test results and analysis

[0064] (1) Effect of day lily extract on sow lactation and piglet growth performance

[0065] ​To evaluate the effects of daylily extract on sow lactation ability and piglet growth performance, 30 three-way hybrid sows at 85 days of pregnancy were randomly divided into control and experimental groups, and fed with basal diet and basal diet supplemented with 600 g / t daylily extract, respectively. The reproductive performance, growth performance and lactation ability were compared and analyzed, and the results were shown in Table 1. From the production performance index, the total number of piglets, live piglets and healthy piglets in the daylily extract group were increased compared with the control group, but the difference was not significant (P>0.05), indicating that daylily extract had no obvious interference on the process of pregnancy and delivery. In terms of growth performance, the birth weight and average individual weight of weaned piglets in the experimental group were significantly higher than those in the control group (P<0.05); the weaned litter weight in the experimental group was extremely significantly higher than that in the control group (P<0.01), with an increase of 30.06%. In addition, lactation ability as an important indicator of sow lactation ability, the lactation ability of sows in the experimental group was 41.97±2.82 kg, which was extremely significantly higher than that in the control group (31.45±2.31 kg) (P<0.01), with an increase of more than 32%, indicating that daylily extract had good lactation promoting effect. The survival rate at weaning in the experimental group was 97.92%, which was close to that in the control group (96.27%), with no significant difference, indicating that the addition of daylily extract did not cause adverse effects on piglet health and survival.

[0066] In summary, under the premise of maintaining consistent feed formula and nutrient structure, the addition of 600 g / t daylily extract in feed can significantly improve sow lactation ability and weaned piglet individual weight and litter weight, showing good lactation and growth promoting effect, with high practical value and industrial application potential.

[0067] Table 1 Effects of daylily extract on sow lactation ability and piglet growth performance

[0068]

[0069] (2) Effects of daylily extract on routine components of colostrum in sows

[0070] To study the effects of daylily extract on the nutritional composition of colostrum in sows, the control group and the daylily extract group were compared and analyzed for colostrum composition, and the results were shown in Table 2. The results showed that the milk fat rate of the daylily extract group was 4.62%, which was significantly higher than that of the control group (P<0.05); the milk protein rate of the daylily extract group was 3.62%, which was significantly higher than that of the control group (P<0.05); the lactose rate of the daylily extract group was 5.02%, which was significantly higher than that of the control group (P<0.05); the total solid rate of the daylily extract group was 12.26%, which was significantly higher than that of the control group (P<0.05).

[0071] The milk fat content of the treatment group (9.38 ± 0.14%) was significantly higher than that of the control group (5.38 ± 0.45%), with an increase of 74.35%, and the difference was extremely significant (P < 0.01); the total dry matter content also increased significantly, from 36.42 ± 0.62% in the control group to 37.70 ± 0.07% (P < 0.01), with an increase of 3.52%. In terms of milk protein content, the treatment group had a slightly higher value of 19.47 ± 0.28% than the control group (18.47 ± 0.70%), but the difference was not significant (P > 0.05); the differences in lactose content and fat-free dry matter content between the two groups were not significant (P > 0.05), indicating that the extract had no significant effect on some of the initial milk nutrients.

[0072] In summary, the results showed that the addition of day lily extract in the diet can significantly increase the milk fat content and total dry matter content of sow colostrum, which is beneficial to enhance the nutritional density of milk, and thus provide more adequate energy support and nutritional basis for early piglets, and has good potential for application in promoting lactation and optimizing colostrum quality.

[0073] Table 2 Effect of day lily extract on the routine components of sow colostrum

[0074]

[0075] (3) Effect of day lily extract on routine serum biochemical indicators of sows and piglets

[0076] The effect of day lily extract on serum biochemical indicators of sows and piglets is shown in Table 3. As can be seen from the table, the addition of day lily extract in the basal diet of sows had no significant effect on glucose, total protein, albumin, triglycerides, total cholesterol and urea nitrogen (P > 0.05), indicating that the addition of day lily extract in the basal diet of sows had no negative effect on the routine physiological state of sows and piglets.

[0077] Table 3 Effect of day lily extract on routine serum biochemical indicators of sows and piglets

[0078]

[0079] Note: The same row without letters or the same letters indicate no significant difference (P > 0.05), and different lowercase letters indicate significant difference (P < 0.05).

