Feed for improving meat quality of Shiqi young pigeons by using herbal tea waste residues and preparation method of feed

Abstract

The invention relates to the technical field of feed science and biological fermentation, and discloses a feed for improving meat quality of Shiqi young pigeons by using herbal tea waste residues and a preparation method thereof, and the method comprises the following steps: mixing the herbal tea waste residues, rice bran and soybean meal in proportion, adding chitosan oligosaccharide, adjusting the water content, and carrying out controllable gradient sterilization; carrying out asymmetric sequential fermentation so as to directionally enrich functional metabolites such as probiotics, antibacterial peptide and butyrate; and drying the fermentation product at low temperature to prepare a functional feed additive, and mixing the functional feed additive with a basic ration. Endogenous antibacterial substances in the raw materials are reserved through a specific sterilization process, a microbial competition environment is constructed by utilizing sequential fermentation, and the low-value herbal tea waste residues are converted into the high-activity biological composition. The feed prepared by the invention can significantly improve the growth performance of Shiqi young pigeons, reduce the shearing force and drip loss of meat products, and increase the intramuscular fat content.

Description

Technical Field

[0001] The invention relates to the field of feed science and bio-fermentation technology, and in particular to a feed for improving the meat quality of Shiqi squab by utilizing herbal tea waste residue and a preparation method thereof. Background Art

[0002] As a high-quality poultry product, the meat quality of Shiqi pigeons is a core indicator of their economic value. Therefore, improving meat quality through feeding management and nutritional regulation has always been a research priority within the industry. Meanwhile, the herbal tea manufacturing industry generates a large amount of plant residue during production, known as herbal tea waste. To reduce environmental pressure and maximize resource utilization, utilizing this plant-rich waste as a feed ingredient has become a technological approach with both economic and environmental benefits.

[0003] However, the direct application of herbal tea waste residue in poultry feed is not ideal, and its application is restricted by many factors. First, the physical and chemical composition of herbal tea waste residue is mainly lignocellulose, which is complex and strong. It wraps nutrients such as proteins and polysaccharides, seriously hindering the decomposition of digestive enzymes in the digestive tract of monogastric poultry such as Shiqi pigeons, resulting in low bioavailability of nutrients. In addition, some plant-derived anti-nutritional factors may remain in the waste residue raw materials. These substances will interfere with the normal digestion and absorption process of poultry and even have an adverse effect on intestinal health.

[0004] Although there have been attempts to use microbial fermentation to process similar plant fiber raw materials in the prior art, these methods are generally relatively extensive. Conventional fermentation processes often use a mixed inoculation of multiple strains at one time and culture under constant conditions. This method does not fully degrade the complex herbal tea waste matrix, making it difficult to effectively break its physical barrier, and the nutritional value is limited. In addition, this type of non-specific fermentation process cannot generate functional metabolites that can significantly improve meat quality, resulting in unstable quality of the final product, and the improvement effect on key indicators such as tenderness and water retention of pigeon meat is unclear, which cannot meet the needs of refined breeding. Summary of the Invention

[0005] In response to the shortcomings of the existing technology, the present invention provides a feed for improving the meat quality of Shiqi pigeons using herbal tea waste and a preparation method thereof, which solves the problem that herbal tea waste has low bioavailability of nutrients due to being rich in lignocellulose, and that existing fermentation technology is difficult to generate functional metabolites that can effectively improve the meat quality of poultry.

[0006] To achieve the above objectives, the present invention is implemented by the following technical solution: a feed additive for improving the meat quality of Shiqi pigeons using herbal tea waste, wherein the additive is a composition prepared by fermenting raw materials comprising the following components: The fermentation matrix is ​​composed of 65 to 75 parts of herbal tea waste residue, 12 to 18 parts of rice bran, and 12 to 18 parts of soybean meal, based on dry matter weight; microbial flora, including Aspergillus niger, Bacillus subtilis, and Lactobacillus plantarum; The inducer is chitosan oligosaccharide accounting for 0.08% to 0.12% of the dry matter weight of the fermentation matrix.

[0007] A feed for improving the meat quality of Shiqi squab, comprising a basic diet and the functional feed additive, wherein the added amount of the functional feed additive accounts for 3% to 8% of the total weight of the feed.

