Application of feed additive for changing fatty acid composition of yolk lipid in feed

Abstract

The invention discloses an application of a feed additive for changing fatty acid composition of yolk lipid in feed. According to the invention, glucurolactone is added into poultry feed to regulate and control the content of polyunsaturated fatty acid and monounsaturated fatty acid in yolk lipid, wherein the polyunsaturated fatty acid comprises n-3 series polyunsaturated fatty acid; by adding glucurolactone into the feed, the fatty acid composition of egg yolk lipid can be changed, and by regulating and controlling the content of polyunsaturated fatty acid and monounsaturated fatty acid in the egg yolk lipid, especially the content of n-3 series polyunsaturated fatty acid, not only is the functional nutritional value of egg yolk increased, but also the quality of eggs is improved; meanwhile, the flavor of the egg yolk can be increased.

Description

Technical Field

[0001] The present invention relates to the field of biotechnology, in particular to application of a feed additive for changing the fatty acid composition of egg yolk lipids in feed. Background Art

[0002] Eggs contain a wealth of vitamins and minerals, as well as proteins with high biological value, 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 component coming from the yolk. The yolk's lipid composition primarily consists of triglycerides, phospholipids, and cholesterol. Unsaturated fatty acids make up over 60% of the fatty acids in triglycerides and phospholipids, of which polyunsaturated fatty acids (PUFAs) account for approximately 20%. PUFAs are essential for human growth and development. Since the human body cannot synthesize them on its own, people generally supplement their intake through eggs. The n-3 series of PUFAs is the most deficient and most versatile known PUFA, possessing important physiological functions, such as contributing to the intellectual development of infants and young children, human brain development, and preventing cardiovascular disease. Therefore, increasing the content of PUFAs, particularly n-3 PUFAs, in eggs is a key issue in enhancing their nutritional value.

[0003] In the prior art, feed additives are generally added to feed for laying hens by using oil feed additives (rubber seeds, flax seeds, etc.), thereby increasing the polyunsaturated fatty acid content of egg yolks. However, there are no reports on using non-oil feed additives to increase the polyunsaturated fatty acid content of egg yolks.

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

[0005] The purpose of the present invention is to provide a method for increasing the content of n-3 polyunsaturated fatty acids in egg yolk lipids to improve the nutritional value of eggs, in order to address the problem that the content of polyunsaturated fatty acids in egg yolk lipids in the prior art is low, especially the content of n-3 polyunsaturated fatty acids is low, which leads to low nutritional value of eggs.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] The present invention discloses the use of a feed additive for changing the fatty acid composition of egg yolk lipids in feed. The feed additive comprises glucuronolactone. The method of changing the fatty acid composition of egg yolk lipids comprises 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 changing of the fatty acid composition of the egg yolk lipids includes increasing the content of n-3 series polyunsaturated fatty acids in the egg yolk lipids.

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

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

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

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

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

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

[0015] Furthermore, the content of the feed additive in the feed is 280-1120 mg / kg.

[0016] Furthermore, the feed comprises, by weight percentage, 50-70% corn, 20-30% soybean meal, 0.5-1.5% soybean oil, 5-10% limestone, 1-3% calcium hydrogen 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] The implementation of the present invention has the following beneficial effects:

[0018] Adding glucuronolactone to feed can change the fatty acid composition of egg yolk lipids. By regulating the content of polyunsaturated fatty acids 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 yolk and improves the quality of eggs, but also increases the flavor of egg yolk. DETAILED DESCRIPTION

[0019] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments, and therefore should not be understood as limiting the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] This embodiment provides the use of a feed additive for modifying the fatty acid composition of egg yolk lipids. The feed additive includes glucuronolactone. Modifying 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 polyunsaturated fatty acids. Adding glucuronolactone to feed can modify the fatty acid composition of egg yolk lipids. By regulating the content of polyunsaturated and monounsaturated fatty acids in the egg yolk lipids, particularly the content of n-3 polyunsaturated fatty acids, the additive 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.

[0022] Optionally, altering the fatty acid composition of egg yolk lipids comprises regulating the total saturated fatty acid content of egg yolk lipids.

[0023] Specifically, total saturated fatty acids include saturated fatty acids and unsaturated fatty acids.

[0024] Optionally, changing the fatty acid composition of egg yolk lipids includes increasing the content of unsaturated fatty acids in egg yolk lipids. Specifically, unsaturated fatty acids include polyunsaturated fatty acids and monounsaturated fatty acids.

