Application of Royal Jelly Acid in Feed Additives for Laying Hens

Abstract

The present invention belongs to the technical field of poultry breeding, and provides the application of royal jelly acid in feed additives for laying hens: adding 0.1%-0.3% royal jelly acid to the feed of laying hens can improve the egg production rate of laying hens. Royal jelly acid can improve the antioxidant capacity of the ovaries and increase the level of reproductive hormones after feeding laying hens, and has the effect of significantly improving the egg-laying performance and eggshell strength of laying hens, especially laying hens in the late egg-laying period. Royal jelly acid is a naturally occurring active ingredient and is a safe and green feed additive. The residue in eggs will not cause harm to human health, but can increase the added value of eggs. The present invention provides a safe and green additive for improving egg-laying performance and eggshell quality, which can be applied to the laying hen breeding industry to solve the current problems of decreased production performance and eggshell quality of laying hens in the late egg-laying period.

Description

Technical Field

[0001] The invention belongs to the technical field of poultry breeding and relates to application of royal jelly acid in laying hen feed additives. Background Art

[0002] The disclosure of this background information is intended to enhance understanding of the general background of the invention and should not necessarily be taken as an acknowledgment or any form of suggestion that this information constitutes the prior art already known to a person skilled in the art.

[0003] Due to the continuous egg-laying process, the ovarian oxidation aging rate of laying hens is much higher than that of other organs. At the same time, there are a lot of environmental, immune, pathogenic bacteria and other stimuli in the modern breeding process, which increase the reactive oxygen species (ROS) in the body tissues. The excessive accumulation of ROS accelerates the arrival of the late egg-laying period. In the late egg-laying period, accompanied by the atrophy of the ovaries, the weakening of antioxidant capacity and the weakening of the ability to synthesize reproductive hormones, the egg production has seriously declined, the breeding cost is high, the eggshell strength has decreased, the egg breakage rate has increased, which is not conducive to transportation and processing, and brings significant economic losses to the breeding industry. With the introduction of the policy of banning antibiotics in feed, the use of safe and green additives in laying hen production has become an effective means to increase egg production and improve eggshell quality.

[0004] Royal jelly acid, or 10-hydroxy-2-decenoic acid (10-HDA), is a medium-chain unsaturated fatty acid with a hydroxyl group at the end. It is the main active ingredient of royal jelly and has multiple physiological functions such as antibacterial, anti-inflammatory, and immunomodulatory, and has broad application prospects. Royal jelly acid is mainly extracted from royal jelly, which is costly and its application is mainly limited to medical purposes. With the deepening of research, royal jelly acid can be mass-produced through fermentation engineering, and the cost has been greatly reduced. As a result, it has become possible to explore new uses of 10-HDA in various fields, especially in poultry farming.

[0005] Patent CN 103948063 A discloses a healthy egg containing royal jelly acid. By feeding 1-50 mg of 10-HDA to each laying hen in drinking water or mixed feed during the laying hen breeding process, the cholesterol content of the egg can be effectively reduced by 28-36%, the lecithin content in the egg can be increased by 5-15%, and the royal jelly acid content in the egg can be 0.05-10 mg / piece; however, there is no significant difference in the egg laying rate of laying hens compared with the control group. Further research on the application of royal jelly acid in the poultry field, especially in the production performance of laying hens, can provide a new way to improve the production performance of laying hens in the later stage of egg laying. Summary of the invention

[0006] In view of the problems of decreased egg-laying ability, poor feed conversion rate, poor eggshell quality, etc. in the late egg-laying period of laying hens, the present invention provides an application of royal jelly acid as a feed additive for laying hens, which can improve the antioxidant capacity of ovaries, increase the level of reproductive hormones, significantly improve the egg production rate of laying hens in the late egg-laying period, reduce the feed-to-egg ratio, and improve the eggshell strength.

[0007] To achieve the above purpose, the present invention adopts the following technical solution.

[0008] The application of royal jelly acid (10-hydroxy-2-decenoic acid, 10-HDA) in improving the egg production rate and eggshell strength of laying hens in the late laying period and reducing the feed-egg ratio.

[0009] The royal jelly acid can be extracted from royal jelly or propolis, chemically synthesized, or fermented by engineered bacteria.

[0010] The egg production rate is the percentage of the number of eggs laid per day to the number of laying hens. For commercial laying hens, this value is no more than 100%, and the closer it is to 100%, the stronger the egg production capacity.

[0011] The feed-to-egg ratio is the ratio of total feed consumption to total egg weight. This parameter is used to evaluate the amount of feed consumed per unit weight of eggs.

