Probiotic composition for improving oxidation resistance of meat breeding pigeons at last growth stage as well as preparation method and application of probiotic composition

Abstract

The invention discloses a probiotic composition for improving the oxidation resistance of meat breeding pigeons at the last growth stage as well as a preparation method and application of the probiotic composition, and belongs to the technical field of microorganisms. The probiotic composition provided by the invention is prepared from the following components: bacillus cereus MYZ425 freeze-dried powder, lactobacillus plantarum freeze-dried powder and saccharomyces boulardii freeze-dried powder, wherein the mass ratio of the bacillus cereus MYZ425 freeze-dried powder to the lactobacillus plantarum freeze-dried powder to the saccharomyces boulardii freeze-dried powder is 1: (2-3): (3-5). According to the present invention, through the combined action of the antioxidant enzyme produced by the bacillus cereus MYZ425 and the antioxidant metabolites of the lactobacillus plantarum and the saccharomyces boulardii, the multi-layer antioxidant network is formed, such that the free radicals are effectively neutralized, and the damage of the oxidative stress to the cells is reduced;

Description

Technical Field

[0001] The present invention belongs to the field of microbial technology, and particularly relates to a probiotic composition for improving the antioxidant performance of meat breeder pigeons in the late growth stage, as well as a preparation method and application thereof. Background Art

[0002] The breeding cycle of meat-breeding pigeons is typically between five and seven years, during which they undergo multiple breeding cycles, each lasting approximately 45 days. As the breeding period increases, especially in high-density environments, the risk of disease transmission increases. This is especially true for meat-breeding pigeons in their later stages of growth. Long-term high-density breeding can lead to the accumulation of oxidative stress, which weakens the pigeons' antioxidant capacity and enhances cell apoptosis, ultimately leading to decreased reproductive and growth performance. To address these issues, with the implementation of ecological farming technologies and health policies, probiotic preparations have become a research hotspot as an alternative to antibiotic feed additives due to their low cost, wide range of applications, and non-toxicity and residue-free properties.

[0003] In the breeding process of meat pigeons, the application of probiotic additives can better enhance the overall production performance and immunity of meat pigeons and reduce the problem of pathogen resistance caused by irregular medication. By adding single or compound probiotics to the feed, the balance of intestinal flora can be adjusted, nutrient absorption can be promoted, the intestinal barrier function can be strengthened, pathogenic microorganisms can be inhibited, and the immune regulation effect can be enhanced. Commonly used single probiotics include lactobacilli, bifidobacteria, bacillus, streptococci, etc.; commonly used compound probiotics include Bacillus subtilis + yeast + lactic acid bacteria + actinomycetes + actinomycetes combination, Clostridium butyricum + lactic acid bacteria combination, Lactobacillus acidophilus + Bifidobacterium lactis and other combinations of bacteria of different genera; the use of these probiotics in daily diets, health sand or drinking water can improve the growth performance and immunity of meat pigeons to varying degrees.

[0004] However, in meat pigeon breeding, the majority of currently used probiotic products are derived from other animals or artificially synthesized, rather than directly isolated from the intestines of healthy meat pigeons. While these exogenous probiotics can improve the growth performance of meat pigeons to a certain extent, they can also disrupt the original intestinal flora and even affect the unique traits of a particular breed. While there have been a few reports on the use of pigeon-derived intestinal strains to prepare probiotic products, relevant research remains scarce, particularly regarding the improvement of antioxidant capacity in late-stage meat pigeons.

[0005] Therefore, in the process of feeding meat breeder pigeons, developing a probiotic composition that can improve the antioxidant properties of meat breeder pigeons in the late growth stage has become one of the problems that technicians in this field urgently need to solve. Summary of the Invention

[0006] In view of the shortcomings of the above-mentioned prior art, the present invention provides a probiotic composition, preparation method, and application for enhancing the antioxidant properties of meat-breeding pigeons in their final stages of growth. The probiotic composition provided by the present invention combines Bacillus cereus MYZ425, isolated from the intestines of healthy meat-breeding pigeons, with Lactobacillus plantarum and Saccharomyces boulardii to form a highly effective antioxidant and anti-apoptotic probiotic preparation. This probiotic preparation not only enhances the antioxidant properties of meat-breeding pigeons, but also improves intestinal health and enhances immunity.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] The present invention provides a probiotic composition for improving the antioxidant performance of meat-breeding pigeons in the late growth stage. The probiotic composition is composed of the following components: Bacillus cereus MYZ425 freeze-dried powder, Lactobacillus plantarum freeze-dried powder and Saccharomyces boulardii freeze-dried powder; the mass ratio of the Bacillus cereus MYZ425 freeze-dried powder, Lactobacillus plantarum freeze-dried powder and Saccharomyces boulardii freeze-dried powder is 1:(2-3):(3-5); the Bacillus cereus MYZ425 strain is derived from the intestine of meat pigeons, and the Bacillus cereus MYZ425 has been deposited in the General Microbiology Center of the China Culture Collection of Microorganisms on August 17, 2022, and is classified and named Bacillus cereus, with a preservation number of CGMCC NO.25548. The address of the preservation unit is: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, Postal Code: 100101.

