Application of feed additives that alter the fatty acid composition of egg yolk lipids in feed

Abstract

This invention discloses the application of a feed additive that alters the fatty acid composition of egg yolk lipids in feed. The invention regulates the content of polyunsaturated and monounsaturated fatty acids in egg yolk lipids by adding glucuronolactone to poultry feed. The polyunsaturated fatty acids include n-3 series polyunsaturated fatty acids. Adding glucuronolactone to the feed alters the fatty acid composition of egg yolk lipids. By regulating the content of polyunsaturated and monounsaturated fatty acids in egg yolk lipids, especially the content of n-3 series polyunsaturated fatty acids, it not only increases the functional nutritional value of the egg yolk and improves the quality of the egg, but also enhances the flavor of the egg yolk.

Description

Technical Field

[0001] This invention relates to the field of biotechnology, and more particularly to the application of feed additives that alter the fatty acid composition of egg yolk lipids in feed. Background Technology

[0002] Eggs are rich in vitamins, minerals, and high-biological-value protein, making them one of the best sources of nutrition for humans. The total lipid content of eggs is 30-33%, with over 99% of this lipid composition coming from the yolk. The lipid components of the yolk mainly include triglycerides, phospholipids, and cholesterol. More than 60% of the fatty acid composition of triglycerides and phospholipids is unsaturated fatty acids, with polyunsaturated fatty acids (PUFAs) accounting for about 20%. PUFAs are essential for human growth and development. Since the human body cannot synthesize them, people generally obtain them by consuming eggs. Among PUFAs, the n-3 series is currently known to be the most deficient and also the most functionally diverse. It has important physiological functions, such as contributing to the intellectual growth of infants and young children, human brain development, and preventing cardiovascular diseases. Therefore, increasing the content of polyunsaturated fatty acids, especially n-3 polyunsaturated fatty acids, in eggs is a key issue in improving their nutritional value.

[0003] In the current technology, feed additives are generally added to the feed of laying hens using oil-based feed additives (such as rubber seeds and flax seeds) to increase the polyunsaturated fatty acid content of egg yolks. However, there are no reports on using non-oil-based feed additives to increase the polyunsaturated fatty acid content of egg yolks.

[0004] Glucuronolactone is a natural chemical metabolite produced by the breakdown of glucose. It is often used in scientific research on liver detoxification. However, there are currently no reports that it can regulate the content of polyunsaturated and monounsaturated fatty acids in egg yolk lipids by altering the fatty acid composition of egg yolk lipids. Summary of the Invention

[0005] The purpose of this invention is to address the problem that the content of polyunsaturated fatty acids, especially n-3 polyunsaturated fatty acids, in egg yolk lipids in the prior art is low, which leads to the low nutritional value of eggs. This invention provides a method to increase the content of n-3 polyunsaturated fatty acids in egg yolk lipids, thereby improving the nutritional value of eggs.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] This invention discloses the application of a feed additive that alters the fatty acid composition of egg yolk lipids in feed. The feed additive includes glucuronolactone, and the alteration of the fatty acid composition of egg yolk lipids involves regulating the content of polyunsaturated fatty acids and monounsaturated fatty acids in egg yolk lipids by using feed containing glucuronolactone. The polyunsaturated fatty acids include n-3 series polyunsaturated fatty acids.

[0008] Furthermore, the alteration of the fatty acid composition of egg yolk lipids includes increasing the content of n-3 series polyunsaturated fatty acids in egg yolk lipids.

[0009] Furthermore, the n-3 series of polyunsaturated fatty acids includes α-linolenic acid and docosahexaenoic acid.

[0010] Furthermore, the polyunsaturated fatty acids include n-6 series polyunsaturated fatty acids.

[0011] Furthermore, the alteration of the fatty acid composition of egg yolk lipids includes increasing the content of n-6 series polyunsaturated fatty acids in egg yolk lipids.

[0012] Furthermore, the n-6 series of polyunsaturated fatty acids includes arachidonic acid.

[0013] Furthermore, the alteration of the fatty acid composition of egg yolk lipids includes increasing the content of monounsaturated fatty acids in egg yolk lipids.

[0014] Furthermore, the monounsaturated fatty acid includes oleic acid.

