Feed additive for producing DHA-rich poultry eggs and method for producing DHA-rich poultry eggs

Abstract

The invention relates to the technical field of feed additives and poultry breeding, and provides a feed additive for producing DHA-rich poultry eggs and a method for producing DHA-rich poultry eggs, the feed additive for producing DHA-rich poultry eggs comprises a component A, a component B and a component C which are stored separately, the component A is flaxseeds, the component B is schizochytrium limacinum powder, and the component C is a natural plant extract. The component C comprises cardamine hirsute and bile acid. In the first stage and the third stage of the poultry egg producing period, cardamine hirsute and bile acid are added into basal feed, flaxseeds are added in the first stage, flaxseeds and schizochytrium limacinum powder are added in the second stage, and schizochytrium limacinum powder is added in the third stage; the first stage starts from the stable egg laying stage and lasts for 1-2 weeks, the second stage lasts for 1-2 weeks, and the third stage lasts until the egg laying stage ends. According to the feed additive, the content of DHA in poultry eggs and the proportion of phospholipid type DHA can be remarkably increased, and the DHA enrichment and storage stability of the poultry eggs is improved.

Description

Technical Field

[0001] This invention relates to the fields of feed additives and poultry farming technology, specifically to a feed additive for producing DHA-rich poultry eggs and a method for producing DHA-rich poultry eggs. Background Technology

[0002] DHA (docosahexaenoic acid) is an essential n-3 polyunsaturated fatty acid that plays a vital role in neural development and metabolic regulation. Eggs, as a nutritionally complete food widely accepted globally, are rich in lipids, various fibers, and trace elements. They are also plentiful, inexpensive, and easy to consume, making them an effective carrier for daily DHA supplementation. Studies have shown that the DHA content in poultry eggs can be regulated through poultry diets. Effective additives include Schizochytrium powder, flaxseed, and fish oil. Schizochytrium powder itself contains abundant DHA, which can be directly accumulated in poultry eggs. Alpha-linolenic acid (ALA) in flaxseed is indirectly converted into DHA in poultry eggs through physiological metabolism, but its conversion efficiency is lower, resulting in a lower DHA accumulation effect compared to Schizochytrium powder.

[0003] Existing DHA-enriched poultry egg production technologies generally suffer from three major pain points: First, relying on "high-dose addition of DHA sources" to passively increase DHA deposition in egg yolks not only leads to a surge in feed costs but also results in significant DHA loss through feces due to the low natural absorption rate of DHA in the laying hen's intestines caused by its large molecular weight and strong hydrophobicity. Second, the metabolic loss of DHA in poultry is ignored; DHA is prone to lipid peroxidation during drying and is easily decomposed as energy through the β-oxidation pathway, further reducing deposition efficiency. Third, the technology is too simplistic; for example, simply adding a DHA source to increase DHA deposition can easily cause side effects such as fatty liver in laying hens and decreased egg production. Furthermore, the instability of DHA leads to DHA loss during egg storage. Summary of the Invention

[0004] To address the problems existing in the background art, the present invention provides a feed additive for producing DHA-rich poultry eggs and a method for producing DHA-rich poultry eggs. The feed additive can significantly increase the DHA content and the proportion of phospholipid DHA in poultry eggs, and improve the DHA enrichment and storage stability of poultry eggs.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: In a first aspect, the present invention provides a feed additive for producing DHA-rich poultry eggs, comprising separately stored components A, B and C, wherein component A is flaxseed, component B is Schizochytrium powder, and component C comprises broken rice straw and bile acids, wherein the broken rice straw and bile acids are stored separately or mixed.

[0006] According to the above scheme, if the broken rice and bile acids in component C are stored together, the mass ratio of broken rice to bile acids is (0.3-0.6):(2-4).

[0007] Secondly, the present invention provides a method for using the above-mentioned feed additive for producing DHA-rich poultry eggs. In the first stage of the poultry laying period, broken rice, bile acids, and flaxseed are added to the basal feed. In the second stage, broken rice, bile acid flaxseed, and Schizochytrium powder are added to the basal feed. In the third stage, broken rice, bile acids, and Schizochytrium powder are added to the basal feed. The first stage begins when the egg production stabilizes and lasts for 1-2 weeks. The second stage begins after the end of the first stage and lasts for 1-2 weeks. The third stage begins after the end of the second stage and continues until the end of the laying period.

[0008] According to the above scheme, based on the mass of the basic feed as 100%, in Stage I, the addition amount of broken rice shepherd's purse is 0.3-0.6%, the addition amount of bile acids is 2-4%, and the addition amount of flaxseed is 10-15%; in Stage II, the addition amount of broken rice shepherd's purse is 0.3-0.6%, the addition amount of bile acids is 2-4%, the addition amount of flaxseed is 10-15%, and the addition amount of Schizochytrium powder is 5-8%; in Stage III, the addition amount of broken rice shepherd's purse is 0.3-0.6%, the addition amount of bile acids is 2-4%, and the addition amount of Schizochytrium powder is 5-8%.

[0009] Thirdly, this invention provides a method for producing DHA-rich poultry eggs. In the first stage of the poultry laying period, broken rice grains, bile acids, and flaxseed are added to the basal feed. In the second stage, broken rice grains, bile acids, flaxseed, and Schizochytrium powder are added to the basal feed. In the third stage, broken rice grains, bile acids, and Schizochytrium powder are added to the basal feed. The first stage begins when the laying period stabilizes and lasts for 1-2 weeks. The second stage begins at the end of the first stage and lasts for 1-2 weeks. The third stage begins at the end of the second stage and continues until the end of the laying period. Poultry eggs laid after the first week of the third stage are DHA-rich poultry eggs.

