Fermented laying duck feed additive as well as preparation method and application thereof

Abstract

The invention relates to a fermentation type laying duck feed additive and a preparation method and application thereof, the preparation method comprises the following steps: mixing a fermentation substrate with a compound bacteria solution, and carrying out anaerobic fermentation to obtain the fermentation type laying duck feed additive, the fermentation substrate comprises brown rice, rice bran, sunflower meal, manioc waste and corn flour; the compound bacteria comprise bacillus licheniformis, lactobacillus bulgaricus and lactobacillus acidophilus. The laying duck feed additive is obtained by fermenting a substrate with a specific formula through specific compound bacteria, compared with the prior art, the phytic acid content and the crude fiber content are obviously reduced, and the crude protein content and the lactic acid content are obviously improved; after the laying ducks eat the feed, the immunity and disease resistance of the laying ducks can be obviously improved, and meanwhile the quality of duck eggs is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of poultry feed, and relates to a fermented laying duck feed additive and a preparation method and application thereof. Background Art

[0002] As people's demand for duck food increases, duck farming has developed rapidly, and the demand for ducklings has surged, which has put higher requirements on the production capacity of laying ducks and the quality of eggshells. In order to improve the immunity of ducks, antibiotics are often added to feed, but long-term use of antibiotics will inhibit the normal function of immune cells in livestock and poultry, reduce disease resistance, and cause antibiotics to accumulate in agricultural and livestock products, bringing more harm to humans. Therefore, it is imperative to find new functional additives that can replace antibiotics.

[0003] At the same time, the existing laying duck feed raw materials are overly dependent on corn and soybean meal, so it is necessary to develop more laying duck feed that can replace traditional corn and soybean meal feed. Summary of the invention

[0004] In view of the deficiencies in the prior art, the object of the present invention is to provide a fermented laying duck feed additive and a preparation method and application thereof.

[0005] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a method for preparing a fermented laying duck feed additive, the preparation method comprising the following steps:

[0007] The fermentation substrate is mixed with the composite bacterial liquid, and anaerobic fermentation is performed to obtain a fermented laying duck feed additive;

[0008] The fermentation substrate includes brown rice, rice bran, sunflower meal, cassava residue and corn flour;

[0009] The composite bacteria include Bacillus licheniformis, Lactobacillus bulgaricus and Lactobacillus acidophilus.

[0010] The present invention creatively develops a new feed additive for laying ducks, which is obtained by fermenting a fermentation substrate of a specific formula with a specific composite bacteria. Compared with before fermentation, the phytic acid and crude fiber contents are significantly reduced, and the crude protein and lactic acid contents are significantly increased. When the feed additive is added to the basic feed, the immunity and disease resistance of the laying ducks can be significantly improved after the laying ducks eat it, and the quality of the duck eggs can be improved, specifically by improving the protein quality, eggshell strength and eggshell thickness of the duck eggs.

[0011] Preferably, the fermentation substrate comprises, by weight, 3-5 parts of brown rice, 1-2 parts of rice bran, 1-2 parts of sunflower meal, 1-2 parts of cassava residue and 0.5-1 part of corn flour.

[0012] When the fermentation substrates are combined in the above-mentioned specific mass ratio, the prepared feed additive has better effects in improving the immune ability of laying ducks and improving the quality of duck eggs.

[0013] The number of portions of brown rice can be selected from 3 portions, 3.5 portions, 4 portions, 4.5 portions, 5 portions, etc.; the number of portions of sunflower meal can be selected from 1 portion, 1.2 portions, 1.5 portions, 1.8 portions, 2 portions, etc.; the number of portions of rice bran can be selected from 1 portion, 1.2 portions, 1.5 portions, 1.8 portions, 2 portions, etc.; the number of portions of cassava residue can be selected from 1 portion, 1.2 portions, 1.5 portions, 1.8 portions, 2 portions, etc.; the number of portions of corn flour can be selected from 0.5 portions, 0.7 portions, 0.8 portions, 0.9 portions, 1 portion, etc.; other specific point values ​​within the above numerical ranges can be selected, and for the sake of brevity, they will not be elaborated here one by one.