[0015] Furthermore, the feed additive is present in the feed at a concentration of 280-1120 mg / kg.

[0016] Furthermore, the feed, by weight percentage, comprises: 50-70% corn, 20-30% soybean meal, 0.5-1.5% soybean oil, 5-10% limestone, 1-3% dicalcium phosphate, 0.1-0.3% methionine, 0.1-0.4% sodium chloride, 0.05-0.2% choline chloride, 0.1-0.5% mineral premix, and 0.01-0.1% vitamin additives.

[0017] Implementing this invention has the following beneficial effects:

[0018] Adding glucuronolactone to feed can alter the fatty acid composition of egg yolk lipids. By regulating the content of polyunsaturated and monounsaturated fatty acids in egg yolk lipids, especially the content of n-3 series polyunsaturated fatty acids, it not only increases the functional nutritional value of egg yolks and improves the quality of eggs, but also enhances the flavor of egg yolks. Detailed Implementation

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments, and therefore should not be construed as limiting the present invention. 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.

[0020] This embodiment provides the application of a feed additive that alters the fatty acid composition of egg yolk lipids in feed. The feed additive includes glucuronolactone. Altering the fatty acid composition of egg yolk lipids involves regulating the content of polyunsaturated and monounsaturated fatty acids in the egg yolk lipids through feed containing glucuronolactone. The polyunsaturated fatty acids include n-3 series polyunsaturated fatty acids. Adding glucuronolactone to feed can alter the fatty acid composition of egg yolk lipids. By regulating the content of polyunsaturated and monounsaturated fatty acids in egg yolk lipids, especially the content of n-3 series polyunsaturated fatty acids, it not only increases the functional nutritional value of the egg yolk and improves the quality of the egg, but also enhances the flavor of the egg yolk.

[0021] Optionally, altering the fatty acid composition of egg yolk lipids includes regulating the total saturated fatty acid content of egg yolk lipids.

[0022] Specifically, total saturated fatty acids include both saturated and unsaturated fatty acids.

[0023] Optionally, altering the fatty acid composition of egg yolk lipids includes increasing the content of unsaturated fatty acids in the egg yolk lipids. Specifically, unsaturated fatty acids include polyunsaturated fatty acids and monounsaturated fatty acids.

[0024] Optionally, altering the fatty acid composition of egg yolk lipids includes regulating the mass ratio between n-3 and n-6 ​​polyunsaturated fatty acids in egg yolk lipids through feeds containing glucuronolactone. An excessively high mass ratio of n-6 to n-3 polyunsaturated fatty acids increases the risk of cardiovascular disease, cancer, inflammation, and autoimmune diseases.

[0025] Optionally, altering the fatty acid composition of egg yolk lipids includes increasing the mass ratio between n-3 and n-6 ​​polyunsaturated fatty acids in the yolk lipids. By decreasing the mass ratio of n-6 to n-3 polyunsaturated fatty acids, human health can be significantly improved.

[0026] Optionally, altering the fatty acid composition of egg yolk lipids includes increasing the content of n-3 series polyunsaturated fatty acids in egg yolk lipids. Increasing the content of n-3 series polyunsaturated fatty acids in egg yolk lipids can significantly improve the nutritional value of eggs and also enhance the salty flavor of the yolk.

[0027] Optionally, n-3 series polyunsaturated fatty acids include alpha-linolenic acid (ALA) and docosahexaenoic acid (DHA). ALA has the effects of dilating blood vessels, reducing blood viscosity, and lowering triglycerides. DHA infiltrates into the platelet phospholipid membrane in the body, becoming a major component of mitochondria and cell membranes, and is metabolized into prostaglandins, thromboxanes, and leukotrienes. These substances directly affect the activity and function of the human body, thus playing a vital role in human health. This application significantly improves the nutritional value of eggs by increasing the content of ALA and DHA in egg yolks, thus solving the problem of severe deficiency in the intake of n-3 series polyunsaturated fatty acids in my country.

[0028] Optional, n-3 series polyunsaturated fatty acids include eicosapentaenoic acid (EPA).

[0029] Optionally, altering the fatty acid composition of egg yolk lipids includes increasing the content of alpha-linolenic acid and docosahexaenoic acid in egg yolk lipids.