[0008] A method for preparing a feed additive for improving the meat quality of Shiqi pigeons by utilizing herbal tea waste residues comprises the following steps: Step 1. Substrate pretreatment: Mix herbal tea waste, rice bran and soybean meal in proportion, add chitosan oligosaccharide inducer, and adjust the moisture content to 56% to 60%; Step 2. Controlled gradient sterilization: treating the matrix obtained in step 1 at a temperature of 83°C to 87°C for 28 to 32 minutes, and then cooling; Step 3. Asymmetric sequential fermentation: Step 31. First, inoculate Aspergillus niger into the substrate treated in step 2, and perform the first stage fermentation at 29°C to 31°C; Step 32. Then, after the first stage fermentation is carried out for 23 to 25 hours, Bacillus subtilis and Lactobacillus plantarum are inoculated into the substrate, wherein the inoculation density of Bacillus subtilis is higher than that of Lactobacillus plantarum, and the second stage fermentation is carried out at 36°C to 38°C; Step 4. Drying: Drying the fermented material at a temperature below 45° C. to obtain the functional feed additive.

[0009] Preferably, the dry matter weight ratio of the herbal tea waste residue, rice bran and soybean meal described in step 1 is 70:15:15.

[0010] Preferably, in step 31, the inoculum amount of Aspergillus niger is 0.4% to 0.6% (v / w) of the dry weight of the substrate.

[0011] Preferably, in step 31, the first stage fermentation is carried out under microaerobic conditions with an aeration volume of 0.1 to 0.2 vvm.

[0012] Preferably, in step 32, the inoculation density of Bacillus subtilis is (0.8-1.2) x10 8 CFU / g dry matrix, the inoculation density of Lactobacillus plantarum is (0.8~1.2)x10 6 CFU / g dry matrix.

[0013] Preferably, after step 32, a maturation and stabilization stage is further included under anaerobic conditions.

[0014] Preferably, the drying treatment in step 4 is low-temperature vacuum drying.

[0015] A method for preparing feed for improving the meat quality of Shiqi squab, comprising the step of mixing a functional feed additive prepared by the method with a basic diet.

[0016] The present invention provides a feed for improving the meat quality of Shiqi pigeons by using herbal tea waste and a preparation method thereof. The feed has the following beneficial effects: 1. This invention utilizes Aspergillus niger for the first stage of fermentation and introduces chitosan oligosaccharides as an inducer, effectively degrading the complex plant cell wall structures (such as lignin and cellulose) in herbal tea waste. This process converts nutrients such as large proteins and polysaccharides, which are previously enclosed within the cell walls and difficult for animals to directly digest and absorb, into small peptides, oligosaccharides, and free amino acids, significantly improving the digestibility and bioavailability of the waste residue's nutrients.

[0017] 2. The asymmetric sequential inoculation method adopted by the present invention introduces a high density of Bacillus subtilis and a low density of Lactobacillus plantarum in the middle and late stages of fermentation. This designed competitive environment not only enriches the final product with highly active live probiotic bacteria, but also, through microbial stress response and metabolic regulation, induces the production of antimicrobial peptides and butyrate, which are difficult to obtain through conventional fermentation. These metabolites work synergistically with the live probiotic bacteria to jointly optimize the intestinal microecological environment of the pigeon.

[0018] 3. This invention innovatively utilizes a controlled gradient sterilization process, which kills most bacteria while selectively retaining the inherent, heat-sensitive, natural antibacterial substances in herbal tea waste. These substances inhibit the growth of bacteria during the initial fermentation phase, ensuring the pure growth of the functional bacterial flora. This self-controlled "inhibition first, release later" mechanism reduces reliance on external sterilization conditions or chemical antibacterial agents, making the production process more environmentally friendly and stable, and reducing the risk of contamination of the finished product by harmful microorganisms.

[0019] 4. The present invention provides an effective way to recycle and reap high-value benefits from the large amounts of herbal tea waste residue produced. Through a systematic bioconversion process, this industrial byproduct, once a costly process, is transformed into a functional product that effectively improves the meat quality and health of Shiqi pigeons. This not only significantly reduces feed costs and environmental pollution, but also provides a new, green source of functional feed for the livestock industry, offering significant economic benefits and sustainable development value. DETAILED DESCRIPTION

[0020] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] The sources and specifications of the main raw materials and reagents used in the following examples and comparative examples are as follows. Reagents not specifically specified are all commercially available products of analytical grade or higher.