[0025] Optionally, altering the fatty acid composition of egg yolk lipids includes regulating the mass ratio of n-3 polyunsaturated fatty acids to n-6 polyunsaturated fatty acids in egg yolk lipids by feeding a feed containing glucuronolactone. Excessively high n-6 / n-3 polyunsaturated fatty acid mass ratios can increase the risk of cardiovascular disease, cancer, inflammation, and autoimmune diseases.

[0026] Optionally, altering the fatty acid composition of egg yolk lipids includes increasing the mass ratio of n-3 polyunsaturated fatty acids to n-6 polyunsaturated fatty acids in egg yolk lipids. By reducing the mass ratio of n-6 / n-3 polyunsaturated fatty acids, human health can be significantly improved.

[0027] Optionally, altering the fatty acid composition of the egg yolk lipids includes increasing the content of n-3 polyunsaturated fatty acids in the egg yolk lipids. By increasing the content of n-3 polyunsaturated fatty acids in the egg yolk lipids, the nutritional value of the egg can be significantly improved, while also improving the salty taste of the egg yolk.

[0028] Optionally, the n-3 series of polyunsaturated fatty acids include α-linolenic acid and docosahexaenoic acid. α-linolenic acid has the effects of dilating blood vessels, reducing blood viscosity, and lowering triglycerides. Docosahexaenoic acid penetrates into the platelet phospholipid membrane in the body, becoming a major component of mitochondria and cell membranes, and is metabolized to produce prostaglandins, thromboxanes, and leukotrienes. These substances directly affect the body's vitality and function, thus playing a vital role in human health. This application greatly improves the nutritional value of eggs by increasing the content of α-linolenic acid and docosahexaenoic acid in egg yolks, solving the problem of severe insufficient intake of n-3 series polyunsaturated fatty acids in my country.

[0029] Optionally, the n-3 series polyunsaturated fatty acids include eicosapentaenoic acid.

[0030] Optionally, changing the fatty acid composition of egg yolk lipids comprises increasing the content of α-linolenic acid and docosahexaenoic acid in egg yolk lipids.

[0031] Optionally, the polyunsaturated fatty acids include n-6 polyunsaturated fatty acids. By regulating the content of n-6 polyunsaturated fatty acids, not only can the flavor of the egg yolk be further improved, but when people consume the egg yolk, the risk of cardiovascular disease can also be reduced, and nerve pain can be alleviated.

[0032] Optionally, changing the fatty acid composition of the egg yolk lipids includes increasing the content of n-6 polyunsaturated fatty acids in the egg yolk lipids. By increasing the content of n-6 polyunsaturated fatty acids in the egg yolk lipids, people's preference for the egg yolk flavor is increased, and the milky flavor of the egg yolk is further enhanced.

[0033] Optionally, the n-6 series polyunsaturated fatty acids include arachidonic acid. By regulating the content of specific types of n-6 series polyunsaturated fatty acids, the egg yolk and milk flavor are enhanced.

[0034] Optionally, altering the fatty acid composition of the egg yolk lipid comprises increasing the arachidonic acid content of the egg yolk lipid.

[0035] Optionally, altering the fatty acid composition of egg yolk lipids comprises regulating the monounsaturated fatty acid content in egg yolk lipids.

[0036] Optionally, changing the fatty acid composition of the egg yolk lipids includes increasing the content of monounsaturated fatty acids in the egg yolk lipids. By increasing the content of monounsaturated fatty acids, the taste and flavor of the egg yolk can be further improved, thereby increasing the overall enjoyment.

[0037] Optionally, the monounsaturated fatty acid includes oleic acid. The milky flavor is formed by the thermal decomposition of stearic acid, oleic acid and linolenic acid. By increasing the oleic acid content in the egg yolk, the milky flavor of the egg yolk can be increased, further improving the flavor of the egg yolk.

[0038] Optionally, the content of the feed additive in the feed is 280-1120 mg / kg. The upper limit of the feed additive content may be, but is not limited to, 1120 mg / kg, 1119 mg / kg, 1118 mg / kg, etc., and the lower limit of the feed additive content may be, but is not limited to, 280 mg / kg, 281 mg / kg, 282 mg / kg, etc.; it is understandable that the content of the feed additive can also be any point value within the above range, which is not enumerated here. By limiting the glucuronolactone within this range, the fatty acid composition of the egg yolk lipids can be further changed, making the difference in the fatty acid composition of the egg yolk lipids before and after the change more obvious and more reliable.