[0010] According to the above scheme, taking the weight of the basic feed as 100%, in Stage I, the addition amount of broken rice shepherd's purse is 0.3-0.6%, the addition amount of bile acids is 2-4%, and the addition amount of flaxseed is 10-15%; in Stage II, the addition amount of broken rice shepherd's purse is 0.3-0.6%, the addition amount of bile acids is 2-4%, the addition amount of flaxseed is 10-15%, and the addition amount of Schizochytrium powder is 5-8%; in Stage III, the addition amount of broken rice shepherd's purse is 0.3-0.6%, the addition amount of bile acids is 2-4%, and the addition amount of Schizochytrium powder is 5-8%.

[0011] According to the above scheme, preferably, the stable egg production period is characterized by an egg production rate of ≥90%, an egg production rate fluctuation range of ≤2%, and a daily average feed intake variation coefficient of <5%.

[0012] According to the above plan, the poultry are laying hens, laying ducks, or laying quails.

[0013] According to the above plan, the breed of laying hens is Chuqin No. 2, purebred Jianghan chicken, recessive white-feathered chicken, yellow chicken, Jinshui black-bone chicken, Jingyang chicken, Hy-Line grey laying hen, Macheng green-shell laying hen, Yunyang big chicken, Lohmann pink laying hen, or Hubei red chicken.

[0014] According to the above scheme, the basic feed is a corn-soybean meal type basic feed, a corn-soybean meal-bran type basic feed, a corn-mixed meal type basic feed, or a corn-rice bran type basic feed.

[0015] According to the above plan, the DHA content in the produced eggs is ≥337mg / 100g.

[0016] Flaxseed is rich in alpha-linolenic acid (ALA). When flaxseed is added as a feed additive in the first stage of laying hens' egg production, the hens continuously ingest ALA. Some ALA undergoes oxidative decomposition or is deposited in tissues including the yolk. Some ALA, as a precursor to DHA, is further converted into DHA through the ALA-EPA-DHA pathway. During this process, the expression and activity of key enzymes in the liver are upregulated, while VLDL synthesis is promoted. Then, in the second stage, DHA-containing Schizochytrium powder is added for transition, and flaxseed is removed in the third stage. The DHA in the Schizochytrium powder can be rapidly assembled into VLDA and transported to the yolk, avoiding the accumulation of DHA in the liver and its consumption by the matrix. This allows the ingested DHA to be rapidly and efficiently enriched into the eggs.

[0017] Selenium in rice bran is a core component in the synthesis of antioxidant enzymes such as glutathione peroxidase. It can reduce oxidative stress on the liver and reproductive system such as the ovary during the metabolism of flaxseed and Schizochytrium powder, protect the normal function of liver cells and oocyte development, and promote the synthesis and secretion of VLDLy. At the same time, the antioxidant effect of selenium can also protect the structural integrity of VLDL, thereby protecting the physiological functions of LDL (low-density lipoprotein), HDL (high-density lipoprotein) and Pv (phosphoprotein vitae), and ensuring that the DHA carried by lipoproteins can resist oxidative stress in the poultry body.

[0018] Bile acids can emulsify DHA-containing fats in feed into tiny particles and promote the expression of apolipoproteins in intestinal cells. This allows DHA-containing fats to esterify and form chylomicrons with apolipoproteins and phospholipids, enabling absorbed DHA to quickly enter the circulation process and avoiding oxidative damage. On the other hand, in the liver, bile acids can promote DHA uptake and form VLDL / VLDLy particles loaded with higher concentrations of DHA. These particles then deposit the DHA in the egg yolk, increasing the enrichment rate of DHA in the egg. In this process, the antioxidant effects of bile acids help protect the normal physiological function of liver cells.

[0019] The beneficial effects of this invention are: In the feed additive of this invention, flaxseed and Schizochytrium powder are added in stages as DHA sources. Flaxseed can induce the upregulation of the metabolic system in laying hens in the early stage, improve the utilization rate of Schizochytrium powder added in the later stage, enhance the transport and deposition efficiency of DHA in Schizochytrium powder, and promote its deposition and enrichment in egg yolk. Bile acids and rice bran can improve the antioxidant performance of poultry, protect the liver and ovaries of poultry, reduce the adverse effects of DHA source addition on poultry, and ensure their production performance. At the same time, they can increase the content of lipoproteins and phospholipids in animals, further improve the transport efficiency of DHA, thereby increasing the content of DHA and phospholipid DHA in egg yolk and enhancing the stability of DHA enrichment.

[0020] Through the synergistic effect of flaxseed, Schizochytrium powder, chopped rice, and bile acids, while ensuring poultry production performance (such as egg production rate), the absolute content of DHA in poultry eggs, the proportion of DHA in total n-3 polyunsaturated fatty acids, and the content and proportion of phospholipid DHA are significantly increased. At the same time, poultry eggs with high DHA content can be obtained in a short period of time, and the stability of DHA enrichment in poultry eggs is enhanced, so that poultry eggs with high DHA content can be obtained quickly, stably, and continuously throughout the entire egg production stabilization period.