[0014] Preferably, the fermentation substrate is crushed before fermentation.

[0015] Preferably, the total viable count of the composite bacterial solution is not less than 5×10 5 CFU / mL, for example 5×10 5 CFU / mL, 1×10 6 CFU / mL, 5×10 6 CFU / mL, 1×10 7 CFU / mL, 5×10 7 CFU / mL, 1×10 8 CFU / mL, 5×10 8 CFU / mL, 1×10 9 CFU / mL, etc. Other specific point values ​​within this numerical range can be selected. For the sake of brevity, they will not be described here one by one.

[0016] Preferably, the ratio of the viable counts of Bacillus licheniformis, Lactobacillus bulgaricus and Lactobacillus acidophilus is (1-3):(1-3):1, for example 1:1:1, 2:1:1, 3:1:1, 1:2:1, 2:2:1, 3:2:1, 1:3:1, 2:3:1, 3:3:1, etc. Other specific point values ​​within this numerical range can be selected. For the sake of brevity, they will not be described one by one here.

[0017] When the three fermentation bacteria in the composite bacteria are in the above-mentioned specific live bacteria ratio, the prepared feed additive has better effects in improving the immunity of laying ducks and the quality of duck eggs.

[0018] Preferably, the ratio of the fermentation substrate to the composite bacterial liquid is 1g:(0.01-0.02)mL, for example, 1g:0.01mL, 1g:0.012mL, 1g:0.014mL, 1g:0.015mL, 1g:0.017mL, 1g:0.2mL, etc. Other specific point values ​​within this numerical range can be selected. For the sake of brevity, they will not be described one by one here.

[0019] Preferably, the mixing further comprises mixing with sugar water.

[0020] Furthermore, the present invention also found that by adding additional sugar water to the fermentation system, the fermentation effect can be significantly improved, and the prepared feed additive is more effective in improving the immunity of laying ducks and improving the quality of duck eggs.

[0021] Preferably, the mass ratio of water to sugar in the sugar water is (35-45):1, for example, 35:1, 36:1, 38:1, 40:1, 41:1, 42:1, 43:1, 45:1, etc.

[0022] Preferably, the ratio of the fermentation substrate to sugar water is 1g:(0.1-0.5)mL, for example, 1g:0.1mL, 1g:0.2mL, 1g:0.3mL, 1g:0.4mL, 1g:0.5mL, etc.

[0023] Other specific point values ​​within the above numerical range can be selected, and for the sake of brevity, they will not be described here one by one.

[0024] Preferably, the sugar water is a glucose aqueous solution and / or a fructose aqueous solution, more preferably a combination of a glucose aqueous solution and a fructose aqueous solution.

[0025] Furthermore, the present invention also found that when the added sugar water uses a combination of a glucose aqueous solution and a fructose aqueous solution, the fermentation effect is better than that of a single type of sugar water.

[0026] Preferably, the anaerobic fermentation comprises: first fermenting at 37-42°C (e.g., 37°C, 38°C, 39°C, 40°C, 41°C, 42°C, etc.) for 3-7 days (e.g., 3 days, 4 days, 5 days, 6 days or 7 days), and then fermenting at 32-37°C (e.g., 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, etc.) for 8-12 days (e.g., 8 days, 9 days, 10 days, 11 days or 12 days). Other specific point values ​​within the above numerical range can be selected, and for the sake of brevity, they will not be repeated here one by one.

[0027] In the fermentation process involved in the preparation method of the present invention, a double-stage fermentation method is adopted. Under the condition of the same fermentation time, the double-stage fermentation is significantly more effective than the single-stage fermentation in improving the immunity of laying ducks and the quality of duck eggs.

[0028] In a second aspect, the present invention provides a fermented laying duck feed additive prepared according to the preparation method described in the first aspect.

[0029] In a third aspect, the present invention provides a laying duck feed, wherein the components of the laying duck feed include a basic laying duck feed and the fermented laying duck feed additive according to the second aspect.