[0022] 1. Microbial strains Aspergillus niger: China General Microorganism Culture Collection Center, accession number CGMCC3.XXXX.

[0023] Bacillus subtilis: China General Microorganism Culture Collection Center, accession number CGMCC1.XXXX.

[0024] Lactobacillus plantarum: China General Microorganism Culture Collection Center, accession number CGMCC1.XXXX.

[0025] 2. Basic raw materials and reagents Herbal tea waste residue: fresh plant residue collected from the process of producing "Yi Fang 24 Flavor Herbal Tea Granules" by Guangdong Yifang Pharmaceutical Co., Ltd. after squeezing and dehydration.

[0026] Rice bran: Wilmar Golden Dragon Fish Cereals & Oils Co., Ltd., food grade.

[0027] Soybean meal: COFCO, feed grade, 43% protein.

[0028] Chitosan oligosaccharide: CAS No. 148411-57-8; product of Zhejiang Jinke Biochemical Co., Ltd., specifications: degree of polymerization 2-6, degree of deacetylation ≥95.0%, food grade.

[0029] Anhydrous glucose: CAS No. 50-99-7; Sinopharm Chemical Reagent Co., Ltd., analytical grade (AR).

[0030] Peptone: CAS No. 73049-73-7; product of Oxoid Company, UK, bacteriological grade.

[0031] Beef extract: CAS No. 68990-09-0; product of Oxoid Company, UK, bacteriological grade.

[0032] Yeast extract powder: CAS No. 8013-01-2; product of Oxoid Company, UK, bacteriological grade.

[0033] Agar: CAS No. 9002-18-0; product of Hispanagar, Spain, bacteriological grade.

[0034] Sodium chloride: CAS No. 7647-14-5; Sinopharm Chemical Reagent Co., Ltd., analytical grade (AR).

[0035] Potassium hydrogen phosphate: CAS No. 7758-11-4; Sinopharm Chemical Reagent Co., Ltd., analytical grade (AR).

[0036] Potassium dihydrogen phosphate: CAS No. 7778-77-0; Sinopharm Chemical Reagent Co., Ltd., analytical grade (AR).

[0037] Tween-80: CAS No. 9005-65-6; Sinopharm Chemical Reagent Co., Ltd., chemically pure (CP).

[0038] Sodium acetate: CAS No. 127-09-3; Sinopharm Chemical Reagent Co., Ltd., analytical grade (AR).

[0039] Triammonium citrate: CAS No. 3458-72-8; Sinopharm Chemical Reagent Co., Ltd., analytical grade (AR).

[0040] Magnesium sulfate: CAS No. 7487-88-9; Sinopharm Chemical Reagent Co., Ltd., analytical grade (AR).

[0041] Manganese sulfate: CAS No. 7785-87-7; Sinopharm Chemical Reagent Co., Ltd., analytical grade (AR).

[0042] Butyric acid standard: CAS No. 107-92-6; product of Sigma-Aldrich, USA, chromatographically pure (≥99.5%).

[0043] 3. Experimental animals and basal diet Shiqi squab: provided by Shiqi pigeon farm in Zhongshan City, Guangdong Province, selected squabs of (1-3) days old, in good health and with uniform weight.

[0044] Basal diet: Prepared according to the NRC (1994) Nutrient Requirements of Poultry. See the table below for composition and nutrient levels. All ingredients were ground through a 40-mesh sieve and mixed thoroughly.

[0045] Example 1: Preparation of functional feed additive (using preferred parameters) This example describes the process of preparing the functional feed additive of the present invention using the preferred process parameters.

[0046] (1) Preparation of bacterial suspension Aspergillus niger suspension: The preserved Aspergillus niger strain was inoculated on potato dextrose agar (PDA) medium and cultured at 30°C for 5 days. The spores were washed with sterile saline and prepared into a concentration of 1.0x10 7 spores / mL of spore suspension.