[0021] Taking Chuqin No. 2 laying hens as an example, during the transition period in stages I and II, the DHA content in the eggs produced was relatively low. At the end of stage II, the DHA content in the eggs was 65 mg / g. One week after entering stage III, the DHA content in the produced eggs reached 337 mg / g, and the phospholipid DHA content reached 297 mg / g. After that, the DHA content in the eggs steadily increased. From week 6 until the end of the laying period, the DHA content remained stable above 420 mg / g, reaching a maximum of 435 mg / g, and the phospholipid DHA content reached 350 mg / g. Moreover, the storage stability was good. Attached Figure Description

[0022] Figure 1The egg production rate of the experimental group, control group 1, and control group 2 hens in Example 1 of this invention; Figure 2 The DHA content and the proportion of DHA in n-3 polyunsaturated fatty acids in eggs from different weeks of the experimental group, control group 1 and control group 2 in Example 1 of the present invention are shown. Figure 3 The DHA content and the proportion of DHA in n-3 polyunsaturated fatty acids in eggs of different weeks in the experimental group, control group 3 and control group 4 in Example 1 of the present invention; Figure 4 The content of phospholipid DHA and its proportion in total DHA in eggs from different weeks of the experimental group, control group 1 and control group 2 in Example 1 of the present invention; Figure 5 The content of phospholipid DHA and its proportion in total DHA in eggs from different weeks of the experimental group, control group 3 and control group 4 in Example 1 of the present invention; Figure 6 The sensory differences in eggs after storage at 37°C for different times in Example 1 of this invention are shown, where A is the egg of control group 2 and B is the egg of experimental group. Detailed Implementation

[0023] The principles and features of the present invention are described below with reference to the accompanying drawings and specific embodiments. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0024] To increase the DHA content in poultry eggs, this invention provides a feed additive for producing DHA-rich poultry eggs, comprising components A, B, and C stored separately. Component A is flaxseed, component B is Schizochytrium powder, and component C includes broken rice straw and bile acids, which are stored separately or mixed.

[0025] When using this additive, in the first stage of the poultry laying period, add broken rice water chestnuts, bile acids, and flaxseed to the basal feed; in the second stage, add broken rice water chestnuts, bile acids, flaxseed, and Schizochytrium powder to the basal feed; and in the third stage, add broken rice water chestnuts, bile acids, and Schizochytrium powder to the basal feed. The first stage begins when the laying period stabilizes and lasts for 1-2 weeks; the second stage begins when the first stage ends and lasts for 1-2 weeks; and the third stage begins when the second stage ends and continues until the end of the laying period.

[0026] Flaxseed and Schizochytrium powder serve as DHA sources, working synergistically. In the first stage of the egg-laying period, flaxseed containing DHA precursors is added to activate relevant metabolic pathways and promote VLDA synthesis. In the second stage, DHA-containing Schizochytrium powder is added simultaneously for a transition. In the third stage, only Schizochytrium powder is added, without flaxseed. The early addition of flaxseed improves the utilization rate of the later-added Schizochytrium powder, enhancing the transport and deposition efficiency of DHA in the powder, promoting DHA accumulation during egg laying, and efficient deposition in the egg yolk. Simultaneously, chopped rice and bile acids are added in all three stages. Bile acids promote the emulsification of DHA-containing lipids in the Schizochytrium powder, forming chylomicrons, which promotes DHA absorption by intestinal cells in poultry and reduces liver burden, protecting the liver. It increases phospholipid content, improves the loading efficiency of DHA and VLDL / VLDLy, enhances the enrichment efficiency of DHA in eggs, and promotes its rapid transport. It also reduces oxidative stress on organs such as the liver and ovaries during the metabolism of flaxseed and Schizochytrium powder, protecting normal liver cell function and oocyte development. Simultaneously, it promotes the synthesis and secretion of VLDLy, protects the integrity of VLDL structure, and safeguards the physiological functions of LDL (low-density lipoprotein), HDL (high-density lipoprotein), and Pv (phosphoprotein yolk). Through the synergistic effect of flaxseed, Schizochytrium powder, and bile acids, it significantly increases the absolute content of DHA in poultry eggs, the proportion of DHA in total n-3 polyunsaturated fatty acids, and the content of phospholipid-type DHA, while ensuring poultry production performance (such as egg production).

[0027] In some specific implementations, if the broken rice and bile acids in component C are stored together, the mass ratio of broken rice to bile acids is (0.3-0.6):(2-4).

[0028] Flaxseed contains ≥20% α-linolenic acid, and its specifications are: obtained by ultra-fine grinding and passing through an 80-mesh sieve; The Schizochytrium powder is obtained by drying and pulverizing the heterotrophic culture of Schizochytrium. After drying, the moisture content is ≤10%, and after pulverizing, it is passed through a 60-mesh sieve. After drying, the broken water chestnuts are pulverized and passed through a 100-mesh sieve. The bile acids are feed-grade bile acids with a purity of ≥90%.

[0029] The above-mentioned feed additives can be used as feed additives for poultry such as laying hens, laying ducks, and laying quails.

[0030] Secondly, the present invention provides a method for using the above-mentioned feed additive for producing DHA-rich poultry eggs. In the first stage of the poultry laying period, broken rice straw, bile acids, and flaxseed are added to the basal feed. In the second stage, broken rice straw, bile acids, flaxseed, and Schizochytrium powder are added to the basal feed. In the third stage, broken rice straw, bile acids, and Schizochytrium powder are added to the basal feed. The first stage begins when the egg production stabilizes and lasts for 1-2 weeks. The second stage begins when the first stage ends and lasts for 1-2 weeks. The third stage begins when the second stage ends and continues until the end of the egg production period.

[0031] According to the above scheme, based on the mass of the basic feed as 100%, in Stage I, the addition amount of broken rice shepherd's purse is 0.3-0.6%, the addition amount of bile acids is 2-4%, and the addition amount of flaxseed is 10-15%; in Stage II, the addition amount of broken rice shepherd's purse is 0.3-0.6%, the addition amount of bile acids is 2-4%, the addition amount of flaxseed is 10-15%, and the addition amount of Schizochytrium powder is 5-8%; in Stage III, the addition amount of broken rice shepherd's purse is 0.3-0.6%, the addition amount of bile acids is 2-4%, and the addition amount of Schizochytrium powder is 5-8%.

