Feed for improving meat quality of Songliao black pigs by cooperatively replacing soybean meal with fermented miscellaneous meal and application of feed

Abstract

The invention belongs to the technical field of livestock and poultry breeding and feed formulas, and particularly relates to feed for improving the meat quality of Songliao black pigs by cooperatively replacing soybean meal with fermented miscellaneous meal and application. The feed is prepared from the following components in parts by mass: 60 to 65 parts of corn, 8 to 12 parts of fermented peanut meal, 6 to 10 parts of fermented sesame seed meal, 3 to 5 parts of soybean meal, 4 to 6 parts of bran, 3 to 5 parts of rice bran, 1 to 2 parts of fish meal, 0.8 to 1.2 parts of stone powder, 0.6 to 0.9 part of calcium hydrogen phosphate, 0.3 to 0.5 part of table salt, 0.2 to 0.4 part of amino acid premix, 0.1 to 0.2 part of vitamin premix, 0.1 to 0.2 part of mineral premix and 0.05 to 0.1 part of compound enzyme preparation, wherein the total mass of the feed is 100 parts. Wherein the mass ratio of the fermented peanut meal to the fermented sesame meal is (1.0-1.5): 1, the proportion of the fermented peanut meal and the fermented sesame meal for synergistically replacing the soybean meal is 70%-85%, the crude protein content of the feed is kept at 16%-18%, and the feed meets the protein requirement of the Songliao black pigs in the fattening period. The feed can meet the growth and metabolism requirements of the Songliao black pigs, and the meat quality is remarkably improved while the breeding cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of livestock and poultry breeding and feed formulation technology, specifically relating to a novel protein feed for Songliao black pigs and its application. In particular, it relates to a feed formulation and feeding method that uses peanut meal and sesame meal to synergistically replace soybean meal, thereby significantly improving the pork quality of Songliao black pigs. It is suitable for large-scale feeding of Songliao black pigs during the fattening period, taking into account both breeding cost control and pork quality optimization. Background Technology

[0002] Songliao Black Pig is a high-quality breed independently developed in my country, combining the bloodlines of Duroc, Landrace, and local Northeast black pigs. This breed is characterized by fast growth, strong resistance, excellent reproductive performance, and tender meat. Its intramuscular fat content, meat color brightness, and flavor substance content are all superior to ordinary commercial pigs. It is a distinctive pig breed that meets consumers' demand for high-quality food and has extremely high breeding and promotion value.

[0003] Currently, soybean meal is a core protein feed ingredient in the pig farming industry, accounting for over 60% of protein feed usage. However, it is highly dependent on imports, and its price fluctuates wildly due to factors such as international grain market volatility and trade policy adjustments. This results in high costs for large-scale Songliao Black Pig farming, hindering the industrial development of this breed. Furthermore, the amino acid profile of traditional single-soybean meal feeds does not fully match the growth and metabolic needs of Songliao Black Pigs. Long-term feeding with soybean meal can lead to insufficient tenderness and intramuscular fat accumulation in pork, making it difficult to fully realize the genetic advantages of Songliao Black Pig meat quality. Excessive use of soybean meal can also cause nutritional imbalances in feed and increase nitrogen emissions from livestock waste, which is inconsistent with the concept of green farming.

[0004] Peanut meal and sesame meal are byproducts of oilseed crops after oil extraction. They are high-quality protein resources among miscellaneous oilseed meals. Peanut meal has a crude protein content of 45%-48%, and sesame meal has a crude protein content of 43%-46%, both close to the protein level of soybean meal (46%-48%). They are also rich in unsaturated fatty acids, vitamin E, calcium, phosphorus, lysine, methionine, and other nutrients. They are widely available and inexpensive, and can reduce feed raw material costs by 15%-25% compared to soybean meal, making them ideal substitutes for soybean meal.

[0005] However, the application of peanut meal and sesame meal in existing technologies has obvious limitations: First, both contain anti-nutritional factors such as phytic acid, tannins, and trypsin inhibitors, which will reduce feed digestibility and utilization, affect the absorption of nutrients by Songliao black pigs, and thus restrict growth performance and meat quality. Second, replacing soybean meal with a single mixed meal can easily lead to an imbalance in amino acid ratio, which cannot meet the nutritional needs of Songliao black pigs during the fattening period, and the replacement ratio has not been optimized for the breed characteristics of Songliao black pigs. Third, existing mixed meal replacement technologies mostly focus on general pig breeds and have not combined with the meat formation mechanism of Songliao black pigs to design synergistic formulas, making it difficult to achieve the dual goals of replacing soybean meal and improving meat quality. In fact, improper replacement ratios may even lead to a decline in pork flavor and a deterioration in meat color.