[0047] Bacillus subtilis suspension: The preserved Bacillus subtilis strain was inoculated into nutrient broth (NB) medium and cultured in a shaker at 37°C and 170 rpm / min for 18 hours. The cells were collected by centrifugation and resuspended in sterile saline to a concentration of 1.0x10 9 CFU / mL of bacterial suspension.

[0048] Lactobacillus plantarum suspension: The preserved Lactobacillus plantarum strain was inoculated into MRS medium and cultured at 37°C for 24 hours. The cells were collected by centrifugation and resuspended in sterile saline to prepare a concentration of 1.0x10 8 CFU / mL of bacterial suspension.

[0049] (2) Preparation and pretreatment of the synergistic fermentation matrix: Herbal tea waste, rice bran, and soybean meal were mixed in a dry matter weight ratio of 70:15:15. Chitosan oligosaccharide was added at 0.1% of the total dry matter weight of the matrix. Sterile water was evenly sprayed into the mixture and stirred until the final moisture content was 58%. The prepared matrix was placed in a solid-state fermentation tank.

[0050] (3) Controlled gradient sterilization: Start the heating program of the fermenter, raise the material temperature to 85℃ and maintain it for 30 minutes. After the sterilization is completed, introduce sterile cooling air to reduce the material temperature to 35℃.

[0051] (4) Asymmetric sequential fermentation Stage 1 (0-24 hours): The Aspergillus niger spore suspension prepared in step (1) was inoculated into the treated substrate at a concentration of 0.5% (v / w) of the substrate dry weight. The fermentation temperature was controlled at 30°C and the aeration rate was 0.15 vvm for stage 1 fermentation.

[0052] The second stage (24-72 hours): After 24 hours of fermentation, the Bacillus subtilis suspension prepared in step (1) and the Lactobacillus plantarum suspension were mixed and inoculated to make the final inoculation density of Bacillus subtilis 1.0x10 8 CFU / g dry substrate, the final inoculation density of Lactobacillus plantarum was 1.0x10 6 CFU / g dry substrate. At the same time, the fermentation temperature was raised to 37°C and the ventilation volume was increased to 0.4 vvm for the second stage of fermentation.

[0053] The third stage (72-96 hours): After 72 hours of fermentation, aeration is stopped and anaerobic maturation is carried out. Fermentation ends after 96 hours.

[0054] (5) Low-temperature drying and finished product processing: The fermented material was dried under low-temperature vacuum conditions at a vacuum degree of 0.09 MPa and a temperature of 42°C until the moisture content of the material was less than 10%. The dried material was crushed and passed through an 80-mesh sieve to obtain a powdered functional feed additive, which was recorded as S1.

[0055] Example 2: Preparation of functional feed additive (using boundary parameter A) The preparation method of this embodiment is basically the same as that of Example 1, except that: Preparation of the synergistic fermentation matrix: The dry matter weight ratio of herbal tea waste, rice bran, and soybean meal was 65:18:17. Chitosan oligosaccharide was added to the matrix at a concentration of 0.08% of the total dry matter weight. The final moisture content was adjusted to 56%.

[0056] Controlled gradient sterilization: maintain at 83°C for 32 minutes.

[0057] Asymmetric sequential fermentation: Stage 1: The inoculum size of Aspergillus niger was 0.4% (v / w) of the substrate dry weight, the fermentation temperature was 29°C, and the aeration rate was 0.1 vvm.

[0058] The second stage: inoculation was carried out after 23 hours of fermentation, the fermentation temperature was 36 ° C, the ventilation volume was 0.3 vvm. The inoculation density of Bacillus subtilis was 0.8x10 8 CFU / g dry substrate, Lactobacillus plantarum inoculation density is 0.8x10 6 CFU / g dry matrix.

[0059] The third stage: anaerobic maturation starts from 71 hours and ends at 94 hours.

[0060] Low-temperature drying: The drying temperature is 40° C. The functional feed additive finally obtained is recorded as S2.

[0061] Example 3: Preparation of functional feed additive (using boundary parameter B) The preparation method of this embodiment is basically the same as that of Example 1, except that: Preparation of the synergistic fermentation matrix: The dry matter weight ratio of herbal tea waste, rice bran, and soybean meal was 75:12:13. Chitosan oligosaccharide was added to the matrix at a concentration of 0.12% of the total dry matter weight. The final moisture content was adjusted to 60%.