[0009] Preferably, the mass ratio of the Bacillus cereus MYZ425 freeze-dried powder, the Lactobacillus plantarum freeze-dried powder and the Saccharomyces boulardii freeze-dried powder is 1:2:3.

[0010] Preferably, in the probiotic composition, the viable count of the Bacillus cereus MYZ425 freeze-dried powder is 5×10 11 CFU / g.

[0011] Preferably, in the probiotic composition, the viable count of the Lactobacillus plantarum freeze-dried powder is 6×10 8 CFU / g.

[0012] Preferably, in the probiotic composition, the viable bacteria count of the freeze-dried powder of Saccharomyces boulardii is 9×10 8 CFU / g.

[0013] The present invention also provides a method for preparing the probiotic composition for improving the antioxidant properties of late-growth meat breeder pigeons, comprising the following steps:

[0014] Strain activation and culture: Streak Bacillus cereus MYZ425 onto a solid LB plate and incubate at 30°C for 24 hours. Then, select a mature single colony and transfer it to LB broth and incubate at 150 rpm and 30°C for 24 hours to obtain a seed culture.

[0015] S2. Bacterial fermentation: The seed culture in step S1 was inoculated with a volume ratio of 5% into the fermentation medium in the fermenter, and the fermentation conditions were set to pH 8.0, a speed of 230 rpm, and a temperature of 28 ° C. The culture was carried out for 48 h to obtain a fermentation broth of Bacillus cereus MYZ425;

[0016] S3. Preparation of Bacillus cereus MYZ425 lyophilized powder: The Bacillus cereus MYZ425 fermentation broth obtained in step S2 was mixed evenly with a lyoprotectant, pre-frozen at -80°C for 2h, and then freeze-dried at -50°C and 10Pa for 14h to obtain Bacillus cereus MYZ425 lyophilized powder;

[0017] S4. Preparation of a probiotic composition: The Bacillus cereus MYZ425 freeze-dried powder obtained in step S3 was mixed evenly with the purchased Lactobacillus plantarum freeze-dried powder and Saccharomyces boulardii freeze-dried powder according to a certain proportion to obtain a probiotic composition.

[0018] Preferably, in step S2, the components of the fermentation medium are: corn steep liquor 15 g / L, peptone 2.0 g / L, NaCl 1.0 g / L, K2HPO4 2.0 g / L, CaCl2-2H2O 0.2 g / L, MgSO4-7H2O 0.1 g / L, and yeast powder 0.5 g / L.

[0019] Preferably, in step S3, each 100 mL of the lyoprotectant contains 11 g of skim milk powder, 11 g of oligofructose and 5 g of sodium glutamate, and the volume ratio of the lyoprotectant to the fermentation broth of Bacillus cereus MYZ425 is 1:1.

[0020] The present invention also discloses the use of the probiotic composition in preparing a product for improving the antioxidant performance of meat breeding pigeons in the late growth stage.

[0021] Preferably, the probiotic composition is added to the feed of meat-breeding pigeons in the late growth stage, and the mass ratio of the probiotic composition to the feed is (1-2):100.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention prepares a probiotic composition by mixing Bacillus cereus MYZ425, isolated from the intestines of healthy meat-breeding pigeons, with Lactobacillus plantarum and Saccharomyces boulardii. The antioxidant enzymes produced by Bacillus cereus MYZ425 work together with the antioxidant metabolites of Lactobacillus plantarum and Saccharomyces boulardii to form a multi-layered antioxidant network, effectively neutralizing free radicals and reducing cellular damage caused by oxidative stress, as follows:

[0024] (i) Lactobacillus plantarum can produce lactic acid in the intestine, provide a low pH environment, inhibit the growth of harmful microorganisms, reduce intestinal inflammatory reactions, and also has antioxidant capacity, can scavenge free radicals, reduce the damage of oxidative stress to cells, thereby enhancing the antioxidant capacity of meat pigeons; the two strains of Bacillus cereus MYZ425 and Saccharomyces boulardii can secrete a variety of antioxidant substances (such as superoxide dismutase (SOD), catalase (CAT) and melatonin, etc.), which can not only directly neutralize free radicals and reduce the level of oxidative stress in the body, but also further enhance the body's reducing power by enhancing the activity of the host's antioxidant enzymes (such as superoxide dismutase SOD, glutathione peroxidase); in particular, melatonin, as a powerful antioxidant, has anti-apoptotic effects, helps protect cells from damage caused by oxidative stress, and maintains the normal function and survival rate of cells.