[0006] Therefore, developing a feed and its application method that can solve the problem of anti-nutritional factors in peanut meal and sesame meal, optimize the synergistic substitution ratio, adapt to the growth and metabolic needs of Songliao black pigs, and significantly improve meat quality while reducing breeding costs has become an urgent technical problem to be solved in the current large-scale breeding of Songliao black pigs. Summary of the Invention

[0007] The purpose of this invention is to provide a feed and its application that uses fermented mixed meals to synergistically replace soybean meal to improve the quality of Songliao black pig meat, in order to solve the problems of high dependence on soybean meal and high breeding costs in existing Songliao black pig feed, as well as the limitations of anti-nutritional factors and poor meat quality improvement effect of single substitution with peanut meal and sesame meal.

[0008] This invention is achieved through the following technical solution:

[0009] A fermented mixed meal synergistically replaces soybean meal to improve the quality of Songliao black pork. Based on 100 parts by total feed weight, it consists of the following components: 60-65 parts corn, 8-12 parts fermented peanut meal, 6-10 parts fermented sesame meal, 3-5 parts soybean meal, 4-6 parts wheat bran, 3-5 parts rice bran, 1-2 parts fish meal, 0.8-1.2 parts limestone powder, 0.6-0.9 parts dicalcium phosphate, 0.3-0.5 parts salt, 0.2-0.4 parts amino acid premix, 0.1-0.2 parts vitamin premix, 0.1-0.2 parts mineral premix, and 0.05-0.1 parts compound enzyme preparation.

[0010] The mass ratio of fermented peanut meal to fermented sesame meal is 1.0-1.5:1, and the two synergistically replace 70%-85% of soybean meal, ensuring that the crude protein content of the feed is maintained at 16%-18%, which meets the protein requirements of Songliao black pigs during the fattening period.

[0011] The application of a fermented mixed meal synergistically replacing soybean meal to improve the quality of Songliao black pig meat, and its application in large-scale feeding of Songliao black pigs during the fattening period to improve the quality of Songliao black pig meat.

[0012] The application of a fermented mixed meal synergistically replacing soybean meal to improve the quality of Songliao black pork includes the following steps:

[0013] S1. Preparation of fermented peanut meal and fermented sesame meal:

[0014] S11. Activation of bacterial strain: Bacillus subtilis and Saccharomyces cerevisiae are mixed at a mass ratio of 2:1 and inoculated into LB medium. The medium is shaken and cultured for 18-24 hours to obtain an activated bacterial strain solution with a concentration of 1×10⁸-5×10⁸ CFU / mL.

[0015] S12. Raw material pretreatment: Crush peanut meal and sesame meal into 80-100 mesh respectively to remove impurities, then add 20%-25% of their respective weights of water, stir evenly, and adjust the moisture content to 50%-55%;

[0016] S13. Fermentation treatment: Spray the activated inoculum solution into the pretreated peanut meal and sesame meal at a ratio of 3%-5% of the total mass of the raw materials, stir evenly, and then put them into a fermentation tank. Ferment at a constant temperature of 30-35℃ for 48-72 hours. After fermentation, dry at 60-65℃ until the moisture content is ≤12%, crush and set aside. The phytic acid removal rate after fermentation is ≥80%, and the tannin removal rate is ≥75%.

[0017] S14. Mixing and blending: Mix fermented peanut meal, fermented sesame meal, corn, remaining soybean meal, wheat bran and other components according to the formula ratio, add compound enzyme preparation, stir thoroughly and evenly, grind to 60-80 mesh, and make into pellet feed with a pellet diameter of 3-5 mm.

[0018] S2. Feeding:

[0019] During the fattening period of Songliao Black Pigs, they are fed with free access to feed and water, 3-4 times a day, with each feeding amount being 2.5%-3.0% of the pig's body weight. The feeding cycle is 30-45 days, until the pigs reach a weight of 110-120kg and are ready for slaughter.

[0020] Further, in step S11, culture with shaking at 30-32℃ and 180-200 r / min.

[0021] Furthermore, in step S13, the mixture is stirred once every 12 hours during the constant temperature fermentation.