[0062] Controlled gradient sterilization: maintain at 87°C for 28 minutes.

[0063] Asymmetric sequential fermentation: Phase 1: The inoculum size of Aspergillus niger was 0.6% (v / w) of the substrate dry weight, the fermentation temperature was 31°C, and the aeration rate was 0.2 vvm.

[0064] The second stage: inoculation was carried out after 25 hours of fermentation, the fermentation temperature was 38 ° C, the ventilation volume was 0.5 vvm. The inoculation density of Bacillus subtilis was 1.2x10 8 CFU / g dry substrate, Lactobacillus plantarum inoculation density was 1.2x10 6 CFU / g dry matrix.

[0065] The third stage: anaerobic maturation starts from 73 hours and ends at 98 hours.

[0066] Low-temperature drying: the drying temperature is 45° C. The functional feed additive finally obtained is recorded as S3.

[0067] Example 4: Preparation of feed for improving the meat quality of Shiqi squab Take 15.0 kg of the functional feed additive prepared in Example 1 and 95.0 kg of the basic diet (its formula is shown in the experimental raw materials section) in a vertical mixer and mix for 15 minutes until uniform. The mixed feed is packaged to obtain the feed for improving the meat quality of Shiqi pigeons of the present invention. The amount of the functional feed additive added is 5% of the total weight of the feed.

[0068] Comparative Example 1: Using untreated herbal tea waste Compared with Example 1, this comparative example does not perform the fermentation and related treatments of steps (2) to (5). Instead, the initial herbal tea waste residue is dried at 60°C to a moisture content of less than 10%, and then pulverized and passed through an 80-mesh sieve to obtain a powdered additive, which is recorded as DS1.

[0069] Comparative Example 2: Conventional mixed fermentation method Compared with Example 1, the differences are as follows: the sterilization method in step (3) is replaced by high-temperature, high-pressure, moist heat sterilization at 121°C for 20 minutes; the fermentation method in step (4) is replaced by mixing and inoculating the three bacterial suspensions of Aspergillus niger, Bacillus subtilis, and Lactobacillus plantarum at the beginning of fermentation, without adding chitosan oligosaccharides to the matrix, and then fermenting at a constant temperature of 32°C for 96 hours. The rest of the method is the same. The functional feed additive finally obtained is recorded as DS2.

[0070] Comparative Example 3: Fermentation without the "controlled gradient sterilization" step Compared with Example 1, the difference is that the controlled gradient sterilization step in step (3) is replaced by conventional high temperature and high pressure moist heat sterilization, that is, treatment at 121°C for 20 minutes. The rest is the same. The functional feed additive finally obtained is recorded as DS3.

[0071] Comparative Example 4: Fermentation without the "asymmetric sequential inoculation" step Compared with Example 1, the difference is that in step (4), the three bacterial suspensions of Aspergillus niger, Bacillus subtilis EP, and Lactobacillus plantarum are mixed and inoculated at the beginning of fermentation according to the final inoculation ratio of Example 1. The fermentation is carried out at 32°C throughout the entire process. All other procedures are the same. The functional feed additive finally obtained is recorded as DS4.

[0072] Comparative Example 5: Fermentation without "inducer" Compared with Example 1, the difference is that chitosan oligosaccharide is not added during the preparation of the cooperative fermentation matrix in step (2), and the rest are the same. The functional feed additive finally obtained is recorded as DS5.

[0073] Test Example 1: Determination of product functional ingredients In order to verify the functionality of the additive prepared by the method of the present invention, the following indicators were measured on the samples (S1, S2, S3, DS1, DS2, DS3, DS4, DS5) prepared in Examples 1 to 3 and Comparative Examples 1 to 5.

[0074] 1.1 Probiotic live bacteria count Sample preparation: 1.0 g of each sample was accurately weighed under sterile conditions, added to a test tube containing 9.0 mL of sterile saline, and thoroughly shaken to mix. -1 Then, gradient dilution was performed to prepare 10 -2 to 10 -8 Serial dilutions.

[0075] Flat plate coating: Lactobacillus count: select 10 -5 , 10 -6 , 10 -7 100 μL of each dilution was spread on MRS agar plates.