[0025] (ii) Simultaneously, Lactobacillus plantarum and Saccharomyces boulardii inhibit the growth of harmful bacteria through competitive exclusion, maintaining intestinal microecological balance and providing a suitable living environment for Bacillus cereus MYZ425, promoting its stable colonization and functional performance. The anti-apoptotic properties of Bacillus cereus MYZ425 help reduce apoptosis caused by long-term high-density rearing, protect the integrity of the intestinal mucosal barrier, and further enhance the overall disease resistance and antioxidant capacity of meat breeder pigeons. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The Gram staining image of Bacillus cereus MYZ425 provided by the present invention;

[0027] Figure 2 This is a diagram showing the changes in ovarian granulosa cells of meat breeder pigeons before and after the addition of the probiotics prepared by the invention. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without creative work are within the scope of protection of the present invention.

[0029] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0030] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0031] The present invention discloses a probiotic composition for improving the antioxidant performance of meat-breeding pigeons in the final growth stage. The probiotic composition is composed of Bacillus cereus MYZ425 freeze-dried powder, Lactobacillus plantarum freeze-dried powder and Saccharomyces boulardii freeze-dried powder in a mass ratio of 1:(2-3):(3-5), wherein the optimal ratio is that the mass ratio of Bacillus cereus MYZ425 freeze-dried powder, Lactobacillus plantarum freeze-dried powder and Saccharomyces boulardii freeze-dried powder is 1:2:3.

[0032] The Bacillus cereus MYZ425 strain originates from the intestine of a pigeon, and the Bacillus cereus MYZ425 is deposited in the General Microbiology Center of the China Culture Collection Administration of Microorganisms with a deposit number of CGMCC NO.25548 and a classification name of Bacillus cereus.

[0033] The present invention also provides a method for preparing the probiotic composition for improving the antioxidant properties of late-stage meat breeder pigeons, which comprises the following specific steps:

[0034] Strain activation and culture: Streak Bacillus cereus MYZ425 onto a solid LB plate and incubate at 30°C for 24 hours. Then, select a mature single colony and transfer it to LB broth and incubate at 150 rpm and 30°C for 24 hours to obtain a seed culture.

[0035] S2. Bacterial fermentation: The seed culture solution from step S1 was inoculated at a volume ratio of 5% into a fermentation medium in a fermenter (corn steep liquor 15 g / L, peptone 2.0 g / L, NaCl 1.0 g / L, K2HPO4 2.0 g / L, CaCl2-2H2O 0.2 g / L, MgSO4-7H2O 0.1 g / L, yeast powder 0.5 g / L). The fermentation conditions were set to pH 8.0, a rotation speed of 230 rpm, and a temperature of 28°C. The culture was incubated for 48 h to obtain a fermentation broth of Bacillus cereus MYZ425.

[0036] S3. Preparation of Bacillus cereus MYZ425 lyophilized powder: The Bacillus cereus MYZ425 fermentation broth obtained in step S2 was mixed with a lyoprotectant (11 g skim milk powder, 11 g oligofructose, and 5 g sodium glutamate per 100 mL of lyoprotectant) in a volume ratio of 1:1, pre-frozen at -80 ° C for 2 h, and then freeze-dried at -50 ° C and 10 Pa for 14 h to obtain Bacillus cereus MYZ425 lyophilized powder;

[0037] S4. Preparation of a probiotic composition: The Bacillus cereus MYZ425 freeze-dried powder obtained in step S3 was mixed evenly with the purchased Lactobacillus plantarum freeze-dried powder and Saccharomyces boulardii freeze-dried powder according to a certain proportion to obtain a probiotic composition.

[0038] Among them, in the probiotic composition prepared above, the number of viable bacteria of Bacillus cereus MYZ425 freeze-dried powder is 5×10 11 CFU / g, the number of viable bacteria of Lactobacillus plantarum freeze-dried powder is 6×10 8 CFU / g, the number of viable bacteria of Saccharomyces boulardii freeze-dried powder is 9×10 8 CFU / g.

