A method for improving the hatch weight of chicks and promoting early growth and development

Abstract

The present application belongs to the field of early nutrition of poultry in the livestock breeding industry, and relates to a method for increasing the hatching weight of chicks and promoting early growth and development and application, wherein taurine cholic acid solution is added to the air chamber of the chicken embryo; through observation of hatching time, incubation performance, growth performance, organ index, transport and absorption of nutrients in the yolk sac, and blood biochemical indicators, it is found that after the embryo egg is added with TCA, the hatching time of chicks is advanced, the incubation time is shortened, the embryo weight at E16 of chicks is significantly increased, the body weight of chicks after hatching is significantly increased, the growth of broilers during the feeding period after hatching is significantly promoted, and the leg muscle yield is significantly increased. In addition, the embryo egg added with TCA accelerates the transport of lipids in YSC to YSM by up-regulating the expression of E16 YSM and lipid transport related genes. The results show that the embryo egg added with taurine cholic acid can reliably promote the growth of broilers and laying hens during the incubation period and the growth of broilers after hatching.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of early nutrition of poultry in the livestock breeding industry, and relates to a method for improving the hatching weight of chicks and promoting early growth and development and application thereof. BACKGROUND

[0002] Since the 1950s, the slaughter age of broilers has been reduced by about 40%, and the slaughter weight has more than doubled. In broiler production, the incubation period accounts for about one-third of the entire life cycle. Disturbance during embryonic development can affect the entire production cycle and cause irreversible losses to broiler producers, so the importance of the incubation period increases. Chicken embryos rely entirely on the nutritional components in the egg, mainly including water, lipids and proteins. In the first week of incubation, glucose reserves are used to maintain metabolism. As the embryo develops and the allantoic chorioidea is formed, lipids become the main energy source. After hatching, the chicks must quickly adapt from using egg nutrients to an exogenous diet of proteins and carbohydrates, and in addition, chicks are usually fasted for 48 hours after hatching until they are sent to the farm. Delayed feed acquisition can lead to increased mortality and developmental retardation. During this critical and challenging stage, embryo addition is an alternative solution to provide essential nutrients to the chicken embryo. By providing nutrition during embryonic development, the negative effects of post-hatching fasting and the transition period are minimized, thereby ensuring the maximum expression of genetic potential throughout the production cycle. The improved nutritional status and physiological changes after embryo addition can resonate throughout the feeding period, resulting in significant health and economic benefits.

[0003] The prior art such as the patent with the publication number CN 107173262 A discloses a method for promoting the growth of hatched chicks by adding bile acids into the embryo, which directly injects a bile acid solution into the embryo at 3 embryonic ages, which can significantly promote the muscle development of the chicken embryo and the growth of the chicken after hatching; but the bile acid used is a mixed acid, and it is not proved which specific bile acid plays a role, and it is dissolved with DMSO (dimethyl sulfoxide, a sulfur-containing organic compound) and diluted with PBS, which stimulates the development of the embryo and affects the hatching rate; at the same time, it is injected into the embryo at 3 embryonic ages, the air chamber of the embryo at 0-4 embryonic ages is too small, the injection volume is limited, and it will affect the further incubation of the embryo. In addition, there are some β-hydroxy-β-methyl butyric acid, N-carbamoyl-L-glutamic acid or mixed nutrients composed of glutamine, taurine and gamma-aminobutyric acid in the embryo, but the ability of these nutrients to improve the hatching weight of chicks and promote early growth and development is limited, which is difficult to meet the demand of the poultry industry for yield increase and breeding benefit increase. SUMMARY

[0004] The application aims to provide a method and application for increasing the hatching weight of chicks and promoting early growth and development, which promotes chicken embryo development, promotes yolk lipid absorption and utilization, increases the hatching weight of chicks, and improves the growth performance and feed conversion efficiency of broilers during the feeding period by adding taurine cholic acid to the air chamber of the embryo.

[0005] In order to achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0006] In the first aspect, the present application provides a method for increasing the hatching weight of chicks and promoting early growth and development, which adds a taurine cholic acid solution to the air chamber of a chicken embryo.

[0007] The inventors found in animal experiments that bile acids can effectively improve fat absorption and increase egg production by promoting pancreatic lipase activity in hens fed with high-fat diets. The primary free bile acids synthesized in the liver are connected with taurine to form taurine-conjugated bile acids. The main source of nutrients during the development of chicken embryos is lipid substances in the yolk sac. Bile acids can reduce the surface tension of lipid and water phases, thereby promoting the digestion, absorption and transport of lipids. Therefore, it is of great significance to take measures to enable the embryo to better absorb and utilize yolk lipids during the incubation period, thereby increasing the body weight of chicks and their growth after hatching. Taurine cholic acid (TCA) is one of the most abundant conjugated bile acids in the serum, liver and intestine of broilers, and plays an important role in lipid absorption and transport. TCA can promote the absorption of lipid substances in the digestive tract.

[0008] In some other embodiments, the taurine cholic acid solution is a sterile normal saline solution of taurine cholic acid.

[0009] In some other embodiments, the concentration of the taurine cholic acid solution is 5-25 mg / mL; preferably, the concentration of the taurine cholic acid solution is 12.5 mg / mL.

