A compound feed additive for improving egg quality, its preparation method and application

Abstract

A compound feed additive for improving egg quality, its preparation method, and its application are disclosed. The raw materials of the compound feed additive are composed of the following by weight percentage: 65-75% three-stage temperature-controlled fermented mulberry leaf powder, 8-12% compound probiotic microcapsule preparation, and 15-25% functional carrier. 5-8% of the compound feed additive prepared according to this invention is added to the basal diet of laying hens and fed continuously for 42-56 days. The three-stage temperature-controlled fermentation of this invention reduces the tannin content in mulberry leaves from 7.2 mg / g to below 4.7 mg / g, with a degradation rate ≥30%. The low tannin content improves feed palatability and effectively solves the problem of decreased feed intake caused by high-dose mulberry leaf addition.

Description

Technical Field

[0001] This invention belongs to the field of livestock and poultry feed additive technology, specifically relating to a compound feed additive that improves egg quality and antioxidant function, and its preparation method. Background Technology

[0002] As people's living standards improve, the requirements for egg quality are becoming increasingly stringent. Not only are eggs required to be nutritionally complete, but also to have vibrant yolk color, good taste, low cholesterol content, and be safe and residue-free. Currently, synthetic pigments (such as canthaxanthin and canthaxanthin yellow) are commonly used in egg-laying hen farming to improve yolk color, and antibiotics are used to prevent disease. However, the long-term use of synthetic pigments and antibiotics poses food safety risks and is inconsistent with the development direction of green and healthy farming.

[0003] Mulberry leaves ( White mulberry Mulberry leaves (L.) are a traditional plant used for both food and medicine, rich in protein (15-35%), flavonoids, polysaccharides, alkaloids, and other nutrients and bioactive substances. Studies have shown that mulberry leaves have multiple functions, including antioxidation, lowering blood sugar, lowering blood lipids, and enhancing immunity. However, mulberry leaves contain a certain amount of anti-nutritional factors such as tannins and phytic acid; the tannin content can reach 5-8 mg / g, and direct high-dose addition may affect the feed intake and production performance of laying hens.

[0004] Existing technologies have reported the direct addition of mulberry leaf powder to laying hen feed (e.g., Al-Kirshi et al., 2010; Zhang et al., 2009), but high-dose addition, such as ≥15%, can lead to a decrease in egg production. To address this issue, some studies have attempted to ferment mulberry leaves. Chinese patent CN107568415A discloses a fermented mulberry leaf feed and its preparation method, using Bacillus subtilis and Lactobacillus plantarum for fermentation. Chinese patent CN121220630A discloses a feed additive composed of mulberry leaf powder and Bacillus licheniformis.

[0005] However, the existing technology still has the following technical problems: 1. Insufficient degradation of anti-nutritional factors: Conventional fermentation methods typically degrade tannins in mulberry leaves by less than 30%, and residual tannins still affect palatability and protein utilization.

[0006] 2. Low utilization rate of active ingredients: The cell wall structure of mulberry leaves is dense, and conventional pulverization makes it difficult to fully release intracellular active ingredients, such as flavonoids and polysaccharides.

[0007] 3. Low survival rate of probiotics: In ordinary mixing processes, the survival rate of probiotics is low in feed processing, storage and gastric acid environment, which affects product stability.

[0008] 4. Limited functionality: Existing products mainly focus on production performance and egg quality, with limited effects on improving antioxidant and immune functions. Summary of the Invention

[0009] To address the technical problems of insufficient degradation of anti-nutritional factors, low utilization rate of active ingredients, low survival rate of probiotics, and limited functionality in existing technologies, this invention provides a compound feed additive that significantly reduces the content of anti-nutritional factors through three-stage temperature-controlled fermentation, improves the release rate of active ingredients through freeze-drying and ultra-fine grinding, and enhances the stability of probiotics through microencapsulation, thereby achieving a synergistic improvement in egg quality, antioxidant capacity, and immune function.

[0010] The technical solution adopted in this invention is a compound feed additive for improving the quality of eggs, wherein the raw materials are composed of the following by mass percentage: Three-stage temperature-controlled fermentation of mulberry leaf powder: 65~75% Compound probiotic microcapsule formulation: 8~12% Functional carrier: 15~25% The three-stage temperature-controlled fermented mulberry leaf powder is prepared by inoculating mulberry leaf powder with Bacillus subtilis, Bacillus licheniformis and Bacillus megaterium in a mass ratio of 2:(0.8~1.2):(0.8~1.2). The aforementioned compound probiotic microcapsule formulation is prepared by microencapsulation of a mixture of Bacillus subtilis, Bacillus licheniformis, and Bacillus megaterium, with an effective viable count ≥1.0 × 10⁻⁶. 10 CFU / g; The functional carrier is ultrafine corn cob powder with a particle size D50≤50μm.