[0030] Optionally, polyunsaturated fatty acids include n-6 series polyunsaturated fatty acids. By regulating the content of n-6 polyunsaturated fatty acids, not only can the flavor of egg yolks be further improved, but when people consume these egg yolks, it can also reduce the risk of cardiovascular disease and help reduce nerve pain.

[0031] Optionally, altering the fatty acid composition of egg yolk lipids includes increasing the content of n-6 series polyunsaturated fatty acids in egg yolk lipids. By increasing the content of n-6 series polyunsaturated fatty acids in egg yolk lipids, people's preference for egg yolk flavor is enhanced, further improving the creamy taste of egg yolks.

[0032] Optionally, n-6 series polyunsaturated fatty acids include arachidonic acid. By adjusting the content of specific types of n-6 series polyunsaturated fatty acids, the flavor and aroma of egg yolk milk are enhanced.

[0033] Optionally, altering the fatty acid composition of egg yolk lipids includes increasing the content of arachidonic acid in egg yolk lipids.

[0034] Optionally, altering the fatty acid composition of egg yolk lipids includes regulating the content of monounsaturated fatty acids in egg yolk lipids.

[0035] Optionally, altering the fatty acid composition of egg yolk lipids includes increasing the content of monounsaturated fatty acids in the egg yolk lipids. Increasing the content of monounsaturated fatty acids can further enhance the taste and flavor of the egg yolk, improving overall palatability.

[0036] Optional, monounsaturated fatty acids include oleic acid. The creamy flavor is formed by the thermal decomposition of stearic acid, oleic acid, and linolenic acid. Increasing the oleic acid content in egg yolks can enhance the creamy flavor of the yolks, further improving their overall taste.

[0037] Optionally, the content of feed additives in the feed is 280-1120 mg / kg. The upper limit of the feed additive content can be, but is not limited to, 1120 mg / kg, 1119 mg / kg, 1118 mg / kg, etc., and the lower limit can be, but is not limited to, 280 mg / kg, 281 mg / kg, 282 mg / kg, etc.; understandably, the content of feed additives can also be any value within the above range, which will not be listed here. By limiting the glucuronolactone within this range, the fatty acid composition of egg yolk lipids can be further altered, making the difference between the fatty acid composition of egg yolk lipids before and after the alteration more obvious and the reliability higher.

[0038] Preferably, the content of feed additives in the feed is 280-560 mg / kg. The upper limit of the feed additive content can be, but is not limited to, 560 mg / kg, 559 mg / kg, 558 mg / kg, etc., and the lower limit can be, but is not limited to, 280 mg / kg, 281 mg / kg, 282 mg / kg, etc.; understandably, the content of feed additives can also be any value within the above range, which will not be enumerated here. Limiting it to this range can reduce feed costs. More preferably, the content of feed additives in the feed is 280 mg / kg. This can further reduce feed costs while also making the egg yolk more nutritious.

[0039] Optional feed formulations include: corn, soybean meal, soybean oil, limestone, dicalcium phosphate, methionine, sodium chloride, choline chloride, mineral premix, and vitamin additives. Feed is food used to feed animals. In livestock and poultry farming, feed, in a narrow sense, refers to food for animals raised in agriculture or animal husbandry. Glucuronolactone is readily available, low in cost, and highly safe. It can be directly mixed with feed, significantly reducing production costs. Furthermore, formulating a properly formulated feed is convenient, quick, and saves time and labor. After entering the poultry's body, the feed can effectively increase the polyunsaturated fatty acid content of egg yolk lipids, thus improving egg quality.