[0030] Preferably, the mass percentage of the fermented egg-laying duck feed additive in the feed is 1-10%, for example 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc. Other specific point values ​​within this numerical range can be selected. For the sake of brevity, they will not be described one by one here.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The present invention creatively develops a new feed additive for laying ducks, which is obtained by fermenting a fermentation substrate of a specific formula with a specific composite bacteria. Compared with before fermentation, the phytic acid and crude fiber contents are significantly reduced, and the crude protein and lactic acid contents are significantly increased. When the feed additive is added to the basic feed, the immunity and disease resistance of the laying ducks can be significantly improved after the laying ducks eat it, and the quality of the duck eggs can be improved, specifically by improving the protein quality, eggshell strength and eggshell thickness of the duck eggs. DETAILED DESCRIPTION

[0033] In order to further explain the technical means and effects adopted by the present invention, the technical solution of the present invention is further described below in conjunction with the preferred embodiments of the present invention, but the present invention is not limited to the scope of the embodiments.

[0034] The Bacillus licheniformis, Lactobacillus bulgaricus and Lactobacillus acidophilus mentioned below are commercially available strains ATCC11091, ATCC11842 and ATCC314, respectively.

[0035] Example 1

[0036] This embodiment provides a fermented laying duck feed additive, and the preparation method thereof is as follows:

[0037] (1) 4 parts of brown rice, 2 parts of rice bran, 1 part of sunflower meal, 2 parts of cassava residue, and 0.5 parts of corn flour are crushed and mixed as a fermentation substrate for later use.

[0038] (2) Inoculate Bacillus licheniformis, Lactobacillus bulgaricus and Lactobacillus acidophilus strains into MRS liquid culture medium respectively, culture them at 37° C. for 18 h for activation, and activate them twice continuously to obtain activation liquid; inoculate the activation liquid into MRS liquid culture medium at an inoculum amount of 5% (v / v), culture them at 37° C. to obtain Bacillus licheniformis fermentation liquid, Lactobacillus bulgaricus fermentation liquid, and Lactobacillus acidophilus fermentation liquid; and dilute and mix them as needed.

[0039] (3) Preparation of composite bacterial solution: The total number of viable bacteria in the composite bacterial solution is 5×10 6 CFU / mL, and the ratio of the viable counts of Bacillus licheniformis, Lactobacillus bulgaricus and Lactobacillus acidophilus was 2:2:1.

[0040] (4) The fermentation substrate and the composite bacterial liquid are mixed in a ratio of 1 g:0.02 mL, stirred and mixed, and then put into a plastic barrel and compacted, sealed with plastic wrap, fermented at 39° C. for 5 days, and then fermented at 35° C. for 9 days to obtain the fermented laying duck feed additive.

[0041] Example 2

[0042] This embodiment provides a fermented laying duck feed additive, and the preparation method thereof is as follows:

[0043] (1) 5 parts of brown rice, 1 part of rice bran, 2 parts of sunflower meal, 1 part of cassava residue, and 0.5 parts of corn flour are crushed and mixed as a fermentation substrate for later use.

[0044] (2) Inoculate Bacillus licheniformis, Lactobacillus bulgaricus and Lactobacillus acidophilus strains into MRS liquid culture medium respectively, culture them at 37° C. for 18 h for activation, and activate them twice continuously to obtain activation liquid; inoculate the activation liquid into MRS liquid culture medium at an inoculum amount of 5% (v / v), culture them at 37° C. to obtain Bacillus licheniformis fermentation liquid, Lactobacillus bulgaricus fermentation liquid, and Lactobacillus acidophilus fermentation liquid; and dilute and mix them as needed.

[0045] (3) Preparation of composite bacterial solution: The total number of viable bacteria in the composite bacterial solution is 1×10 6 CFU / mL, and the ratio of the viable counts of Bacillus licheniformis, Lactobacillus bulgaricus and Lactobacillus acidophilus was 3:1:1.

[0046] (4) The fermentation substrate and the composite bacterial liquid are mixed at a ratio of 1 g:0.01 mL, stirred and mixed, and then put into a plastic barrel and compacted, sealed with plastic wrap, fermented at 41° C. for 3 days, and then fermented at 37° C. for 8 days to obtain the fermented laying duck feed additive.

