Application of glycyrrhetinic acid as feed additive in improving egg laying rate of laying hens

Abstract

The application discloses application of glycyrrhetinic acid as a feed additive to improve the egg laying rate of laying hens. In the laying hen diet of the application, only glycyrrhetinic acid is added, and no chemical synthetic drugs and hormone substances are added, so that the safety of chicken and egg products is guaranteed from the source. The application fully considers the feed cost in application and feed preparation problems, selects glycyrrhetinic acid with low cost, fully plays the medicinal value of traditional Chinese medicinal materials, and the glycyrrhetinic acid is a natural plant extract, has no toxic side effects on laying hens, meanwhile, the preparation and purification method of the glycyrrhetinic acid is simple, the market price is low, and the glycyrrhetinic acid has the advantages of large-scale application.

Description

Technical Field

[0001] This invention relates to the field of feed additive technology, and in particular to the application of glycyrrhetinic acid as a feed additive in improving the egg production rate of laying hens. Background Technology

[0002] Currently, there are many feed additives used to improve the breeding value of laying hens, mainly including antibiotics, hormones, minerals, and probiotics. Antibiotics may lead to increased antibiotic resistance. The use of hormones and minerals may result in hormone and mineral residues in chicken meat, potentially posing a threat to the health of both humans and laying hens. Probiotics are easily inactivated, and some probiotics carrying different acquired genes may become pathogenic to laying hens due to bacterial gene recombination.

[0003] Traditional Chinese medicine (TCM) is widely used in the addition of herbs to laying hen feed. Adding TCM to feed can not only regulate the immune function of laying hens, exhibiting non-specific antibacterial effects without causing dependence, but also improve laying hen production performance, increase egg production rate, improve egg quality, and reduce cholesterol content. For example, CN103875973A discloses a feed additive for laying hens during their laying period and its preparation method. This feed additive includes TCM additives, enzyme compositions, and vitamin D3. The TCM additives include the following raw materials: seaweed, Atractylodes lancea, Codonopsis pilosula, Codonopsis pilosula, chrysanthemum, comfrey, pollen, Sophora japonica leaves, chicken gizzard lining, Citrus reticulata, Amomum villosum, Dioscorea opposita, hyacinth bean, jujube, Curculigo orchioides, wolfberry, walnut kernel, Cuscuta chinensis, glutinous rice root, and Tagetes patula. This feed additive can not only reduce the cholesterol content of laying hen eggs but also increase egg production rate and egg weight. However, this feed contains many types of TCM additives, making preparation complicated and costly. Summary of the Invention

[0004] The purpose of this invention is to provide an application of glycyrrhetinic acid as a feed additive to improve the egg production rate of laying hens. This invention, by adding glycyrrhetinic acid as a feed additive to the feed of laying hens, can improve the egg production rate and egg quality, and has the advantages of low cost and simple feed additive formulation.

[0005] The technical solution provided by this invention is as follows: the application of glycyrrhetinic acid as a feed additive to improve the egg production rate of laying hens.

[0006] In the above-mentioned application, glycyrrhetinic acid reduces follicular cell apoptosis by regulating the BCL-2-related signaling pathway, thereby improving the aging status of ovarian function in laying hens.

[0007] In the aforementioned applications, the appropriate addition level of glycyrrhetinic acid in the diet of laying hens is 50-150 mg / kg.

[0008] The foregoing application, the optimal adding amount of glycyrrhetinic acid in the laying hen diet is 100 mg / kg.

[0009] Compared with the prior art, the application has the following beneficial effects:

[0010] 1、 The laying hen diet of the application only adds glycyrrhetinic acid, without adding any chemical synthetic drugs and hormone substances, thereby ensuring the safety of chicken and egg products from the source. According to the basic theory of traditional Chinese medicine, liquorice can tonify the spleen and replenish qi, and has the effect of clearing heat and detoxifying. Therefore, the main active ingredient of liquorice, glycyrrhetinic acid (molecular weight 470.69 Da, which belongs to a small molecule compound), is added to the basic diet of laying hens, so that the effect of Chinese herbal medicine can be fully played, the immunity of laying hens is enhanced, the egg production is increased, the egg production interval of aging laying hens is shortened, the economic value of aging laying hens is improved, and the development of the laying hen breeding industry is promoted to a higher level.

[0011] 2、 After the egg-laying peak of laying hens, with the increase of the age of laying hens, the apoptosis rate of ovarian follicle cells increases, which affects the health and egg production rate of laying hens, and seriously reduces the economic value of laying hens. The experimental results show that glycyrrhetinic acid has the effect of resisting cell apoptosis, which can regulate the BCL-2 related signal pathway, prevent follicle cell apoptosis, maintain the number of follicles, and improve the ovarian aging condition of laying hens. After feeding the feed additive of the application, the egg production rate of aging laying hens is significantly increased, the egg quality is significantly improved, the number of PF and SYF in the ovary is significantly increased, and the number of follicle atresia is significantly decreased.