[0040] Optionally, the feed, by weight percentage, includes: 50-70% corn, 20-30% soybean meal, 0.5-1.5% soybean oil, 5-10% limestone, 1-3% dicalcium phosphate, 0.1-0.3% methionine, 0.1-0.4% sodium chloride, 0.05-0.2% choline chloride, 0.1-0.5% mineral premix, and 0.01-0.1% vitamin additives. The weight percentages of corn, soybean meal, soybean oil, limestone, dicalcium phosphate, methionine, sodium chloride, choline chloride, mineral premix, and vitamin additives can be any values ​​within the above range and are not listed here. A suitable feed formulation ensures sufficient energy for poultry without reducing egg production and quality, while also reducing production costs and improving economic efficiency. Preferably, the feed, by weight percentage, comprises: 55-65% corn, 25-30% soybean meal, 0.5-1.5% soybean oil, 7-10% limestone, 1-2% dicalcium phosphate, 0.1-0.2% methionine, 0.2-0.4% sodium chloride, 0.05-0.1% choline chloride, 0.1-0.3% mineral premix, and 0.01-0.05% vitamin additives. More preferably, the feed, by weight percentage, comprises: 60% corn, 28.43% soybean meal, 1% soybean oil, 8.30% limestone, 1.50% dicalcium phosphate, 0.15% methionine, 0.3% sodium chloride, 0.09% choline chloride, 0.2% mineral premix, and 0.03% vitamin additives. Optionally, the feed is used to feed laying hens, specifically Hy-Line Brown laying hens. Hy-Line Brown laying hens are highly adaptable and can be widely used in poultry farming, offering certain economic benefits.

[0041] The following describes specific embodiments of this application in conjunction with the above-mentioned application of feed additives that alter the fatty acid composition of egg yolk lipids in feed. The following embodiments describe the technical solutions of this application in more detail. These embodiments are for illustrative purposes only, as various modifications and variations within the scope of the disclosure of this application will be apparent to those skilled in the art. The materials used in the embodiments are commercially available or synthesized using conventional methods and can be used directly without further processing. The instruments and apparatus used in the embodiments are also commercially available.

[0042] Example 1: Grouping Design of Experimental Animals

[0043] Two hundred and fifty-six healthy Hy-Line Brown chickens at 42 weeks of age (peak laying period) with similar egg production performance (individual egg production rate higher than 95%) were randomly divided into two groups (eight replicates per group, with 16 chickens per replicate). The control group was fed a basal diet, while the glucuronolactone group received a basal diet supplemented with 280 mg / kg glucuronolactone. Both groups continued to be fed for eight weeks, and samples were taken on the last day of the eight-week period.

[0044] Example 2: Formulation of the experimental basal diet and analysis of its nutrient levels

[0045] The basal diets and their nutrient levels are shown in Tables 1 and 2. The basal diets were consistent in each stage of the experiment, and glucuronolactone was added to the diets of each group according to the experimental design.

[0046] Table 1: Composition of basal diet.

[0047]

[0048] Table 2: Nutritional Levels

[0049]

[0050] Note: 1) Per kilogram of vitamin supplement: Vitamin A, Vitamin D3, Vitamin E, Vitamin K3, Vitamin B1, Vitamin B2, Vitamin B6, Vitamin B1 12 The contents of the following were 13500 IU, 3900 IU, 30 IU, 4.80 mg, 3.00 mg, 7.50 mg, 6.00 mg, and 0.024 mg, respectively; folic acid, biotin, niacin, and calcium pantothenate were 1.50 mg, 0.18 mg, 45 mg, and 18 mg, respectively.

[0051] 2) The contents of Fe, Zn, Mn, Se, I, Co and Cu per kilogram of mineral premix are 144.00 mg, 144.00 mg, 120.00 mg, 0.70 mg, 0.96 mg, 1.00 mg and 20 mg, respectively.

[0052] 3) Nutritional level: calculated according to NRC (1994).

[0053] Example 3: Effect of dietary supplementation with glucuronolactone on egg yolk quality

[0054] 1) Experimental Method: After the experiment, three eggs were randomly selected from each replicate for the determination of yolk quality. The yolk color was measured using an egg quality analyzer (MINOLTA, Japan); the yolk weight was weighed, and the yolk specific gravity was calculated using the following formula: Yolk specific gravity (%) = (yolk weight / egg weight) × 100; yolk samples were taken, and the crude fat content was determined using the Soxhlet fat extraction method.

[0055] 2) Experimental results: As shown in Table 1, the addition of glucuronolactone to the feed had no significant effect on the color, proportion and crude fat content of the egg yolk.