[0010] In some other embodiments, the amount of the taurine cholic acid solution added is 0.1-0.5 mL; preferably, the amount of the taurine cholic acid solution added is 0.2 mL.

[0011] In some other embodiments, the chicken embryo is a chicken embryo incubated to 9-11 embryonic ages; preferably, the chicken embryo is a chicken embryo incubated to 11 embryonic ages.

[0012] The inventors found in the research process that the air chamber of a chicken embryo at 0-4 embryonic ages is too small, the injection volume is limited and will affect the further incubation of the embryo; with the development of the embryo, injection into the air chamber after 15 embryonic ages will reduce the effect due to the weakening of the penetration effect. Therefore, the injection time is generally 5-14 days after incubation. The present application found through the research of suitable injection time that the injection of taurine cholic acid in the air chamber at 11 embryonic ages has low embryo mortality and the most significant effect.

[0013] In some other embodiments, the taurine cholic acid solution is also filtered and sterilized before being added; preferably, the filtering and sterilizing is performed by using a 0.22 μm sterile filter.

[0014] In a second aspect, the present application provides a use of taurine cholic acid in increasing the hatching weight of chicks and promoting early growth and development.

[0015] In some other embodiments, the increasing the hatching weight of chicks and promoting early growth and development is shortening the hatching time, improving the hatching performance, improving the growth performance, improving the organ index, improving the transport and absorption of nutrients in the yolk sac, or reducing the blood lipid level.

[0016] In a third aspect, the present application provides a method for increasing the hatching weight of chicks and promoting early growth and development by taurine cholic acid, which uses the method for increasing the hatching weight of chicks and promoting early growth and development in the first aspect to add taurine cholic acid into the air chamber of the chicken embryo.

[0017] In a fourth aspect, the present application provides a use of taurine cholic acid in preparing a product for increasing the hatching weight of chicks and promoting early growth and development.

[0018] The present application has the following beneficial effects:

[0019] (1) In the process of embryo incubation, the present application adds taurine cholic acid (TCA) solution into the air chamber of the chicken embryo, and through observation of the hatching time, hatching performance, growth performance, organ index, transport and absorption of nutrients in the yolk sac, and blood biochemical indicators, it is found that after the embryo is added with TCA, the hatching time of chicks is advanced, the hatching time is shortened, the embryo weight at E16 is significantly increased, the body weight of chicks after hatching is significantly increased, the growth of broilers during the feeding period is significantly promoted, and the leg muscle yield is significantly increased. In addition, the addition of TCA to the embryo accelerates the transport of lipids in YSC to YSM by up-regulating the expression of E16 YSM and lipid transport related genes. The above results all show that the addition of taurine cholic acid to the embryo can reliably promote the growth of broilers and egg-laying hens during the incubation period and the growth of broilers after hatching.

[0020] (2) The taurine cholic acid (TCA) solution proposed in the present application is added to the air chamber of the embryo, which has little stimulation to the chicken embryo development, is simple and convenient to operate, has high efficiency, and is suitable for large-scale use in production. BRIEF DESCRIPTION OF DRAWINGS

[0021] The drawings constituting a part of the specification of the present application serve to provide a further understanding of the present application, and the illustrative embodiments of the present application and their description serve to explain the present application, and do not constitute an improper limitation on the present application.

[0022] Figure 1 It is the operation process of adding taurine cholic acid to the embryo in the embodiments of the present application; whereinFigure 1 Figure 1 is a tool for embryo injection, Figure 1 Figure 2 is a small drill machine drilling a hole at the air cell end, Figure 1 Figure 3 is a small hole drilled at the air cell end, Figure 1 Figure 4 is a sterile syringe inserted into the small hole and the depth of insertion, Figure 1 Figure 5 is a slow injection of taurocholic acid into the air cell of the embryo, Figure 1 Figure 6 is a paraffin seal of the egg hole;

[0023] Figure 2 Figure 8 is the effect of different doses of taurocholic acid added to embryos of different ages on the hatchability, yolk sac ratio and chick weight in the embodiments of the present application; wherein Figure 2 Figure 8(A) is the hatchability, Figure 2 Figure 8(B) is the E16 yolk sac ratio, Figure 2 Figure 8(C) is the D0 yolk sac ratio, Figure 2 Figure 8(D) is the E16 chick weight, Figure 2 Figure 8(E) is the D0 chick weight, data is represented as Mean ± SD (n = 8), *P < 0.05;

[0024] Figure 3 Figure 9 is the effect of taurocholic acid added to embryos on the hatch time of Hyline Brown laying hens and AA broiler chickens in the embodiments of the present application; wherein Figure 3 Figure 9(A) is Hyline Brown laying hens, Figure 3 Figure 9(B) is AA broiler chickens;

[0025] Figure 4 Figure 10 is the effect of taurocholic acid added to embryos on the lipid content of the yolk sac membrane (YSM) and yolk sac content (YSC) of Hyline Brown laying hens in the embodiments of the present application; wherein Figure 4 Figure 10(A) is triglyceride (TG), Figure 4 Figure 10(B) is free fatty acid (NEFA), Figure 4 Figure 10(C) is glycerol, Figure 4 Figure 10(D) is total cholesterol (TCH), Figure 4 Figure 10(E) is free cholesterol (FCH), Figure 4 Figure 10(F) is cholesterol ester (CE); data is represented as Mean ± SD (n = 8), *P < 0.05;