[0047] Example 3

[0048] This embodiment provides a fermented laying duck feed additive, and the preparation method thereof is as follows:

[0049] (1) 3 parts of brown rice, 2 parts of rice bran, 2 parts of sunflower meal, 1.5 parts of cassava residue and 1 part of corn flour are crushed and mixed as a fermentation substrate for later use.

[0050] (2) Inoculate Bacillus licheniformis, Lactobacillus bulgaricus and Lactobacillus acidophilus strains into MRS liquid culture medium respectively, culture them at 37° C. for 18 h for activation, and activate them twice continuously to obtain activation liquid; inoculate the activation liquid into MRS liquid culture medium at an inoculum amount of 5% (v / v), culture them at 37° C. to obtain Bacillus licheniformis fermentation liquid, Lactobacillus bulgaricus fermentation liquid, and Lactobacillus acidophilus fermentation liquid; and dilute and mix them as needed.

[0051] (3) Preparation of composite bacterial solution: The total number of viable bacteria in the composite bacterial solution is 1×10 6 CFU / mL, and the ratio of the viable counts of Bacillus licheniformis, Lactobacillus bulgaricus and Lactobacillus acidophilus was 1:3:1.

[0052] (4) The fermentation substrate and the composite bacterial liquid are mixed in a ratio of 1 g:0.02 mL, stirred and mixed, and then put into a plastic barrel and compacted, sealed with plastic wrap, fermented at 38° C. for 7 days, and then fermented at 34° C. for 10 days to obtain the fermented laying duck feed additive.

[0053] Example 4

[0054] This embodiment provides a fermented duck feed additive, and the preparation method thereof is different from that of embodiment 1 only in step (4): the fermentation substrate and the composite bacterial solution are mixed at a ratio of 1 g:0.02 mL, and mixed with sugar water (a mixed aqueous solution of equal mass of glucose and fructose, with a water-sugar mass ratio of 40:1 in the mixed solution) at a ratio of 1 g:0.3 mL, stirred and mixed, and then put into a plastic barrel and compacted, sealed with a plastic wrap, fermented at 39° C. for 5 days, and then fermented at 35° C. for 9 days to obtain the fermented duck feed additive. The other steps remain the same.

[0055] Example 5

[0056] This embodiment provides a fermented duck feed additive, and the preparation method thereof is different from that of embodiment 1 only in step (4): mixing the fermentation substrate and the composite bacterial solution at a ratio of 1 g:0.02 mL, and mixing with sugar water (glucose aqueous solution, water-sugar mass ratio of 40:1) at a ratio of 1 g:0.3 mL, stirring and mixing, and then filling into a plastic barrel and compacting, sealing with a plastic wrap, fermenting at 39° C. for 5 days, and then fermenting at 35° C. for 9 days to obtain the fermented duck feed additive. The other steps remain the same.

[0057] Example 6

[0058] This embodiment provides a fermented duck feed additive, and the preparation method thereof is different from that of embodiment 1 only in step (4): the fermentation substrate and the composite bacterial solution are mixed at a ratio of 1 g:0.02 mL, and mixed with sugar water (fructose aqueous solution, the water-sugar mass ratio is 40:1) at a ratio of 1 g:0.3 mL, and after stirring and mixing, the mixture is put into a plastic barrel and compacted, sealed with a plastic wrap, and fermented at 39° C. for 5 days, and then fermented at 35° C. for 9 days to obtain the fermented duck feed additive. The other steps remain the same.

[0059] Example 7

[0060] This embodiment provides a fermented duck feed additive, and the preparation method thereof is different from that of embodiment 1 only in step (4): mixing the fermentation substrate and the composite bacterial solution at a ratio of 1 g:0.02 mL, stirring and mixing, and then filling into a plastic barrel and compacting, sealing with a plastic wrap, and fermenting at 39° C. for 14 days to obtain the fermented duck feed additive. The other steps remain the same.

[0061] Example 8

[0062] This embodiment provides a fermented laying duck feed additive, and the preparation method thereof is different from that of embodiment 1 only in step (4): mixing the fermentation substrate and the composite bacterial solution at a ratio of 1 g:0.02 mL, stirring and mixing, putting into a plastic barrel, compacting, sealing with a plastic wrap, and fermenting at 35° C. for 14 days to obtain the fermented laying duck feed additive. The other steps remain the same.

