Laying hen feed additive combined with 25-hydroxyvitamin D3 and organic manganese and application of laying hen feed additive

Abstract

The invention discloses a laying hen feed additive combined with 25-hydroxyvitamin D3 and organic manganese and application of the laying hen feed additive, belongs to the technical field of feed additives, and solves the problem that an existing modifier indirectly relieves eggshell defects mainly by supplementing trace elements, resisting bacteria or improving eggshell color and luster. In order to solve the problems in the prior art that existing laying hens are poor in pastoid structure abnormity and calcification defects, but lack targeted regulation and control on pastoid structure abnormity and calcification defects of the laying hens, the feed additive comprises the following components: organic manganese and hydroxy vitamin D. The feed additive is used for being added into a basic ration of the laying hens. In the embodiment of the invention, the HyD and the organic manganese are added into the daily ration, so that the thickness and the width of the mastoid layer can be reduced, the eggshell calcification coverage uniformity can be directly improved, the formation of dark spots can be reduced, and the anti-cracking capability of the eggshell can be remarkably improved by cooperatively regulating and controlling the structure of the mastoid layer of the eggshell and reducing gaps and fragile areas of the eggshell. Further, the eggshell calcification covering uniformity is improved, dark spots caused by mastoid layer abnormity are reduced, and the surface smoothness and integrity of the eggshell are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of feed additives, and particularly relates to a laying hen feed additive combined with 25-hydroxyvitamin D3 and organic manganese and application thereof. Background Art

[0002] As an important livestock and poultry product, the quality of eggs directly affects consumer choice and breeding efficiency. Eggshell quality is one of the core indicators to measure the commodity value of eggs, and dark-spotted eggs (also known as "spotted eggs"), as a typical defect in eggshell quality, have become a difficult problem that needs to be solved urgently in current egg production. The appearance of dark-spotted eggs is mainly due to abnormal changes in the eggshell papillary layer and the eggshell membrane structure. Specifically, the density and smoothness of the eggshell papillary layer are greatly reduced, and its internal gaps are significantly enlarged, and the thickness is much higher than that of normal eggs. At the same time, the inner membrane reticular structure of dark-spotted eggs becomes sparse, which makes it impossible for the eggshell to be evenly calcified during the formation process, and the eggshell calcium deposition is reduced, which ultimately leads to an increase in the effective layer thickness of the eggshell and the overall eggshell thickness of the dark-spotted eggs, showing a dark spot feature in appearance.

[0003] Trace elements such as zinc, copper, and manganese are coenzymes for key enzymes involved in the synthesis of eggshell matrix proteins (such as glycoproteins and proteoglycans), directly regulating papillae formation and calcification. For example, manganese is involved in the glycosylation of eggshell membrane glycoproteins, and its deficiency can lead to a loose papillae structure and uneven calcium deposition. However, traditional inorganic manganese (such as manganese sulfate) has low bioavailability and easily antagonizes with other components, making it difficult to meet the precise requirements for eggshell formation in practical applications.

[0004] At the same time, Chinese patent CN116889263A discloses an eggshell improver for use in mixed feed, wherein the eggshell improver includes the following components: organic iron, organic zinc, organic manganese, phytase, calcium formate, dandelion extract, and poplar flower extract. The improver can significantly improve soft and broken eggs, deformed eggs, sand-peeled eggs, watermarked eggs, and light eggshell color caused by various reasons, and can relieve mild salpingitis (severe inflammation requires the use of oregano and double inflammation net for prevention and control), and can prevent the eggs themselves from being contaminated by miscellaneous bacteria. However, existing improvers mainly alleviate eggshell defects indirectly by supplementing trace elements, antibacterial or improving eggshell color, but lack targeted regulation of the core causes of dark-spotted eggs (abnormal papillary layer structure and uneven calcification), and affect the eggshell thickness, eggshell strength, and eggshell ratio of eggs, resulting in reduced egg quality. To address the above problems, we propose a laying hen feed additive combined with 25-hydroxyvitamin D3 and organic manganese and its application. Summary of the Invention

[0005] The purpose of the present invention is to address the shortcomings of the existing technology and provide a laying hen feed additive combined with 25-hydroxyvitamin D3 and organic manganese and its application, so as to solve the problem that the existing improvers mainly alleviate eggshell defects indirectly by supplementing trace elements, antibacterial or improving eggshell color, but lack targeted regulation of the abnormal papillary layer structure and calcification defects of dark-spotted eggs, and affect the eggshell thickness, eggshell strength and eggshell ratio of the eggs.

[0006] The present invention is achieved by providing a laying hen feed additive that combines 25-hydroxyvitamin D3 and organic manganese, and a laying hen feed additive that combines 25-hydroxyvitamin D3 and organic manganese, characterized in that the feed additive includes the following components: organic manganese and hydroxyvitamin D, and the feed additive is used to be added to the laying hen basal diet, and the concentration gradient of the organic manganese added to the basal diet is 0-125ppm, and the content of the hydroxyvitamin D added to the basal diet is 50-100μg / Kg.

[0007] Among them, the basic daily diet includes the following raw materials in parts by weight: 60-65 parts of corn, 20-26 parts of soybean meal, 0.2-1 parts of soybean oil, 5-10 parts of coarse stone powder, 0.1-1 parts of premix, and 0.01-0.05 parts of carrier.

[0008] Preferably, the basic diet comprises the following raw materials in parts by weight: 61-64 parts of corn, 22-24 parts of soybean meal, 0.3-0.9 parts of soybean oil, 4-9 parts of coarse stone powder, 0.2-0.8 parts of premix, and 0.02-0.04 parts of carrier.

[0009] Preferably, the basic diet comprises the following raw materials in parts by weight: 62.5 parts of corn, 24.5 parts of soybean meal, 0.5 parts of soybean oil, 8.5 parts of coarse stone powder, 0.38 parts of premix, and 0.02 parts of carrier.

[0010] Preferably, the premix comprises the following components: rice husk powder, zeolite powder, calcium hydrogen phosphate, stone powder, sodium chloride, methionine, lysine, multivitamins, phytic acid, choline, and baking soda.

[0011] Preferably, the concentration gradient of organic manganese added to the basic diet is 0, 25, 50, 75, 100, and 125 ppm, respectively.

