Forage grass silage additive as well as preparation method and application thereof

Abstract

The invention relates to the technical field of livestock feed, and discloses a forage grass silage additive as well as a preparation method and application thereof. The additive is prepared by compounding a mixed traditional Chinese medicine extract, a mixed bacterial agent and a coating material. The mixed traditional Chinese medicine extract is prepared by extracting and compounding five traditional Chinese medicines, the mixed microbial inoculum comprises three special lactic acid bacteria for silage, and the mixed traditional Chinese medicine extract and the mixed microbial inoculum synergistically exert antibacterial and fermentation-promoting effects. A microcapsule structure is formed through a specific coating process, so that the stability of active ingredients is guaranteed. The additive is suitable for various forage grass such as corn straw and alfalfa, can effectively reduce the pH value of a silage system, increase the lactic acid content, inhibit putrefying bacteria breeding, reduce degradation of nutritional ingredients and remarkably improve the fermentation quality and nutritional value of silage, and is safe and convenient to use.

Description

Technical Field

[0001] This invention relates to the field of livestock feed technology, and in particular to a forage silage additive, its preparation method, and its application. Background Technology

[0002] In the field of livestock feed technology, forage silage is a key technology for ensuring a balanced nutritional supply for ruminants throughout the year. However, traditional silage methods and the application of additives still face many challenges and cannot fully meet the demands of modern animal husbandry for high-quality feed.

[0003] In existing technologies, silage additives often focus on a single function, such as using only lactic acid bacteria agents or chemical preservatives. Single-agent agents are often insufficient to cover the entire silage fermentation process, making it difficult to balance the initial acid production rate with later stability, resulting in an unstable fermentation process susceptible to contamination by other microorganisms. While chemical additives can rapidly lower pH, they may pose a risk of residue and have limited effect on improving feed nutritional value and palatability. Furthermore, some technologies attempt to use plant extracts, but these often lack synergistic effects due to their single composition, significantly reducing their overall efficacy in antibacterial, antioxidant, and lactic acid bacteria proliferation promotion.

[0004] More importantly, existing technologies generally neglect the stability of functional ingredients in complex silage environments. Whether it's live microorganisms or active ingredients from traditional Chinese medicine, their activity is easily diminished by factors such as temperature, pH fluctuations, and microbial competition when added directly without protection, leading to actual application effects far from expectations. These shortcomings ultimately manifest as poor silage quality and excessive degradation of nutrients such as protein, thereby reducing the nutritional value and safety of the feed.

[0005] Therefore, developing a novel composite additive that can synergistically enhance efficiency, maintain stability and high efficiency, and comprehensively improve silage quality has become a pressing technical challenge in this field. Summary of the Invention

[0006] The purpose of this invention is to address the problems of existing silage additives having limited functionality and insufficient synergistic effects, making it difficult to cover the needs of the entire silage cycle. Furthermore, the active ingredients are easily affected by environmental factors, leading to unstable silage fermentation, the growth of harmful bacteria, and excessive degradation of nutrients. Additionally, some additives pose a risk of residue. Therefore, this invention proposes a forage silage additive, its preparation method, and its application.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A forage silage additive is prepared by combining a mixture of traditional Chinese medicine extracts, a mixture of microbial agents, and a coating material. The mixture of traditional Chinese medicine extracts is prepared by extracting and mixing Astragalus membranaceus, hawthorn, Eucommia ulmoides leaves, Morinda officinalis, and Achyranthes bidentata. The mixture of microbial agents is prepared by mixing freeze-dried Lactobacillus bromide powder, freeze-dried Lactobacillus plantarum powder, and freeze-dried Pediococcus lactis powder. The coating material includes sodium alginate, glycerol, chitosan, and CaCl2.

[0008] Five traditional Chinese medicines—Astragalus membranaceus, hawthorn, Eucommia ulmoides leaf, Morinda officinalis, and Achyranthes bidentata—are selected for their synergistic effects in meeting the requirements of silage production. Astragalus membranaceus polysaccharides and saponins possess antioxidant properties, enhancing animal immunity; hawthorn's organic acids rapidly lower pH, promoting lactic acid bacteria colonization; Eucommia ulmoides leaf's chlorogenic acid and flavonoids exhibit strong antibacterial and antioxidant properties, inhibiting putrefactive bacteria; Morinda officinalis polysaccharides provide nutrient substrates for lactic acid bacteria; and Achyranthes bidentata saponins assist in antibacterial activity and promote forage digestion. These five herbs work together to create a comprehensive function of antibacterial, antioxidant, and nutrient absorption promotion, without inhibiting lactic acid bacteria; on the contrary, they enhance bacterial stability.