[0011] Furthermore, the compound feed additive is composed of the following raw materials by mass percentage: Three-stage temperature-controlled fermented mulberry leaf powder: 70% Compound probiotic microcapsule formulation: 10% Functional carrier: 20%.

[0012] The total flavonoid content of the three-stage temperature-controlled fermented mulberry leaf powder is ≥50 mg / g, the total polysaccharide content is ≥35 mg / g, and the tannin content is ≤4.7 mg / g.

[0013] This invention also relates to a method for preparing a compound feed additive, the method comprising the following steps: S1. Preparation of mulberry leaf powder using a three-stage temperature-controlled fermentation process. S1-1, First stage: Mix mulberry leaf powder with water at a mass ratio of 1:0.6~1:0.8, adjust the pH to 6.2~6.8, inoculate with Bacillus subtilis and Bacillus licheniformis at a total inoculation amount of 0.2~0.4% of the mulberry leaf powder mass, and ferment for 24~36 hours at 30~35℃ and an aeration rate of 0.5~1.0 vvm; S1-2, Second Stage: After the first stage is completed, inoculate with Bacillus megaterium at an inoculation rate of 0.1-0.2% of the mulberry leaf powder mass, and continue fermentation for 12-24 hours at 35-40℃ under static conditions; S1-3, Third Stage: After the second stage is completed, lower the temperature to 25~30℃ and continue fermentation for 12~24 hours; S1-4, after fermentation, is dried at a low temperature of 50~55℃ until the moisture content is ≤8%, then frozen and ultra-finely pulverized at -15~-10℃ for 10~20 minutes, and passed through a 100~200 mesh sieve; S2. Preparation of compound probiotic microcapsule formulations S2-1, Bacillus subtilis, Bacillus licheniformis and Bacillus megater were activated and cultured to the logarithmic growth phase, the fermentation broth was centrifuged to collect the cells, and washed 2-3 times with physiological saline. S2-2, mix the three types of bacteria at a mass ratio of 2:(0.8~1.2):(0.8~1.2), add a protectant, and adjust the bacterial concentration to 1.0×10⁻⁶. 11 CFU / g; S2-3, using sodium alginate 2.5% w / v and chitosan 0.5% w / v as wall materials, was encapsulated by extrusion method to obtain microcapsules with a particle size of 50~100μm; S2-4 is obtained by freeze-drying for 24-30 hours; S3. Preparation of functional carriers Crush the corn cobs to a particle size D50≤50μm; S4. Mixing: Weigh each component obtained in steps S1-S3 by weight percentage, place them in a three-dimensional mixer and mix for 30-45 minutes. The coefficient of variation of the mixing uniformity should be ≤5%. S5. Packaging: Vacuum-packed or nitrogen-filled packaging, stored at 4℃.

[0014] In step S2-2, the protective agent consists of 5% skim milk powder, 3% trehalose, and 1% glycerol.

[0015] The present invention also relates to the application of a compound feed additive for improving the quality of eggs, wherein 5-8% of the compound feed additive is added to the basic diet of laying hens and fed continuously for 42-56 days.

[0016] The compound feed additive is used during the peak egg production period of laying hens, at 26-38 weeks of age.

[0017] The beneficial effects of this invention are: 1. Anti-nutritional factors are fully degraded. The three-stage temperature-controlled fermentation reduces the tannin content in mulberry leaves from 7.2 mg / g to below 4.7 mg / g, with a degradation rate of ≥30%. The low tannin content improves feed palatability and effectively solves the problem of decreased feed intake caused by high doses of mulberry leaves.

[0018] 2. Active ingredients are fully released; freeze-drying reduces the D50 particle size of mulberry leaf powder from 282μm (by conventional grinding) to ≤30μm. This reduced particle size significantly improves the dissolution rate of active ingredients. Probiotic stability is improved, and egg quality is significantly enhanced. Adding 5-8% (ideally 8%) of compound feed additive to the basal diet of laying hens significantly increases egg quality indicators such as yolk color, Haugh units, and PUFA ratio, while significantly reducing yolk cholesterol. Antioxidant capacity and immune function are also significantly improved. Detailed Implementation

[0019] In specific implementation of the present invention, Example 1: Preparation of Compound Feed Additive (1) Preparation of mulberry leaf powder by three-stage temperature-controlled fermentation Take mulberry leaves of the Ji Sang No. 3 variety, dry them, pulverize them, and pass them through a 40-mesh sieve to obtain mulberry leaf powder. Take 100 kg of mulberry leaf powder, add 70 kg of water, mix well, and adjust the pH to 6.5.