[0012] Preferably, the content of hydroxyvitamin D added to the basic diet is 69 μg / Kg, and the hydroxyvitamin D is 25-hydroxyvitamin D3.

[0013] The application of the laying hen feed additive combined with 25-hydroxyvitamin D3 and organic manganese in improving the eggshell color and quality of laying hens.

[0014] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0015] In the embodiments of the present invention, the addition of HyD and organic manganese to the diet can reduce the thickness and width of the papillary layer (making the papillary layer denser and with fewer gaps), directly improving the uniformity of eggshell calcification coverage and reducing the formation of dark spots. Furthermore, by synergistically regulating the structure of the eggshell papillary layer (reducing the thickness and width of the papillary layer and enhancing its density), the gaps and fragile areas in the eggshell are reduced, significantly improving the eggshell's resistance to cracking. This further improves the uniformity of eggshell calcification coverage, reduces the formation of dark spots caused by abnormalities in the papillary layer, and improves the surface smoothness and integrity of the eggshell. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of dark-spotted eggs selected by the four-level classification method of the present invention is shown. DETAILED DESCRIPTION

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of the application are only for the purpose of describing specific embodiments and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0018] Existing improvers mainly alleviate eggshell defects indirectly by supplementing trace elements, antibacterial or improving eggshell color, but lack targeted regulation of the abnormal structure of the papillary layer and calcification defects of dark-spotted eggs, and affect the eggshell thickness, eggshell strength and eggshell ratio of eggs. In response to the above problems, we proposed a laying hen feed additive combined with 25-hydroxyvitamin D3 and organic manganese and its application. The feed additive includes the following components: organic manganese, hydroxyvitamin D. In the embodiment of the present invention, the addition of HyD and organic manganese to the diet can reduce the thickness and width of the papillary layer (the papillary layer is denser and the gaps are reduced), directly improve the uniformity of the eggshell calcification coverage, reduce the formation of dark spots, and by synergistically regulating the structure of the eggshell papillary layer (reducing the thickness and width of the papillary layer and enhancing the density), reduce the gaps and fragile areas of the eggshell, and significantly improve the eggshell's resistance to rupture. This improves the uniformity of the eggshell calcification coverage, reduces the formation of dark spots caused by abnormalities in the papillary layer, and improves the surface smoothness and integrity of the eggshell.

[0019] It should be noted that HyD (Hydroxyvitamin D) in this embodiment is used to refer to the active precursor form of vitamin D after hydroxylation metabolism in the body (such as 25-hydroxyvitamin D2 or D3). This abbreviation is commonly used to refer to the hydroxylated active form of vitamin D in the fields of animal nutrition, veterinary medicine and vitamin metabolism research.

[0020] Example 1

[0021] The embodiment of the present invention provides a laying hen feed additive combined with 25-hydroxyvitamin D3 and organic manganese, wherein the feed additive comprises the following components: organic manganese and hydroxyvitamin D, and the feed additive is added to the basic diet of laying hens;

[0022] The basic diet includes the following raw materials in parts by weight: 60 parts of corn, 20 parts of soybean meal, 0.2 parts of soybean oil, 5 parts of coarse stone powder, 0.1 parts of premix, and 0.01 parts of carrier.

[0023] In this embodiment, the carrier is used for balancing feed and can be wheat bran or wheat flour.

[0024] The premix comprises the following components: rice husk powder, zeolite powder, calcium hydrogen phosphate, stone powder, sodium chloride, methionine, lysine, multivitamins, phytic acid, choline and baking soda.

[0025] The premix is ​​provided for every kilogram of complete feed, and its content may be: 77.5g rice husk powder, 87.5g zeolite powder, 212.5g calcium hydrogen phosphate, 375g stone powder, 55g sodium chloride, 37.5g methionine, 15g lysine, 17.5g multivitamin, 10g phytic acid, 25g choline, 37.5g baking soda, and 50g others.

[0026] In this embodiment, the concentration gradient of organic manganese added to the basic diet is 0 ppm.

[0027] The content of hydroxyvitamin D added to the basic diet was 69 μg / Kg, and the hydroxyvitamin D was 25-hydroxyvitamin D3.

[0028] At the same time, it should be noted that the main nutrients of the basic diet include metabolizable energy 11.31%, crude protein 15.36%, calcium 3.61%, total phosphorus 0.49%, methionine 0.35%, lysine 0.8%, and lysine methionine 0.62%.

[0029] Example 2

[0030] In this embodiment, the other raw material ratios of the laying hen feed additive combined with 25-hydroxyvitamin D3 and organic manganese are the same as those in Example 1. The feed additive includes the following components: organic manganese and hydroxyvitamin D. The feed additive is added to the basic diet of laying hens;

[0031] The basic diet includes the following raw materials by weight: 65 parts of corn, 26 parts of soybean meal, 1 part of soybean oil, 10 parts of coarse stone powder, 1 part of premix, and 0.05 parts of carrier.

[0032] The concentration gradient of organic manganese added to the basic diet was 25 ppm.

[0033] Example 3

[0034] In this embodiment, the other raw material ratios of the laying hen feed additive combined with 25-hydroxyvitamin D3 and organic manganese are the same as those in Example 1. The feed additive includes the following components: organic manganese and hydroxyvitamin D. The feed additive is added to the basic diet of laying hens;

[0035] The basic diet includes the following raw materials in parts by weight: 61 parts of corn, 22 parts of soybean meal, 0.3 parts of soybean oil, 4 parts of coarse stone powder, 0.2 parts of premix, and 0.02 parts of carrier.

[0036] The concentration gradient of organic manganese added to the basic diet was 50 ppm.

[0037] Example 4

[0038] In this embodiment, the other raw material ratios of the laying hen feed additive combined with 25-hydroxyvitamin D3 and organic manganese are the same as those in Example 1. The feed additive includes the following components: organic manganese and hydroxyvitamin D. The feed additive is added to the basic diet of laying hens;

[0039] The basic diet includes the following raw materials in parts by weight: 64 parts of corn, 24 parts of soybean meal, 0.9 parts of soybean oil, 9 parts of coarse stone powder, 0.8 parts of premix, and 0.04 parts of carrier.

[0040] The concentration gradient of organic manganese added to the basic diet was 75 ppm.