[0076] Bacillus count: Heat the above gradient dilutions in a water bath at 80°C for 10 minutes to kill non-spore-forming bacteria. After cooling, select 10 -5 , 10 -6 , 10 -7 100 μL of each dilution was spread on nutrient agar (NA) medium plates.

[0077] Culture and Enumeration: Incubate MRS plates in a 37°C anaerobic incubator for 48 hours; incubate NA plates in a 37°C constant-temperature incubator for 24 hours. Count plates with 30 to 300 colonies. Repeat three times for each sample. Results are expressed as log CFU / g dry substrate.

[0078] 1.2 Determination of short-chain fatty acid (butyrate) content Sample extraction: Accurately weigh 5.0 g of each sample, add 50 mL of ultrapure water, and vortex for 30 minutes. Centrifuge at 8000 rpm / min at 4°C for 10 minutes, and collect the supernatant. Add 25% metaphosphoric acid solution to the supernatant, refrigerate at 4°C overnight, centrifuge again, collect the supernatant, and filter through a 0.22 μm filter.

[0079] Chromatographic analysis: Gas chromatography (GC) was used. The column was an Agilent HP-INNOWAX (30 m × 0.25 mm × 0.25 μm). The inlet temperature was 250°C, and the detector (FID) temperature was 250°C. The column temperature program was: initial temperature 100°C, hold for 5 minutes, then increase to 180°C at a rate of 8°C / min, hold for 5 minutes. Quantification was performed using an external standard method, with a standard curve constructed using butyric acid standards.

[0080] 1.3 Evaluation of in vitro antibacterial activity Sample filtrate preparation: Accurately weigh 1.0 g of each sample, add 10 mL of sterile saline, and extract with shaking for 2 hours. Centrifuge at 4°C, 10,000 rpm / min for 15 minutes. Remove the supernatant and filter through a 0.22 μm sterile filter membrane to obtain the filtrate to be tested.

[0081] Indicator bacteria culture: Escherichia coli (E. coli ATCC 25922) and Staphylococcus aureus (S. aureus ATCC 25923) were inoculated into LB liquid medium, cultured at 37°C until the logarithmic growth phase, and the bacterial concentration was adjusted to about 1×10 6 CFU / mL.

[0082] Inhibition zone determination: Use the agar diffusion method. Evenly spread the indicator bacteria solution on the surface of an LB agar plate. After drying, use a sterile hole punch to create a 6.0 mm diameter circular hole in the plate. Add 100 μL of each test filtrate to each well. After incubating the plate in a 37°C incubator for 18–24 hours, measure the diameter (mm) of the inhibition zone using a vernier caliper.

[0083] Measurement results The results of functional component determination of each group of samples are summarized in Table 1.

[0084] Table 1: Determination results of functional components of each group of samples Results Analysis: The results in Table 1 show that samples S1, S2, and S3 prepared using the methods of Examples 1-3 significantly surpassed the control samples in terms of viable probiotic counts, butyrate content, and in vitro antimicrobial activity. Untreated herbal tea waste DS1 contained virtually no target functional ingredients. Compared to DS2, prepared using conventional mixed fermentation, the samples prepared using the present invention exhibited significant increases in various functional indicators, demonstrating the overall effectiveness of the specific process described herein.

[0085] The effect of the controlled gradient sterilization step provided in the method of the present invention can be confirmed by comparing the data of S1 and DS3. Although DS3, which is sterilized at high temperature and high pressure, can also obtain fermentation products, its various functional indicators are lower than those of S1. This is because the controlled gradient sterilization, while killing miscellaneous bacteria, retains some endogenous antibacterial substances in the herbal tea waste, creating conditions for the dominant growth of Aspergillus niger in the early stage of fermentation, forming the basis for subsequent efficient fermentation. At the same time, the comparison results of S1 and DS5 show that the addition of chitosan oligosaccharide inducer can effectively promote the decomposition of the substrate, provide more sufficient precursor substances for the subsequent functional metabolism of probiotics, and thus obtain higher butyrate content and antimicrobial active substance production.