[0009] Preferably, the preparation method of the mixed traditional Chinese medicine extract includes the following steps: S1: Wash and air-dry Astragalus membranaceus, hawthorn, Eucommia ulmoides leaves, Morinda officinalis and Achyranthes bidentata respectively, place them in a 40-50℃ forced-air drying oven and dry them at a low temperature until the moisture content is ≤8%, then pulverize them with a universal pulverizer and pass them through a standard sieve to obtain 2-5mm of each Chinese herbal medicine granules; S2: Take the above-mentioned Chinese herbal medicine granules, use an ethanol solution with a volume fraction of 60-70% as the extraction solvent, add it to the extraction device at a material-to-liquid ratio of 1:10-15 g / mL, reflux at 50-70℃ for 1-2 hours, repeat the extraction 1-2 times, combine the two extracts, filter through a 200-300 mesh filter cloth, and concentrate under reduced pressure at 40-50℃ and -0.08MPa to -0.1MPa until there is no alcohol odor, thus extracting Astragalus membranaceus extract, Crataegus pinnatifida extract, Eucommia ulmoides leaf extract, Morinda officinalis extract and Achyranthes bidentata extract respectively; S3: Weigh out Astragalus membranaceus extract, Crataegus pinnatifida extract, Eucommia ulmoides leaf extract, Morinda officinalis extract and Achyranthes bidentata extract according to a mass ratio of 1:0.3-0.4:0.7-0.9:0.2-0.4:0.2-0.4, place them in a high-speed mixer, and mix for 15-20 minutes at 25-30℃ and 500-800 rpm to obtain the mixed Chinese herbal extract.

[0010] Preferably, the preparation method of the mixed bacterial agent specifically involves: preparing bacterial strains with a viable count ≥10⁻⁶. 11Freeze-dried *Lactobacillus bruneri* powder, freeze-dried *Lactobacillus plantarum* powder, and freeze-dried *Pediococcus lactis* powder (CFU / g, moisture content ≤5%) were weighed according to the specified mass ratio and placed in a sterile high-speed mixer. The mixture was stirred for 10-15 minutes at 25-30℃ and 500-800 rpm to obtain the mixed microbial agent. Three silage-specific strains—*Lactobacillus bruneri*, *Lactobacillus plantarum*, and *Pediococcus lactis*—were selected, their functions working synergistically to form a fermentation pattern. *Lactobacillus plantarum* ferments rapidly, quickly lowering the pH and establishing an acidic environment in the early stages of silage; *Lactobacillus bruneri* is highly acid-resistant, surviving stably under low pH conditions and inhibiting *Clostridium* by producing acetic acid, ensuring stability in the later stages of silage; *Pediococcus lactis* has excellent aroma production, improving the palatability of the forage. The combined use of these three strains covers the entire silage cycle, avoiding the limitations of single-strain functions.

[0011] Preferably, the mass ratio of the freeze-dried Lactobacillus brunelli powder, freeze-dried Lactobacillus plantarum powder, and freeze-dried Pediococcus lactis powder is 1:0.5-0.7:0.3-0.6.

[0012] Preferably, the mass ratio of the mixed Chinese herbal extract to the mixed microbial agent is 1:1.2-1.4.

[0013] Preferably, the method for preparing the forage silage additive is characterized by comprising the following steps: Step 1: Weigh the mixed bacterial agent and add it to a sodium alginate solution and glycerol with a mass fraction of 1.2-1.5%. Stir at 25-30℃ and 200-400rpm for 15-30 minutes, and then sonicate intermittently at 100-200W for 5-10 minutes to obtain a uniform dispersion. Step 2: Weigh the mixed Chinese herbal extracts, dissolve them in deionized water, stir at 40-60℃ and 300-500rpm for 1-1.5h, filter through 150-200 mesh and cool to 25-30℃ to obtain the coating solution; Step 3: Pour the dispersion into the coating solution and stir at 25-30℃ and 300-400rpm for 1-1.5h. Add 0.6-0.8% CaCl2 solution by mass and continue stirring for 30-45min to obtain a suspension. Step 4: Pour 0.8-1.0% chitosan solution into the suspension and stir at 25-30℃ and 300-400rpm for 1.5-2h. Add 0.6-0.8% CaCl2 solution and crosslink for 30-60min. Then, centrifuge at 2000-3000rpm for 10-20min to collect the precipitate. Wash with deionized water 2-3 times and vacuum dry at 45-65℃ and -0.06MPa to -0.08MPa for 4-6h to obtain the forage silage additive.

[0014] Preferably, in the first step, the volume ratio of the sodium alginate solution to glycerol is 1:0.002-0.005.

[0015] Preferably, in the fourth step, the volume ratio of the chitosan solution to the suspension is 1:0.6-0.8.

[0016] Using the above technical solution, a compound bacterial agent is added to a sodium alginate solution and an appropriate amount of glycerol. The colloidal properties of sodium alginate anionic polysaccharides encapsulate the bacterial cells, while glycerol provides moisturizing protection, enhancing the bacterial cells' resistance to adverse conditions. Combined with room-temperature stirring and intermittent ultrasonic treatment, heat damage to the bacterial cells is avoided, resulting in a uniformly dispersed bacterial agent colloidal solution. Simultaneously, a mixed traditional Chinese medicine extract is dissolved in water to prepare a homogeneous traditional Chinese medicine coating solution. After mixing the bacterial agent colloidal solution and the traditional Chinese medicine coating solution, the traditional Chinese medicine components are fixed through ionic cross-linking between calcium ions and sodium alginate, forming a dual-core structure with "lactic acid bacteria as the core and active traditional Chinese medicine components as the intermediate layer," preventing the loss of core functional components. Then, the electrostatic adsorption between cationic chitosan and anionic sodium alginate is used to construct a dense shell layer outside the dual-core structure, which is further strengthened by secondary calcium ion cross-linking. Finally, through low-temperature vacuum drying and washing purification, a forage silage additive is obtained.