[0041] Example 5

[0042] In this embodiment, the other raw material ratios of the laying hen feed additive combined with 25-hydroxyvitamin D3 and organic manganese are the same as those in Example 1. The feed additive includes the following components: organic manganese and hydroxyvitamin D. The feed additive is added to the basic diet of laying hens;

[0043] The basic diet includes the following raw materials in parts by weight: 62.5 parts of corn, 24.5 parts of soybean meal, 0.5 parts of soybean oil, 8.5 parts of coarse stone powder, 0.38 parts of premix, and 0.02 parts of carrier.

[0044] The concentration gradient of organic manganese added to the basic diet was 100 ppm.

[0045] Example 6

[0046] In this embodiment, the other raw material ratios of the laying hen feed additive combined with 25-hydroxyvitamin D3 and organic manganese are the same as those in Example 1. The feed additive includes the following components: organic manganese and hydroxyvitamin D. The feed additive is added to the basic diet of laying hens;

[0047] The basic diet includes the following raw materials in parts by weight: 62.5 parts of corn, 24.5 parts of soybean meal, 0.5 parts of soybean oil, 8.5 parts of coarse stone powder, 0.38 parts of premix, and 0.02 parts of carrier.

[0048] The concentration gradient of organic manganese added to the basic diet was 125 ppm.

[0049] Comparative Example 1

[0050] This comparative example is a single organic manganese group, that is, organic protein manganese is added to the basal diet. In this example, the basal diet is not supplemented with hydroxyvitamin D, and the concentration gradient of organic protein manganese is 0 ppm.

[0051] Comparative Example 2

[0052] This comparative example is a single organic manganese group, that is, organic protein manganese is added to the basal diet. In this example, the basal diet is not supplemented with hydroxyvitamin D, and the concentration gradient of organic protein manganese is 25 ppm.

[0053] Comparative Example 3

[0054] This comparative example is a single organic manganese group, that is, organic protein manganese is added to the basal diet. In this example, the basal diet is not supplemented with hydroxyvitamin D, and the concentration gradient of organic protein manganese is 50 ppm.

[0055] Comparative Example 4

[0056] This comparative example is a single organic manganese group, that is, organic protein manganese is added to the basal diet. In this example, the basal diet is not supplemented with hydroxyvitamin D, and the concentration gradient of organic protein manganese is 75 ppm.

[0057] Comparative Example 5

[0058] This comparative example is a single organic manganese group, that is, organic protein manganese is added to the basal diet. In this example, the basal diet is not supplemented with hydroxyvitamin D, and the concentration gradient of organic protein manganese is 100 ppm.

[0059] Comparative Example 6

[0060] This comparative example is a single organic manganese group, that is, organic protein manganese is added to the basal diet. In this example, the basal diet is not supplemented with hydroxyvitamin D, and the concentration gradient of organic protein manganese is 125 ppm.

[0061] Performance testing:

[0062] A total of 2,304 64-week-old, healthy, and similarly weighted and egg-laying hens from the Nongda No. 5 late-laying line were selected. A two-week pre-trial was conducted before the start of the experiment, followed by an eight-week trial. All hens were fed a basal diet. During the trial, hens were randomly divided into 12 treatment groups, each with six replicates and 32 hens per replicate. Organic manganese was provided by Debon Organic Micronutrients, and hydroxyvitamin D (25-OHD3) was purchased from DSM. The basal diet was formulated in accordance with the NY / T332004 (2004) standard for laying hens.

[0063] The experimental groups and treatments are as follows: the test groups are (1)-(12), (1)-(6) are organic manganese groups alone, i.e., organic protein manganese concentration gradients of 0, 25, 50, 75, 100, and 125 ppm are added to the basal diet; (7)-(12) are organic manganese and 25-OHD3 co-addition treatments, i.e., 69 μg / kg 25-OHD3 is added to the diets of (1)-(6), that is, (1)-(6) correspond to comparative examples 1-6, and (7)-(12) correspond to examples 1-6. Feeding is based on the principle of free access to feed and drinking water.

[0064] Egg Sample Collection: Three eggs were randomly selected from each replicate at weeks 4, 6, and 8 of the formal experiment for egg quality and eggshell quality. In addition, one additional egg was randomly selected from each replicate at week 8 of the formal experiment for eggshell ultrastructure measurement. Three eggs were randomly selected from each replicate at weeks 4, 6, and 8 of the formal experiment. The yolks were separated, blended with a whisk, and placed in 10 mL centrifuge tubes. The tubes were then stored at -80°C for the measurement of trace element deposition in the yolks. Three eggs were randomly selected from each replicate at weeks 4, 6, and 8 of the formal experiment. The contents were removed, and the shells were repeatedly washed with double-distilled water until no residual egg white remained. The eggs were then air-dried indoors for 48 hours (room temperature: 27-28°C), ground into a powder, and the three samples were combined into a single sample for the measurement of trace element deposition in the eggshells.

[0065] The henhouses were inspected several times daily, and any laying hen deaths were recorded. Eggs were collected from each replicate at 5:00 PM each day, and the number of eggs laid and the number of laying hens were accurately recorded. Egg weights were also calculated. The feed consumption of laying hens was calculated every two weeks during the experimental period. After the formal experimental period, the egg production rate, average egg weight, daily egg production, daily feed intake, FCR and mortality were calculated for the entire period and the four weeks before the experiment (laying hens 64-67 weeks of age) and the four weeks after the experiment (laying hens 68-71 weeks of age). According to the 2×6 experimental design, a two-way ANOVA was performed using the general linear model in SPSS27.0 software to evaluate the interactive effect of HyD supplementation and manganese gradient. When the differences in the variance analysis were significant, Tukey's multiple comparison analysis was used; P < 0.05 indicated a significant difference, and 0.05 < P ≤ 0.1 indicated a trend of difference. The experimental data are expressed as mean and standard error. Table 1 shows the effects of whether HyD was added to the basal diet and the manganese level on the production performance of laying hens during the entire experimental period.

[0066] Table 1

[0067]

[0068] As shown in Table 1, there was no significant interaction between dietary HyD supplementation and organic manganese level on egg production performance in the late laying period (P>0.05). Under these experimental conditions, HyD supplementation significantly reduced average egg weight (P<0.05) but significantly increased daily egg production (P<0.05). HyD supplementation also tended to reduce feed-to-egg ratio (P=0.056). HyD supplementation increased egg production by 2 percentage points and reduced egg breakage by 0.12 percentage points, but the differences were not significant.