[0039] The present invention also provides the use of the probiotic composition in preparing a product for improving the antioxidant performance of meat breeding pigeons in the late growth stage.

[0040] The probiotic composition is added into the feed of meat-breeding pigeons in the late growth stage, and the mass ratio of the probiotic composition to the feed is (1-2):100.

[0041] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0042] Example 1

[0043] 1. Isolation, screening, identification and preservation of Bacillus cereus MYZ425

[0044] 1.1 Strain isolation and purification

[0045] Primary screening culture medium: corn steep liquor 15 g / L, peptone 2.0 g / L, NaCl 1.0 g / L, K2HPO4 2.0 g / L, CaCl2-2H2O 0.2 g / L, MgSO4-7H2O 0.1 g / L, yeast powder 0.5 g / L.

[0046] Rescreened inorganic salt liquid culture medium: alkaline lignin 5 g, potassium dihydrogen phosphate 1 g, dipotassium hydrogen phosphate 1 g, magnesium sulfate 0.2 g, anhydrous calcium chloride 0.1 g, ferrous sulfate 0.05 g, manganese chloride 0.02 g, ammonium sulfate 2 g, distilled water 1000 mL, pH 7.0.

[0047] (1) Primary screening: Prepare culture medium (corn steep liquor 15 g / L, peptone 2.0 g / L, NaCl 1.0 g / L, K2HPO4 2.0 g / L, CaCl2-2H2O 0.2 g / L, MgSO4-7H2O 0.1 g / L, yeast powder 0.5 g / L) was sterilized at 121° C. for 30 min, and then 4-5 g of the pigeon small intestine content and 100 mL of the above culture medium were placed in a conical flask, and cultured on a shaking table at 30° C. and 120 rpm for 3 days to obtain a bacterial liquid; 100 μL of the bacterial liquid after shaking culture was taken out and evenly coated on the surface of a pre-prepared inorganic salt culture dish (1 g of potassium dihydrogen phosphate, 1 g of potassium hydrogen phosphate, 0.2 g of magnesium sulfate, 0.1 g of anhydrous calcium chloride, 0.05 g of ferrous sulfate, 0.02 g of manganese chloride, 2 g of ammonium sulfate, 1000 mL of distilled water, pH 7.0) with guaiacol as the sole carbon source, and the coated culture dish was placed in a constant temperature incubator at 37° C. in the dark for culturing for 72 hours, and preliminary screening was performed based on phenotypic differences such as the morphology, color, and size of the colonies.

[0048] (2) Rescreening: ① Select the colonies with better growth from the single colonies screened above, pick each selected colony with a high-temperature sterilized toothpick and inoculate it into an inorganic salt liquid culture medium, and culture it at 37°C for more than 24 hours until the culture medium becomes turbid; ② Prepare a BM culture medium plate containing aniline blue, use high-temperature sterilized tweezers to transfer the above bacterial spots inoculated in the inorganic salt liquid culture medium (5 per batch) to the BM culture medium plate in batches, and culture it in a constant temperature incubator at 37°C in the dark for more than 24 hours until a blue color circle appears; ③ According to the size of the color circle, select the 20 best performing colonies from each batch and re-screen. Use high-temperature sterilized toothpicks to inoculate these colonies into new inorganic salt liquid culture medium, divide them into three batches for treatment, and culture them at 35°C for more than 24 hours; ④ Then, use an inoculation loop to streak 5 colonies from each batch (20 in total) onto the corresponding solid culture medium plate from the above-mentioned inorganic salt liquid culture medium, and culture them in the dark in a constant temperature incubator at 37°C for more than 24 hours to form clearly identifiable single colonies; ⑤ Use a high-temperature sterilized toothpick to pick up the single colony with good growth and transfer it to a new inorganic salt liquid culture medium, culture it in a shaker at 35°C for more than 24 hours, and further separate and purify it to obtain a strain named MYZ425.

[0049] 1.2 Taxonomic identification and preservation of strains

[0050] The strain MYZ425 obtained above was subjected to Gram staining and microscopic examination. Figure 1 As shown, the isolated strain is purple and belongs to Gram-positive bacteria.

[0051] A single colony was picked and genomic DNA was extracted using a DNA extraction kit. The genomic DNA was amplified by PCR using 16s rDNA universal primers and then sent to Shanghai Sangon Biotechnology Co., Ltd. for sequencing. The 16s rDNA gene sequence of strain MYZ425 was obtained as shown in SEQ ID NO.1. The sequence was entered into the NCBI website for BLAST comparison, which showed that strain MYZ425 belonged to the genus Bacillus.