[0056] Table 1: Effect of glucuronolactone addition on egg yolk quality

[0057]

[0058] Example 4: Effect of dietary supplementation with glucuronolactone on the fatty acid composition of egg yolk lipids

[0059] 1) Targeted Lipidomics Detection Method: Fatty acids in egg yolk samples were characterized by gas chromatography and quantified using an internal standard method. The specific procedure was as follows: A fresh egg yolk sample (200.00 ± 0.02 mg) was weighed, and 100 μL of internal standard solution (C7 fatty acid methyl ester, 5.00 mg / mL) was added, followed by 2 mL of methanol solution (5% H2SO4, V:V) and 300 μL of toluene. The bottle containing the above sample solution was sealed, the solution was shaken well, and then heated in a 95℃ water bath for 1.5 hours for lipid hydrolysis and fatty acid extraction. Subsequently, the mixture was cooled to room temperature, corrected with 1 mL of hexane and 2 mL of 0.90% (w / w) NaCl, and vortexed for 1 minute. Finally, the top hexane phase was collected by centrifugation (5000 × g, 5 min), and fatty acid methyl esters were obtained by drying the hexane phase with nitrogen. Gas chromatographic analysis of fatty acid methyl esters was performed using an Agilent 6890N gas chromatograph equipped with a flame ionization detector (FID) and a DB-FastFAME column (30 m × 0.25 mm × 0.25 μm, Agilent). The injection port temperature was 250°C, the injection volume was 2 μL, and the split ratio was 20:1. Ultra-high purity helium was used as the carrier gas at a flow rate of 1.0 mL / min. The column temperature was: 80°C for 0.5 min, then increased to 165°C at 40°C / min, held for 1 min, then increased to 230°C at 4°C / min, and held for 6 min. The detector temperature was 260°C, the H2 flow rate was 30 mL / min, and the air flow rate was 300 mL / min.

[0060] Statistical methods: Independent samples t-tests were performed on the two groups of data using SPSS 26.0. The results are expressed as mean ± standard error, and P < 0.05 was considered significant.

[0061] 2) Experimental Results: As shown in Table 2, compared with the control group, the total fatty acid content and unsaturated fatty acid content of egg yolk lipids in the glucuronolactone group were significantly increased, but there was no significant effect on the saturated fatty acid content in egg yolk lipids. Studies have shown that excessive intake of saturated fatty acids can lead to elevated blood cholesterol, triglycerides, and low-density lipoprotein cholesterol, subsequently causing arterial stenosis, atherosclerosis, and increasing the risk of coronary heart disease. Unsaturated fatty acids can lower harmful cholesterol and triglycerides in the blood, effectively controlling the concentration of blood lipids. They also increase the content of beneficial high-density lipoprotein, and maintaining low blood lipid levels plays a crucial role in maintaining health, preventing cardiovascular disease, and improving endocrine function. Adding glucuronolactone to the diet can increase the content of unsaturated fatty acids in egg yolks, thereby further promoting human health.

[0062] Further analysis of the n-3 and n-6 ​​series PUFAs in egg yolk lipids revealed that, compared to the control group, the contents of both n-3 and n-6 ​​series PUFAs were increased in the glucuronolactone group, and the mass ratio of n-3 to n-6 series PUFAs was also increased. Studies have shown that n-3 and n-6 ​​series PUFAs are essential amino acids that cannot be synthesized in the body and are mainly derived from feed. During animal husbandry, the feed consumed by animals generally contains a large amount of n-6 series PUFAs, leading to a much higher deposition of n-6 series PUFAs in livestock products compared to n-3 PUFAs. An excessively high n-6 / n-3 PUFA ratio increases the probability of cardiovascular disease, cancer, inflammation, and autoimmune diseases in humans. The results of this experiment indicate that adding glucuronolactone to the feed significantly improves the n-6 / n-3 series PUFA ratio in egg yolks.

[0063] Further analysis of the content of n-3 series PUFAs in egg yolk lipids revealed that, compared with the control group, the glucuronolactone group showed significantly increased levels of alpha-linolenic acid (ALA) and docosahexaenoic acid (DHA), but no significant effect on eicosapentaenoic acid (EPA). n-3 series PUFAs have significant positive effects on inhibiting chronic diseases such as diabetes, heart disease, and hyperlipidemia in humans. They can participate in and regulate cellular metabolic processes, thereby reducing blood cholesterol and triglyceride levels. The results of this experiment indicate that adding glucuronolactone to the diet can increase the content of alpha-linolenic acid and docosahexaenoic acid in egg yolks.