[0026] Figure 4 Figure 11 is the effect of taurocholic acid added to embryos on the lipid content of the yolk sac membrane (YSM) and yolk sac content (YSC) of AA broiler chickens in the embodiments of the present application; wherein Figure 5 Figure 11(A) is triglyceride (TG), Figure 5 Figure 11(B) is free fatty acid (NEFA), Figure 5Medium (C) is Glycerol (Glycerol), Figure 5 (D) is Total Cholesterol (TCH), Figure 5 (E) is Free Cholesterol (FCH), Figure 5 Medium (F) is Cholesterol Ester (CE), data expressed as Mean ± SD (n = 8), *P < 0.05, **P < 0.05;

[0027] Figure 5 Effect of embryonated eggs added with taurocholic acid on the expression of E16 yolk sac membrane (YSM) lipid transport related genes; wherein Figure 5 Medium (A) is Hyline Brown laying hens, Figure 6 Medium (B) is AA broilers, data expressed as Mean ± SD (n = 8), *P < 0.05, **P < 0.001;

[0028] Figure 6 Effect of embryonated eggs added with taurocholic acid on the growth performance of AA broilers after hatching; wherein Figure 6 Medium (A) is average body weight, Figure 7 Medium (B) is average daily gain, Figure 7 Medium (C) is average daily feed intake, Figure 7 Medium (D) is feed conversion ratio, data expressed as Mean ± SEM (n = 6), *TCA group was significantly different from NC group P < 0.05, *TCA group was significantly different from PC group P < 0.05;

[0029] Figure 7 Effect of embryonated eggs added with taurocholic acid on the organ index of AA broilers after hatching;

[0030] wherein Figure 7 Medium (A) is liver index, Figure 8 Medium (B) is breast muscle index, Figure 8 Medium (C) is leg muscle index, data expressed as Mean ± SD (n = 6), *P < 0.05;

[0031] Figure 8 Effect of embryonated eggs added with taurocholic acid on the mRNA level of leg muscle proliferation and differentiation related regulatory factors; wherein Figure 8 Medium (A) is D0, wherein Figure 9 Medium (B) is D21, wherein Figure 9 Medium (C) is D42, data expressed as Mean ± SD (n = 6), *P < 0.05, **P < 0.001, ***P < 0.0001. DETAILED DESCRIPTION

[0032] Example 1

[0033] (1) Method for adding tauroursodeoxycholic acid into air cell of embryo

[0034] The operation steps for adding tauroursodeoxycholic acid into air cell of embryo are shown in Fig. 1. At the 11th embryonic age of embryo incubation, the air cell addition site is determined by candling and transferred to a clean bench. The addition site of embryo is sterilized with 75% alcohol, and a small hole with a diameter of about 1 mm is drilled at the air cell end by a small electric drill (drill diameter: 1 mm) (step (1)-(3) in Fig. 1). A 1 mL sterile syringe is inserted into the drilled hole, and the insertion depth is about 0.5 cm (step (4) in Fig. 1). Tauroursodeoxycholic acid is slowly injected into the air cell of embryo, and the dosage is 0.2 mL (step (5) in Fig. 1). After the addition is completed, the egg hole is immediately sealed with paraffin (step (6) in Fig. 1), and transferred to the incubator for incubation according to the normal incubation procedure. The incubation procedure is as follows: 1-3 embryonic age: temperature is 38.0°C, relative humidity is 60-75%; 4-18 embryonic age: temperature is 37.8°C, relative humidity is 50-65%; 19-21 embryonic age: temperature is 37.3°C, relative humidity is 65-75%. Figure 9 Figure 9 Example 2 Figure 1 Figure 1 Study on suitable time and dosage of adding tauroursodeoxycholic acid into embryo Figure 1 180 fertilized eggs with similar weight (egg weight 55-65 g, average egg weight 60.8 g) were selected for incubation, and embryo addition test was performed at the 9th embryonic age (E9) and the 11th embryonic age (E11), respectively. The embryo addition operation was performed according to the method described in Example 1. There were 20 chicken embryos in each treatment group, and the test treatments were as follows at each incubation period:

[0035] (I) Negative control (NC: Negative control): no addition treatment;

[0036] (II) Positive control (PC: Positive control): 0.2 mL of saline solution was added;

[0037] (III) 1 mg TCA: 0.2 mL of 5.0 mg / mL TCA was added;

[0038] (IV) 2.5 mg TCA: 0.2 mL of 12.5 mg / mL TCA was added;

[0039] (V) 5 mg TCA: 0.2 mL of 25 mg / mL TCA was added.

[0040]

[0041]

[0042]

[0043] ​​​​​At the 16th embryonic age (E16) of chicken embryo, the eggs with similar weight were selected in each group, and the yolk sac and liver were separated, weighed and organ index was calculated. On the day of hatching (D0), the chicks with similar weight to the average weight in the group were selected in each group, the body weight was counted, the chicks were killed by neck dislocation, the yolk sac and liver were separated, weighed and organ index was calculated. Organ index = organ weight / live body weight x 100%.