[0039] Preferably, the content of the feed additive in the feed is 280-560 mg / kg. The upper limit of the content of the feed additive may be, but is not limited to, 560 mg / kg, 559 mg / kg, 558 mg / kg, etc., and the lower limit of the content of the feed additive may be, but is not limited to, 280 mg / kg, 281 mg / kg, 282 mg / kg, etc.; understandably, the content of the feed additive may also be any point value within the above range, which is not enumerated here. Being limited to this range, the cost of the feed can be reduced. Further preferably, the content of the feed additive in the feed is 280 mg / kg. This can further reduce the cost of the feed while also increasing the nutritional value of the egg yolk.

[0040] Optionally, the feed formula includes: corn, soybean meal, soybean oil, limestone, calcium hydrogen phosphate, methionine, sodium chloride, choline chloride, mineral premix, and vitamin additives. Feed is food used to feed animals. When used in livestock and poultry farming, feed, in a narrow sense, refers to the food of animals raised in agriculture or animal husbandry. Glucuronolactone is readily available, low-cost, and highly safe. Direct mixing with feed significantly reduces production costs. Furthermore, properly formulated feed is convenient, fast, and time-saving. Once introduced into the poultry, the feed can effectively increase the polyunsaturated fatty acid content of egg yolk lipids, thereby improving egg quality.

[0041] Optionally, the feed, calculated by weight, includes: 50-70% corn, 20-30% soybean meal, 0.5-1.5% soybean oil, 5-10% limestone, 1-3% calcium hydrogen 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, calcium hydrogen phosphate, methionine, sodium chloride, choline chloride, mineral premix, and vitamin additives can be any value within the above ranges, and are not enumerated here. A suitable feed ratio can ensure sufficient energy for poultry feeding without reducing egg production and quality, while also reducing production costs and achieving good economic benefits. Preferably, the feed comprises, by weight percentage, 55-65% corn, 25-30% soybean meal, 0.5-1.5% soybean oil, 7-10% limestone, 1-2% calcium hydrogen 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. Further preferably, the feed comprises, by weight percentage, 60% corn, 28.43% soybean meal, 1% soybean oil, 8.30% limestone, 1.50% calcium hydrogen 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, and the laying hens are Hy-Line Brown laying hens. Hy-Line Brown laying hens have strong adaptability and can be widely used in breeding, with certain breeding economic benefits.

[0042] The following describes specific examples of the present application in conjunction with the application of the feed additive for modifying the fatty acid composition of egg yolk lipids in feed. The following examples further describe the technical solutions of the present application. These examples are intended for illustrative purposes only, as various modifications and variations within the scope of the present disclosure will be apparent to those skilled in the art. The materials used in the examples are commercially available or synthesized according to conventional methods and can be used directly without further processing. The instruments and devices used in the examples are also commercially available.

[0043] Example 1: Grouping design of experimental animals

[0044] A total of 256 healthy Hy-Line Brown chickens aged 42 weeks (peak egg production) with similar egg production performance (individual egg production rate above 95%) were randomly divided into two groups (8 replicates per group, 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 of glucuronolactone. Both groups were fed for 8 weeks, and samples were collected on the last day of the 8-week period.

[0045] Example 2: Preparation of experimental basal diets and analysis of nutritional levels

[0046] The experimental basal diet and its nutritional levels are shown in Tables 1 and 2. The basal diet was the same in each stage of the experiment, and glucuronolactone was added to the diet of each group according to the experimental design.

[0047] Table 1: Basal diet composition.

[0048]

[0049] Table 2: Nutritional levels

[0050]

[0051]

[0052] Note: 1) Vitamin A, Vitamin D3, Vitamin E, Vitamin K3, Vitamin B1, Vitamin B2, Vitamin B6, Vitamin B 12 The contents of vitamin B6, B6, C12, D4, D5, D6 and D7 are 13500IU, 3900IU, 30IU, 4.80mg, 3.00mg, 7.50mg, 6.00mg and 0.024mg respectively; the contents of folic acid, biotin, niacin and calcium pantothenate are 1.50mg, 0.18mg, 45mg and 18mg respectively.