[0063] Comparative Example 1

[0064] This comparative example provides a fermented duck feed additive. The preparation method thereof is different from that of Example 1 in that in step (2), only Lactobacillus bulgaricus fermentation broth and Lactobacillus acidophilus fermentation broth are prepared, and in step (3), a composite bacterial solution is prepared: the total number of viable bacteria in the composite bacterial solution is 5×10 6 CFU / mL, and the ratio of viable counts of Lactobacillus bulgaricus to Lactobacillus acidophilus was 2:1. Other steps remained the same.

[0065] Comparative Example 2

[0066] This comparative example provides a fermented duck feed additive. The preparation method thereof is different from that of Example 1 in that in step (2), only Bacillus licheniformis fermentation broth and Lactobacillus acidophilus fermentation broth are prepared, and in step (3), a composite bacterial solution is prepared: the total number of viable bacteria in the composite bacterial solution is 5×10 6 CFU / mL, and the ratio of the number of viable bacteria of Bacillus licheniformis to that of Lactobacillus acidophilus was 2:1. The other steps remained the same.

[0067] Comparative Example 3

[0068] This comparative example provides a fermented duck feed additive. The preparation method thereof is different from that of Example 1 in that in step (2), only Bacillus licheniformis fermentation liquid and Lactobacillus bulgaricus fermentation liquid are prepared, and in step (3), a composite bacterial liquid is prepared: the total number of viable bacteria in the composite bacterial liquid is 5×10 6 CFU / mL, and the ratio of the number of viable bacteria of Bacillus licheniformis to that of Lactobacillus bulgaricus was 1:1. The other steps remained the same.

[0069] Comparative Example 4

[0070] This comparative example provides a fermented laying duck feed additive, the preparation method of which is different from that of Example 1 only in that brown rice and sawdust are missing in step (1), and the reduced amount thereof is proportionally distributed to the mass of other fermentation raw materials, and the mixture is crushed and mixed as a fermentation substrate for standby use. The other steps remain the same.

[0071] Comparative Example 5

[0072] This comparative example provides a fermented laying duck feed additive, the preparation method of which is different from that of Example 1 only in that in step (1), sunflower meal and cassava residue are missing, and the reduced amount thereof is proportionally distributed to the mass of other fermentation raw materials, crushed and mixed as a fermentation substrate for standby use. The other steps remain the same.

[0073] Test Example 1

[0074] The contents of various nutrients (phytic acid, crude protein, crude fat, crude fiber, lactic acid) of the fermentation substrate of Example 1 before and after fermentation were detected, as shown in Table 1:

[0075] Table 1

[0076] Before fermentation After fermentation Phytic acid content (mg / g) 31.87±1.28 15.53±0.58 Crude protein (g / kg) 115.54±0.78 166.64±1.61 Crude fat (%DW) 4.30±0.09 4.57±0.09 Crude fiber (%DW) 8.64±0.06 6.18±0.06 Lactic acid content (mg / g) 5.63±0.33 34.17±1.41

[0077] It can be seen from the data results in Table 1 that the laying duck feed additive involved in the present invention is obtained by fermenting a fermentation substrate of a specific formula with a specific composite bacteria. Compared with before fermentation, the phytic acid and crude fiber contents in the fermented product are significantly reduced, and the crude protein and lactic acid contents are significantly increased.

[0078] Test Example 2

[0079] 140 laying ducks aged 30 weeks were selected and divided into 14 groups, each group having 10 ducks, and fed according to the conventional breeding process of the farm for 6 weeks. The basic feed ingredients were: 60% corn, 25% soybean meal, 10% bran, and 5% stone powder. Groups 1-13 were fed with 5% of the additives prepared in Examples 1-8 and Comparative Examples 1-5 in the basic feed, and the remaining group was a control group, which was fed with the basic feed.

[0080] After the feeding was completed, the ducks were fasted for 5 h. Serum was collected from each group. Blood was collected from the toe vein and centrifuged at 3600 r / min and 4°C for 10 min to prepare serum. IgA was determined by ELISA. The results are shown in Table 2.