[0044] Example 3

[0045] Effect test of adding taurine cholic acid into the air chamber of embryonic eggs to improve the hatching weight of laying hens

[0046] 300 Hyline Brown commercial fertilized eggs with similar weight (egg weight 50-60 g, average egg weight 57.6 g) were selected for incubation, and randomly divided into 3 groups. Embryo addition test was carried out on the 11th day of incubation, and the test treatments were as follows: negative control group: no treatment; positive control group: add 0.2 mL of normal saline; taurine cholic acid (TCA) group: add 0.2 mL of 12.5 mg / mL taurine cholic acid solution into the air chamber. The embryo addition method and incubation procedure were the same as in Example 1.

[0047] At the 16th embryonic age (E16) of chicken embryo, the eggs with similar weight were selected in each group, and the yolk sac, liver, breast muscle and leg muscle were separated, weighed and organ index was calculated. On D0, the chicks with similar weight to the average weight in the group were selected in each group, the body weight was counted, the chicks were killed by neck dislocation, the yolk sac, liver, breast muscle and leg muscle were separated, weighed and organ index was calculated. Organ index = organ weight / live body weight x 100%. Yolk sac content (YSC) and yolk sac membrane (YSM) tissue samples were collected, placed in 2 mL cryogenic tubes, frozen in liquid nitrogen, and stored at -80℃ for testing.

[0048] Example 4

[0049] Effect test of adding taurine cholic acid into the air chamber of embryonic eggs to improve the hatching weight of broilers

[0050] 240 Arbor Acres (AA) commercial fertilized eggs with similar weight (egg weight 50-60 g, average egg weight 55.0 g) were selected for incubation, and randomly divided into 3 groups with 6 replicates. Embryo addition test was carried out on the 11th day of incubation, and the test treatments were as follows: negative control group: no treatment; positive control group: add 0.2 mL of normal saline; taurine cholic acid (TCA) group: add 0.2 mL of 12.5 mg / mL taurine cholic acid solution into the air chamber. The embryo addition method and incubation procedure were the same as in Example 1.

[0051] At 16 embryonic age (E16), each group selected eggs with similar weight, separated yolk sac, liver, breast muscle and leg muscle, weighed and calculated organ index. On the day of hatching (D0), each group selected chickens with similar average weight in the group, calculated body weight, and killed the broiler chickens in a neck dislocation manner, separated yolk sac, liver, breast muscle and leg muscle, weighed and calculated organ index. Organ index = organ weight / live body weight x 100%. Collect yolk sac content (YSC) and yolk sac membrane (YSM) tissue samples, put them into 2 mL cryogenic tubes, place them in liquid nitrogen for quick freezing, and store them at -80°C for testing.

[0052] Example 5

[0053] Effect test of adding taurine cholic acid to embryonic eggs to promote early growth of broilers after hatching

[0054] 1. Test design of animal experiment

[0055] The test selected 540 AA commercial fertile eggs with similar weight (egg weight 50-60 g, average egg weight 55.1 g) for incubation, and randomly divided them into 3 groups, 6 replicates in each group. The embryonic egg addition test was carried out on the 11th day of incubation, and the test treatments were as follows: negative control group: no treatment; positive control group: addition of 0.2 mL of normal saline; taurine cholic acid (TCA) group: addition of 0.2 mL of 12.5 mg / mL taurine cholic acid solution to the air chamber. The embryonic egg addition method and incubation procedure were the same as in Example 1.

[0056] After the broilers hatched, 96 chicks with similar average body weight and hatching time were selected from each treatment, and randomly divided into 6 replicates, with 16 chickens in each replicate. They were raised according to the standard feeding procedure until 42 days, divided into early stage 1-21 days (0-3 wk) and late stage 21-42 days (3-6 wk), and the broilers were allowed to freely eat and drink during the test period. The production performance was calculated every week. The composition of the test diet is shown in Table 1. On the day of hatching (D0), at 21 days of age (D21), at 42 days of age (D42), broilers with similar average body weight in each group were selected, body weight was calculated, wing vein blood was collected, plasma was separated by centrifugation at 3,000 rpm for 15 min at 4°C, and stored at -20°C in aliquots for testing. The broilers were killed in a neck dislocation manner, liver, breast muscle and leg muscle were separated and weighed, and organ index = organ weight / live body weight x 100%. Biceps femoris tissue samples were collected, put into 2 mL cryogenic tubes, placed in liquid nitrogen for quick freezing, and stored at -80°C for testing.

[0057] Table 1 Composition and nutrient level of test diet

[0058]

[0059]

[0060] 1 The premix provides per kg of feed: VA, 8000 IU; VD3, 1000 IU; VE, 20 IU; VK, 0.5 mg; VB1, 2 mg; VB2, 8 mg; VB3, 35 mg; VB5, 10 mg; VB6, 3.5 mg; VB12, 0.01 mg; biotin, 0.18 mg; folic acid, 0.55 mg; choline, 1300 mg; iron, 100 mg; zinc, 100 mg; manganese, 120 mg; copper, 8 mg; iodine, 0.7 mg; selenium, 0.3 mg;

[0061] 2 The premix provides per kg of feed: VA, 6000 IU; VD3, 750 IU; VE, 10 IU; VK, 0.5 mg; VB1, 2 mg; VB2, 5 mg; VB3, 30 mg; VB5, 10 mg; VB6, 3 mg; VB12, 0.01 mg; biotin, 0.15 mg; folic acid, 0.55 mg; choline, 1000 mg; iron, 80 mg; zinc, 80 mg; manganese, 100 mg; copper, 8 mg; iodine, 0.7 mg; selenium, 0.3 mg;

[0062] 3 The measured values of the nutrient composition.