[0053] 2) In each kilogram of mineral premix: the contents of Fe, Zn, Mn, Se, I, Co and Cu are 144.00 mg, 144.00 mg, 120.00 mg, 0.70 mg, 0.96 mg, 1.00 mg and 20 mg respectively.

[0054] 3) Nutritional level: calculated according to NRC (1994).

[0055] Example 3: Effect of Adding Glucuronolactone to the Diet on Egg Yolk Quality

[0056] 1) Test Method: After the test, three eggs were randomly selected from each replicate for yolk quality measurement. Yolk color was measured using an egg quality analyzer (MINOLTA, Japan). Yolk weight was measured, and yolk specific gravity was calculated using the following formula: Yolk specific gravity (%) = (yolk weight / egg weight) × 100. Yolk samples were taken and crude fat content was determined using the Soxhlet fat extraction method.

[0057] 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 egg yolk.

[0058] Table 1: Effect of glucuronolactone addition on egg yolk quality

[0059]

[0060] Example 4: Effect of dietary glucuronolactone supplementation on the fatty acid composition of egg yolk lipids

[0061] 1) Targeted lipidomics detection method: The fatty acids of the egg yolk sample were characterized by gas chromatography and quantified by the internal standard method. The specific process is as follows: weigh the fresh egg yolk sample (200.00±0.02 mg), add 100 μL of internal standard solution (carbon 17 fatty acid methyl ester, 5.00 mg / mL), and then add 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, and then placed in a 95°C water bath and heated 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 chromatography analysis of fatty acid methyl esters was performed on an Agilent 6890N gas chromatograph equipped with a flame ionization detector and a DB-FastFAME column (30 m × 0.25 mm × 0.25 μm, Agilent). The inlet temperature was 250°C, the injection volume was 2 μL, and the split ratio was 20:1. The carrier gas was ultra-high-purity helium at a flow rate of 1.0 mL / min. The column temperature was as follows: 80°C for 0.5 min, then 40°C / min to 165°C, held for 1 min, then 4°C / min to 230°C, 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.

[0062] Statistical method: SPSS26.0 was used to perform independent sample T test analysis on the two groups of data. The results were expressed as mean ± standard error, and P < 0.05 was considered significant.

[0063] 2) Test results: As shown in Table 2, compared with the control group, the total fatty acid content and unsaturated fatty acid content of the egg yolk lipids in the glucuronolide group were significantly increased, but there was no significant effect on the saturated fatty acid content in the egg yolk lipids; studies have shown that excessive intake of saturated fatty acids can lead to increased blood cholesterol, triglycerides, and low-density lipoprotein cholesterol, which can subsequently cause arterial stenosis, form atherosclerosis, and increase the risk of coronary heart disease. Unsaturated fatty acids can reduce cholesterol and triglycerides in the blood that are harmful to the human body, and can effectively control the concentration of blood lipids in the human body. It also increases the content of high-density lipoproteins that are beneficial to the human body. Maintaining low blood lipid levels plays a key role in maintaining good health, preventing cardiovascular diseases, and improving endocrine function. Adding glucurononolide to the feed can increase the content of unsaturated fatty acids in egg yolks, which can further promote human health.

[0064] Further analysis of the n-3 and n-6 ​​PUFA content in egg yolk lipids revealed a moderate increase in both n-3 and n-6 ​​PUFA content in the glucuronolide group compared to the control group, with an increased mass ratio of n-3 to n-6 PUFA. Studies have shown that n-3 and n-6 ​​PUFA are essential amino acids that cannot be synthesized in the body and are primarily derived from feed. During animal production, animal feed typically contains significant amounts of n-6 PUFA, leading to a much higher accumulation of n-6 PUFA than n-3 PUFA in livestock and poultry products. Excessive n-6 / n-3 PUFA ratios increase the risk of cardiovascular disease, cancer, inflammation, and autoimmune diseases. These results demonstrate that the addition of glucuronolide to feed significantly improves the n-6 / n-3 PUFA ratio in egg yolks of laying hen.

[0065] Further analysis of the content of n-3 PUFAs in egg yolk lipids revealed that the glucuronolide group significantly increased α-linolenic acid (ALA) and docosahexaenoic acid (EPA) levels compared to the control group, but had no significant effect on eicosapentaenoic acid (DHA). n-3 PUFAs have a significant positive effect on inhibiting chronic diseases such as diabetes, heart disease, and hyperlipidemia. They participate in and regulate cellular metabolism, thereby reducing blood cholesterol and triglyceride levels. These results indicate that dietary glucuronolide can increase the content of α-linolenic acid and docosahexaenoic acid in egg yolks.