[0032] Thirdly, this invention provides a method for producing DHA-rich poultry eggs. In the first stage of the poultry laying period, broken rice grains, bile acids, and flaxseed are added to the basal feed. In the second stage, the basal feed is changed to include broken rice grains, bile acids, flaxseed, and Schizochytrium powder. In the third stage, broken rice grains, bile acids, and Schizochytrium powder are added to the basal feed. The first stage begins when the laying period stabilizes and lasts for 1-2 weeks. The second stage begins at the end of the first stage and lasts for 1-2 weeks. The third stage begins at the end of the second stage and continues until the end of the laying period. Poultry eggs laid after the first week of the third stage are DHA-rich poultry eggs.

[0033] In some specific implementation plans, the stable egg production period is defined as an egg production rate of ≥90%, with a fluctuation range of ≤2% and a coefficient of variation of daily feed intake <5%. During this period, egg weight is stable, and there are no abnormalities in fecal condition or mental state.

[0034] According to the above scheme, taking the weight of the basic feed as 100%, in Stage I, the addition amount of broken rice shepherd's purse is 0.3-0.6%, the addition amount of bile acids is 2-4%, and the addition amount of flaxseed is 10-15%; in Stage II, the addition amount of broken rice shepherd's purse is 0.3-0.6%, the addition amount of bile acids is 2-4%, the addition amount of flaxseed is 10-15%, and the addition amount of Schizochytrium powder is 5-8%; in Stage III, the addition amount of broken rice shepherd's purse is 0.3-0.6%, the addition amount of bile acids is 2-4%, and the addition amount of Schizochytrium powder is 5-8%.

[0035] In some specific embodiments, in Stage I, the amount of broken rice water chestnut added is 0.5%, the amount of bile acid added is 3%, and the amount of flaxseed added is 13%; in Stage II, the amount of broken rice water chestnut added is 0.5%, the amount of bile acid added is 3%, the amount of flaxseed added is 13%, and the amount of Schizochytrium powder added is 6%; in Stage III, the amount of broken rice water chestnut added is 0.5%, the amount of bile acid added is 3%, and the amount of Schizochytrium powder added is 6%.

[0036] In some specific embodiments, the poultry is a laying hen, a laying duck, or a laying quail.

[0037] In some specific embodiments, the breed of laying hen is Chuqin No. 2, purebred Jianghan chicken, recessive white-feathered chicken, yellow chicken, Jinshui black-bone chicken, Jingyang chicken, Hy-Line grey laying hen, Macheng green-shell laying hen, Yunyang large chicken, Lohmann pink laying hen or Hubei red chicken.

[0038] In some specific embodiments, the basal feed is a corn-soybean meal type basal feed.

[0039] In some specific implementations, the produced eggs contain ≥337mg / 100g of DHA and ≥297mg / 100g of phospholipid DHA. More preferably, the DHA content reaches approximately 435mg / 100g and the phospholipid DHA content reaches approximately 350mg / 100g.

[0040] The basal feed in the following examples is a corn-soybean meal type basal feed with the following formula: corn 60.20%, soybean meal 18.50%, rapeseed meal 4.50%, fish meal 2.00%, wheat bran 4.50%, limestone powder 8.00%, dicalcium phosphate 1.00%, salt 0.30%, and premix 1.00%.

[0041] Example 1 In this embodiment, feed additives were applied to the laying hens, and the selected laying hen breed was Chuqin No. 2. Healthy laying hens with similar egg production rate and weight at 21 weeks of age were selected and randomly divided into seven groups: experimental group and control group 1 (blank control group), control group 2, control group 3, control group 4, control group 5, and control group 6. Each group was divided into 3 replicates, with 15 laying hens in each replicate.

[0042] The feeding period is divided into a pre-trial period (2 weeks) and a formal trial period (24 weeks). The feeds during the pre-trial and formal trial periods are as follows: Preliminary trial period (2 weeks): Both the experimental group and the control group (1-7 weeks) were fed a common corn-soybean meal basal diet; Formal trial period (24 weeks): During the formal trial period, both the experimental group and the control group were divided into three stages from week 1 to week 24. Stage I was week 1, stage II was week 2, and stage III was week 3 to week 24. Different additive components were added to the basic feed for each cycle of the experimental group and the control group. The addition of additives is shown in Table 1 below.

[0043] Table 1

[0044] In the table, the basic feed weight is 100%, the amount of broken rice grass added is 0.5%, the amount of bile acid added is 3%, the amount of flaxseed added is 13%, and the amount of Schizochytrium powder added is 6%.

[0045] The laying hens are raised in tiered cages, fed 120 g / day per hen (calculated based on the total weight of basic feed and feed additives), and fed twice a day (08:00 and 15:00), with free access to water.

[0046] Egg production rate of laying hens, lipoprotein in eggs, DHA content in eggs, proportion of DHA in total n-3 polyunsaturated fatty acids, and content and proportion of phospholipid DHA in DHA were measured.

[0047] 1. Egg production rate At the end of weeks 2, 4, 6, 8, 16, and 24 of the trial period, the number of eggs laid by each hen in the experimental group, control group 1, and control group 2 were recorded, and the egg production rate of each group was calculated. The results are as follows: Figure 1 As shown, in control group 2, which only received DHA sources (flaxseed and Schizochytrium powder), the egg production rate was significantly lower than that of control group 1 (blank control group). However, when bile acids and barley grass (experimental group) were added simultaneously to the DHA source, the egg production rate rebounded significantly compared to control group 2, which only received DHA sources, and was comparable to the blank control group without any additives. This data indicates that adding only DHA sources (flaxseed and Schizochytrium powder) affects the egg production performance of laying hens, causing a decrease in egg production rate. However, the combined addition of bile acids and barley grass effectively alleviated the inhibitory effect of DHA sources on egg production performance, significantly reducing the adverse effects of DHA sources on egg production rate, a key production performance indicator. Bile acids emulsify the fats in the liver and intestines, expand the contact of lipases, promote fat absorption, and improve energy utilization. Selenium in rice can reduce oxidative stress on organs such as the liver and ovaries during the metabolism of flaxseed and Schizochytrium residue, protect the normal function of liver cells and oocyte development, avoid the negative impact of DHA on egg production performance, and jointly inhibit the decline in egg production rate.