[0069] When HyD was not added to the diet, the feed-to-egg ratio was lowest in the 75mg / kg organic manganese group and highest in the 125mg / kg group. When HyD was added, the egg production rate was highest at 25mg / kg organic manganese, and the average egg weight was highest in the 125mg / kg organic manganese group.

[0070] Table 2 shows the effects of dietary HyD supplementation and manganese level on laying hen performance during the first four weeks of the experiment. During the first four weeks of the experiment, dietary HyD supplementation and organic manganese level had no significant effect on egg production rate, average egg weight, daily egg production, average daily feed intake, and egg breakage rate in the late laying period (P>0.05). However, there was an interaction effect on feed-to-egg ratio in laying hens. There was no significant effect between dietary HyD supplementation and organic manganese level, but HyD supplementation significantly reduced feed-to-egg ratio (P<0.05). When HyD was supplemented, the average daily feed intake was lowest in the 25 mg / kg organic manganese group and highest in the 75 mg / kg group.

[0071] Table 2

[0072]

[0073] Table 3 shows the effects of Hyd addition and manganese level on the performance of laying hens in the fourth week after the experiment. As shown in Table 3, there was no significant interaction effect of Hyd addition and manganese level on the performance of laying hens in the fourth week after the experiment (P>0.05). Under the conditions of this experiment, the addition of HyD significantly improved the laying rate and daily egg production of laying hens (P<0.05, Table 3), and significantly reduced the feed-to-egg ratio (P<0.05, Table 3).

[0074] Table 3

[0075]

[0076] Determination of egg quality and eggshell quality:

[0077] Determination of egg quality: The egg quality analyzer was used to determine the egg white height, yolk color, and Haugh units. The instrument program settings were fixed, and the operation strictly followed the instrument instruction manual. The analytical balance was used to determine the yolk weight, and the yolk specific gravity and eggshell specific gravity were calculated. The yolk specific gravity = (yolk weight / egg weight) x 100%, and the eggshell specific gravity = (eggshell weight / egg weight) x 100%.

[0078] Determination of eggshell quality: The analytical balance was used to determine the weight of the egg. The eggshell color refractometer was calibrated with white 81.8 and black 0. The eggshell color of the obtuse end, equator, and acute end was measured, and the average value was taken as the eggshell color value. The eggshell strength tester was used to determine the eggshell strength. The eggshell was cleaned with distilled water to remove the egg white residue, and then dried in the room (room temperature: 27-28°C) for 48 hours. The analytical balance was used to determine the weight of the eggshell, and the eggshell specific gravity was calculated. The eggshell specific gravity = (eggshell weight / egg weight) x 100%. The eggshell thickness tester was used to determine the thickness of the eggshell at the obtuse end, equator, and acute end, and the average value was taken as the eggshell thickness. Table 4 shows the effects of Hyd addition and manganese level on the egg quality of laying hens in the fourth week of the experiment.

[0079] Table 4

[0080]

[0081] As shown in Table 4, regarding egg quality in the fourth week of the experiment, there was no significant interaction effect between dietary HyD supplementation and organic manganese level on egg shape index, eggshell strength, yolk ratio, eggshell thickness, albumen height, yolk color, and Haugh unit of late-laying hens (P>0.05). However, there was a significant interaction effect on Haugh unit, with no significant effect between dietary HyD supplementation and organic manganese level. Under the conditions of this experiment, HyD supplementation significantly improved eggshell ratio (P<0.05, Table 4). In the group without HyD supplementation, eggshell strength showed a linear and quadratic change with increasing dose; eggshell ratio showed a quadratic change with increasing dose, with the highest eggshell ratio in the group with 50 mg / kg organic manganese level; and egg Haugh unit showed a quadratic change with increasing dose, with the highest Haugh unit in the group with 0 mg / kg organic manganese level.

[0082] Table 5 shows the effects of dietary HyD supplementation and manganese level on egg quality in the sixth week of the experiment. As shown in Table 5, there were no significant (P>0.05) interactions between dietary HyD supplementation and varying levels of organic manganese on egg shape index, eggshell color, yolk to eggshell ratio, albumen height, yolk color, and Haugh units in late-laying hens. However, there was an interaction effect on eggshell strength, with no significant effect between dietary HyD supplementation and organic manganese level. Under these experimental conditions, the addition of HyD significantly reduced egg shape index (P<0.05). In the diets without HyD supplementation, eggshell strength showed a linear and significant change with increasing dose, with the optimal effect achieved at an organic manganese level of 125 mg / kg. In the diets supplemented with HyD, eggshell strength showed a linear and significant change with increasing dose.

[0083] Table 5

[0084]

[0085] Table 6 shows the effects of dietary HyD supplementation and manganese level on egg quality in the eighth week of the experiment. As shown in Table 6, the addition of HyD or varying levels of organic manganese to the diet had no significant effect on egg shape index, eggshell color, yolk ratio, eggshell ratio, albumen height, yolk color, and Haugh units in late-laying hens (P>0.05). However, an interaction effect was observed for eggshell strength and eggshell thickness, with no significant effect between dietary HyD supplementation and organic manganese level. Under these experimental conditions, the addition of HyD significantly reduced the egg shape index (P<0.05, Table 6). There was no significant effect between dietary HyD supplementation and organic manganese level. Among the HyD supplemented groups, the organic manganese level of 75 mg / kg produced the highest eggshell strength and the best effect among all groups, and increased eggshell thickness compared to the group without HyD. In the group with HyD added to the diet, the eggshell strength changed quadratically with increasing dose, and the best effect was achieved when the organic manganese level was 75 mg / kg; in the group with HyD added to the diet, the eggshell thickness changed linearly with increasing dose, and the best effect was achieved when the organic manganese level was 75 mg / kg; in the group with HyD added to the diet, the eggshell ratio was the highest in the group with organic manganese level of 75 mg / kg (P < 0.05).