[0020] First stage: Inoculate 0.15 kg each of Bacillus subtilis and Bacillus licheniformis, and ferment for 30 hours at 32℃ and an aeration rate of 0.8 vvm.

[0021] Second stage: Inoculate with 0.15 kg of Bacillus megaterium and ferment at 38°C under static conditions for 18 hours.

[0022] Third stage: Cool down to 28℃ and continue fermentation for 18 hours.

[0023] After fermentation, the powder was dried at 52℃ to a moisture content of 7.5%. It was then pulverized for 15 minutes at -15℃ using a vibrating cryogenic ultrafine pulverizer and passed through a 150-mesh sieve to obtain ultrafine powder with a D50=26.5μm.

[0024] Tests showed that the total flavonoids were 52.3 mg / g, the total polysaccharides were 34.8 mg / g, and the tannins were 4.7 mg / g, which was 34.7% lower than the 7.2 mg / kg of unfermented mulberry leaf powder.

[0025] (2) Preparation of compound probiotic microcapsule formulation Bacillus subtilis, Bacillus licheniformis, and Bacillus megaterium were activated and cultured to the logarithmic growth phase. The fermentation broth was centrifuged at 8000 rpm for 10 minutes, and the cells were collected and washed three times with physiological saline.

[0026] The three bacterial cultures were mixed in a mass ratio of 2:1:1, and a preservative was added, consisting of 5% skim milk powder, 3% trehalose, and 1% glycerol, to adjust the bacterial concentration to 1.0 × 10⁻⁶. 11 CFU / g.

[0027] Sodium alginate (2.5% w / v) and chitosan (0.5% w / v) were used as wall materials. The bacterial suspension was mixed with sodium alginate solution and extruded dropwise through 0.5 mm pores into a 2% calcium chloride solution to form gel beads, which were then cured for 30 minutes. The beads were then transferred to a 0.5% chitosan solution for coating and left for 30 minutes. Finally, the mixture was freeze-dried for 28 hours.

[0028] The prepared microcapsules had a particle size of 50-100 μm and an effective viable bacteria count of 1.2 × 10⁻⁶. 10 CFU / g.

[0029] (3) Preparation of functional carriers The corn cobs were crushed and passed through a 300-mesh sieve to obtain ultrafine corn cob powder with a D50 of 48μm.

[0030] (4) Preparation of compound feed additives Weigh 70 kg of three-stage temperature-controlled fermented mulberry leaf powder, 10 kg of compound probiotic microcapsule preparation, and 20 kg of functional carrier, and mix them in a three-dimensional mixer for 40 minutes. The coefficient of variation of the mixing uniformity was found to be 4.2%. Vacuum packaged and stored at 4℃.

[0031] Example 2: Application of compound feed additives in laying hen feed Experimental Design Three hundred healthy 26-week-old Hy-Line Brown laying hens were randomly divided into 6 groups, with 5 replicates per group and 10 hens per replicate. The experimental groups are as follows: The pre-trial period was 7 days, and the formal trial period was 56 days. The basal diet was a corn-soybean meal diet, formulated according to the NRC (1994) nutritional requirements for laying hens.

[0032] result 1. Production performance Note: Different letters in the same column indicate significant differences, P<0.05.

[0033] The results showed that the group with 8% compound additive had the highest egg production rate of 92.8% and the lowest feed conversion ratio of 1.99, which was 4.7% higher than the control group and 7.4% lower than the control group.

[0034] 2. Egg quality Note: Different uppercase letters in the same column indicate extremely significant differences (P<0.01), and different lowercase letters indicate significant differences (P<0.05).

[0035] The egg yolk color of the 8% compound additive group reached 10.1, which was 34.7% higher than that of the control group; the Haugh unit reached 92.5, which was 20.6% higher than that of the control group.

[0036] 3. Composition of cholesterol and fatty acids in egg yolks Compared with the control group, the 8% compound additive group had 13.0% lower cholesterol in egg yolks, 23.4% higher PUFA ratio, and 30.7% higher DHA content.

[0037] 4. Serum antioxidant markers Compared with the control group, the 8% compound additive group showed a 73.4% increase in T-AOC, a 35.1% increase in SOD, and a 43.8% decrease in MDA.

[0038] 5. Serum immune markers Compared with the control group, the 8% compound additive group showed a 23.5% increase in IgG and a 34.1% increase in IL-4.