[0048] 2. Effects of rice bran and bile acids on lipoproteins in eggs Eggs were collected from the experimental group, control group 1, control group 5, control group 6, and control group 7 after the 8th week of the trial period. After screening and removing substandard eggs, 30 eggs were randomly retained from each group. Lipoproteins were extracted from the eggs in each group, and the lipoprotein content in the egg yolks was recorded. The results are shown in Table 2 below.

[0049] Table 2

[0050] Table 2 shows that different additives significantly affected the distribution of lipoproteins in eggs produced by laying hens. Adding bile acids alone increased the levels of HDL and LDL in eggs, but the increase was limited. However, the combined addition of *Capsella bursa-pastoris* and bile acids resulted in significantly higher HDL and Pv levels in eggs compared to other groups, with LDL levels also remaining at a high level. This indicates that *Capsella bursa-pastoris* and bile acids have a synergistic effect; their combined addition helps increase the lipoprotein content in eggs, thereby promoting DHA accumulation and positively impacting the nutritional quality of eggs.

[0051] 3. DHA content in eggs, its proportion of total n-3 polyunsaturated fatty acids, and DHA type. Eggs from the experimental group, control group 1, control group 2, control group 3, and control group 4 were collected after weeks 1, 2, 3, 4, 5, 6, 7, 8, 12, 16, 20, and 24 of the trial period. After screening and removing substandard eggs from each group, 30 eggs were randomly retained from each group. The content of DHA and total n-3 polyunsaturated fatty acids in each group's eggs was measured. The content of phospholipid-type DHA was measured at weeks 4, 8, 16, and 24 (except for control group 1, which was only measured after week 8).

[0052] 1) The DHA content and the proportion of DHA in n-3 polyunsaturated fatty acids in eggs from the experimental group, control group 1, and control group 2 at different weeks during the trial period. Figure 2 As shown.

[0053] Depend on Figure 2It was found that from week 1 to week 24, the DHA content and proportion in both the experimental group and control group 2 were higher than those in control group 1. Especially from week 3 onwards, the DHA content and proportion in both the experimental group and control group 2 were significantly higher than those in control group 1. This indicates that the addition of DHA sources (flaxseed in week 1, flaxseed and Schizochytrium powder in week 2, and Schizochytrium powder in week 3) effectively enhanced the accumulation of DHA in eggs, significantly increasing the DHA content and proportion. Compared with control group 1, the DHA content in control group 2 continued to rise in the early stage (weeks 3-12), but began to decline after week 12. Control group 2 showed significant DHA accumulation in the early stage, but failed to maintain stability in the later stage, indicating that adding only DHA sources increased the metabolic pressure on the body, increased the burden on the liver, and insufficient antioxidant capacity, thus affecting the stable deposition of DHA.

[0054] Compared with control group 2, the DHA content in the experimental group was higher at all time points, especially in the later stage (weeks 8-24). While the DHA content and proportion in control group 2 showed a decreasing trend (DHA content decreased from 326.35 mg / 100g to 229.82 mg / 100g), the DHA content and proportion in the experimental group remained stable, with the DHA content consistently maintained at 430-435 mg / 100g and the DHA proportion remaining around 70%. This indicates that the combined use of *Capsella bursa-pastoris* and bile acids can increase DHA content and enhance accumulation stability. *Capsella bursa-pastoris* and bile acids not only synergistically promoted the accumulation efficiency of DHA in eggs but also significantly enhanced its stability during long-term feeding. This is because bile acids promote lipid absorption, while *Capsella bursa-pastoris* provides antioxidant protection, thereby promoting the stable deposition of DHA in laying hens.

[0055] 2) The DHA content and the proportion of DHA in n-3 polyunsaturated fatty acids in eggs from the experimental group, control group 3, and control group 4 at different weeks during the formal period. Figure 3 As shown. By Figure 3 It can be known that: By comparing the data of the experimental group and control group 3, it can be found that in the first two weeks, the experimental group used flaxseed (rich in ALA, α-linolenic acid), while control group 3 used Schizochytrium powder (direct DHA source). Compared with the experimental group, the DHA content and DHA ratio of control group 3 were slightly higher in the early stage, indicating that DHA was absorbed faster in eggs using direct DHA source. From the third week onwards, the feed for both groups was exactly the same, but the DHA content of the experimental group was significantly higher than that of control group 3, and the DHA ratio also showed the same trend. After the eighth week, the difference between the two groups narrowed, but the experimental group was still slightly higher. This indicates that flaxseed pretreatment can enhance the deposition efficiency of subsequent direct DHA source by inducing the upregulation of fatty acid metabolism enzyme system in laying hens (such as Δ6-desaturase and elongation enzyme).