[0063] 2. Determination index and method

[0064] (1) Hatching performance: the hatching rate was calculated; the body weight of each chick was measured on the day of hatching, and the average body weight was calculated;

[0065] (2) The hatching time of chicks was recorded from the time when the chicks were completely out of the eggshell at 480 h after hatching.

[0066] (3) Growth performance: the body weight, daily weight gain, feed intake, feed conversion ratio and mortality rate were calculated every week during the feeding period;

[0067] (4) Organ index: one broiler chicken close to the average body weight was selected from each repetition on the day of hatching, at 21 days of age (D21) and at 42 days of age (D42), respectively, and was sacrificed by bleeding in the neck after blood collection from the wing vein, and the liver, breast muscle and leg muscle were separated, weighed and the organ index was calculated. Organ index = organ weight / live weight × 100%.

[0068] (5) Lipid content determination: The content of triglyceride (TG) and non-esterified fatty acid (NEFA) in YSC and YSM was determined by spectrophotometry according to the instructions of the kit (Nanjing Jiancheng Bioengineering Institute). The content of glycerol, total cholesterol (TCH) and free cholesterol (FCH) in YSC and YSM was detected by glycerol colorimetric assay kit (E-BC-K340-M, Elabscience), total cholesterol colorimetric assay kit (E-BC-K109-M, Elabscience) and free cholesterol colorimetric assay kit (E-BC-K004-M, Elabscience), respectively. Cholesterol ester (CE) = TCH - FCH.

[0069] (6) Blood biochemical indicators: Wing vein blood was collected and centrifuged at 3,000 rpm for 15 min at 4°C to separate the plasma, which was stored at -20°C for testing. The content of aspartate aminotransferase (AST), alanine aminotransferase (ALT), albumin (ALB), total protein (TP), TG, TCH, high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) was determined by an automatic biochemical analyzer, and the reagent kit was purchased from Wako Pure Chemical Industries, Ltd. (Japan). The NEFA was detected according to the instructions of the kit, which was purchased from Nanjing Jiancheng Bioengineering Institute.

[0070] (7) YSM gene mRNA level detection: Total RNA was extracted from YSM using TRIzol reagent (NCM Biotech). After measuring the concentration and quality of RNA using a NanoDrop spectrophotometer (DeNovix), reverse transcription was performed to obtain cDNA. Primers were designed using Primer5.0 software (SPS Corporation, CA, USA) and synthesized by Sangon Biotechnology (Shanghai, China). The mRNA value was normalized to the expression of chicken GAPDH mRNA, and the comparative 2 -ΔCT method was used to determine the gene expression level.

[0071] (8) Data statistics

[0072] The data were analyzed by ANOVA method of SAS (Version 8c, SAS Institute, 1998) statistical software, and the single factor ANOVA model was used to analyze the regulatory effects of embryonic egg addition of taurocholic acid on the hatchability performance, growth performance, lipid content, gene expression and blood biochemical indicators of broilers. Duncan's method was used for multiple comparisons. The experimental data were represented by mean ± standard deviation (Mean ± SD), and P < 0.05 was considered significant.

[0073] 3. Test results

[0074] (1) Study on the appropriate time and dosage of TCA addition to embryos

[0075] The effects of adding different concentrations of taurine at different embryonic stages on hatchability, yolk sac specific gravity, and chick weight, as follows: Figure 1 As shown, where Figure 1 (A) represents the hatching rate. Figure 2 (B) represents the specific gravity of the yolk sac in E16. Figure 2 (C) represents the specific gravity of the D0 yolk sac. Figure 2 (D) represents the weight of an E16 chicken embryo. Figure 2 (E) represents the weight of chicks at D0. It can be seen that the hatching rate of different concentrations of TCA added at E9 was lower than that added at E11. The hatching rate of adding 2.5 mg TCA at E9 was 25% lower than that added at E11. At E16, the yolk sac specific gravity of the chicks added at E11 was significantly lower than that of the PC group, and the embryo weight was significantly higher than that of the NC group (P<0.05). At D0, the yolk sac specific gravity of the chicks added at E11 was significantly reduced, and the chick weight was significantly higher than that of the NC group (P<0.05). In summary, adding 2.5 mg / egg of TCA at E11 has the best effect on yolk sac absorption, weight gain, and hatching rate.

[0076] (2) Effect of adding taurine to embryos on hatching time of chicks

[0077] The effect of adding taurine to embryos on the incubation time of chicks, such as Figure 2 As shown, the peak hatching time for Hy-Line Brown eggs after TCA treatment occurred around 495 hours after incubation, while the peak hatching time for chicks in the NC and PC groups was around 500 hours. For AA broiler chickens, the PC and TCA groups showed similar hatching time trends, with the peak hatching time around 500 hours after incubation. However, the peak hatching time for the NC group was around 510 hours after incubation. In conclusion, the addition of TCA significantly advanced the hatching time, shortened the incubation period, and improved farming efficiency.