[0052] The physiological and biochemical characteristics of MYZ425 were identified in accordance with the Manual of Identification of Common Bacteria Systems, as shown in Table 1 below. As can be seen from Table 1, the strain MYZ425 cannot produce acid and gas by fermenting mannitol, lactose, galactose, xylose, and arabinose, has no motility, cannot grow in 10% NaCl, and cannot grow normally at 5°C and 45°C. All other reactions are positive. Based on the individual morphological characteristics, colony morphological characteristics and the results of the above physiological and biochemical tests of the strain MYZ425, with reference to the Bergey's Manual of Identification of Bacteria and the Manual of Identification of Common Bacteria Systems, the strain MYZ425 was identified as Bacillus cereus, classified and named: Bacillus cereus, and deposited in the General Microbiology Center of the China Microorganism Culture Collection Administration, with a deposit date of August 17, 2022, and a deposit number of CGMCC. No. 25548. Address of the depository: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, China 100101.

[0053] Table 1 Physiological and biochemical identification results of strain MYZ425

[0054]

[0055]

[0056] Note: In the table, “+” indicates positive, and “-” indicates negative.

[0057] SEQ ID NO.1:

[0058] ttatggaga gtttgatcct ggctcaggat gaacgccggc ggcgtgccta atacatgcaa

[0059] gtcgagcgaa tggattaaga gcttgctctt atgaagttag cggcggacgg gtgagtaaca

[0060] cgtgggtaac ctgcccataa gactgggata actccgggaa accggggcta ataccggata

[0061] acattttgaa ccgcatggtt cgaaattgaa aggcgacttc ggctgtcact tatggatgga

[0062] cccgcgtcgc attagctagt tggtgaggta acggctcacc aaggcaacga tgcgtagccg

[0063] acctgagagg gtgatcggcc acactgggac tgagacacgg cccagactcc tacgggaggc

[0064] agcagtaggg aatcttccgc aatggacgaa agtctgacgg agcaacgccg cgtgagtgat

[0065] gaaggctttc gggtcgtaaa actctgttgt taggaagaa caagtgctag ttgaataagc

[0066] tggcaccttg acggtaccta accagaaagc cacggctaac tacgtgccag cagccgcggt

[0067] aatacgtagg tggcaagcgt tatccggaat tattgggcgt aaagcgcgcg caggtggttt

[0068] cttaagtctg atgtgaaagc ccacggctca accgtggagg gtcattggaa actgggagac

[0069] ttgagtgcag aaggaaag tggaattcca tgtgtagcgg tgaaatgcgt agagatatgg

[0070] aggaacacca gtggcgaagg cgactttctg gtctgaaact gacactgagg cgcgaaagcg

[0071] tggggagcaa acaggattag ataccctggt agtccacgcc gtaaacgatg agtgctaagt

[0072] gttagagggt ttccgccctt tcgtgctgaa gttaacgcat taagcactcc gcctggggag

[0073] tacggccgca aggctgaaac tcaaaggaat tgacggggc ccgcacaagc ggtggagcat

[0074] gtggtttaat tcgaagcaac gcgaagaacc ttaccaggtc ttgacatcct ctgaaaaccc

[0075] tagagagatagg gcttctcctt cgggagcaga gtgacaggtg gtgcatggtt gtcgtcagct

[0076] cgtgtcgtga gatgttgggt taagtcccgc aacgagcgca acccttgatc ttagttgcca

[0077] tcattaagtt gggcactcta aggtgactgc cggtgacaaa ccggaggaag gtggggatga

[0078] cgtcaaatca tcatacccct tatgacctgg gctacacacg tgctacaatg gacggtacaa

[0079] agagctgcaa gaccgcgagg tggagctaat ctcataaaac cgttctcagt tcggattgta

[0080] ggctgcaact cgcctacatg aagctgggaat cgctagtaat cgcggatcag catgccgcgg

[0081] tgaatacgtt cccgggcctt gtacacaccg cccgtcacac cacgagagtt tgtaacaccc

[0082] gaagtcggtg gggtaacctt tttggagcca gccgcctaag gtgggacaga tgattggggt

[0083] g.

[0084] Example 2

[0085] The preparation method of the probiotic composition in this embodiment comprises the following specific steps:

[0086] Strain activation and culture: Streak Bacillus cereus MYZ425 onto a solid LB plate and incubate at 30°C for 24 h. Then, select a mature single colony and transfer it to a liquid culture medium containing LB broth. Incubate at 150 rpm and 30°C for 24 h to obtain a seed culture.