[0056] Comparing the experimental group and control group 4, control group 4, with its dual DHA source of "flaxseed + Schizochytrium," showed a significantly higher DHA content (52.25 mg / 100g in week 1 and 103.05 mg / 100g in week 2) and the highest DHA percentage compared to the experimental group in the first two weeks. However, starting from week 3, both the DHA content and percentage in the experimental group increased significantly and were significantly higher than those in control group 4. The DHA content in control group 4 peaked at week 8 (325.43 mg / 100g) and then declined continuously, reaching 292.95 mg / 100g and a percentage of 54.16% by week 24, while the experimental group remained stable at 431.88 mg / 100g and 71.53%. This trend suggests that although flaxseed can promote DHA deposition in the short term, the metabolism of ALA in flaxseed produces a lot of free radicals. Long-term continuous addition may increase the body's oxidative stress by introducing excessive polyunsaturated fatty acids, which may ultimately inhibit the stable deposition of DHA.

[0057] The dynamic changes in DHA content and proportion in eggs from the experimental group, control group 3, and control group 4 show that the experimental group's "pre-treatment of flaxseed + subsequent conversion to Schizochytrium" achieved the best balance between DHA deposition efficiency and stability.

[0058] 3) DHA in eggs is mainly divided into phospholipid DHA and triglyceride DHA. Phospholipid DHA can be directly generated and recognized by blood-brain barrier transport proteins, with a simple transport pathway. Triglyceride DHA, on the other hand, requires multiple metabolic transformations, and only a small amount can be converted into a transportable form. Therefore, phospholipid DHA has a greater effect on the brain, improving cognitive and memory functions. The content of phospholipid DHA and its proportion in total DHA in eggs from the experimental group, control group 1, and control group 2 at different weeks during the formal period were measured. The results are as follows: Figure 4 As shown.

[0059] Depend on Figure 4It was found that throughout the feeding cycle, the content and proportion of phospholipid DHA in the experimental group were consistently significantly higher than those in the control group 2. At week 4, the experimental group (297.45 mg / 100g) was 54.3% higher than the control group 2 (192.79 mg / 100g). At week 24, the content in the experimental group remained stable (351.16 mg / 100g), while the control group 2 significantly decreased to 146.01 mg / 100g, at which point the experimental group's content was 2.4 times that of the control group 2. The proportion of phospholipid DHA in the experimental group steadily increased from 77.34% at week 4 to over 81% after week 8. The proportion in the control group 2 started low (66.17%) and continued to decrease after week 8, reaching 63.53% by week 24. This is because the synergistic effect of broken rice (providing antioxidant protection) and bile acids (promoting lipid absorption) not only increases the total amount of functional lipids—phospholipid DHA—but also ensures that DHA is enriched in a more stable and bioavailable form of phospholipid by maintaining a stable metabolic environment in the body, thus achieving a dual improvement in the quality and stability of DHA eggs.

[0060] 4) The content of phospholipid DHA and its proportion in total DHA in eggs from the experimental group, control group 3, and control group 4 at different weeks during the formal period. Figure 5 As shown.

[0061] Depend on Figure 5 It was found that by comparing the content and proportion of phospholipid DHA in the experimental group and the control group 3, the experimental group was consistently significantly higher than the control group 3. For example, in week 8, the phospholipid DHA content in the experimental group (359.56 mg / 100g) was about 45 mg / 100g higher than that in the control group 3 (312.71 mg / 100g); more importantly, the difference in the proportion of phospholipid DHA was more stable and significant (the experimental group maintained 81%-82% throughout the process, while the control group 3 was 73%-74%). This is because the experimental group used flaxseed pretreatment to adjust the metabolic state of the laying hens to the optimal level, enabling them to produce more bioavailable phospholipid DHA more efficiently from high-quality DHA sources in the subsequent process.

[0062] By comparing the content and proportion of phospholipid DHA in the experimental group and the control group 4, the phospholipid DHA content and proportion in the control group 4 were both lower and continued to decrease over time. At week 24, its content (113.49 mg / 100g) was only one-third of that in the experimental group (351.16 mg / 100g), and its proportion (38.74%) was less than half that of the experimental group (81.31%). This is because flaxseed is rich in ALA, which undergoes a series of elongations and desaturations in the body to generate EPA and DHA. However, these newly synthesized DHAs first synthesize triglyceride-type DHA. When a large amount of fatty acids rush to the triglyceride synthesis pathway, they competitively inhibit the phospholipid synthesis pathway metabolically. The addition method in the experimental group reduced metabolic competition, allowing the DHA and bile acid-promoting phospholipid precursors provided by *Schizochytrium* to be preferentially and efficiently used for the synthesis of phospholipid DHA in the stable environment created by *Capsella bursa-pastoris*.

[0063] In summary, compared with the control groups, the experimental group showed significant advantages in multiple indicators. Adding the feed additive of this invention to the diet of laying hens can significantly increase the absolute content of DHA in eggs, the proportion of DHA in total n-3 polyunsaturated fatty acids, and the content and proportion of phospholipid-type DHA.

[0064] 4. Egg storage experiment 1) At the end of week 8, eggs from the experimental group and control group 2 were collected and stored at 37℃ for 60 days. At 30 and 60 days of storage, 30 eggs were randomly selected from each group. The contents of DHA, phospholipid DHA, triglyceride DHA, and total n-3 polyunsaturated fatty acids in the eggs were measured for each storage day. The results are shown in Table 3 below.

[0065] Table 3

[0066] Table 3 shows that the storage time of eggs significantly affected their nutritional composition. After 30 days of storage, the DHA content in the experimental group decreased to 269.22 mg / 100g, with a retention rate of approximately 62%; while in control group 2 it decreased to 166.74 mg / 100g, with a retention rate of approximately 51%. After 60 days of storage, the DHA content in the experimental group was 169.81 mg / 100g, with a retention rate decreasing to 39%; while in control group 2 it significantly decreased to 81.27 mg / 100g, with a retention rate of only 25%. Throughout the 60-day storage period, the absolute DHA retention and relative retention rate in the experimental group were significantly higher than those in control group 2, indicating that the DHA degradation rate in the experimental group was slower and the stability was stronger. During storage, the proportion of phospholipid DHA in the experimental group showed strong stability, decreasing only slightly from 82.4% to 82.03% and then to 78.53%; while the proportion in control group 2 decreased significantly from 69.35% to 60.26% and 51.36%. This indicates that phospholipid molecules provide structural protection for DHA during storage, helping to maintain its oxidative stability. In summary, storage experiments demonstrate that *Cistanche deserticola* and bile acids can reduce DHA degradation during storage; significantly improve the stability of phospholipid-type DHA, and reduce its oxidative decomposition.