[0012] 3、 The application fully considers the feed cost and feed preparation problem in application, selects glycyrrhetinic acid with low cost, fully plays the medicinal value of traditional Chinese herbal medicine, and glycyrrhetinic acid is a natural plant extract, which has no toxic and side effects on laying hens. At the same time, the preparation and purification method of glycyrrhetinic acid is simple, the market price is low, and it has the advantages of large-scale application. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is the picture of the morphology of each follicle of the ovary of the control group (Control) and the glycyrrhetinic acid adding group (GA group, experimental group 3) of laying hens;

[0014] Figure 2 is a statistical diagram of the number of follicles of laying hens;

[0015] Figure 3 is an analysis of the influence of glycyrrhetinic acid on the expression of aging-related genes of the ovary of laying hens. DETAILED DESCRIPTION

[0016] The application will be further described in conjunction with the specific embodiments. The examples given are only to illustrate the application, and are not intended to limit the scope of the application. The examples provided below can serve as a guide for further improvement by those of ordinary skill in the art, and do not in any way constitute a limitation on the application. In the following examples, the experimental methods are conventional methods, and are performed according to the techniques or conditions described in the literature in the art or according to the product instructions, unless otherwise specified. The materials, reagents, etc. used in the following examples can be obtained commercially, unless otherwise specified.

[0017] Example: Application of glycyrrhizinic acid as a feed additive.

[0018] The test animals were 480-day-old aging laying hens, 60 in number, in good health and with similar body weight. They were divided into six groups, each of ten, and were caged, free to eat and drink. A feed additive, glycyrrhizinic acid, was added to the feed of the laying hens. The amount of the feed additive added to the daily ration of the laying hens included: control group: no addition; experimental group 1: 25 mg / kg; experimental group 2: 50 mg / kg; experimental group 3: 100 mg / kg; experimental group 4: 150 mg / kg; experimental group 5: 175 mg / kg. The feed intake and egg production were recorded every day during the test period, and the health condition was observed. The egg quality was detected on the 30th day, wherein the scoring index of the egg quality was measured by an egg quality measuring instrument. The test results are as follows:

[0019] Table 1. Effect of glycyrrhizinic acid on the egg production rate and egg quality of aging laying hens

[0020]

[0021] Table 1 shows the changes in the egg production rate and egg quality of the laying hens after the addition of glycyrrhizinic acid. As shown in Table 1, after the addition of the feed additive, glycyrrhizinic acid, the aging laying hens in the experimental groups had different degrees of improvement and increase in the egg production rate, eggshell strength, eggshell thickness, etc. as compared with the control group. According to the curve fitting of the additive amount on the production performance of the laying hens, it was found that the suitable amount of glycyrrhizinic acid added to the daily ration of the laying hens was 50-150 mg / kg. The results of experimental group 3 also showed that, as compared with the other groups, the aging laying hens had significant improvement in the egg production rate, etc. when the addition amount was 100 mg / kg, and thus it was the optimal additive amount among these concentrations.

[0022] Further, during the feeding process, the effect of glycyrrhizinic acid on the number of follicles at each level of the ovary of the aging laying hens was studied, Figure 1 Pictures of the appearance and morphology of the ovary of the laying hens in the control group (Control) and the GA group (experimental group 3) are given, Figure 2A statistical chart of follicle counts in laying hens is provided (PF: graded follicles; LYF: large yellow follicles; SYF: small yellow follicles; LWF: large white follicles; SWF: small white follicles; AF: atretic follicles). From... Figure 1 The results show that the number of follicles in the GA group was higher than that in the Control group. Figure 2 The results showed that the number of PF and SYF follicles in the GA group was significantly higher than that in the Control group, while the number of AF follicles was significantly lower (P < 0.05). This indicates that feeding the feed additive of this invention significantly increased the number of intermediate follicles and significantly decreased the number of follicle atresia in the ovaries of aging laying hens, thus alleviating ovarian aging in laying hens.

[0023] Furthermore, qPCR was used to detect the effect of glycyrrhetinic acid on the expression of apoptosis / senescence-related genes in ovarian cells of aging laying hens. Figure 3 This study analyzed the effects of glycyrrhetinic acid on the expression of genes related to ovarian aging in laying hens. Compared with the control group, the expression levels of BAX, Caspase-3, and p21 genes were significantly decreased in the glycyrrhetinic acid group (P < 0.05), while the expression levels of GPX1 and BCL-2 genes were significantly increased (P < 0.05), especially the expression level of BCL-2 gene. This indicates that glycyrrhetinic acid can prevent apoptosis of ovarian follicle cells and reduce the expression of aging-related genes in laying hens by regulating the BCL-2-related signaling pathway.

[0024] In summary, the laying hen diet of this invention only adds glycyrrhetinic acid, without any chemically synthesized drugs or hormones, thus ensuring the safety of chicken and egg products from the source. This invention fully considers feed costs and feed preparation issues in its application, selecting the low-cost glycyrrhetinic acid to fully utilize the medicinal value of traditional Chinese medicine. Furthermore, glycyrrhetinic acid is a natural plant extract with no toxic side effects on laying hens. In addition, the preparation and purification methods for glycyrrhetinic acid are simple, and its commercial price is low, giving it advantages for large-scale application.

[0025] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. The use of glycyrrhetinic acid as a feed additive for increasing the egg laying rate of laying hens, characterized in that: The glycyrrhetinic acid is added in the amount of 100 mg / kg in the daily ration of the laying hens, and the glycyrrhetinic acid reduces the apoptosis of follicle cells by adjusting the BCL-2 related signal path, so as to improve the aging condition of the ovary of the laying hens.

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