[0086] Table 6

[0087]

[0088] Determination of eggshell ultrastructure: In the eighth week of the formal experiment, three egg samples were randomly taken from each replicate, the egg contents were separated, the eggshells were repeatedly washed with double-distilled water, and dried indoors (approximately 48 hours). One eggshell sample (approximately 0.3 cm) from the equator was selected. 2 ), these samples were neatly fixed on a copper plate and sprayed with gold, and then the ultrastructure of the longitudinal section of the eggshell was observed and photographed using a scanning electron microscope at a magnification of 220x and a 100μm scale. Then, according to the method described by predecessors, the effective thickness, papilla thickness and papilla width in the eggshell ultrastructure were measured using the Smile View software provided by the scanning electron microscope. The results are shown in Table 7. Table 7 shows the effects of whether HyD was added to the basal diet and the manganese level on the eggshell ultrastructure.

[0089] Table 7

[0090]

[0091]

[0092] As shown in Table 7, there was no significant interaction effect between the presence or absence of HyD and the organic manganese level in the basal diet on papilla thickness in the late laying period. However, there was a significant interaction effect on papilla width and effective layer thickness. In the papilla width, the 75 mg / kg organic manganese level in the HyD-free group was significantly greater than that in the 25 mg / kg group. There was no significant effect between the HyD-added and organic manganese levels. In the effective layer thickness, the 75 and 100 mg / kg organic manganese levels in the HyD-free group were significantly greater than those in the 25 and 50 mg / kg groups. In the HyD-added group, the 0 and 50 mg / kg organic manganese levels were significantly greater than those in the 100 and 125 mg / kg groups. Under the conditions of this experiment, the presence or absence of HyD had no significant effect on papilla width, papilla thickness, or effective layer thickness in the eggshell ultrastructure (P>0.05). When HyD was not added to the basal diet, the width of the eggshell papillae showed a quadratic significant change with increasing dose. The papillae width was the lowest in the group with 0 mg / kg organic manganese level. When HyD was not added to the diet, the effective layer thickness showed a linear and quadratic significant change with increasing dose. The effective layer thickness was the highest in the group with 75 mg / kg organic manganese level. When HyD was added to the diet, the width of the eggshell papillae showed a linear and quadratic change with increasing dose. When HyD was added to the diet, the thickness of the effective layer of the eggshell showed a linear and quadratic change with increasing dose. The effective layer thickness was the highest in the group with 50 mg / kg organic manganese level.

[0093] Serum and Tissue Sample Collection: At the end of the feeding experiment, six laying hens, each weighing approximately the average of each replicate, were fasted for 12 hours. The next morning, blood was collected from the wing vein into 10 mL non-anticoagulant vacuum tubes. The blood was allowed to rest at room temperature for 30 minutes, then centrifuged (3500 rpm) to separate the serum and stored at −80°C for further analysis. After blood collection, the hens were euthanized by cervical dislocation and exsanguination. The abdominal cavity was rapidly opened, and the liver, spleen, kidney, and abdominal fat were weighed and photographed for subsequent calculation of organ indices and organ index scores. Portions of liver tissue were quickly frozen in liquid nitrogen and stored at −80°C for further analysis. Oviduct and uterine samples were removed, placed in 2 mL centrifuge tubes, quickly frozen in liquid nitrogen, and stored at −80°C for analysis of antioxidant activity and related gene expression. Liver samples were aliquoted into 5 mL centrifuge tubes, quickly frozen in liquid nitrogen, and stored at −80°C for determination of trace element content in liver tissue. Table 8 shows the test results of the effects of adding HyD or not and the manganese level in the basal diet on the deposition of trace elements in the liver (fresh matter basis, mg / kg).

[0094] Table 8

[0095]

[0096] As shown in Table 8, under the experimental conditions, the addition of HyD significantly reduced the deposition of calcium, iron, copper, and zinc from the fourth week of the experiment (P < 0.05, Table 8). Among them, there was a significant interaction effect between the addition of HyD in the basal diet and the organic manganese level on the deposition of calcium, phosphorus, iron, copper, and manganese in the egg yolks of laying hens in the fourth week. The results showed that in the diet without HyD, the calcium deposition in the group with an organic manganese level of 75 mg / kg (i.e., comparative example 4) was significantly higher than that in the groups with an organic manganese level of 25, 50, and 125 mg / kg; in the diet with HyD, the organic manganese levels of 25 and 50 mg / kg were extremely significantly higher than those in the groups with an organic manganese level of 0, 100, and 125 mg / kg (P < 0.001). The phosphorus interaction was manifested as follows: in the group without HyD supplementation, phosphorus deposition in the groups with organic manganese levels of 0, 75, 100, and 125 mg / kg was significantly higher than in the group with organic manganese levels of 25 and 50 mg / kg; in the group with HyD supplementation, organic manganese levels of 75 mg / kg (i.e., Example 4) were significantly higher than those in the group with organic manganese levels of 0 mg / kg (P < 0.05). The iron interaction was manifested as follows: in the group without HyD supplementation, there was no significant effect between organic manganese levels; in the group with HyD supplementation, iron content was significantly higher in the group with organic manganese levels of 50 mg / kg than in the group with organic manganese levels of 100 mg / kg (P < 0.05). The copper interaction was manifested as follows: in the group without HyD supplementation, copper content was significantly higher in the groups with organic manganese levels of 100 and 125 mg / kg than in the other groups; in the group with HyD supplementation, copper content was significantly higher in the groups with organic manganese levels of 75 and 125 mg / kg than in the other groups (P < 0.05). Manganese interactions were observed in the following ways: the organic manganese content in the 100 mg / kg group was significantly higher than that in the 0, 25, 50, and 75 mg / kg groups when HyD was not added; the organic manganese content in the 75 mg / kg group was significantly higher than that in the 0, 25, and 100 mg / kg groups when HyD was added (P < 0.05). Zinc interactions were observed in the 75 mg / kg group when HyD was not added, with a significantly higher zinc content than that in the 50 and 125 mg / kg groups; and the zinc content in egg yolks in the 50 and 75 mg / kg group when HyD was added was significantly higher than that in the 100 mg / kg group (P < 0.05).

[0097] When HyD was not added to the diet, the copper, manganese and zinc elements in the egg yolk showed linear and quadratic significant changes with increasing doses. The manganese deposition was the highest in the group with an organic manganese level of 100 mg / kg; the zinc deposition was the highest in the group with an organic manganese level of 75 mg / kg. When HyD was added to the diet, the copper, manganese and zinc elements in the egg yolk showed linear and quadratic significant changes with increasing doses, while the phosphorus element showed a quadratic significant change with increasing doses. The phosphorus, copper and manganese deposition was the highest in the group with an organic manganese level of 75 mg / kg; the zinc deposition was the highest when the organic manganese level was 50 mg / kg.