[0067] 2) At the end of week 8, eggs from the experimental group and control group 1 were collected and stored at 37℃ for 75 days. The external appearance, internal morphology, and odor of the eggs were observed at 15, 30, 45, 60, and 75 days of storage. The sensory results of the eggs were as follows: Figure 6 As shown.

[0068] After 60 days of storage, the experimental group eggs showed the following differences in color: the yolks darkened slightly after shelling, while the albumen remained clear and transparent with no other abnormal colors; the egg whites had a characteristic eggy smell without any other off-odors; the eggshells were clean and intact, without cracks or mold, and no black spots or foreign objects were visible inside when viewed under light; after shelling, the yolks became flatter, the albumen decreased, and no yolk breakage occurred; no foreign objects were visible to normal vision. In contrast, control group 1 experienced yolk breakage after 45 days of storage, while the experimental group did not develop yolk breakage until 75 days. This indicates that under 37℃ storage conditions, the presence of *Centella asiatica* and bile acids extended the egg storage period by 67%. This is because the natural antioxidants in *Centella asiatica* can deposit in the yolk, directly protecting DHA from oxidative rancidity; bile acids promote lipid absorption, ensuring the absorption efficiency of nutrients such as DHA and antioxidants (from *Centella asiatica*), reducing the metabolic burden on the laying hen.

[0069] The feed additive of this invention is also applicable to feeding other breeds of laying hens, such as purebred Jianghan chickens, recessive white-feathered chickens, yellow chickens, Jinshui black-bone chickens, Jingyang chickens, Hy-Line Grey laying hens, Macheng green-shell laying hens, Yunyang large chickens, Lohmann pink laying hens, Hubei red chickens, etc., all of which can increase the content of DHA, phospholipid DHA and its proportion in the eggs produced by laying hens.

[0070] Specifically, when the selected laying hen breed is purebred Jianghan chicken, using the feed additive of this invention, the DHA content in the eggs increased from 4.26 mg / 100g to 375.47 mg / 100g by the end of the 8th week, an increase of about 88 times, and the phospholipid DHA content increased from 0.44 mg / 100g to 304.73 mg / 100g, an increase of about 693 times.

[0071] When the selected laying hen breed is the Invisible White-feathered Chicken, using the feed additive of this invention, the DHA content in the eggs increased from 3.06 mg / 100g to 371.76 mg / 100g by the end of the 8th week, an increase of approximately 121 times, and the phospholipid DHA content increased from 0.3 mg / 100g to 295.03 mg / 100g, an increase of approximately 983 times.

[0072] Example 2 In this embodiment, the feed of the present invention is applied to egg-laying quails.

[0073] Egg-laying quails were randomly divided into two groups: an experimental group and a control group. Each group consisted of three replicates, with 15 egg-laying quails in each replicate.

[0074] The feeding period is divided into a pre-trial period (1 week) and a formal trial period (8 weeks). The feeds used during the pre-trial and formal trial periods are as follows: Pre-trial period (1 week): Both the experimental group and the blank control group were fed with ordinary corn-soybean meal basal feed; Formal trial period (8 weeks): In the first week, the experimental group added 13% flaxseed to the ordinary corn-soybean meal basal diet on the basis of the basal diet. In the second week, 13% flaxseed and 6% Schizochytrium powder were added to the basal diet. From the third to the eighth week, 6% Schizochytrium powder was added to the basal diet. Rice crackers and bile acids were added throughout the process.

[0075] In this embodiment, healthy quails with similar egg production rate and weight at 7 weeks of age were selected and raised in tiered cages. They were fed twice a day (08:00 and 15:00) at a rate of 24g / d per bird (calculated after adding additives), with free access to water.

[0076] Quail eggs were collected after the 8th week of the trial period. After screening and removing substandard eggs, 30 eggs were randomly retained from each group, and the content of DHA and phospholipid DHA in each group of quail eggs was detected. The results are shown in Table 4 below.

[0077] Table 4

[0078] After using the feed additive of this invention, the total DHA content in quail eggs significantly increased from 3.34 mg / 100g to 100.63 mg / 100g, an increase of 30.1 times; simultaneously, the phospholipid DHA content significantly increased from 1.06 mg / 100g to 70.65 mg / 100g, an increase of 66.7 times, and the proportion of phospholipid DHA increased from 31.8% to 70.2%. The results indicate that this feed additive can significantly increase both the absolute DHA content and the content and proportion of phospholipid DHA in quail eggs, producing high-quality quail eggs rich in DHA, and achieving efficient enrichment of both DHA and phospholipid DHA.

[0079] Example 3 In this embodiment, the feed of the present invention is applied to laying ducks.

[0080] The laying ducks were randomly divided into two groups: an experimental group and a control group. Each group had three replicates, with 15 laying quails per replicate.