[0017] Preferably, the forage silage additive is used in corn stalks, alfalfa, rye grass, and rice straw.

[0018] Preferably, the method of use is as follows: add 0.1-0.3% of the forage silage additive to the forage at the dry weight, mix evenly, and then seal and ensile for 30-60 days.

[0019] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention enables the mixed Chinese herbal extracts and mixed microbial agents to work synergistically. Lactobacillus plantarum rapidly establishes an acidic environment, while Lactobacillus bryler ensures stable fermentation in the later stages. Combined with the antibacterial and lactic acid bacteria colonization effects of the Chinese herbal ingredients, it can effectively reduce the pH value of the silage system, increase lactic acid accumulation, inhibit the reproduction of putrefactive bacteria, reduce the generation of butyric acid and ammonia nitrogen, avoid spoilage problems during silage, and make the entire fermentation process easier to control.

[0020] 2. The microcapsule structure formed by the specific coating process of this invention can effectively protect the active ingredients of fungi and traditional Chinese medicine, reduce the impact of environmental factors such as temperature and pH fluctuations on their activity, prevent premature loss or failure of functional ingredients, and ensure that the additives continue to play a role throughout the entire silage cycle. Compared with uncoated products, the application effect is more stable.

[0021] 3. The compound formulation of the additive in this invention can reduce excessive protein degradation during silage, significantly improve the retention rate of dry matter and crude protein, while reducing the content of neutral detergent fiber and acid detergent fiber, increasing the content of water-soluble carbohydrates, and optimizing the nutritional structure of the feed. In addition, the aroma-producing effect of *Pediococcus lactis* can also improve feed palatability, making it more suitable for the nutritional needs of ruminants.

[0022] 4. The additive of this invention is prepared using natural Chinese herbal extracts, specialized lactic acid bacteria, and biodegradable coating materials, posing no risk of chemical residues and ensuring safe and reliable use. It is also compatible with various common forages such as corn stalks, alfalfa, rye grass, and rice straw, requiring only a small dosage and being easy to use, thus meeting the silage production needs in different scenarios. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with existing known technologies. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0024] Example 1: I. Preparation of mixed traditional Chinese medicine extracts: S1: Wash and air-dry Astragalus membranaceus, hawthorn, Eucommia ulmoides leaves, Morinda officinalis and Achyranthes bidentata respectively, place them in a 40℃ forced-air drying oven and dry them at a low temperature until the moisture content is 8%, then pulverize them with a universal pulverizer and pass them through a standard sieve to obtain 2mm of each Chinese herbal medicine granules; S2: Take the above-mentioned Chinese herbal medicine granules, use 60% ethanol solution as the extraction solvent, add it to the extraction device at a material-liquid ratio of 1:10 g / mL, reflux at 50℃ for 1 hour, repeat the extraction once, combine the two extracts, filter through a 200-mesh filter cloth, and concentrate under reduced pressure at 40℃ and -0.08MPa until there is no alcohol taste, thus extracting Astragalus membranaceus extract, Crataegus pinnatifida extract, Eucommia ulmoides leaf extract, Morinda officinalis extract and Achyranthes bidentata extract respectively; S3: Weigh out Astragalus membranaceus extract, Crataegus pinnatifida extract, Eucommia ulmoides leaf extract, Morinda officinalis extract and Achyranthes bidentata extract in a mass ratio of 1:0.3:0.7:0.2:0.2, place them in a high-speed mixer, and mix for 15 minutes at 25°C and 500 rpm to obtain the mixed Chinese herbal extract.

[0025] II. Preparation of mixed bacterial agent: Take 10 live bacteria per sample. 11 Freeze-dried Lactobacillus bruneri powder, freeze-dried Lactobacillus plantarum powder, and freeze-dried Pediococcus lactis powder (CFU / g, moisture content 5%) were weighed at a mass ratio of 1:0.5:0.3 and placed in a sterile high-speed mixer. The mixture was then mixed at 25°C and 500 rpm for 10 minutes to obtain the mixed bacterial agent.

[0026] III. Preparation of Silage Additives for Forage: Step 1: Weigh 28.8g of mixed bacterial agent and add it to 288mL of 1.2% sodium alginate solution and 0.576mL of glycerol. Stir at 25℃ and 200rpm for 15min, then sonicate intermittently at 100W for 5min to obtain a uniform dispersion. Step 2: Weigh 24g of mixed Chinese herbal extract, dissolve it in 240mL of deionized water, stir at 40℃ and 300rpm for 1h, filter through 150 mesh and cool to 25℃ to obtain the coating solution; Step 3: Pour 180 mL of dispersion into 180 mL of coating solution, stir at 25 °C and 300 rpm for 1 h, add 144 g of 0.6% CaCl2 solution dropwise, and continue stirring for 30 min to obtain a suspension. Step 4: Pour 216 mL of 0.8% chitosan solution into 360 mL of suspension, stir at 25 °C and 300 rpm for 1.5 h, add 43.2 mL of 0.6% CaCl2 solution dropwise, crosslink for 30 min; then centrifuge at 2000 rpm for 10 min to collect the precipitate, wash twice with deionized water, and vacuum dry at 45 °C and -0.06 MPa for 4 h to obtain the forage silage additive.