[0022] Further, in step S14, the compound enzyme preparation is a mixture of cellulase, phytase, and protease in a mass ratio of 1:2:3.

[0023] Further, in step S2, the Songliao black pigs being fed weigh 60-110 kg.

[0024] Further, in step S2, during the feeding period, control the temperature of the breeding environment to 18-22℃ and the humidity to 60%-70%, ventilate 2-3 times a day for 30-60 minutes each time, clean up the feces regularly, and keep the breeding environment clean.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] 1. Significantly reduce breeding costs and achieve efficient substitution of soybean meal: Fermented peanut meal and sesame meal are used to replace 70%-85% of soybean meal, making full use of low-cost miscellaneous meal resources. Compared with traditional all-soybean meal feed, feed costs can be reduced by 15%-25%, while reducing dependence on imported soybean meal, improving the economic benefits of breeding and the industry's ability to resist risks.

[0027] 2. Solving the problem of anti-nutritional factors in mixed meals and improving nutrient utilization: Through the synergistic fermentation of Bacillus subtilis and Saccharomyces cerevisiae, anti-nutritional factors such as phytic acid and tannins in peanut meal and sesame meal are effectively removed. The phytic acid removal rate is ≥80% and the tannin removal rate is ≥75%. At the same time, large molecular proteins are degraded into small molecular peptides and amino acids. The digestibility and utilization rate of crude protein in feed for Songliao black pigs is increased by 10%-15%, reducing nutrient waste and nitrogen emissions from livestock waste, which is in line with the concept of green farming.

[0028] 3. Significantly improves the meat quality of Songliao black pigs: By optimizing the synergistic ratio of peanut meal and sesame meal, and combining precise nutritional supplementation, amino acid balance is achieved. At the same time, flavor-related nutrients such as unsaturated fatty acids and vitamin E are supplemented. After feeding, the shear force of the longissimus dorsi muscle of Songliao black pigs is reduced by 18%-25% (the meat is more tender), the intramuscular fat content is increased by 20%-30%, the meat color brightness (L* value) is increased by 8%-12%, the redness (a* value) is increased by 10%-15%, and the content of flavor substances (inosinic acid, fatty acids) is increased by 15%-20%. No PSE meat or DFD meat is produced, giving full play to the meat quality advantages of Songliao black pigs.

[0029] 4. Adapted to the characteristics of Songliao Black Pig breed, ensuring growth performance: The formula is precisely matched to the growth and metabolic needs of Songliao Black Pig during the fattening period. While improving meat quality, it does not affect the growth rate and survival rate of pigs. Experiments show that Songliao Black Pigs fed with the feed of this invention can gain 750-850g per day and have a survival rate of ≥98%, which is not significantly different from traditional soybean meal feed, thus taking into account both meat quality improvement and growth performance.

[0030] 5. Simple process and easy to scale up: The fermentation process and feed preparation process are mature, the required equipment is conventional, the raw materials are widely available, and it can be adapted to large-scale and standardized breeding models. There is no need to modify existing breeding equipment, and the cost of promotion and application is low. It is of great significance to promote the industrialization of Songliao black pig and promote the resource utilization of miscellaneous oilseed meals. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 The effect of fermented miscellaneous meals on α-diversity of cecal contents;

[0033] Figure 2 Bar chart comparing the relative abundance of core cecal microbiota in fermented miscellaneous meals of Songliao black pigs;

[0034] Figure 3 Bar chart comparing the relative content of core metabolites in the cecum of Songliao black pigs from fermented miscellaneous meals;

[0035] Figure 4 To investigate the pathway for the enrichment of KEGG, a differential metabolite in the cecum of Songliao black pigs, by fermented miscellaneous meal. Detailed Implementation

[0036] The present invention will be further described below with reference to embodiments:

[0037] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0038] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this invention, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0039] This invention addresses the problems of high dependence on soybean meal and high breeding costs in existing Songliao Black Pig feed, as well as the limitations of anti-nutritional factors and poor meat quality improvement effects of single substitution with peanut meal and sesame meal. It provides a feed and its application that uses peanut meal and sesame meal as a synergistic substitute for soybean meal, achieving multiple goals: reducing soybean meal consumption, lowering breeding costs, and significantly improving the meat quality of Songliao Black Pigs, thus promoting the green development of the Songliao Black Pig industry. To solve the problem of high breeding costs due to reliance on imported soybean meal in existing Songliao Black Pig feed, this invention utilizes low-cost peanut meal and sesame meal to achieve efficient substitution of soybean meal, reducing feed costs. Simultaneously, it optimizes the synergistic ratio of peanut meal and sesame meal to suit the growth and metabolic needs of Songliao Black Pigs during the fattening period, avoiding nutritional imbalances caused by single meal substitutions. The aim is to improve the intramuscular fat content, tenderness, meat color, and flavor compound content of pork through nutritional regulation, fully leveraging the genetic advantages of Songliao Black Pig meat quality.