[0081] The feeding period is divided into a pre-trial period (2 weeks) and a formal trial period (8 weeks). The feeds used during the pre-trial and formal trial periods are as follows: Pre-trial period (2 weeks): Both the experimental group and the blank control group were fed with ordinary corn-soybean meal basal feed; Formal trial period (8 weeks): In the first week, the experimental group added 13% flaxseed to the ordinary corn-soybean meal basal diet on the basis of the basal diet. In the second week, 13% flaxseed and 6% Schizochytrium powder were added to the basal diet. From the third to the eighth week, 6% Schizochytrium powder was added to the basal diet. Rice crackers and bile acids were added throughout the process.

[0082] In this embodiment, healthy laying ducks with similar egg production rate and weight at 18 weeks of age were selected and raised in cages in a tiered manner. They were fed twice a day (08:00 and 15:00) at a rate of 150g / d per duck (calculated after adding additives), with free access to water.

[0083] Duck eggs were collected after the 8th week of the trial period. After screening and removing substandard eggs, 30 eggs were randomly retained from each group, and the content of DHA and phospholipid DHA in each group of duck eggs was detected. The results are shown in Table 5 below.

[0084] Table 5

[0085] After using the feed additive of this invention, the total DHA content in duck eggs significantly increased from 34.25 mg / 100g to 450.97 mg / 100g, an increase of 13.2 times; simultaneously, the phospholipid DHA content significantly increased from 14.23 mg / 100g to 370.47 mg / 100g, an increase of 26.0 times, and the proportion of phospholipid DHA increased from 41.5% to 82.2%. The results indicate that this feed additive can significantly increase both the absolute DHA content and the content and proportion of phospholipid DHA in duck eggs, producing high-quality duck eggs rich in DHA, and achieving efficient enrichment of both DHA and phospholipid DHA.

[0086] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A feed additive for producing DHA-rich poultry eggs, characterized in that, It includes components A, B and C stored separately. Component A is flaxseed, component B is Schizochytrium powder, and component C includes broken rice and bile acids, which are stored separately or mixed.

2. The method of using the feed additive for producing DHA-rich poultry eggs as described in claim 1, characterized in that, During the first stage of the egg-laying period of poultry, add broken rice, bile acids and flaxseed to the basal feed; during the second stage, add broken rice, bile acids, flaxseed and Schizochytrium powder to the basal feed; during the third stage, add broken rice, bile acids and Schizochytrium powder to the basal feed. Phase I begins when egg production stabilizes and lasts for 1-2 weeks. Phase II begins when Phase I ends and lasts for 1-2 weeks. Phase III begins when Phase II ends and continues until the end of the egg-laying period.

3. The method of using the feed additive for producing DHA-rich poultry eggs according to claim 2, characterized in that, Based on the mass of the aforementioned basic feed as 100%, In Phase I, the addition amount of broken rice water chestnuts is 0.3-0.6%, the addition amount of bile acids is 2-4%, and the addition amount of flaxseed is 10-15%. In Phase II, the addition amount of broken rice water chestnut is 0.3-0.6%, the addition amount of bile acid is 2-4%, the addition amount of flaxseed is 10-15%, and the addition amount of Schizochytrium powder is 5-8%. In the third stage, the amount of broken rice water chestnut added is 0.3-0.6%, the amount of bile acid added is 2-4%, and the amount of Schizochytrium powder added is 5-8%.

4. A method for producing DHA-rich poultry eggs, characterized in that, During the first stage of the egg-laying period in poultry, add broken rice, bile acids, and flaxseed to the basal feed; In Phase II, broken rice shepherd's purse, bile acids, flaxseed and Schizochytrium powder were added to the basal feed; In Phase III, crushed rice, bile acids, and Schizochytrium powder were added to the basal feed. Phase I begins when egg production stabilizes and lasts for 1-2 weeks. Phase II begins at the end of Phase I and lasts for 1-2 weeks. Phase III begins at the end of Phase II and continues until the end of the egg-laying period. Eggs laid after the first week of Phase III are DHA-rich.

5. The method for producing DHA-rich poultry eggs according to claim 4, characterized in that, Based on the weight of the aforementioned basic feed as 100%, in Stage I, the addition amount of broken rice shepherd's purse is 0.3-0.6%, the addition amount of bile acids is 2-4%, and the addition amount of flaxseed is 10-15%; in Stage II, the addition amount of broken rice shepherd's purse is 0.3-0.6%, the addition amount of bile acids is 2-4%, the addition amount of flaxseed is 10-15%, and the addition amount of Schizochytrium powder is 5-8%; in Stage III, the addition amount of broken rice shepherd's purse is 0.3-0.6%, the addition amount of bile acids is 2-4%, and the addition amount of Schizochytrium powder is 5-8%.

6. The method for producing DHA-rich poultry eggs according to claim 4, characterized in that, The stable egg production period is defined as an egg production rate of ≥90%, with a fluctuation range of ≤2% in the egg production rate and a coefficient of variation of <5% in the average daily feed intake.

7. The method for producing DHA-rich poultry eggs according to any one of claims 4-6, characterized in that, The poultry mentioned are laying hens, laying ducks, or laying quails.

8. The method for producing DHA-rich poultry eggs according to claim 7, characterized in that, The breeds of laying hens are Chuqin No. 2, purebred Jianghan chicken, recessive white-feathered chicken, yellow chicken, Jinshui black-bone chicken, Jingyang chicken, Hy-Line grey laying hen, Macheng green-shell laying hen, Yunyang big chicken, Lohmann pink laying hen, or Hubei red chicken.

9. The method for producing DHA-rich poultry eggs according to claim 8, characterized in that, The basic feed is a corn-soybean meal type basic feed, a corn-soybean meal-wheat bran type basic feed, a corn-mixed meal type basic feed, or a corn-rice bran type basic feed.

10. The method for producing DHA-rich poultry eggs according to claim 8, characterized in that, The produced eggs contain ≥337 mg / 100g of DHA.

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