[0098] Table 9 shows the test results of the effects of adding HyD or not and the manganese level in the basal diet on the trace element deposition in egg yolks in the fourth week (dry matter basis, mg / kg).

[0099] Table 9

[0100]

[0101] As shown in Table 9, under the conditions of this experiment, the addition of HyD significantly reduced the deposition of calcium, iron, copper, and zinc from the fourth week of the experiment (P < 0.05, Table 9). This shows that there was a significant interaction effect between the addition of HyD in the basal diet and the organic manganese level on the deposition of calcium, phosphorus, iron, copper, and manganese in egg yolks of laying hens in the fourth week. In the basal diet without HyD, the calcium deposition in the organic manganese level of 75 mg / kg was significantly higher than that in the organic manganese levels of 25, 50, and 125 mg / kg groups; in the diet with HyD, the organic manganese levels of 25 and 50 mg / kg were extremely significantly higher than those in the organic manganese levels of 0, 100, and 125 mg / kg groups (P < 0.001). A phosphorus interaction was observed: in the HyD-free diet, phosphorus deposition was significantly higher in the organic manganese levels of 0, 75, 100, and 125 mg / kg compared to the organic manganese levels of 25 and 50 mg / kg. In the HyD-supplemented diet, organic manganese levels of 75 mg / kg were significantly higher than those in the 0 mg / kg group (P < 0.05). An iron interaction was observed: in the HyD-free diet, there was no significant effect of organic manganese levels; in the HyD-supplemented diet, iron content was significantly higher in the 50 mg / kg group than in the 100 mg / kg group (P < 0.05). A copper interaction was observed: in the HyD-free diet, organic manganese levels of 100 and 125 mg / kg were significantly higher than in the other groups; in the HyD-supplemented diet, organic manganese levels of 75 and 125 mg / kg were significantly higher than in the other groups (P < 0.05). Manganese interactions were observed in the following ways: the organic manganese content in the 100 mg / kg group was significantly higher than that in the 0, 25, 50, and 75 mg / kg groups when HyD was not added; the organic manganese content in the 75 mg / kg group was significantly higher than that in the 0, 25, and 100 mg / kg groups when HyD was added (P < 0.05). Zinc interactions were observed in the 75 mg / kg group when HyD was not added, with a significantly higher zinc content than that in the 50 and 125 mg / kg groups; and the zinc content in egg yolks in the 50 and 75 mg / kg group when HyD was added was significantly higher than that in the 100 mg / kg group (P < 0.05).

[0102] When HyD was not added to the diet, the copper, manganese and zinc elements in the egg yolk showed linear and quadratic significant changes with the increase in the dose. The manganese deposition was the highest in the group with an organic manganese level of 100 mg / kg; the zinc deposition was the highest in the group with an organic manganese level of 75 mg / kg.

[0103] When HyD was added to the diet, copper, manganese and zinc in egg yolk showed linear and quadratic significant changes with increasing dose, while phosphorus showed quadratic significant changes with increasing dose; the group with an organic manganese level of 75 mg / kg (Example 4) had the highest phosphorus, copper and manganese deposition; when the organic manganese level was 50 mg / kg, zinc deposition was the highest.

[0104] Table 10 shows the test results of the effects of adding HyD or not and the manganese level in the basal diet on the deposition of trace elements in egg yolks in the eighth week (dry matter basis, mg / kg).

[0105] Table 10

[0106]

[0107] As shown in Table 10, under the experimental conditions, supplementation with HyD significantly reduced calcium, phosphorus, and iron accumulation in the eighth week (P < 0.05). Significant interactions between the presence or absence of HyD in the basal diet and the organic manganese level on calcium, phosphorus, iron, and copper accumulation in egg yolks at week eight were observed. For calcium, the 100 mg / kg organic manganese level in the HyD-free diet was significantly higher than the 0, 25, and 50 mg / kg organic manganese levels. For HyD-supplemented diets, the 25 and 75 mg / kg organic manganese levels were significantly higher than the 125 mg / kg organic manganese level (P < 0.05). For phosphorus, the organic manganese level in the HyD-free diet had no significant effect among the different levels. However, the 25 mg / kg organic manganese level in the HyD-supplemented diet was significantly higher than the other groups (P < 0.05). The iron interaction was shown as follows: in the diet without HyD, the iron content of the 50 mg / kg organic manganese group was significantly higher than that of the other groups; in the diet with HyD, the iron content of the 0 mg / kg organic manganese group was significantly higher than that of the other groups (P < 0.05). The copper interaction was shown as follows: in the diet without HyD, the copper content of the 75 and 125 mg / kg organic manganese groups was significantly higher than that of the 0 mg / kg organic manganese group; in the diet with HyD, the copper content of the 0 and 75 mg / kg organic manganese groups was significantly higher than that of the 50, 100, and 125 mg / kg organic manganese groups (P < 0.05).

[0108] When HyD was not added to the diet, the calcium and copper elements in the egg yolks of laying hens in the eighth week showed linear and quadratic significant changes with increasing doses, while the iron element showed linear and quadratic significant changes with increasing doses; the group with an organic manganese level of 100 mg / kg had the highest calcium deposition; the group with an organic manganese level of 50 mg / kg had the highest phosphorus and manganese deposition; the group with an organic manganese level of 125 mg / kg had the highest copper deposition; in the group with HyD added to the diet, the calcium, phosphorus, iron, copper, manganese and zinc elements showed linear and quadratic significant changes with increasing doses; the group with an organic manganese level of 25 mg / kg had the highest calcium and phosphorus deposition; the group with an organic manganese level of 0 mg / kg had the highest iron deposition; and the group with an organic manganese level of 75 mg / kg had the highest copper, manganese and zinc deposition.

[0109] Table 11 shows the test results of the effects of adding HyD or not and the manganese level in the basal diet on the deposition of trace elements in the eggshells of eggs in the fourth week (dry matter basis).