[0081] After the feeding was completed, 10 eggs were randomly selected from each group and the Haugh unit was measured using an automatic egg quality analyzer (the Haugh unit is used to measure the protein content and freshness of duck eggs, the larger the value, the better); the eggshell strength was measured using an eggshell strength analyzer; and the eggshell thickness was measured using an eggshell thickness tester. The results are shown in Table 2.

[0082] Table 2

[0083] Group IgA (mg / mL) Haff Unit <![CDATA[Eggshell strength (kg / cm 2 )]]> Eggshell thickness (mm) Control group 1.57 67.4 3.11 0.27 Example 1 2.03 81.9 3.87 0.38 Example 2 1.91 80.3 3.90 0.40 Example 3 1.99 81.6 3.85 0.38 Example 4 2.18 86.2 3.98 0.42 Example 5 2.11 85.7 3.91 0.39 Example 6 2.09 83.3 3.88 0.38 Example 7 1.87 78.1 3.67 0.35 Example 8 1.84 80.4 3.73 0.36 Comparative Example 1 1.68 71.6 3.39 0.32 Comparative Example 2 1.72 75.7 3.52 0.35 Comparative Example 3 1.70 74.3 3.44 0.35 Comparative Example 4 1.63 72.0 3.36 0.34 Comparative Example 5 1.75 71.5 3.42 0.31

[0084] It can be seen from the data results in Table 2 that the fermented laying duck feed additive involved in the present invention is added to the basic feed, which can significantly improve the immunity and disease resistance of laying ducks after feeding, and at the same time improve the quality of duck eggs, specifically by improving the protein quality, eggshell strength and eggshell thickness of duck eggs.

[0085] The applicant declares that the present invention illustrates the technical solution of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0086] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0087] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A method for preparing a fermented laying duck feed additive, characterized in that: The preparation method comprises the following steps: The fermentation substrate is mixed with the composite bacterial liquid, and anaerobic fermentation is performed to obtain a fermented laying duck feed additive; The fermentation substrate includes brown rice, rice bran, sunflower meal, cassava residue and corn flour; The composite bacteria include Bacillus licheniformis, Lactobacillus bulgaricus and Lactobacillus acidophilus.

2. The method for preparing a fermented laying duck feed additive according to claim 1, characterized in that: The fermentation substrate comprises, by weight, 3-5 parts of brown rice, 1-2 parts of rice bran, 1-2 parts of sunflower meal, 1-2 parts of cassava residue and 0.5-1 part of corn flour; Preferably, the fermentation substrate is crushed before fermentation.

3. The method for preparing the fermented laying duck feed additive according to claim 1 or 2, characterized in that: The total viable count of the composite bacterial solution is not less than 5×10 5 CFU / mL; Preferably, the ratio of the viable counts of Bacillus licheniformis, Lactobacillus bulgaricus and Lactobacillus acidophilus is (1-3):(1-3):

1.

4. The method for preparing a fermented laying duck feed additive according to any one of claims 1 to 3, characterized in that: The ratio of the fermentation substrate to the composite bacterial solution is 1 g: (0.01-0.02) mL.

5. The method for preparing a fermented laying duck feed additive according to any one of claims 1 to 4, characterized in that: The mixing also includes mixing with sugar water; Preferably, the water-sugar mass ratio in the sugar water is (35-45):1; Preferably, the ratio of the fermentation substrate to sugar water is 1 g: (0.1-0.5) mL.

6. The method for preparing the fermented laying duck feed additive according to claim 5, characterized in that: The sugar water is a glucose aqueous solution and / or a fructose aqueous solution.

7. The method for preparing a fermented laying duck feed additive according to any one of claims 1 to 6, characterized in that: The anaerobic fermentation comprises: firstly fermenting at 37-42° C. for 3-7 days, and then fermenting at 32-37° C. for 8-12 days.

8. A fermented laying duck feed additive prepared by the preparation method according to any one of claims 1 to 7.

9. A laying duck feed, characterized in that: The components of the laying duck feed include basic laying duck feed and the fermented laying duck feed additive according to claim 8.

10. The laying duck feed according to claim 9, characterized in that: The mass percentage of the fermented laying duck feed additive in the feed is 1-10%.