[0012] A method for improving laying hen production performance and eggshell strength, comprising the following steps:

[0013] Add royal jelly acid to laying hen feed.

[0014] The amount of royal jelly acid added is 0.1%-0.3% of the weight of the feed; preferably 0.1%-0.2%.

[0015] The feeding time is more than 1 week, such as 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks; preferably, the feeding time is 4 weeks and more.

[0016] The best time to add royal jelly acid is in the late egg-laying period.

[0017] The present invention has the following advantages:

[0018] Royal jelly acid can improve the antioxidant capacity of the ovaries and increase the level of reproductive hormones after feeding laying hens, and has a significant effect on improving the egg production rate of laying hens, especially those in the late egg-laying period. At the same time, royal jelly acid can also reduce the feed-to-egg ratio and reduce feeding costs; it also has a significant improvement effect on the strength of the eggshell. Royal jelly acid is a naturally occurring active ingredient and is a safe and green feed additive. Its residue in eggs will not cause harm to human health, but can increase the added value of eggs. The present invention provides a safe and green additive for improving eggshell quality and egg production rate, which can be used in the laying hen breeding industry to solve the current problems of reduced production performance and poor eggshell quality in the late egg-laying period of laying hens. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The effect of dietary 10-HDA on serum reproductive hormone levels in laying hens, express P <0.05, express P <0.01;

[0020] Figure 2 The effect of dietary 10-HDA on serum antioxidant levels, among which, express P <0.05, express P <0.01;

[0021] Figure 3 The effect of dietary 10-HDA on the antioxidant level of the ovary, among which, express P <0.05, express P <0.01;

[0022] Figure 4 The effect of dietary 10-HDA on eggshell strength is shown in Figure 2. express P <0.05. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with embodiments and drawings, but the present invention is not limited by the following embodiments.

[0024] Example 1 Effects of dietary 10-HDA on production performance and physiology of laying hens

[0025] 192 healthy Hy-Line brown laying hens of 58 weeks of age in the late egg-laying period with similar egg-laying performance were randomly divided into 4 treatment groups, with 6 replicates in each treatment group and 8 hens in each replicate. The control group was fed a basal diet (CK), and the experimental groups were fed with 0.1%, 0.2% and 0.3% 10-HDA on the basis of the basal diet. The adaptation period was 1 week, and the experimental period was 8 weeks. Laying hens were raised in horizontal cages (length, width and height were 65, 65, and 50 cm, respectively), fed twice a day (07:00 a.m. and 16:30 p.m.), had free access to water, maintained 16 hours of artificial light (05:00 a.m.-21:00 p.m.), maintained a temperature of about 23°C, and a relative humidity of about 55%. The formulas of all experimental diets met the standards for laying hens.

[0026] 1. Effects of dietary 10-HDA on production performance of laying hens

[0027] During the experiment, the number of eggs laid and the weight of eggs were recorded at 16:00 every day, and the feed intake was recorded weekly to calculate the egg production rate, average daily feed intake and feed-egg ratio to evaluate the production performance of laying hens.

[0028] Egg production rate (%) = number of eggs laid / number of laying hens × 100%

[0029] Average egg weight (g) = total egg weight / total number of eggs;

[0030] Average daily feed intake (g) = total feed intake / (number of chickens × number of experimental days);

[0031] Feed-to-egg ratio = total feed consumption / total egg weight.

[0032] Table 1 Effects of dietary 10-HDA on production performance of laying hens

[0033]

[0034] Note: Different letters in the same row represent P = 0.05 level is significantly different.

[0035] The results showed that during the first 8 weeks of the experiment, the egg production rate of the basal diet group decreased significantly, while the egg production rate of the group supplemented with 10-HDA was significantly higher than that of the basal diet group ( P <0.05, the feed-egg ratio was significantly reduced ( P <0.05). In the 1-4 weeks, the egg production rate of the 0.2% 10-HDA group was 7.3% higher than that of the basal diet group, and the feed-egg ratio was reduced by 6.9%. In the 5-8 weeks of the experiment, the egg production rate of the 0.2% 10-HDA group was 14.2% higher than that of the basal diet group, and the feed-egg ratio was reduced by 13.4%. This shows that 10-HDA can increase the egg production rate of laying hens in the late laying period and reduce the feed-egg ratio, especially when the 0.2% addition dosage has the most obvious effect.