[0066] Further analysis of the content of n-6 PUFAs in egg yolk lipids revealed significantly higher levels of arachidonic acid and oleic acid in the glucuronolide group compared to the control group. Studies have shown that arachidonic acid, a member of the n-6 long-chain polyunsaturated fatty acid family, is crucial for brain and optic nerve development, playing a crucial role in improving intelligence and visual acuity. Oleic acid, an n-9 monounsaturated fatty acid, can regulate blood lipid levels, lower cholesterol, and effectively reduce the risk of hypercholesterolemia, cardiovascular disease, and coronary heart disease. Furthermore, the content of arachidonic acid and oleic acid in egg yolks was significantly positively correlated with the eggy and milky flavors of the yolk.

[0067] In summary, adding glucuronolactone to the basal diet can significantly increase the polyunsaturated fatty acid content and monounsaturated fatty acid content of 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.

[0068] Table 2: Effect of glucuronolactone addition on the fatty acid composition of egg yolk lipids

[0069]

[0070]

[0071] Example 5: Effect of Adding Glucuronolactone to the Diet on Egg Yolk Flavor

[0072] 1) Test Method: The sensory quality of egg yolk samples was evaluated using a quantitative descriptive analysis method based on GB / T 39625-2020 / ISO13299:2016. The specific process was as follows: 10 evaluators (aged 25-35, half male and half female) with strong odor and flavor sensory abilities were selected and trained. The evaluators had good reproducibility and stability. The egg samples were numbered and uniformly steamed at high temperature for 15 minutes. After cooling to room temperature, the yolks were separated, numbered, and sealed. They were then placed in an incubator to maintain the temperature prior to evaluation. The egg yolk samples were randomly distributed to the evaluators, who evaluated the samples without knowing the sample treatment. After discussion, a vocabulary of three aroma, five flavor, and six texture descriptors was determined. After the descriptors were determined, reference materials (cooked egg, wine nose, pure milk, sucrose, salt solution, and seaweed) were discussed and defined to which the descriptors were compared. These reference materials were then used to train the panelists. Samples were rated on a scale of 0 (low) to 15 (high) for aroma, taste, texture, and preference. Before each sample evaluation, the evaluator cleaned the mouth of any remaining sample with purified water. Each replicate sample was evaluated three times, once daily.

[0073] 2) Test Results: As shown in Table 3, compared with the control group, the glucuronolide group significantly increased the milky flavor score of the egg yolk, with a trend toward increased salty flavor and increased flavor preference. There was no significant effect on the odor and texture of the egg yolk. Furthermore, no significant difference was observed in overall liking between the two groups. Studies have shown that, in the evaluation of egg yolk flavor, 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 increase the milky flavor score. These results are consistent with the results of Example 1, which showed increased oleic acid and arachidonic acid content. Furthermore, the flavor score of the egg yolk was positively correlated with the content of n-3 polyunsaturated fatty acids, consistent with the structure of increased n-3 PUFA content in Example 1. Overall liking of the egg yolk flavor was highly positively correlated with texture preference, followed by flavor and odor preference. This suggests that the texture and flavor of the egg yolk are the primary factors influencing the flavor preference of the egg yolk of different egg varieties.

[0074] In summary, the addition of glucuronolactone to the feed can significantly improve the taste score of egg yolk sensory evaluation, especially the preference for milky flavor and salty taste, indicating that the addition of glucuronolactone to the feed improves the flavor of egg yolk.

[0075] Table 3: Sensory evaluation of egg yolk

[0076]

[0077]

[0078] Example 6: Effects of different levels of feed additives on the content of polyunsaturated fatty acids and monounsaturated fatty acids in egg yolk

[0079] 1) Experimental Design: 450 healthy, 42-week-old Hailan Brown chickens (at peak egg production) with similar egg production performance (egg production rate greater than 95%) were randomly divided into five groups (six replicates per group, 15 chickens per replicate). These groups included a 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, while the glucuronolactone groups 1 to 5 were supplemented with 70 mg / kg, 140 mg / kg, 280 mg / kg, 560 mg / kg, and 1120 mg / kg of glucuronolactone, respectively, in the basal diet. The three groups were fed for 8 weeks, and samples were collected on the last day of the 8-week diet. The basal diet was consistent with that in Example 2.