[0039] The above experiments demonstrate that the compound feed additive prepared using this invention uses readily available and inexpensive raw materials. The three-stage temperature-controlled fermentation, freeze-drying ultrafine grinding, and microencapsulation processes can all be implemented on existing feed production lines, requiring moderate equipment investment. Microencapsulation technology and vacuum packaging ensure stable product quality during a 6-month storage period. Adding 5-8% to laying hen feed can significantly improve egg quality, lower cholesterol, enhance antioxidant and immune functions, and completely replace synthetic pigments.

Claims

1. A compound feed additive for improving the quality of eggs, characterized in that: The raw materials are composed of the following by weight percentage: Three-stage temperature-controlled fermentation of mulberry leaf powder: 65~75% Compound probiotic microcapsule formulation: 8~12% Functional carrier: 15~25% The three-stage temperature-controlled fermented mulberry leaf powder is prepared by inoculating mulberry leaf powder with Bacillus subtilis, Bacillus licheniformis and Bacillus megaterium in a mass ratio of 2:(0.8~1.2):(0.8~1.2). The composite probiotic microcapsule preparation is prepared by microcapsule embedding treatment of mixed bacteria bodies of Bacillus subtilis, Bacillus licheniformis and Bacillus megaterium, and the effective viable bacterial count is ≥1.0×10 10 CFU / g. The functional carrier is ultrafine corn cob powder with a particle size D50≤50μm.

2. The compound feed additive for improving egg quality according to claim 1, characterized in that: The raw materials are composed of the following by weight percentage: Three-stage temperature-controlled fermented mulberry leaf powder: 70% Compound probiotic microcapsule formulation: 10% Functional carrier: 20%.

3. A compound feed additive for improving egg quality according to claim 1 or 2, characterized in that: The total flavonoid content of the three-stage temperature-controlled fermented mulberry leaf powder is ≥50 mg / g, the total polysaccharide content is ≥35 mg / g, and the tannin content is ≤4.7 mg / g.

4. A method for preparing the compound feed additive as described in claim 1, characterized in that: The preparation method comprises the following steps: S1. Preparation of mulberry leaf powder using a three-stage temperature-controlled fermentation process. S1-1, First stage: Mix mulberry leaf powder with water at a mass ratio of 1:0.6~1:0.8, adjust the pH to 6.2~6.8, inoculate with Bacillus subtilis and Bacillus licheniformis at a total inoculation amount of 0.2~0.4% of the mulberry leaf powder mass, and ferment for 24~36 hours at 30~35℃ and an aeration rate of 0.5~1.0 vvm; S1-2, Second Stage: After the first stage is completed, inoculate with Bacillus megaterium at an inoculation rate of 0.1-0.2% of the mulberry leaf powder mass, and continue fermentation for 12-24 hours at 35-40℃ under static conditions; S1-3, Third Stage: After the second stage is completed, lower the temperature to 25~30℃ and continue fermentation for 12~24 hours; S1-4, after fermentation, is dried at a low temperature of 50~55℃ until the moisture content is ≤8%, then frozen and ultra-finely pulverized at -15~-10℃ for 10~20 minutes, and passed through a 100~200 mesh sieve; S2. Preparation of compound probiotic microcapsule formulations S2-1, Bacillus subtilis, Bacillus licheniformis and Bacillus megater were activated and cultured to the logarithmic growth phase, the fermentation broth was centrifuged to collect the cells, and washed 2-3 times with physiological saline. S2-2, mix the three types of bacteria at a mass ratio of 2:(0.8~1.2):(0.8~1.2), add a protectant, and adjust the bacterial concentration to 1.0×10⁻⁶. 11 CFU / g; S2-3, using sodium alginate 2.5% w / v and chitosan 0.5% w / v as wall materials, was encapsulated by extrusion method to obtain microcapsules with a particle size of 50~100μm; S2-4 is obtained by freeze-drying for 24-30 hours; S3. Preparation of functional carriers Crush the corn cobs to a particle size D50≤50μm; S4. Mixing: Weigh each component obtained in steps S1-S3 by weight percentage, place them in a three-dimensional mixer and mix for 30-45 minutes. The coefficient of variation of the mixing uniformity should be ≤5%. S5. Packaging: Vacuum-packed or nitrogen-filled packaging, stored at 4℃.

5. The method for preparing the compound feed additive according to claim 4, characterized in that: In step S2-2, the protective agent consists of 5% skim milk powder, 3% trehalose, and 1% glycerol.

6. The application of a compound feed additive for improving egg quality, characterized in that: Add 5-8% compound feed additive to the basic diet of laying hens and feed continuously for 42-56 days.

7. The application according to claim 6, characterized in that: The compound feed additive is used during the peak egg production period of laying hens, at 26-38 weeks of age.

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