[0064] Further analysis of the content of n-6 series PUFAs in egg yolk lipids revealed that, compared with the control group, the content of arachidonic acid and oleic acid in the egg yolk of the glucuronolactone group was significantly increased. The study indicates that arachidonic acid belongs to the n-6 series of long-chain polyunsaturated fatty acids and is an important substance for the development of the human brain and optic nerve, playing a vital role in improving intelligence and enhancing visual acuity. Oleic acid, on the other hand, belongs to the n-9 monounsaturated fatty acid group, which can regulate blood lipid levels, lower cholesterol, effectively reduce the occurrence of hypercholesterolemia and cardiovascular diseases, and lower the risk of coronary heart disease. Furthermore, the content of arachidonic acid and oleic acid in egg yolk was significantly positively correlated with the eggy and milky flavor of the egg yolk.

[0065] In conclusion, the addition of glucuronolactone to the basal diet can significantly increase the content of polyunsaturated fatty acids and monounsaturated fatty acids in egg yolks, promote the deposition of α-linolenic acid, docosahexaenoic acid, arachidonic acid and oleic acid, and significantly improve the functional nutritional value of eggs.

[0066] Table 2: Effect of glucuronolactone addition on fatty acid composition of egg yolk lipids

[0067]

[0068] Example 5: Effect of dietary supplementation with glucuronolactone on egg yolk flavor

[0069] 1) Test Methods: According to GB / T 39625-2020 / ISO13299:2016, the sensory quality of egg yolk samples was evaluated using quantitative descriptive analysis. The specific process was as follows: Ten evaluators (aged 25-35, half male and half female) with strong descriptive abilities, good repeatability, and stability were selected and trained. Egg samples were numbered and uniformly boiled at high temperature for 15 minutes. After cooling to room temperature, the yolks were separated, numbered, and sealed. Before evaluation, they were kept warm in a constant temperature incubator. Egg yolk samples were randomly distributed to the evaluators, who evaluated the samples without knowing the sample treatment. After discussion, three aroma, five taste, and six texture descriptive terms were determined. After determining the descriptive terms, reference materials (cooked egg, wine aroma, pure milk, sucrose, salt solution, seaweed) were discussed and defined. The team members were trained using these reference materials. The samples were evaluated on an average scale of 0 (low) to 15 (high) for odor, taste, texture, and liking. Before each sample evaluation, the evaluator used purified water to clean any remaining sample from the mouth. Each replicate sample was evaluated three times, once daily.

[0070] 2) Experimental Results: As shown in Table 3, compared with the control group, the milky flavor score of the egg yolk in the glucuronolactone group was significantly increased, and there was also a trend of increasing salty flavor and flavor preference. It had no significant effect on the odor and texture of the egg yolk. Furthermore, there was no significant difference in overall preference between the two groups. The study indicates that in the evaluation of egg yolk flavor, the milky flavor is formed by the thermal decomposition of stearic acid, oleic acid, and linolenic acid. Increased oleic acid and arachidonic acid content in egg yolk may improve the milky flavor score. This result is consistent with the increase in oleic acid and arachidonic acid content in Example 1. The flavor score in egg yolk is positively correlated with the content of n-3 series polyunsaturated fatty acids, which is consistent with the structure of increased n-3 series PUFA content in Example 1. The overall flavor preference of egg yolk is highly positively correlated with texture preference, followed by flavor and odor preference. This indicates that the texture and flavor of egg yolk are the main factors affecting the flavor preference of egg yolks from different egg varieties.

[0071] In conclusion, the addition of glucuronolactone to the diet can significantly improve the taste score of egg yolks in sensory evaluation, especially the preference for milky and salty flavors, indicating that the addition of glucuronolactone to the diet improves the flavor of egg yolks.

[0072] Table 3: Sensory Evaluation of Egg Yolk

[0073]

[0074] Example 6: Effects of different amounts of feed additives on the content of polyunsaturated and monounsaturated fatty acids in egg yolks

[0075] 1) Experimental Design: 450 healthy Hy-Line Brown chickens at 42 weeks of age (peak laying period) with similar egg production performance (layout rate higher than 95%) were randomly divided into 5 groups (6 replicates per group, 15 chickens per replicate). These were the control group, glucuronolactone group 1, glucuronolactone group 2, glucuronolactone group 3, glucuronolactone group 4, and glucuronolactone group 5. The control group was fed a basal diet. Groups 1 through 5 received glucuronolactone supplemented to their basal diet at 70 mg / kg, 140 mg / kg, 280 mg / kg, 560 mg / kg, and 1120 mg / kg respectively. All three groups continued this diet for 8 weeks, and samples were taken on the last day of the 8-week period. The basal diet was the same as in Example 2.