[0027] Example 2: I. Preparation of mixed traditional Chinese medicine extracts: S1: Wash and air-dry Astragalus membranaceus, hawthorn, Eucommia ulmoides leaves, Morinda officinalis and Achyranthes bidentata respectively, place them in a 45℃ forced-air drying oven and dry them at a low temperature until the moisture content is 8%, then pulverize them with a universal pulverizer and pass them through a standard sieve to obtain 4mm of each Chinese herbal medicine granules. S2: Take the above-mentioned Chinese herbal medicine granules, use 64% ethanol solution as the extraction solvent, add it to the extraction device at a material-to-liquid ratio of 1:12 g / mL, reflux at 60℃ for 1.5 h, repeat the extraction once, combine the two extracts, filter through a 250-mesh filter cloth, and concentrate under reduced pressure at 45℃ and -0.09 MPa until there is no alcohol taste, thus extracting Astragalus membranaceus extract, Crataegus pinnatifida extract, Eucommia ulmoides leaf extract, Morinda officinalis extract and Achyranthes bidentata extract respectively; S3: Weigh out Astragalus membranaceus extract, Crataegus pinnatifida extract, Eucommia ulmoides leaf extract, Morinda officinalis extract and Achyranthes bidentata extract in a mass ratio of 1:0.35:0.8:0.3:0.3, place them in a high-speed mixer, and mix for 18 minutes at 28°C and 600 rpm to obtain the mixed Chinese herbal extract.

[0028] II. Preparation of mixed bacterial agent: Take 10 live bacteria per sample. 11Freeze-dried Lactobacillus bruneri powder, freeze-dried Lactobacillus plantarum powder, and freeze-dried Pediococcus lactis powder (CFU / g, moisture content 5%) were weighed at a mass ratio of 1:0.6:0.4 and placed in a sterile high-speed mixer. The mixture was then mixed at 28°C and 600 rpm for 12 minutes to obtain the mixed bacterial agent.

[0029] III. Preparation of Silage Additives for Forage: Step 1: Weigh 37.75g of mixed bacterial agent and add it to 358mL of 1.4% sodium alginate solution and 1.1mL of glycerol. Stir at 28℃ and 300rpm for 20min, then sonicate intermittently at 180W for 8min to obtain a uniform dispersion. Step 2: Weigh 27.5g of mixed Chinese herbal extract, dissolve it in 330mL of deionized water, stir at 50℃ and 400rpm for 1.2h, filter through 180 mesh and cool to 28℃ to obtain the coating solution; Step 3: Pour 200 mL of dispersion into 200 mL of coating solution, stir at 28 °C and 350 rpm for 1.2 h, add 160 g of 0.7% CaCl2 solution dropwise, and continue stirring for 40 min to obtain a suspension; Step 4: Pour 280 mL of 0.9% chitosan solution into 400 mL of suspension, stir at 28℃ and 350 rpm for 1.8 h, add 56 mL of 0.7% CaCl2 solution dropwise, crosslink for 40 min; then centrifuge at 2500 rpm for 15 min to collect the precipitate, wash twice with deionized water, and vacuum dry at 60℃ and -0.07 MPa for 4-6 h to obtain the forage silage additive.

[0030] Example 3: I. Preparation of mixed traditional Chinese medicine extracts: S1: Wash and air-dry Astragalus membranaceus, hawthorn, Eucommia ulmoides leaves, Morinda officinalis and Achyranthes bidentata respectively, place them in a 50℃ forced-air drying oven and dry them at a low temperature until the moisture content is 8%, then pulverize them with a universal pulverizer and pass them through a standard sieve to obtain 5mm of each Chinese herbal medicine granules. S2: Take the above-mentioned Chinese herbal medicine granules, use 70% ethanol solution as the extraction solvent, add it to the extraction device at a material-liquid ratio of 1:15 g / mL, reflux at 70℃ for 2 hours, repeat the extraction twice, combine the two extracts, filter through a 300-mesh filter cloth, and concentrate under reduced pressure at 50℃ and -0.1MPa until there is no alcohol taste, thus extracting Astragalus membranaceus extract, Crataegus pinnatifida extract, Eucommia ulmoides leaf extract, Morinda officinalis extract and Achyranthes bidentata extract respectively; S3: Weigh out Astragalus membranaceus extract, Crataegus pinnatifida extract, Eucommia ulmoides leaf extract, Morinda officinalis extract and Achyranthes bidentata extract in a mass ratio of 1:0.4:0.9:0.4:0.4, place them in a high-speed mixer, and mix for 20 minutes at 30°C and 800 rpm to obtain the mixed Chinese herbal extract.