[0110] Table 11

[0111]

[0112] As shown in Table 11, under the experimental conditions, the addition of HyD significantly increased the deposition of manganese and zinc in the fourth week of the experiment (P < 0.001). There was an interactive effect between the addition of HyD to the basal diet and the organic manganese level on the deposition of iron, copper, manganese, and zinc in eggshells of laying hens in the fourth week. The iron interaction was manifested as the iron content of the group without HyD supplementation and the organic manganese level of 0 mg / kg was significantly higher than that of the group with organic manganese level of 125 mg / kg. The iron content of the group with HyD supplementation and the organic manganese level of 125 mg / kg was significantly higher than that of the group with organic manganese level of 100 mg / kg (P < 0.05). The copper interaction was shown as follows: in the diet without HyD, the copper content of the organic manganese level of 0 mg / kg was significantly higher than that of the organic manganese levels of 100 and 125 mg / kg; in the diet with HyD, the copper content of the organic manganese level of 50 mg / kg was significantly higher than that of the organic manganese level of 0 mg / kg (P < 0.05). The manganese interaction was shown as follows: in the diet without HyD, the manganese content of the organic manganese levels of 75 and 100 mg / kg was significantly higher than that of the other groups; in the diet with HyD, the manganese content of the organic manganese levels of 50 and 75 mg / kg was significantly higher than that of the other groups (P < 0.05).

[0113] The zinc element interaction was manifested as follows: when HyD was not added to the diet, the zinc content in the groups with organic manganese levels of 0, 25 and 50 mg / kg was significantly higher than that in other groups; when HyD was added to the diet, the manganese content in the groups with organic manganese level of 75 mg / kg was significantly higher than that in the groups with organic manganese level of 100 and 125 mg / kg (P < 0.05).

[0114] Without adding HyD in the feed, the iron, copper, manganese and zinc elements in the eggshell of the laying hens in the fourth week showed linear and quadratic changes with the increase of the dose; the manganese element content in the groups with organic manganese levels of 75 and 100 mg / kg was significantly higher than that in other groups; the zinc element content in the groups with organic manganese levels of 0, 25 and 50 mg / kg was significantly higher than that in other groups. With the addition of HyD in the feed, the zinc element in the eggshell of the laying hens in the fourth week showed linear and quadratic changes with the increase of the dose, while the deposition of the manganese element in the eggshell showed linear changes with the increase of the dose; the manganese element content in the groups with organic manganese levels of 50 and 75 mg / kg was significantly higher than that in other groups (P<0.05).

[0115] Effects of adding HyD in the basic diet and manganese levels on dark spot eggs of laying hens:

[0116] It should be noted that the traditional dark spot scoring method has three-level scoring, four-level scoring, five-level scoring and six-level scoring. In this test, four-level scoring method is used for comparison and statistics. The dark spot egg selected by the four-level classification method is shown in the following table. Figure 1 As shown in the following table, Figure 1 The schematic diagram of the dark spot egg selected by the four-level classification method of the present application is shown in the following table, wherein, Figure 1 From left to right, they are 1st, 2nd, 3rd and 4th dark spot eggs, which are used as standards to distinguish other levels of dark spots. This method is more refined than the 2nd or 3rd classification standard, and does not increase or decrease much workload. At the same time, since the dark spot level of the eggs stored for 1-2 weeks basically does not change, this standard can be used to distinguish the dark spot eggs produced in multiple days.

[0117] Among them, the dark spot detection test is carried out for nine weeks, but since the number of dark spot level one is small, the number of eggs of dark spot level one and dark spot level two is counted as a group, and the number of eggs of dark spot level three and dark spot level four is counted as a group. Details are shown in Tables 12-15. Table 12 shows the effects of adding HyD in the basic diet and manganese levels on the dark spot egg level of the first week. Table 13 shows the effects of adding HyD in the basic diet and manganese levels on the dark spot egg level of the fourth week. Table 14 shows the effects of adding HyD in the basic diet and manganese levels on the dark spot egg level of the sixth week. Table 15 shows the effects of adding HyD in the basic diet and manganese levels on the dark spot egg level of the ninth week.

[0118] The group with added HyD was named HyD group. For example, in the group without added HyD, the group with manganese concentration of 25 mg / kg was named HyD-25; in the group with added HyD, the group with manganese concentration of 25 mg / kg was named HyD+25. As shown in Table 12, in the first week of the experiment, the number and proportion of eggs with dark spots of level one and level two for HyD-75, HyD+50 and HyD+125 were significantly higher than the number and proportion of eggs with dark spots of level one and level two for HyD+25; the number and proportion of eggs with dark spots of level three and level four were the opposite. It can be seen that adding HyD to the basal diet can reduce the amount of organic manganese added in the feed and effectively reduce the dark spot grade score of eggs.

[0119] Table 12

[0120]

[0121] Table 13

[0122]

[0123] As shown in Table 13, in the fourth week of the experiment, the number and proportion of eggs with dark spots of level 1 and level 2 of HyD+75 were significantly higher than the number and proportion of eggs with dark spots of level 1 and level 2 of HyD-50.

[0124] Table 14

[0125]

[0126] As shown in Table 14, in the sixth week of the experiment, there was no significant difference in the number and proportion of dark-spotted eggs of grade 1 and grade 2 between each group, and there was no significant difference in the number and proportion of dark-spotted eggs of grade 3 and grade 4 between each group. This may be related to the effect and duration of HyD and organic manganese.

[0127] Table 15

[0128]

[0129] As shown in Table 15, in the ninth week of the experiment, there was no significant difference in the number and proportion of dark-spotted eggs of grade 1 and grade 2 between each group, and there was no significant difference in the number and proportion of dark-spotted eggs of grade 3 and grade 4 between each group. This may be related to the effect and duration of HyD and organic manganese.

[0130] As can be seen from this: For dark-spotted eggs, the results of the analysis of dark-spotted eggs from the end of the fifth week, the sixth week, and the seventh week were not significant between the groups. This may be because the low-dose supplementation in the early stage did not meet the body's needs. As time went on, the effect of the high-dose supplement on dark-spotted eggs gradually decreased. From the results of several weeks, it can be seen that the number and proportion of dark-spotted eggs in the HyD+75 group (corresponding to Example 4) were greater, and the effect was better.