[0076] 2) The test method is the same as in Example 4.

[0077] 3) Experimental Results: As shown in Table 4, when the amount of glucuronolactone added was 280-560 mg / kg, the content of n-3 series polyunsaturated fatty acids and n-6 ​​series polyunsaturated fatty acids in the egg yolk increased significantly, especially the content of ALA, DHA, AA and OA. Moreover, there was no significant difference in experimental data between the amounts of glucuronolactone added at 280 mg / kg and 560 mg / kg. However, when the amount of glucuronolactone added was as high as 1120 mg / kg, the content of n-3 series polyunsaturated fatty acids and n-6 ​​series polyunsaturated fatty acids tended to decrease. Therefore, in order to reduce the cost of feed while increasing the nutritional value of egg yolk, this application selected 280 mg / kg as the optimal amount of glucuronolactone added.

[0078] Table 4: Effects of different amounts of feed additives on the content of various fatty acids in egg yolks

[0079]

[0080] The above experiments show that glucuronolactone increases the content of n-3 series polyunsaturated fatty acids, n-6 series polyunsaturated fatty acids, and monounsaturated fatty acids in egg yolk lipids by altering the fatty acid composition of egg yolk lipids, thereby increasing the functional nutritional value and flavor of egg yolk. Example 3 shows that adding glucuronolactone to feed has no significant effect on the color, proportion, or crude fat content of egg yolk. Example 4 shows that adding glucuronolactone to diet can increase the content of unsaturated fatty acids in egg yolk, significantly improve the ratio of n-6 series PUFAs to n-3 series PUFAs in egg yolk, and can enhance the nutritional value of specific strains. The increased content of alpha-linolenic acid and docosahexaenoic acid enhances the salty flavor of eggs, while also increasing the content of arachidonic acid and oleic acid in the yolk, further improving the egg and milky aroma and significantly enhancing the functional nutritional value of eggs. Example 5 shows that adding glucuronolactone to the diet significantly improves the taste score in the sensory evaluation of egg yolks, especially enhancing the preference for milky and salty flavors, thus significantly improving the flavor of egg yolks. Example 6 shows that the optimal amount of glucuronolactone added to the diet is 280 mg / kg, which not only ensures good nutritional value of the egg yolks but also reduces feed costs.

[0081] As can be seen from the above embodiments, the present invention has the following beneficial effects:

[0082] Adding glucuronolactone to feed can alter the fatty acid composition of egg yolk lipids. By regulating the content of polyunsaturated and monounsaturated fatty acids in egg yolk lipids, especially the content of n-3 series polyunsaturated fatty acids, it not only increases the functional nutritional value of egg yolks and improves the quality of eggs, but also enhances the flavor of egg yolks.

[0083] The above description is merely some embodiments of the present invention and is not intended to limit the present invention. Those skilled in the art should understand that the present invention can have various changes and modifications, and any modifications, equivalent substitutions and improvements made in accordance with the present invention fall within the scope of protection claimed by the present invention.

Claims

1. Use of a feed additive which modifies the fatty acid composition of egg yolk lipids on a feed, characterised in that, The feed additive comprises glucurolactone, and the change of the fatty acid composition of the egg yolk lipid comprises increasing the content of alpha-linolenic acid, docosahexaenoic acid, arachidonic acid or oleic acid in the egg yolk lipid by feeding the feed containing glucurolactone.

2. Use according to claim 1, characterized in that, The content of the feed additive in the feed is 280-1120 mg / kg.

3. Use according to claim 2, characterized in that, The feed comprises, by weight percentage, corn 50-70%, soybean meal 20-30%, soybean oil 0.5-1.5%, limestone 5-10%, calcium hydrogen phosphate 1-3%, methionine 0.1-0.3%, sodium chloride 0.1-0.4%, choline chloride 0.05-0.2%, mineral premix 0.1-0.5%, vitamin additive 0.01-0.1%.

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