[0087] S2. Bacterial liquid fermentation: The seed culture liquid in step S1 was inoculated into the fermentation medium in the fermentation tank (corn steep liquor 15 g / L, peptone 2.0 g / L, NaCl 1.0 g / L, K2HPO4 2.0 g / L, CaCl2-2H2O 0.2 g / L, MgSO4-7H2O 0.1 g / L, yeast powder 0.5 g / L) at a volume ratio of 5%. The fermentation conditions were set to pH 8.0, a rotation speed of 230 rpm, and a temperature of 28°C. The culture was cultured for 48 hours to obtain Bacillus cereus MYZ425 fermentation liquid.

[0088] S3. Preparation of Bacillus cereus MYZ425 lyophilized powder: The Bacillus cereus MYZ425 fermentation broth obtained in step S2 was mixed with a lyophilization protectant (each 100 mL of lyophilization protectant contained 11 g of skim milk powder, 11 g of oligofructose and 5 g of sodium glutamate) in a volume ratio of 1:1, pre-frozen at -80°C for 2 h, and then freeze-dried at -50°C and 10 Pa for 14 h to obtain Bacillus cereus MYZ425 lyophilized powder.

[0089] S4. Preparation of a probiotic composition: The Bacillus cereus MYZ425 freeze-dried powder obtained in step S3 was uniformly mixed with freeze-dried Lactobacillus plantarum powder and freeze-dried Saccharomyces boulardii powder purchased from Weikang Probiotics Co., Ltd. in a mass ratio of 1:2:3 to prepare a probiotic composition.

[0090] Example 3

[0091] The preparation method of the probiotic composition in this embodiment comprises the following specific steps:

[0092] Strain activation and culture: Streak Bacillus cereus MYZ425 onto a solid LB plate and incubate at 30°C for 24 h. Then, select a mature single colony and transfer it to a liquid culture medium containing LB broth. Incubate at 150 rpm and 30°C for 24 h to obtain a seed culture.

[0093] S2. Bacterial liquid fermentation: The seed culture liquid in step S1 was inoculated into the fermentation medium in the fermentation tank (corn steep liquor 15 g / L, peptone 2.0 g / L, NaCl 1.0 g / L, K2HPO4 2.0 g / L, CaCl2-2H2O 0.2 g / L, MgSO4-7H2O 0.1 g / L, yeast powder 0.5 g / L) at a volume ratio of 5%. The fermentation conditions were set to pH 8.0, a rotation speed of 230 rpm, and a temperature of 28°C. The culture was cultured for 48 hours to obtain Bacillus cereus MYZ425 fermentation liquid.

[0094] S3. Preparation of Bacillus cereus MYZ425 lyophilized powder: The Bacillus cereus MYZ425 fermentation broth obtained in step S2 was mixed with a lyophilization protectant (each 100 mL of lyophilization protectant contained 11 g of skim milk powder, 11 g of oligofructose and 5 g of sodium glutamate) in a volume ratio of 1:1, pre-frozen at -80°C for 2 h, and then freeze-dried at -50°C and 10 Pa for 14 h to obtain Bacillus cereus MYZ425 lyophilized powder.

[0095] S4. Preparation of a probiotic composition: The Bacillus cereus MYZ425 freeze-dried powder obtained in step S3 was uniformly mixed with freeze-dried Lactobacillus plantarum powder and freeze-dried Saccharomyces boulardii powder purchased from Weikang Probiotics Co., Ltd. in a mass ratio of 1:2:4 to prepare a probiotic composition.

[0096] Example 4

[0097] The preparation method of the probiotic composition in this embodiment comprises the following specific steps:

[0098] Strain activation and culture: Streak Bacillus cereus MYZ425 onto a solid LB plate and incubate at 30°C for 24 h. Then, select a mature single colony and transfer it to a liquid culture medium containing LB broth. Incubate at 150 rpm and 30°C for 24 h to obtain a seed culture.

[0099] S2. Bacterial liquid fermentation: The seed culture liquid in step S1 was inoculated into the fermentation medium in the fermentation tank (corn steep liquor 15 g / L, peptone 2.0 g / L, NaCl 1.0 g / L, K2HPO4 2.0 g / L, CaCl2-2H2O 0.2 g / L, MgSO4-7H2O 0.1 g / L, yeast powder 0.5 g / L) at a volume ratio of 5%. The fermentation conditions were set to pH 8.0, a rotation speed of 230 rpm, and a temperature of 28°C. The culture was cultured for 48 hours to obtain Bacillus cereus MYZ425 fermentation liquid.