[0086] The core step of the present invention, namely asymmetric sequential fermentation, has a technical effect that is clearly reflected in the comparison between S1 and DS4. The number of viable probiotic bacteria in S1 and DS4 is at a similar level, but the butyrate content and antibacterial activity of S1 are much higher than those of DS4. The mechanism is that the asymmetric sequential inoculation in S1 creates a specific competitive environment for Bacillus subtilis and Lactobacillus plantarum. The high-density Bacillus subtilis synthesizes and secretes more antibacterial substances under the quorum sensing effect; while the low-density Lactobacillus plantarum changes its metabolic flux under competitive pressure and synthesizes more butyrate. The conventional mixed inoculation used by DS4 does not have this controlled interspecies competition mechanism, and therefore cannot obtain high-content functional metabolites in a targeted manner.

[0087] Test Example 2: Shiqi pigeon feeding test and performance evaluation In order to verify the effect of the functional feed additive of the present invention in practical application, a 28-day feeding experiment on Shiqi squab was conducted.

[0088] 2.1 Experimental Animals and Grouping A total of 270 3-day-old, healthy, and uniformly weighted Shiqi squab pigeons were randomly divided into 9 groups, with 6 replicates in each group and 5 pigeons in each replicate.

[0089] Control group: fed with basal diet.

[0090] Example groups 1 to 3: 5% of samples S1, S2, and S3 were added to the basal diet, respectively.

[0091] Comparative groups 1 to 5: 5% of samples DS1, DS2, DS3, DS4, and DS5 were added to the basal diet, respectively.

[0092] 2.2 Feeding Management and Index Measurements During the experiment, all squabs were housed under identical environmental conditions and had free access to feed and water. Squabs were weighed at the beginning (day 0) and end (day 28) of the experiment, and feed consumption was recorded for each replicate. Average daily gain (ADG) and feed-to-weight ratio (FCR) were calculated.

[0093] At the end of the experiment, two squabs were randomly selected from each replicate and killed by bleeding through the carotid artery. Their left breast muscle samples were collected for the determination of meat quality indicators.

[0094] Shear force measurement: Heat breast muscle samples in an 80°C water bath until the core temperature reaches 75°C. Cool to room temperature. Cut strips along the muscle fibers and measure the shear force (N) using a digital muscle tenderizer.

[0095] Drip loss determination: Accurately weigh approximately 20 g of fresh breast muscle sample (W1), hang it in a sealed bag, and place it in a refrigerator at 4°C for 24 hours. Remove it, absorb the surface moisture with filter paper, and weigh it again (W2). Drip loss (%) = [(W1 - W2) / W1] × 100.

[0096] Determination of intramuscular fat content: The breast muscle samples were freeze-dried and then crushed, and the crude fat content (%) was determined by Soxhlet extraction.

[0097] Measurement results The production performance and meat quality index test results of each group of Shiqi squab are summarized in Table 2.

[0098] Table 2: Results of production performance and meat quality indexes of Shiqi pigeons in each group Result Analysis The feeding test results in Table 2 show that compared with the control group and the comparative example groups, the groups fed the example supplemented with samples S1, S2, and S3 showed significant improvements in average daily gain, feed-to-weight ratio, shear force, drip loss, and intramuscular fat content of the Shiqi squab. Untreated herbal tea waste residue (DS1 group) had no positive effect on production performance or meat quality. This result confirms that the preparation method of the present invention can transform herbal tea waste residue into a functional additive that effectively improves the production performance and meat quality of Shiqi squab.

[0099] The improved production performance of the additive prepared by the present method is directly related to the bioavailability of its nutrients. The action of Aspergillus niger during the initial fermentation phase degrades the difficult-to-use large polysaccharides in herbal tea waste into small molecules, significantly increasing the nutritional value of the substrate. Comparison of data from the S1 and DS5 groups (lacking an inducer) reveals that the introduction of chitosan oligosaccharides further enhances this process, resulting in higher weight gain and feed conversion efficiency in the S1 group compared to the DS5 group. These readily absorbable nutrients provide the material foundation for the rapid growth of squabs.