[0031] II. Preparation of mixed bacterial agent: Take 10 live bacteria per sample. 11 Freeze-dried Lactobacillus bruneri powder, freeze-dried Lactobacillus plantarum powder, and freeze-dried Pediococcus lactis powder (CFU / g, moisture content 5%) were weighed at a mass ratio of 1:0.7:0.6 and placed in a sterile high-speed mixer. The mixture was then mixed at 30°C and 800 rpm for 15 minutes to obtain the mixed bacterial agent.

[0032] III. Preparation of Silage Additives for Forage: Step 1: Weigh 43.4g of mixed bacterial agent and add it to 434mL of 1.5% sodium alginate solution and 2.2mL of glycerol. Stir at 30℃ and 400rpm for 30min, then sonicate intermittently at 200W for 10min to obtain a uniform dispersion. Step 2: Weigh 31g of mixed Chinese herbal extract, dissolve it in 465mL of deionized water, stir at 60℃ and 500rpm for 1.5h, filter through 200 mesh and cool to 30℃ to obtain the coating solution; Step 3: Pour 250 mL of dispersion into 250 mL of coating solution, stir at 30 °C and 400 rpm for 1.5 h, add 220 g of 0.8% CaCl2 solution dropwise, and continue stirring for 45 min to obtain a suspension. Step 4: Pour 400 mL of 1.0% chitosan solution into 500 mL of suspension, stir at 30℃ and 400 rpm for 2 h, add 80 mL of 0.8% CaCl2 solution dropwise, crosslink for 60 min; then centrifuge at 3000 rpm for 20 min to collect the precipitate, wash three times with deionized water, and vacuum dry at 65℃ and -0.08 MPa for 6 h to obtain the forage silage additive.

[0033] Comparative Example 1: Based on Example 2, the difference is that a single Astragalus extract was used to replace the mixed Chinese herbal extracts, and a forage silage additive was prepared with mixed microbial agents and coating materials. The rest was the same as in Example 2.

[0034] Comparative Example 2: Based on Example 2, the difference is that a single Lactobacillus plantarum powder was used to replace the mixed bacterial agent and mixed Chinese herbal extracts and coating materials to prepare the forage silage additive, and the rest was the same as Example 2.

[0035] Comparative Example 3: Based on Example 2, the difference is that the mixed Chinese herbal extracts were removed, and only the mixed microbial agent and coating material were used to prepare the forage silage additive. The rest is the same as Example 2.

[0036] Comparative Example 4: Based on Example 2, the difference is that the mixed microbial agent was removed, and only the mixed Chinese herbal extract and coating material were used to prepare the forage silage additive. The rest is the same as Example 2.

[0037] Comparative Example 5: Based on Example 2, the difference is that the mixed microbial agent and the mixed Chinese herbal extract are directly mixed and stirred evenly without the coating step to obtain the forage silage additive. The rest is the same as Example 2.

[0038] Comparative Example 6: Based on Example 2, the difference is that the mixed microbial agent is used as a forage silage additive, and the rest is the same as Example 2.

[0039] Comparative Example 7: Based on Example 2, the difference is that the mixed Chinese herbal extracts were used as forage silage additives, and the rest was the same as in Example 2.

[0040] Comparative Example 8: Based on Example 2, the difference is that a single hawthorn extract was used to replace the mixed Chinese herbal medicine extract, and a forage silage additive was prepared with mixed microbial agents and coating materials. The rest is the same as in Example 2.

[0041] Comparative Example 9: Based on Example 2, the difference is that a single Eucommia ulmoides leaf extract was used to replace the mixed Chinese herbal extracts, and a forage silage additive was prepared with mixed microbial agents and coating materials. The rest is the same as in Example 2.

[0042] Comparative Example 10: Based on Example 2, the difference is that a single Morinda officinalis extract was used to replace the mixed Chinese herbal extracts, and a forage silage additive was prepared with mixed microbial agents and coating materials. The rest is the same as in Example 2.

[0043] Comparative Example 11: Based on Example 2, the difference is that a single Achyranthes bidentata extract was used to replace the mixed Chinese herbal extracts, and a forage silage additive was prepared with mixed microbial agents and coating materials. The rest was the same as in Example 2.

[0044] Comparative Example 12: Based on Example 2, the difference is that a single freeze-dried Lactobacillus bromide powder was used to replace the mixed bacterial agent, and a forage silage additive was prepared with mixed Chinese herbal extracts and coating materials. The rest is the same as Example 2.

[0045] Comparative Example 13: Based on Example 2, the difference is that a single freeze-dried Pediococcus lactis powder was used to replace the mixed bacterial agent, and a forage silage additive was prepared with mixed Chinese herbal extracts and coating materials. The rest is the same as in Example 2.

[0046] Comparative Example 14: Based on Example 2, the difference is that the mass ratio of Astragalus membranaceus, Crataegus pinnatifida, Eucommia ulmoides leaf, Morinda officinalis and Achyranthes bidentata extracts in the mixed Chinese herbal extract was changed to 1:0.6:0.5:0.1:0.1, and the rest was the same as in Example 2.