[0131] In terms of egg quality, whether HyD is added to the diet and different levels of organic manganese have an interactive effect on the improvement of eggshell thickness, eggshell strength and eggshell ratio. In the group without HyD addition, the best effect was achieved when the organic manganese level was 125 mg / kg, but in the group with HyD addition, the best effect was achieved when the organic manganese level was 75 mg / kg (corresponding to Example 4). This shows that adding HyD to the diet can reduce the amount of organic manganese added to the diet. From a microstructural point of view, the addition of HyD and different levels of organic manganese in the diet has a certain effect on reducing the thickness and width of the papilla layer, thereby affecting the strength and thickness of the eggshell.

[0132] In terms of trace element accumulation, dietary HyD supplementation significantly increased phosphorus, manganese, and zinc accumulation (P < 0.05). There was an interactive effect between dietary HyD supplementation and varying levels of organic manganese on calcium, iron, and manganese accumulation in the livers of laying hens. There was also an interactive effect between dietary HyD supplementation and varying levels of organic manganese on calcium, iron, and manganese accumulation in the livers of laying hens. Dietary HyD supplementation facilitated the absorption and utilization of organic manganese, reducing the amount of organic manganese supplemented. In terms of trace element accumulation in egg yolk, manganese accumulation showed a quadratic correlation with increasing dietary HyD supplementation. Dietary HyD supplementation facilitated the absorption and utilization of organic manganese, reducing the amount of organic manganese supplemented in the diet. In terms of trace element accumulation in eggshell, HyD supplementation significantly increased copper, manganese, and zinc accumulation (P < 0.05). There was an interactive effect between dietary HyD supplementation and varying levels of organic manganese on iron, copper, manganese, and zinc accumulation in eggshells of laying hens in their sixth week (P < 0.05, Table 11). In general, when HyD was added to the diet and the organic manganese level was 75 mg / kg (corresponding to Example 4), the deposition effect of trace elements was the best.

[0133] The combined use of organic manganese and 25-hydroxyvitamin D3 can improve egg quality, eggshell strength, eggshell structure and mineral deposition without negatively affecting the production performance of laying hens, and has a certain effect on reducing the grade of dark-spotted eggs. Among them, the HyD+75 group has the best effect and is the most economical.

[0134] In summary, the present application provides a laying hen feed additive combined with 25-hydroxyvitamin D3 and organic manganese and application thereof, in the present application, the addition of HyD and organic manganese in the diet can reduce the thickness and width of the papillary layer (the papillary layer is denser and the gap is reduced), directly improve the uniformity of eggshell calcification, reduce the formation of dark spots, and by synergistically regulating the structure of the eggshell papillary layer (reducing the thickness and width of the papillary layer and enhancing the density), reducing the eggshell gap and fragile area, significantly improving the eggshell anti-breaking ability. Further improve the uniformity of eggshell calcification, reduce the formation of dark spots caused by abnormal papillary layer, improve the surface smoothness and integrity of the eggshell, and for the abnormal structure of the papillary layer and calcification defects of dark spot eggs, the present application precisely regulates the eggshell formation process through the synergistic mechanism of HyD and organic manganese, significantly improves the eggshell quality; at the same time, the interaction effect and the best addition amount between the components are verified through experiments, and the problems of lack of pertinence, poor component synergy and unspecific effect in the prior art are solved.

[0135] It should be noted that for the foregoing embodiments, in order to simply describe, they are all expressed as a series of action combinations, but those skilled in the art should know that the present application is not limited by the order of the described actions, because according to the present application, certain steps can be performed in other order or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification all belong to preferred embodiments, and the actions and modules involved are not necessarily necessary for the present application.

[0136] The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the protection scope of the application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on these embodiments, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application. Although the present application has been described in detail with reference to the above embodiments, those of ordinary skill in the art can still combine, add or delete the features of the embodiments of the present application according to the circumstances without making creative labor, so as to obtain different other technical solutions which do not deviate from the concept of the present application in essence, and these technical solutions also belong to the scope of the present application.

Claims

1. A laying hen feed additive combined with 25-hydroxyvitamin D3 and organic manganese, characterized in that: The feed additive comprises the following components: organic manganese and hydroxyvitamin D. The feed additive is used to be added to the basic diet of laying hens, and the concentration gradient of the organic manganese added to the basic diet is 0-125 ppm, and the content of the hydroxyvitamin D added to the basic diet is 50-100 μg / kg; Among them, the basic daily diet includes the following raw materials in parts by weight: 60-65 parts of corn, 20-26 parts of soybean meal, 0.2-1 parts of soybean oil, 5-10 parts of coarse stone powder, 0.1-1 parts of premix, and 0.01-0.05 parts of carrier.

2. The laying hen feed additive combined with 25-hydroxyvitamin D3 and organic manganese according to claim 1, characterized in that: The basic diet includes the following raw materials in parts by weight: 61-64 parts of corn, 22-24 parts of soybean meal, 0.3-0.9 parts of soybean oil, 4-9 parts of coarse stone powder, 0.2-0.8 parts of premix, and 0.02-0.04 parts of carrier.

3. The laying hen feed additive combined with 25-hydroxyvitamin D3 and organic manganese according to claim 2, characterized in that: The basic diet includes the following raw materials in parts by weight: 62.5 parts of corn, 24.5 parts of soybean meal, 0.5 parts of soybean oil, 8.5 parts of coarse stone powder, 0.38 parts of premix, and 0.02 parts of carrier.

4. The laying hen feed additive combined with 25-hydroxyvitamin D3 and organic manganese according to claim 2, characterized in that: The premix comprises the following components: rice husk powder, zeolite powder, calcium hydrogen phosphate, stone powder, sodium chloride, methionine, lysine, multivitamins, phytic acid, choline and baking soda.

5. The laying hen feed additive combined with 25-hydroxyvitamin D3 and organic manganese according to claim 1, characterized in that: The concentration gradients of organic manganese added to the basic diet are 0, 25, 50, 75, 100, and 125 ppm respectively.

6. The laying hen feed additive combined with 25-hydroxyvitamin D3 and organic manganese according to claim 5, characterized in that: The content of hydroxyvitamin D added to the basic diet was 69μg / Kg.

7. The laying hen feed additive combined with 25-hydroxyvitamin D3 and organic manganese according to claim 6, characterized in that: The hydroxyvitamin D is 25-hydroxyvitamin D3.

8. Use of the laying hen feed additive combined with 25-hydroxyvitamin D3 and organic manganese according to any one of claims 1 to 7 in improving the eggshell color and quality of laying hens.

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