[0100] The improvement in the meat quality indicators of Shiqi pigeons is the result of the synergistic effect of the probiotics and specific metabolites in the functional additives. As shown in Test Example 1, the method of the present invention can enrich highly active probiotics, antibacterial substances and butyrate. These components act together on the intestinal system of the pigeon, maintain the balance of the intestinal microecology, promote intestinal health, and thus affect the nutritional distribution of the whole body and the physiological state of muscle tissue. Comparison of the results of the S1 and DS3 groups (lack of controlled gradient sterilization) and the S1 and DS4 groups (lack of asymmetric sequential inoculation) shows that it is the setting of these specific process steps that ensures the directional and efficient accumulation of functional metabolites, which is ultimately reflected in the comprehensive improvement of the water holding capacity (low drip loss), tenderness (low shear force) and flavor (high intramuscular fat content) of the meat. While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A feed additive for improving the meat quality of Shiqi pigeon by using herbal tea waste residue, characterized in that: The additive is a composition prepared by fermenting raw materials comprising the following components: The fermentation matrix is ​​composed of 65 to 75 parts of herbal tea waste residue, 12 to 18 parts of rice bran, and 12 to 18 parts of soybean meal, based on dry matter weight; microbial flora, including Aspergillus niger, Bacillus subtilis, and Lactobacillus plantarum; The inducer is chitosan oligosaccharide accounting for 0.08% to 0.12% of the dry matter weight of the fermentation matrix.

2. A feed for improving the meat quality of Shiqi pigeon, characterized in that: The method comprises a basic diet and the functional feed additive according to claim 1, wherein the added amount of the functional feed additive accounts for 3% to 8% of the total weight of the feed.

3. A method for preparing a feed additive for improving the meat quality of Shiqi pigeons by using herbal tea waste residue, characterized in that: The feed additive for improving the meat quality of Shiqi pigeons using herbal tea waste as claimed in claim 1 comprises the following steps: Step 1. Substrate pretreatment: Mix herbal tea waste, rice bran and soybean meal in proportion, add chitosan oligosaccharide inducer, and adjust the moisture content to 56% to 60%; Step 2. Controlled gradient sterilization: treating the matrix obtained in step 1 at a temperature of 83°C to 87°C for 28 to 32 minutes, and then cooling; Step 3. Asymmetric sequential fermentation: Step 31. First, inoculate Aspergillus niger into the substrate treated in step 2, and perform the first stage fermentation at 29°C to 31°C; Step 32. Then, after the first stage fermentation is carried out for 23 to 25 hours, Bacillus subtilis and Lactobacillus plantarum are inoculated into the substrate, wherein the inoculation density of Bacillus subtilis is higher than that of Lactobacillus plantarum, and the second stage fermentation is carried out at 36°C to 38°C; Step 4. Drying: Dry the fermented material at a temperature below 45° C. to obtain a functional feed additive.

4. The method for preparing a feed additive for improving the meat quality of Shiqi pigeon by using herbal tea waste according to claim 3, wherein: The dry matter weight ratio of the herbal tea waste residue, rice bran and soybean meal described in step 1 is 70:15:

15.

5. The method for preparing a feed additive for improving the meat quality of Shiqi pigeon by using herbal tea waste according to claim 3, wherein: In step 31, the inoculum amount of Aspergillus niger is 0.4% to 0.6% (v / w) of the dry weight of the substrate.

6. The method for preparing a feed additive for improving the meat quality of Shiqi pigeon by using herbal tea waste according to claim 3, wherein: In step 31, the first stage fermentation is carried out under microaerobic conditions with an aeration volume of 0.1 to 0.2 vvm.

7. The method for preparing a feed additive for improving the meat quality of Shiqi pigeon by using herbal tea waste according to claim 3, characterized in that: In step 32, the inoculation density of Bacillus subtilis is (0.8-1.2) x10 8 CFU / g dry matrix, the inoculation density of Lactobacillus plantarum is (0.8~1.2)x10 6 CFU / g dry matrix.

8. The method for preparing a feed additive for improving the meat quality of Shiqi pigeon by using herbal tea waste according to claim 3, wherein: After step 32, a maturation and stabilization stage is also included under anaerobic conditions.

9. The method for preparing a feed additive for improving the meat quality of Shiqi pigeon by using herbal tea waste according to claim 3, wherein: The drying process in step 4 is low-temperature vacuum drying.

10. A method for preparing feed for improving the meat quality of Shiqi pigeon, characterized in that: The method comprises the step of mixing the functional feed additive prepared by the method according to any one of claims 3 to 9 with a basic diet.

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