[0047] Comparative Example 15: Based on Example 2, the difference is that the mass ratio of freeze-dried Lactobacillus bruneri, Lactobacillus plantarum, and Pediococcus lactis powder was changed to 1:0.8:0.7, and the rest was the same as in Example 2.

[0048] Comparative Example 16: Based on Example 2, the difference is that the mass ratio of the mixed Chinese herbal extract to the mixed bacterial agent is changed to 1:2, and the rest is the same as Example 2.

[0049] Test example: The forage silage additives prepared in Examples 1-3 and Comparative Examples 1-16 were added at 0.2% of the dry weight of alfalfa, mixed evenly, sealed and ensiled for 50 days to obtain alfalfa silage, and then tested.

[0050] 1. Fermentation quality determination: Take 15g of each group of alfalfa silage, add 135mL of sterile distilled water, place in a sterile centrifuge tube, vortex at 4℃ for 30min, then centrifuge at 8000r / min for 10min, take the supernatant and filter through a 0.45um filter membrane to obtain filtrate, test the pH value of filtrate according to standard GB / T10468-1989; test the organic acid (including lactic acid, acetic acid, and butyric acid) and ammonia nitrogen content of filtrate according to standard DB15 / T1455-2018.

[0051] 2. Nutritional index determination: 100g samples of alfalfa silage from each group were dried in an oven at 110℃ until constant weight, then crushed and sieved to determine the nutritional components; the dry matter content was determined according to standard GB / T6435-2006; the crude protein content was determined according to standard GB / T6432-1994; the neutral detergent fiber and acid detergent fiber content were determined using the Panthen cellulose analysis method, and the soluble carbohydrate content was determined using the anthrone reagent method.

[0052] The control group consisted of alfalfa and water-sealed silage without any silage additives, and the test results are as follows: Table 1. Results of fermentation quality determination of alfalfa silage in the examples and comparative examples.

[0053] Note: "-" indicates that the substance was not detected. Table 2. Results of nutrient index determination of alfalfa silage in the examples and comparative examples.

[0054] Analysis of the data in Tables 1 and 2 shows that the forage silage additives prepared in Examples 1-3, when applied to alfalfa silage, exhibit excellent fermentation quality and good nutrient retention. They can effectively reduce the pH value of the silage system, increase lactic acid content, inhibit butyric acid production, reduce ammonia nitrogen accumulation, and simultaneously increase dry matter and crude protein content while reducing neutral detergent fiber content. All indicators are superior to the control group.

[0055] Compared with Example 2, the fermentation quality and nutrient retention of Comparative Example 1 were significantly worse. This is because Comparative Example 1 only used a single Astragalus extract to replace the mixed Chinese herbal extracts. Although the mixed microbial agents and coating materials were retained, the single Astragalus extract could not achieve the synergistic effect of the five active ingredients of Chinese herbal medicines. It lacked the comprehensive functions of rapid pH reduction by hawthorn organic acid, antibacterial and antioxidant properties of Eucommia ulmoides leaf components, nutritional substrate provided by Morinda officinalis polysaccharide, and antibacterial and digestive aid properties of Achyranthes bidentata saponins. The fermentation quality and nutrient retention of Comparative Examples 8-11 all showed varying degrees of deterioration. These comparative examples all involved replacing mixed Chinese herbal extracts with single herbal extracts. Comparative Example 8 (single hawthorn) was the most effective in this category because hawthorn organic acids can rapidly lower pH and promote lactic acid bacteria colonization. However, it still lacked the synergistic functions of Astragalus membranaceus' antioxidant properties, Eucommia ulmoides leaf's antibacterial properties, Morinda officinalis' energy supply for lactic acid bacteria, and Achyranthes bidentata's auxiliary antibacterial and digestive-promoting effects. Comparative Example 9 (single Eucommia ulmoides leaf) had outstanding antibacterial and antioxidant effects, but it lacked the ability of organic acids to rapidly lower pH, making its effect slightly inferior to Comparative Example 8. Comparative Examples 10 (single Morinda officinalis) and 11 (single Achyranthes bidentata) did not have the core functions of directly lowering pH and producing acid, and could only play an auxiliary role. Therefore, they were the worst performing groups in this category, with their indicators being close to those of Comparative Example 1 (single Astragalus membranaceus) and Comparative Example 7. This fully demonstrates that the combination and specific ratio of the five Chinese herbal extracts are the core to achieving comprehensive functions, and that a single Chinese herbal extract cannot replace the synergistic effect of mixed Chinese herbal extracts.