[0078] (3) Effects of adding taurine to eggs on embryonic development during the incubation period of Hy-Line Brown chickens

[0079] The effects of taurine (TCA) addition to embryos on the growth performance of Hy-Line Brown chicken embryos during incubation are shown in Table 2. Table 2 shows that TCA addition significantly increased embryo weight at E16 (P<0.05). At E16, compared with the NC group, the yolk sac index in the TCA group was significantly lower (P<0.05). However, there were no significant differences in liver, pectoral muscle, and leg muscle indices between the TCA group and the control group (P>0.05).

[0080] Table 2. Effects of TCA addition to embryos on body weight and organ index in E16 Hy-Line Brown chickens.

[0081]

[0082] Note: Data are expressed as Mean ± SD (n = 8), a,b Means with different superscripts are significantly different (P < 0.05).

[0083] The effects of TCA injection on hatchability and organ index of HLB chicks are shown in Table 3. From Table 3, it can be seen that Figure 2 HLB (A) is HLB brown egg chicken; Figure 3 HLB (B) is AA broiler; The hatchability of each treatment group was more than 90%, which indicated that TCA injection at E11 did not have negative effects on hatchability and mortality of HLB brown egg chicken. At D0, the body weight of TCA group was significantly higher than that of PC group (P < 0.05). Compared with NC and PC groups, the yolk sac index of TCA group was significantly decreased (P < 0.05), the liver index of TCA group was significantly higher than that of PC group (P < 0.05), the leg muscle index of TCA group was significantly higher than that of NC and PC groups (P < 0.05), but there was no significant difference in breast muscle index among the treatment groups (P > 0.05).

[0084] In summary, TCA injection at E11 did not affect the hatchability and mortality of HLB brown egg chicken, decreased the yolk sac index of broiler at E16 and after hatching, significantly increased the body weight of chick at E16 and after hatching, and significantly increased the leg muscle index after hatching.

[0085] Table 3 Effects of TCA injection on hatchability and D0 body weight and organ index of HLB brown egg chicken

[0086]

[0087] Note: Data are expressed as Mean ± SD (n = 8), a,b Means with different superscripts are significantly different (P < 0.05).

[0088] (4) Effects of TCA injection on AA broiler embryonic development during incubation period

[0089] The effects of TCA injection on AA broiler embryonic growth performance during incubation period are shown in Table 4. From Table 4, it can be seen that TCA injection significantly increased the embryo weight at E16 (P < 0.05). At E16, compared with NC and PC groups, the yolk sac index of TCA group was significantly decreased (P < 0.05). Compared with PC group, the liver index of TCA group was significantly increased (P < 0.05), the breast muscle index of TCA group was significantly higher than that of NC group (P < 0.05), but there was no significant difference in leg muscle index between TCA group and control groups (P > 0.05).

[0090] Table 4 Effects of TCA addition in the air cell on E16 broiler body weight and organ index

[0091]

[0092] Note: Data are expressed as Mean ± SD (n = 8), a,b Means with different letters are significantly different (P < 0.05).

[0093] Effects of TCA addition in the air cell on hatchability and D0 broiler body weight and organ index are shown in Table 5. As shown in Table 5, hatchability of all treatment groups was above 90%, and TCA group had higher hatchability than NC and PC groups, which indicated that TCA addition in the air cell at E11 had no negative effects on hatchability and mortality of broilers. At D0, broiler body weight of TCA group was significantly higher than that of PC group (P < 0.05). Compared with NC and PC groups, yolk sac index of TCA group was significantly lower (P < 0.05), and leg muscle index of TCA group was significantly higher than that of PC group (P < 0.05), while liver index and breast muscle index of all treatment groups had no significant difference (P > 0.05).

[0094] In summary, TCA addition in the air cell at E11 had no negative effects on hatchability and mortality of broilers, reduced yolk sac index of E16 embryo and broiler after hatching, significantly increased broiler body weight at E16 embryo and after hatching, and significantly increased leg muscle index of broiler after hatching.

[0095] Table 5 Effects of TCA addition in the air cell on hatchability and D0 broiler body weight and organ index

[0096]

[0097] Note: Data are expressed as Mean ± SD (n = 8), a,b Means with different letters are significantly different (P < 0.05).

[0098] (5) Effects of TCA addition in the air cell on lipid transport in yolk sac of chicken embryo

[0099] Effects of TCA addition in the air cell on lipid content in yolk sac of Hy-Line Brown laying hens are shown in Table 6. As shown in Table 6, among which (A) is triglyceride (TG), Figure 3 (B) is non-esterified fatty acid (NEFA), Figure 3 (C) is glycerol, Figure 4 (D) is total cholesterol (TCH), Figure 4 (E) is free cholesterol (FCH). Figure 4 Figure 4 Figure 4 Figure 4 ​​​FCH, and CE in TCA group were significantly lower than those in NC group (P<0.05). In YSM, NEFA in TCA group was significantly higher than that in PC group (P<0.05).