[0100] S3. Preparation of Bacillus cereus MYZ425 lyophilized powder: The Bacillus cereus MYZ425 fermentation broth obtained in step S2 was mixed with a lyophilization protectant (each 100 mL of lyophilization protectant contained 11 g of skim milk powder, 11 g of oligofructose and 5 g of sodium glutamate) in a volume ratio of 1:1, pre-frozen at -80°C for 2 h, and then freeze-dried at -50°C and 10 Pa for 14 h to obtain Bacillus cereus MYZ425 lyophilized powder.

[0101] S4. Preparation of a probiotic composition: The Bacillus cereus MYZ425 freeze-dried powder obtained in step S3 was uniformly mixed with the freeze-dried powder of Lactobacillus plantarum and freeze-dried powder of Saccharomyces boulardii purchased from Weikang Probiotics Co., Ltd. in a mass ratio of 1:3:5 to prepare a probiotic composition.

[0102] Example 5

[0103] This example is the use of the probiotic composition prepared in Example 2 in meat breeder pigeons at the end of their growth period.

[0104] The probiotic composition prepared in Example 2 was added to the daily basal feed of meat breeder pigeons, and the mixture was added and mixed according to the mass ratio of the probiotic composition to the feed of 0.5:100, 1:100, 1.5:100, and 2:100, respectively.

[0105] 300 healthy European meat pigeons of similar age and weight were randomly selected and divided into 5 groups (Group A, Group B, Group C, Group D, and Group E), with 6 replicates in each group and 10 meat pigeons in each replicate for feeding; the control group consisted of Group A: a basic diet without the addition of the probiotic composition, Group B: the mass ratio of the probiotic composition to the basic diet was 0.5:100, Group C: the mass ratio of the probiotic composition to the basic diet was 1:100, Group D: the mass ratio of the probiotic composition to the basic diet was 1.5:100, and Group E: the mass ratio of the probiotic composition to the basic diet was 2:100; the experiment was carried out in Henan Tianming Pigeon Industry Co., Ltd., and after feeding for 4 weeks, the meat pigeons in each group were tested, and blood was taken from the wing vein of the meat pigeons in each group to detect antioxidant indicators. At the same time, the birth weight of the squabs was monitored, and the test results are shown in Table 2.

[0106] Table 2

[0107]

[0108] As can be seen from Table 2, after adding the probiotic composition to the diet: the total antioxidant capacity, glutathione peroxidase, and total superoxide dismutase contents of each group of meat breeding pigeons increased. This is because these enzymes can effectively scavenge free radicals in the body, reduce the damage of oxidative stress to cells, and protect cells from the effects of oxidative stress; the malondialdehyde (MDA) content in the serum of each group of meat breeding pigeons decreased significantly, indicating that the level of oxidative stress was effectively controlled, the lipid peroxidation reaction of the cell membrane was reduced, and the cell structure and function were better protected; the lactate dehydrogenase content in the meat breeding pigeons of each group decreased significantly, indicating that the antioxidant mechanism in the cells was effectively activated, reducing the damage of oxidative stress to the cell structure.

[0109] At the same time, it can be seen from Table 2 that after feeding the probiotic composition prepared in Example 2 of the present invention, the birth weight of the squabs hatched by each group of meat breeder pigeons was significantly increased compared with the control group. This is because the Lactobacillus plantarum and Saccharomyces boulardii in the probiotic composition can secrete a variety of digestive enzymes (such as proteases, cellulases, etc.) to promote the absorption of nutrients, and Bacillus cereus MYZ425 maintains intestinal barrier function by regulating the balance of intestinal microecology, further improving nutrient absorption efficiency and promoting intestinal nutrient absorption.

[0110] The ovarian tissues of the meat breeder pigeons in Groups A, B, C, D and E after 4 weeks of feeding were observed by paraffin section. The changes in ovarian granulosa cells before and after the addition of the probiotic composition are shown in the figure below. Figure 2 As shown. Figure 2It can be seen that after feeding the probiotic composition prepared in Example 2 of the present invention, the ovarian granulosa cells of each group of meat breeder pigeons are evenly distributed and compact, the cell density is significantly increased, and the apoptosis phenomenon is significantly reduced; this indicates that the probiotic composition helps maintain the health of the ovaries, effectively reduces cell damage caused by oxidative stress, maintains the functional stability of the ovaries, helps to increase the egg production rate, prolong the breeding cycle of meat breeder pigeons, and thus comprehensively improves the overall reproductive performance.