[0056] Compared to Example 2, Comparative Example 2 showed insufficient fermentation efficiency and stability. This is because Comparative Example 2 only used a single *Lactobacillus plantarum* powder to replace the mixed inoculant, which could not cover the needs of the entire silage cycle. It lacked the acid-resistant and antibacterial ability of *Lactobacillus bruneri* and the aroma-producing effect of *Pediococcus lactis*, thus limiting the synergistic fermentation effect. The fermentation efficiency and stability of Comparative Examples 12-13 were also insufficient. These comparative examples involved replacing the mixed inoculant with a single lactic acid bacteria. Comparative Example 12 (single *Lactobacillus bruneri*) was the most effective in this category due to its strong acid resistance, ability to ensure stability in the later stages of silage, and absence of butyric acid production. Its nutrient retention effect was also closer to that of Example 2. Comparative Example 13 (single *Pediococcus lactis*) only possessed aroma-producing properties and lacked the core functions of *Lactobacillus plantarum* in rapidly lowering pH and *Lactobacillus bruneri* in inhibiting bacteria in the later stages. Therefore, trace amounts of butyric acid were produced, and the fermentation effect was similar to that of Comparative Example 2 (single *Lactobacillus plantarum*). These comparative examples demonstrate that the synergistic combination of three silage-specific lactic acid bacteria is the key to covering the entire silage cycle. A single strain cannot simultaneously meet the dual needs of acid production in the early stages of silage and stability in the later stages.

[0057] Compared with Example 2, the fermentation performance of Comparative Example 3 was slightly worse. This is because Comparative Example 3 removed the mixed Chinese herbal extract, thus losing the synergistic effect between the Chinese herbal components and the mixed bacterial agent. The role of the Chinese herbal components in assisting antibacterial activity and promoting lactic acid bacteria colonization could not be exerted, thereby affecting the silage quality.

[0058] Compared with Example 2, the fermentation quality of Comparative Example 4 was significantly reduced. This is because Comparative Example 4 removed the mixed microbial agent, which lacked the effect of the microbial agent in synergistic fermentation to rapidly reduce the pH value. The mixed Chinese herbal extract lacked the support of microbial agent, making it difficult to effectively inhibit the growth of putrefactive bacteria and ensuring the stable progress of the silage process.

[0059] Compared with Example 2, Comparative Example 5 is slightly inferior in various indicators. This is because Comparative Example 5 was not coated and did not form a microcapsule structure with "lactic acid bacteria as the core, traditional Chinese medicine active ingredients as the middle layer, and chitosan as the shell". The bacterial agent and traditional Chinese medicine active ingredients are easily lost due to environmental influences during silage, resulting in insufficient stability and insufficient effect.

[0060] Compared with Example 2, the fermentation effect of Comparative Example 6 was not as good as that of Example 2. This is because Comparative Example 6 only used mixed bacterial agents, which lacked the synergistic effect of mixed Chinese herbal extracts and the protection of microcapsule structures. The bacterial cells were easily affected by the external environment and their activity was reduced, so they could not fully exert their fermentation efficiency.

[0061] Compared with Example 2, the fermentation quality of Comparative Example 7 was poor. This is because Comparative Example 7 relied solely on mixed Chinese herbal extracts, which lacked both the synergistic fermentation support of mixed microbial agents and the protection of the active ingredients of Chinese herbal medicines by microcapsule structures. As a result, the ingredients were easily lost, and it was difficult to quickly build an acidic fermentation environment, which made it difficult to inhibit the growth of spoilage bacteria and meet the needs of the entire silage cycle.

[0062] Compared to Example 2, the indicators of Comparative Examples 14-16 were inferior to those of Example 2 but superior to the single-component replacement group. These comparative examples show that the core formulation deviates from the design scope of this invention. Comparative Example 14 shows a deviation in the ratio of mixed Chinese herbal extracts, with an excessively high proportion of hawthorn and an excessively low proportion of Morinda officinalis and Achyranthes bidentata. Although it can lower the pH to some extent, it lacks the nutrient substrate provided by Morinda officinalis for lactic acid bacteria, resulting in insufficient lactic acid accumulation and weakened synergistic effect. Comparative Example 15 shows a deviation in the ratio of mixed bacterial agents, with an excessively high proportion of Lactobacillus plantarum and Pediococcus lactis, resulting in a lower relative proportion of Lactobacillus brunelli, which slightly affects the stability in the later stage of silage. Comparative Example 16 shows a deviation in the mass ratio of mixed Chinese herbal extracts to mixed bacterial agents (1:2). Although the excessive bacterial agent increases the acid production capacity, the insufficient Chinese herbal components cannot fully exert the synergistic antibacterial and nutritional preservation effects. These comparative examples demonstrate that the range of component ratios defined by this invention is the key to achieving the optimal synergistic effect, and deviations from the ratio will lead to a decrease in the function of the additives.

[0063] In summary, the test results of all comparative examples have verified from different perspectives the necessity and rationality of the compounding of five kinds of Chinese herbal extracts, the synergistic effect of three kinds of silage-specific lactic acid bacteria, the specific ratio range of core components, and the exclusive microencapsulation process in this invention. The cooperation and synergistic effect of each technical feature are essential to achieve a comprehensive improvement in the fermentation quality and nutritional value of silage feed.