[0080] 2) The test method is consistent with that of Example 4.

[0081] 3) Test results: As shown in Table 4, when the addition amount of glucuronolactone was 280-560 mg / kg, the content of n-3 series polyunsaturated fatty acids and n-6 ​​series polyunsaturated fatty acids in the obtained egg yolk was significantly increased, especially the content of ALA, EPA, AA and OA was significantly increased. The addition amount of glucuronolactone was 280 mg / kg and 560 mg / kg, respectively, and there was no significant difference in the experimental data between the two. However, when the addition amount of glucuronolactone 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 and increase the nutritional value of egg yolk, this application selected 280 mg / kg as the optimal addition amount of glucuronolactone.

[0082] Table 4: Effects of different levels of feed additives on the content of various fatty acids in egg yolk

[0083]

[0084]

[0085] From the above experiments, it can be seen 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 changing the fatty acid composition of egg yolk lipids, thereby increasing the functional nutritional value and flavor of egg yolk; from Example 3, it can be seen that adding glucuronolactone to the feed has no significant effect on the color, proportion and crude fat content of egg yolk; from Example 4, it can be seen that adding glucuronolactone to the feed can increase the content of unsaturated fatty acids in egg yolk, significantly improve the ratio of n-6 series PUFA / n-3 series PUFA in egg yolk, and can increase the nutritional value of specific species. The content of α-linolenic acid and docosahexaenoic acid improves the salty taste of the eggs, while also increasing the content of arachidonic acid and oleic acid in the egg yolk, further improving the egg flavor and milky flavor of the egg yolk, and significantly improving the functional nutritional value of the eggs; as shown in Example 5, the addition of glucuronolactone to the feed can significantly improve the taste score of the egg yolk sensory score, especially the preference for milky flavor and salty taste, which significantly improves the flavor of the egg yolk; as shown in Example 6, the optimal amount of glucuronolactone added to the feed is 280 mg / kg, which not only can improve the nutritional value of the egg yolk, but also can reduce the cost of feed.

[0086] It can be seen from the above embodiments that the present invention has the following beneficial effects:

[0087] Adding glucuronolactone to feed can change the fatty acid composition of egg yolk lipids. By regulating the content of polyunsaturated fatty acids 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 yolk and improves the quality of eggs, but also increases the flavor of egg yolk.

[0088] What is described above are only some embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art should understand that the present invention may be subject to various changes and improvements, and any modifications, equivalent substitutions and improvements made in accordance with the present invention shall fall within the scope of protection required by the present invention.

Claims

1. Application of a feed additive for changing the fatty acid composition of egg yolk lipids in feed, characterized in that: The feed additive includes glucuronolide, and the changing of the fatty acid composition of egg yolk lipid includes regulating the content of polyunsaturated fatty acids and monounsaturated fatty acids in egg yolk lipid by feed containing glucuronolide, wherein the polyunsaturated fatty acids include n-3 series polyunsaturated fatty acids.

2. The use according to claim 1, characterized in that: The method of changing the fatty acid composition of egg yolk lipids includes increasing the content of n-3 series polyunsaturated fatty acids in egg yolk lipids.

3. The use according to claim 1, characterized in that: The n-3 series polyunsaturated fatty acids include α-linolenic acid and docosahexaenoic acid.

4. The use according to any one of claims 1 to 3, characterized in that: The polyunsaturated fatty acids include n-6 series polyunsaturated fatty acids.

5. The use according to claim 4, characterized in that: The method of changing the fatty acid composition of egg yolk lipids includes increasing the content of n-6 series polyunsaturated fatty acids in egg yolk lipids.

6. The use according to claim 4, characterized in that: The n-6 series polyunsaturated fatty acids include arachidonic acid.

7. The use according to any one of claims 1 to 3, characterized in that: The changing of the fatty acid composition of egg yolk lipids includes increasing the content of monounsaturated fatty acids in egg yolk lipids.

8. The use according to any one of claims 1 to 3, characterized in that: The monounsaturated fatty acid includes oleic acid.

9. The use according to any one of claims 1 to 3, characterized in that: The content of the feed additive in the feed is 280-1120 mg / kg.

10. The use according to claim 9, characterized in that: The feed comprises, by weight percentage, 50-70% corn, 20-30% soybean meal, 0.5-1.5% soybean oil, 5-10% limestone, 1-3% calcium hydrogen 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 additive.

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