[0036] 2. Effects of dietary 10-HDA on serum reproductive hormone levels

[0037] On the 56th day of the experiment, one chicken was randomly selected from each replicate, and blood samples were collected from the wing vein using a coagulation tube. After standing at room temperature for 1 hour, the blood was centrifuged at 4℃ and 3000rpm for 20 minutes, and the serum was collected and stored at -20℃. The levels of luteinizing hormone (LH), chicken follicle-stimulating hormone (FSH), and estradiol (E2) in the serum of laying hens in each group were detected using a chicken enzyme-linked immunosorbent assay (ELISA) kit.

[0038] The results are as follows Figure 1 As shown in Figure 2, dietary supplementation with 10-HDA significantly increased the levels of reproductive hormones LH, FSH, and E2 in serum ( P<0.05), in which 0.1%-0.3% 10-HDA addition increased the reproductive hormone LH level by 19.64%-40.61%, FSH level by 6.9%-39.45%, and E2 level by 13.67%-16.85%, respectively.

[0039] 3. Effect of dietary 10-HDA on serum antioxidant levels

[0040] On the 56th day of the experiment, one chicken was randomly selected from each replicate, and blood samples were collected from the wing vein using a coagulant tube. After standing at room temperature for 1 hour, the blood was centrifuged at 4℃ 3000rpm for 20 minutes, and the serum was collected and stored at -20℃. The levels of catalase (CAT), total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-px), and malondialdehyde (MDA) in the serum of laying hens in each group were detected using kits.

[0041] The results are as follows Figure 2 As shown, the 0.2% 10-HDA group significantly increased the levels of CAT, T-SOD and GSH-px in serum ( P <0.05, and reduced malondialdehyde (MDA) levels ( P <0.05). The addition of 0.2% 10-HDA increased the levels of serum total superoxide dismutase (T-SOD), catalase (CAT), and glutathione peroxidase (GSH-px) by 44.21%, 7.5%, and 14.47%, respectively; and decreased the level of malondialdehyde (MDA) by 46.97%.

[0042] 4. Effect of dietary 10-HDA on ovarian antioxidant levels

[0043] Take an appropriate amount of ovarian tissue, rinse with 0.9% saline, cut into pieces for later use, add PBS at a mass volume ratio of 1:10 between tissue and PBS, and grind thoroughly on ice with an electric homogenizer. Centrifuge the prepared homogenate at 12,000g for 5 minutes at 4°C, and take the supernatant to measure the levels of catalase (CAT), total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-px), and malondialdehyde (MDA) according to the instructions of the kit.

[0044] The results are as follows Figure 3 As shown, 10-HDA increased the levels of ovarian catalase (CAT), total superoxide dismutase (T-SOD), and glutathione peroxidase (GSH-px), and decreased the level of malondialdehyde (MDA) ( P<0.05). Among them, 0.1% 10-HDA addition increased the level of ovarian catalase (CAT) by 80.14%; 0.2% 10-HDA addition increased the level of total superoxide dismutase (T-SOD) by 37.76%, the level of glutathione peroxidase (GSH-px) by 12.54%, and reduced the level of malondialdehyde (MDA) by 36.86%.

[0045] 5. Effect of dietary 10-HDA on eggshell quality

[0046] In the 4th and 8th weeks of the experiment, three eggs were randomly selected from each replicate (n=6) for eggshell strength measurement. Figure 4 The results showed that adding 10-HDA to feed can improve the eggshell strength. In the fourth week, 0.1%-0.3% 10-HDA can significantly increase the eggshell strength by 11.26%-19.20%.

[0047] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. The application of royal jelly acid in improving the egg production rate and eggshell strength of laying hens in the late egg-laying period and reducing the feed-egg ratio, characterized in that: Royal jelly acid is added to laying hen feed; the amount of royal jelly acid added is 0.1%-0.3% of the feed weight.

2. The use according to claim 1, characterized in that: Royal jelly acid is derived from royal jelly or propolis extraction, chemical synthesis, or fermentation by engineered bacteria.

3. The use according to claim 1, characterized in that: The egg production rate is the percentage of the daily egg production and the number of laying hens; the feed-to-egg ratio is the ratio of the total feed consumption and the total egg weight.

4. A method for improving the production performance of laying hens and the strength of eggshells, characterized in that: The following steps are involved: Add royal jelly acid to laying hen feed; The amount of royal jelly acid added is 0.1%-0.3% of the feed weight; The best time to add royal jelly acid is in the late egg-laying period.

5. The method according to claim 4, characterized in that The amount of royal jelly acid added is 0.1%-0.2% of the weight of the feed.

6. The method according to claim 4, characterized in that The amount of royal jelly acid added is 0.2% of the weight of the feed.

7. The method according to claim 4, characterized in that The feeding time is more than 1 week.

8. The method according to claim 4, characterized in that Feeding time is 4 weeks and above.

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