[0111] The above is a detailed introduction to the probiotic composition disclosed in the present invention for improving the antioxidant properties of meat-breeding pigeons in the late growth stage, as well as its preparation method and application. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in several ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A probiotic composition for improving the antioxidant properties of late-stage meat breeder pigeons, characterized in that: The probiotic composition consists of the following components: Bacillus cereus MYZ425 freeze-dried powder, Lactobacillus plantarum freeze-dried powder and Saccharomyces boulardii freeze-dried powder, wherein the mass ratio of the Bacillus cereus MYZ425 freeze-dried powder, the Lactobacillus plantarum freeze-dried powder and the Saccharomyces boulardii freeze-dried powder is 1:(2-3):(3-5); the Bacillus cereus MYZ425 is deposited in the General Microbiology Center of China National Microbiological Culture Collection Committee with a deposit number of CGMCC NO.25548 and a classification name of Bacillus cereus; The Bacillus cereus MYZ425 strain originates from the intestine of a pigeon.

2. A probiotic composition for improving the antioxidant properties of late-stage meat breeder pigeons according to claim 1, characterized in that: The mass ratio of the Bacillus cereus MYZ425 freeze-dried powder, the Lactobacillus plantarum freeze-dried powder and the Saccharomyces boulardii freeze-dried powder is 1:2:

3.

3. A probiotic composition for improving the antioxidant performance of late-stage meat breeder pigeons according to claim 1, characterized in that: In the probiotic composition, the number of viable bacteria of the Bacillus cereus MYZ425 freeze-dried powder is 5×10 11 CFU / g.

4. A probiotic composition for improving the antioxidant performance of late-stage meat breeder pigeons according to claim 1, characterized in that: In the probiotic composition, the viable count of the Lactobacillus plantarum freeze-dried powder is 6×10 8 CFU / g.

5. The probiotic composition for improving the antioxidant performance of late-stage meat breeder pigeons according to claim 1, characterized in that: In the probiotic composition, the number of viable bacteria of the lyophilized powder of Saccharomyces boulardii is 9×10 8 CFU / g.

6. The method for preparing the probiotic composition for improving the antioxidant performance of late-stage meat breeder pigeons according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Activation and cultivation of strains: streak Bacillus cereus MYZ425 on a LB solid plate, culture at 30°C for 24 hours, pick a mature single colony and transfer it into a liquid culture medium of LB broth, culture it at 150 rpm and 30°C for 24 hours to obtain a seed culture solution; S2. Bacterial fermentation: The seed culture solution in step S1 was inoculated with a volume ratio of 5% into the fermentation medium in the fermenter, and the fermentation conditions were set to pH 8.0, a speed of 230 rpm, and a temperature of 28 ° C. The culture was carried out for 48 hours to obtain a fermentation solution of Bacillus cereus MYZ425; S3. Preparation of Bacillus cereus MYZ425 lyophilized powder: The Bacillus cereus MYZ425 fermentation broth obtained in step S2 was mixed evenly with a lyophilization protective agent, pre-frozen at a temperature of -80°C for 2 hours, and then freeze-dried at a temperature of -50°C and 10Pa for 14 hours to obtain Bacillus cereus MYZ425 lyophilized powder; S4. Preparation of a probiotic composition: The Bacillus cereus MYZ425 freeze-dried powder obtained in step S3 is uniformly mixed with the purchased Lactobacillus plantarum freeze-dried powder and Saccharomyces boulardii freeze-dried powder according to a certain proportion, so as to prepare a probiotic composition.

7. The method for preparing the probiotic composition for improving the antioxidant performance of late-stage meat breeder pigeons according to claim 6, characterized in that: In step S2, the components of the fermentation medium are: corn steep liquor 15 g / L, peptone 2.0 g / L, NaCl 1.0 g / L, K2HPO4 2.0 g / L, CaCl2-2H2O 0.2 g / L, MgSO4-7H2O 0.1 g / L, and yeast powder 0.5 g / L.

8. The method for preparing the probiotic composition for improving the antioxidant performance of late-stage meat breeder pigeons according to claim 6, characterized in that: In step S3, each 100 mL of the lyophilized protective agent contains 11 g of skim milk powder, 11 g of oligofructose and 5 g of sodium glutamate, and the volume of the lyophilized protective agent and the fermentation broth of Bacillus cereus MYZ425 is 1:

1.

9. Use of the probiotic composition according to any one of claims 1 to 5 in the preparation of a product for improving the antioxidant properties of meat breeder pigeons at the end of growth.

10. The use of the probiotic composition according to claim 9, characterized in that: The probiotic composition is added into the feed of meat pigeons in the late growth stage, and the mass ratio of the probiotic composition to the feed is (1-2):100.

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