[0080] (4) Effect of day lily extract on reproductive hormones in sow serum and whey

[0081] To explore the regulation of daylily extract on hormone levels in lactating sows, the levels of three main reproductive-related hormones in serum and colostrum on the day of delivery were studied, including insulin-like growth factor 1 (IGF-1), prolactin (PRL), and estradiol (E2), as shown in Table 4.

[0082] The results showed that compared with the control group, the addition of daylily extract in the diet could significantly increase the levels of prolactin (PRL) and estradiol (E2) in serum and colostrum (P<0.05), indicating that it had good hormone regulation effect and helped to enhance the development of mammary glands and lactation function. Although the level of insulin-like growth factor 1 (IGF-1) in serum of sows in the test group showed an upward trend, the difference was not significant, suggesting that its potential regulatory effect still needs further study.

[0083] In summary, daylily extract can significantly regulate lactation-related hormone levels at the key stage of delivery and lactation, especially in prolactin and estradiol, which has a positive promoting effect and provides good endocrine support for the improvement of lactation performance of sows.

[0084] Table 4 Effect of daylily extract on reproductive hormones in serum and whey of sows

[0085]

[0086] Note: The same row of data without letters or the same letters indicate no significant difference (P>0.05), and different lowercase letters indicate significant difference (P<0.05).

[0087] (5) Effect of daylily extract on antioxidant capacity in serum and whey of sows

[0088] To evaluate the effect of daylily extract on antioxidant capacity in serum and colostrum of piglets and sows, the levels of glutathione peroxidase (GSH-PX), malondialdehyde (MDA), total antioxidant capacity (T-AOC), and superoxide dismutase (SOD) in serum of piglets and colostrum of sows were analyzed, as shown in Table 5.

[0089] The results showed that compared with the control group, the activities of GSH-PX and SOD in serum of piglets in the daylily extract group were significantly increased (P<0.05), while the levels of MDA and T-AOC showed no significant difference (P>0.05). In colostrum of sows, the activities of GSH-PX and SOD were also significantly higher than those in the control group (P<0.05), while the levels of MDA and T-AOC showed no significant difference.

[0090] In summary, the addition of daylily extract in the diet of lactating sows can effectively enhance the activities of some antioxidant enzymes in colostrum and serum of piglets, especially for GSH-PX and SOD, suggesting its potential application in regulating the antioxidant system and improving the redox balance.

[0091] Table 5 Effect of daylily extract on the antioxidant capacity in serum of piglets and colostrum of sows

[0092]

[0093] Note: The same row of data without letters or the same letters represent no significant difference (P>0.05), and different lowercase letters represent significant difference (P<0.05).

[0094] (6) Effect of daylily extract on immune indicators in serum of sows, colostrum and umbilical cord blood of piglets

[0095] To evaluate the potential regulatory effect of daylily extract on the immune level of lactating sows and piglets, the main immunoglobulin indicators in serum of sows on the day of delivery, colostrum and umbilical cord blood of piglets were determined, including immunoglobulin A (IgA), immunoglobulin G (IgG) and immunoglobulin M (IgM), and the results are shown in Table 6.

[0096] The results showed that compared with the control group, the levels of IgA, IgG and IgM in serum of sows in the daylily extract group were significantly increased (P<0.05), by 39.6%, 17.4% and 27.0%, respectively; in colostrum, the levels of immunoglobulin were also significantly higher than those in the control group (P<0.05), among which IgA, IgG and IgM were increased by 26.8%, 30.3% and 39.6%, respectively; in the umbilical cord blood of piglets, the levels of IgA, IgG and IgM were also significantly increased (P<0.05), with an increase of 27.3%, 26.3% and 42.7%, respectively.

[0097] In summary, daylily extract can significantly enhance the humoral immune level of sows and piglets, especially in promoting the content of immunoglobulin in colostrum and umbilical cord blood, suggesting that it can help to improve the level of passive immunity of newborn piglets and enhance their early disease resistance, with good application value and promotion prospects.

[0098] Table 6 Effect of daylily extract on immune indicators in serum of sows, colostrum and umbilical cord blood of piglets

[0099]

[0100] *: Means in the same column with no letters or with the same letter are not significantly different (P>0.05), and means with different lowercase letters are significantly different (P<0.05).