[0100] Effects of embryo injection of TCA on mRNA levels of lipid transport related genes in Yolk sac membrane of AA broiler embryos are shown in Figure 4 . As shown in Figure 4 , wherein Figure 5 (A) is triglyceride (TG), Figure 5 (B) is non-esterified fatty acid (NEFA), Figure 5 (C) is glycerol, Figure 5 (D) is total cholesterol (TCH), Figure 5 (E) is free cholesterol (FCH), Figure 5 (F) is cholesteryl ester (CE); in YSC, TG in TCA group was significantly lower than that in NC and PC groups (P<0.05), and CE in TCA group was significantly lower than that in NC group (P<0.05). In YSM, NEFA in TCA group was significantly higher than that in PC group (P<0.05).

[0101] Effects of embryo injection of TCA on mRNA levels of lipid transport related genes in Yolk sac membrane of AA broiler embryos are shown in Figure 5 , wherein Figure 5 (A) is Hyline Brown laying hen, Figure 5 (B) is AA broiler; the test results show that in YSM of Hyline Brown laying hen, embryo injection of TCA can up-regulate the expression of lipid transport related genes such as FABP3, APOA1 and MTP. In YSM of AA broiler, embryo injection of TCA can up-regulate the expression of lipid transport related genes such as FABP1, FABP3 and APOB.

[0102] The above results show that after embryo injection of TCA, the mRNA expression of lipid transport related genes in YSM is up-regulated, thereby promoting the transport of lipids in YSC to YSM to promote the growth and development of embryos, shorten the incubation time, and improve the body weight of chicks.

[0103] (6) Effects of embryo injection of TCA on growth performance of broilers

[0104] Effects of embryo injection of TCA on growth performance of broilers after hatching are shown in Figure 6 and Table 6. From Table 6 and Figure 6 , wherein Figure 6 (A) is average body weight, Figure 7 (B) is average daily gain, Figure 7 (C) is average daily feed intake,Figure 7 (D) represents the feed conversion ratio; it can be seen that the hatching rate of each treatment group was around 88%. Adding TCA to the eggs significantly increased the weight of chicks after hatching (P<0.05). Throughout the rearing period (1-42 days old), the weight of broilers treated with TCA was significantly higher than that in the PC group (P<0.05). At 7, 14, and 21 days of age, the weight of broilers in the TCA group was significantly higher than that in the PC and NC groups (P<0.05). At 7 and 14 days of age, the average daily weight gain of broilers in the TCA group was significantly higher than that in the NC group (P<0.05). During the 1-21 day age period, the average daily weight gain in the TCA group was significantly higher than that in the PC and NC groups (P<0.05). Compared with the PC group, the average daily weight gain during the 21-42 day age period and throughout the 1-42 day age period was significantly higher in the TCA group (P<0.05). Compared with the NC group, TCA treatment significantly reduced feed conversion ratio in the 1-21 day age stage and throughout the 1-42 day age stage (P<0.05), with a decreasing trend in feed conversion ratio in the 21-42 day age stage (P=0.066). There were no significant differences in feed intake and mortality rate throughout the 1-42 day age stage among the groups (P>0.05), and the mortality rate was lower in the TCA group.

[0105] In conclusion, adding taurine to eggs at the E11 embryonic age does not affect the hatchability of broilers, but significantly increases the weight of chicks after hatching and the total weight of broilers throughout the 1-42 day rearing period, reduces the feed conversion ratio, significantly increases the average daily weight gain, and does not significantly change the average daily feed intake and mortality rate.

[0106] Table 6. Effects of TCA addition on hatchability and growth performance of broiler chickens.

[0107]

[0108]

[0109] Note: Data is expressed as Mean±SEM (n=6). a,b Different letters indicate significant differences (P<0.05).

[0110] (7) Effect of adding taurine to embryos on organ index of broilers

[0111] The effect of adding taurine to embryos on organ indices of broilers after hatching is shown in the figure. Figure 7 ,in Figure 7 (A) represents the liver index. Figure 7 (B) represents the pectoral muscle index. Figure 8 (C) represents the leg muscle index; from Figure 8It was found that there were no significant differences in liver, breast muscle and leg muscle indexes among the three groups at D0(P>0.05). At E21, the breast muscle index in the TCA group was significantly higher than that in the NC group(P<0.05), but there were no significant differences in liver and leg muscle indexes between the TCA and PC groups and the NC group(P>0.05). At E42, the liver index in the TCA group was significantly lower than that in the NC group(P<0.05), while the leg muscle index in the TCA group was significantly higher than that in the NC group(P<0.05), and there was no significant difference in the breast muscle index among the three groups(P>0.05).

[0112] (8)Effects of adding taurine cholic acid to embryonated eggs on blood biochemical indexes of broilers

[0113] Effects of adding taurine cholic acid to embryonated eggs on blood biochemical indexes of broilers at E21 are shown in Table 7. It was found that, at E21, the content of ALB in plasma in the TCA group was significantly lower than that in the NC group(P<0.05), the contents of TG, TCH and HDL-C in plasma in the TCA group were significantly lower than those in the NC and PC groups(P<0.05), and the contents of LDL-C and NEFA in plasma in the TCA group were significantly lower than those in the PC group(P<0.05). However, there were no significant differences in the contents of ALT, AST and TP in plasma among the three groups(P>0.05).