[0064] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A forage silage additive, characterized in that, It is prepared by combining a mixture of traditional Chinese medicine extracts, a mixture of microbial agents and a coating material; the mixture of traditional Chinese medicine extracts is prepared by extracting and mixing Astragalus membranaceus, Crataegus pinnatifida, Eucommia ulmoides leaves, Morinda officinalis and Achyranthes bidentata; the mixture of microbial agents is prepared by mixing freeze-dried Lactobacillus brunelli powder, freeze-dried Lactobacillus plantarum powder and freeze-dried Pediococcus lactis powder; the coating material includes sodium alginate, glycerol, chitosan and CaCl2.

2. The forage silage additive as described in claim 1, characterized in that, The preparation method of the mixed traditional Chinese medicine extract includes the following steps: S1: Wash and air-dry Astragalus membranaceus, hawthorn, Eucommia ulmoides leaves, Morinda officinalis and Achyranthes bidentata respectively, place them in a 40-50℃ forced-air drying oven and dry them at a low temperature until the moisture content is ≤8%, then pulverize them with a universal pulverizer and pass them through a standard sieve to obtain 2-5mm of each Chinese herbal medicine granules; S2: Take the above-mentioned Chinese herbal medicine granules, use an ethanol solution with a volume fraction of 60-70% as the extraction solvent, add it to the extraction device at a material-to-liquid ratio of 1:10-15 g / mL, reflux at 50-70℃ for 1-2 hours, repeat the extraction 1-2 times, combine the two extracts, filter through a 200-300 mesh filter cloth, and concentrate under reduced pressure at 40-50℃ and -0.08MPa to -0.1MPa until there is no alcohol odor, thus extracting Astragalus membranaceus extract, Crataegus pinnatifida extract, Eucommia ulmoides leaf extract, Morinda officinalis extract and Achyranthes bidentata extract respectively; S3: Weigh out Astragalus membranaceus extract, Crataegus pinnatifida extract, Eucommia ulmoides leaf extract, Morinda officinalis extract and Achyranthes bidentata extract according to a mass ratio of 1:0.3-0.4:0.7-0.9:0.2-0.4:0.2-0.4, place them in a high-speed mixer, and mix for 15-20 minutes at 25-30℃ and 500-800 rpm to obtain the mixed Chinese herbal extract.

3. The forage silage additive as described in claim 1, characterized in that, The specific method for preparing the mixed bacterial agent is as follows: [The following text appears to be a separate, unrelated section:] ...with a viable bacterial count ≥ 10... 11 Freeze-dried Lactobacillus bruneri powder, freeze-dried Lactobacillus plantarum powder, and freeze-dried Pediococcus lactis powder with CFU / g and moisture content ≤5% were weighed according to the mass ratio and placed in a sterile high-speed mixer. The mixture was then mixed for 10-15 minutes at 25-30℃ and 500-800 rpm to obtain the mixed bacterial agent.

4. The forage silage additive as described in claim 1, characterized in that, The mass ratio of the freeze-dried Lactobacillus brunelli powder, freeze-dried Lactobacillus plantarum powder, and freeze-dried Pediococcus lactis powder is 1:0.5-0.7:0.3-0.

6.

5. The forage silage additive as described in claim 1, characterized in that, The mass ratio of the mixed Chinese herbal extract to the mixed microbial agent is 1:1.2-1.

4.

6. A method for preparing a forage silage additive as described in any one of claims 1-5, characterized in that, Includes the following steps: Step 1: Weigh the mixed bacterial agent and add it to a sodium alginate solution and glycerol with a mass fraction of 1.2-1.5%. Stir at 25-30℃ and 200-400rpm for 15-30 minutes, and then sonicate intermittently at 100-200W for 5-10 minutes to obtain a uniform dispersion. Step 2: Weigh the mixed Chinese herbal extracts, dissolve them in deionized water, stir at 40-60℃ and 300-500rpm for 1-1.5h, filter through 150-200 mesh and cool to 25-30℃ to obtain the coating solution; Step 3: Pour the dispersion into the coating solution and stir at 25-30℃ and 300-400rpm for 1-1.5h. Add 0.6-0.8% CaCl2 solution by mass and continue stirring for 30-45min to obtain a suspension. Step 4: Pour 0.8-1.0% chitosan solution into the suspension and stir at 25-30℃ and 300-400rpm for 1.5-2h. Add 0.6-0.8% CaCl2 solution and crosslink for 30-60min. Then, centrifuge at 2000-3000rpm for 10-20min to collect the precipitate. Wash with deionized water 2-3 times and vacuum dry at 45-65℃ and -0.06MPa to -0.08MPa for 4-6h to obtain the forage silage additive.

7. The preparation method according to claim 6, characterized in that, In the first step, the volume ratio of sodium alginate solution to glycerol is 1:0.002-0.

005.

8. The preparation method according to claim 6, characterized in that, In the fourth step, the volume ratio of the chitosan solution to the suspension is 1:0.6-0.

8.

9. The application of a forage silage additive as described in any one of claims 1-5 in corn stalks, alfalfa, rye grass, and rice straw.

10. The application as described in claim 9, characterized in that, The method of use is as follows: Add 0.1-0.3% of the dry weight of the forage silage additive to the forage, mix well, seal and ensilage for 30-60 days.

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