[0101] 6. Test Conclusion

[0102] This study systematically evaluated the application effect of daylily extract in the diet of sows during lactation. Through comparative analysis of multiple-dimensional indicators such as sow lactation performance, colostrum composition, reproductive hormone level, antioxidant capacity, and immune indicators, the results showed that:

[0103] (1) Promote lactation and increase weaning weight: Under the premise of not affecting the pregnancy and delivery process, the addition of daylily extract in the diet can significantly improve the lactation performance of sows (increase by more than 32%, P<0.01), effectively increase the weaning litter weight (P<0.01) and individual weight (P<0.05) of 21-day-old piglets, showing good lactation promotion and growth promotion effects.

[0104] (2) Optimize the nutritional quality of colostrum: Daylily extract can significantly increase the milk fat content (P<0.01) and total dry matter content (P<0.05) in sow colostrum, enhancing the nutritional density of milk and providing better early nutritional sources for piglets.

[0105] (3) Do not interfere with the basic physiological state: The addition of daylily extract does not significantly affect the serum biochemical indicators of sows and piglets, indicating that it has good safety in terms of regular nutrient metabolism and liver and kidney function. Significant hormone regulation effect: Daylily extract can significantly increase the levels of prolactin (PRL) and estradiol (E2) in sow serum and colostrum (P<0.05), providing endocrine regulation support for the lactation process; although there is a trend of increasing insulin-like growth factor 1 (IGF-1), the difference is not significant.

[0106] (4) Enhance antioxidant capacity: In piglet serum and sow colostrum, daylily extract significantly increases the activities of glutathione peroxidase (GSH-PX) and superoxide dismutase (SOD) (P<0.05), indicating that it has good antioxidant system activation ability and helps maintain the body's oxidation-reduction balance.

[0107] (5) Increase immunoglobulin levels: Daylily extract can significantly increase the levels of IgA, IgG, and IgM in sow serum, colostrum, and piglet umbilical cord blood (P<0.05), especially in colostrum and umbilical cord blood, showing effective enhancement of passive immunity to newborn piglets.

[0108]

[0109]

[0110] ​​In summary, the day lily extract as a natural, safe, with multiple physiological regulation of functional plant feed additives, with good promote lactation, enhance milk, enhance antioxidant and immune function, can significantly improve the lactation and production performance of sows, has broad industrialization application potential and popularization prospect.

[0111] The above is only the embodiment of the present application, and the specific technical solutions or common knowledge of the scheme are not described in detail. It should be pointed out that for those skilled in the art, without departing from the technical scheme of the present application, a number of modifications and improvements can be made, which should also be considered as the protection scope of the present application, which will not affect the effect and practicality of the patent. The protection scope of the present application should be subject to the content of its claims, and the specific implementation mode and the like in the specification can be used to explain the content of the claims.

Claims

1. A method for preparing a lilyturf extract for promoting lactation in sows, characterized by, The method comprises the following steps: S1, raw material pretreatment: fresh or dried day lily raw material is selected, impurities are removed, and then the day lily is cut into pieces for use; S2, extraction: the treated day lily is mixed with 80%-95% ethanol or pure water at a solid-liquid ratio of 1:5-1:10, and then reflux extraction is performed multiple times under a preset temperature condition; S3, filtration and concentration: the extraction liquids are combined, impurities are removed through filtration, and then the extraction liquids are concentrated into thick paste through a reduced pressure method; S4, drying: the thick paste obtained through concentration is treated by spray drying or vacuum drying, the obtained material is crushed, and then day lily extract powder is obtained. In S1, the day lily raw material includes day lily flowers, stems, leaves or roots.

2. The method of claim 1, wherein the preparation method of the day lily extract for promoting lactation in sows is characterized by: In S2, the multiple times of reflux extraction under a preset temperature condition comprises reflux extraction at 80-100 ℃ for 0.5-2 hours, and the extraction is performed 1-3 times.

3. The method of claim 1, wherein the preparation method of the day lily extract for promoting lactation in sows is characterized by: In S2, the volume fraction of ethanol is 90%.

4. The method of claim 1, wherein the preparation method of the day lily extract for promoting lactation in sows is characterized by: In S4, the day lily extract powder contains flavonoids and hydroxyl fatty acid active ingredients.

5. The method of claim 1, wherein the preparation method of the day lily extract for promoting lactation in sows is characterized by: The day lily extract is applied to promote lactation of sows, and the extract is added into the basic daily ration of sows at an addition amount of 200-1600 g / t.

6. Use of the extract of day lily for promoting lactation in sows prepared by the method according to any one of claims 1-5, characterized in that: ​

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