[0114] Table 7 Effects of adding taurine cholic acid to embryonated eggs on blood biochemical indexes of broilers at E21

[0115]

[0116] Note: Data are expressed as Mean ± SD (n = 6), a,b Values with different superscripts are significantly different (P<0.05).

[0117] Effects of adding taurine cholic acid to embryonated eggs on blood biochemical indexes of broilers at E42 are shown in Table 8. It was found that, at E42, the contents of TCH and HDL-C in plasma in the TCA group were significantly lower than those in the NC group(P<0.05), but there were no significant differences in the contents of ALT, AST, ALB, TP, TG, LDL-C and NEFA in plasma among the three groups(P>0.05). In summary, adding taurine cholic acid to embryonated eggs significantly reduced the blood lipid content of broilers.

[0118] Table 8 Effects of adding taurine cholic acid to embryonated eggs on blood biochemical indexes of broilers at E42

[0119]

[0120]

[0121] Note: Data are expressed as Mean ± SD (n = 6), a,b Means with different letters are significantly different (P < 0.05).

[0122] (9) Effect of embryo added tauroursodeoxycholic acid on mRNA level of proliferation and differentiation related regulatory factors in thigh muscle of broilers

[0123] Effect of embryo added tauroursodeoxycholic acid on mRNA level of proliferation and differentiation related regulatory factors in thigh muscle of broilers Figure 8 , wherein Figure 8 (A) is D0, wherein Figure 8 (B) is D21, wherein Figure 9 (C) is D42,. As shown in Figure 9 Figure 9 Figure 9 Figure 9 at D0, the mRNA expression levels of proliferation and differentiation related regulatory factors MyoD, MyoG, Myf5, PAX3, PCNA and MRF4 in the thigh muscle of the TCA group were significantly higher than those of the PC group (P < 0.05). At 21 days of age, the mRNA expression of MyoD, Myf5 and PAX3 in the thigh muscle of the TCA group was significantly higher than that of the PC group (P < 0.05), and at 42 days of age, the mRNA expression of MyoG, Myf5 and PAX3 in the thigh muscle of the TCA group was significantly higher than that of the NC and PC groups (P < 0.05). In summary, embryo added TCA promotes muscle development and improves meat production ability by up-regulating the mRNA levels of proliferation and differentiation related regulatory factors in the thigh muscle at D0, D21 and D42.

[0124] The preferred embodiments of the present application have been described above with the preferred embodiments, but the present application is not limited to the above examples. It will be appreciated by those skilled in the art that the present application can be variously changed and modified. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the scope of the present application.

Claims

1. A method of increasing hatch weight and promoting early growth and development in a young chicken, characterized by, adding a taurine cholic acid solution into the air chamber of the chicken embryo; the concentration of the taurine cholic acid solution is 5-25 mg / mL; the adding amount of the taurine cholic acid solution is 0.1-0.5 mL; the chicken embryo is a chicken embryo hatched to 9-11 embryonic age.

2. The method of increasing hatch weight and promoting early growth and development of young chickens according to claim 1, wherein, the taurine cholic acid solution is a sterile normal saline solution of taurine cholic acid.

3. The method of increasing hatch weight and promoting early growth and development of young chickens according to claim 1, wherein, the concentration of the taurine cholic acid solution is 12.5 mg / mL.

4. The method of increasing hatch weight and promoting early growth and development of young chickens according to claim 1, wherein, the adding amount of the taurine cholic acid solution is 0.2 mL.

5. The method of increasing hatch weight and promoting early growth and development of young chickens according to claim 1, wherein, the chicken embryo is a chicken embryo hatched to 11 embryonic age.

6. The method of increasing hatch weight and promoting early growth and development of young chickens according to claim 1, wherein, further comprising filtering sterilization before adding the taurine cholic acid solution.

7. The method of increasing hatch weight and promoting early growth and development of young chickens according to claim 6, wherein, the filtering sterilization is sterilization by using a 0.22 μm sterile filter.

8. Use of taurocholic acid for increasing the hatch weight and promoting early growth and development of chicks, characterized in that, adding a taurine cholic acid solution into the air chamber of the chicken embryo; the concentration of the taurine cholic acid solution is 5-25 mg / mL; the adding amount of the taurine cholic acid solution is 0.1-0.5 mL; and the chicken embryo is a chicken embryo hatched to 9-11 embryonic age.

9. The use of taurocholic acid according to claim 8, characterized in that, the improving hatchling weight and promoting early growth and development of the chicken embryo is shortening the incubation time, improving the incubation performance, improving the growth performance, improving the organ index, improving the transport and absorption of nutrients in the yolk sac or reducing the blood lipid level.

10. A method of increasing hatch weight and promoting early growth and development in a young chicken by administering tauroursodeoxycholic acid, characterized in that, the method for improving the hatchling weight and promoting the early growth and development of the chicken embryo according to any one of claims 1-7 is used to add taurine cholic acid into the air chamber of the chicken embryo.

11. Use of taurocholic acid in the manufacture of a product for increasing the hatch weight of a young chicken and promoting early growth and development, characterised in that, adding a taurine cholic acid solution into the air chamber of the chicken embryo; the concentration of the taurine cholic acid solution is 5-25 mg / mL; the adding amount of the taurine cholic acid solution is 0.1-0.5 mL; and the chicken embryo is a chicken embryo hatched to 9-11 embryonic age.

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