[0040] This invention optimizes the synergistic ratio of peanut meal and sesame meal, combines microbial fermentation to remove anti-nutritional factors, and adds precise nutritional supplements to form a special feed suitable for the fattening period of Songliao black pigs.

[0041] Specifically, the feed of the present invention, which uses fermented mixed meals to synergistically replace soybean meal and improve the quality of Songliao black pork, is composed of the following components based on a total feed weight of 100 parts: 60-65 parts corn, 8-12 parts fermented peanut meal, 6-10 parts fermented sesame meal, 3-5 parts soybean meal, 4-6 parts wheat bran, 3-5 parts rice bran, 1-2 parts fish meal, 0.8-1.2 parts limestone powder, 0.6-0.9 parts dicalcium phosphate, 0.3-0.5 parts salt, 0.2-0.4 parts amino acid premix, 0.1-0.2 parts vitamin premix, 0.1-0.2 parts mineral premix, and 0.05-0.1 parts compound enzyme preparation.

[0042] The mass ratio of fermented peanut meal to fermented sesame meal is 1.0-1.5:1, and the two synergistically replace 70%-85% of soybean meal, ensuring that the crude protein content of the feed is maintained at 16%-18%, which meets the protein requirements of Songliao black pigs during the fattening period.

[0043] The application of the above-mentioned fermented mixed meal synergistically replacing soybean meal to improve the quality of Songliao black pork includes the following steps:

[0044] S1. Preparation of fermented peanut meal and fermented sesame meal:

[0045] S11. Strain activation: Bacillus subtilis and Saccharomyces cerevisiae are mixed at a mass ratio of 2:1 and inoculated into LB medium. The medium is incubated at 30-32℃ with shaking at 180-200 rpm for 18-24 hours to obtain an activated strain solution with a concentration of 1×10⁻⁶. 8 -5×10 8 CFU / mL;

[0046] S12. Raw material pretreatment: Crush peanut meal and sesame meal into 80-100 mesh respectively to remove impurities, then add 20%-25% of their respective weights of water, stir evenly, and adjust the moisture content to 50%-55%;

[0047] S13. Fermentation treatment: Spray the activated inoculum solution into the pretreated peanut meal and sesame meal at a ratio of 3%-5% of the total raw material mass. After stirring evenly, put them into a fermentation tank and ferment at a constant temperature of 30-35℃ for 48-72 hours. Stir once every 12 hours during the fermentation. After the fermentation is completed, dry at 60-65℃ until the moisture content is ≤12%. Crush and set aside for later use. The phytic acid removal rate after fermentation is ≥80%, and the tannin removal rate is ≥75%.

[0048] S14. Mixing and blending: Mix fermented peanut meal, fermented sesame meal, corn, remaining soybean meal, wheat bran and other components according to the formula ratio, add compound enzyme preparation (cellulase, phytase and protease mixed in a mass ratio of 1:2:3), stir thoroughly and evenly, grind to 60-80 mesh, and make into pellet feed with a pellet diameter of 3-5mm.

[0049] S2, Feeding:

[0050] This feed is suitable for Songliao Black Pigs weighing 60-110kg during the fattening period. It is fed with free access to feed and water, 3-4 times a day, with each feeding amount being 2.5%-3.0% of the pig's body weight. The feeding cycle is 30-45 days, until the pigs reach a weight of 110-120kg and are ready for slaughter.

[0051] During the feeding period, control the temperature of the breeding environment to 18-22℃ and the humidity to 60%-70%. Ventilate 2-3 times a day for 30-60 minutes each time, clean up the manure regularly, and keep the breeding environment clean.

[0052] Example 1

[0053] Preparation of feed substitutes for soybean meal using sesame meal and peanut meal:

[0054] 1. Per 100 kg, the feed composition is as follows: 62 kg corn, 10 kg fermented peanut meal, 8 kg fermented sesame meal, 4 kg soybean meal, 5 kg wheat bran, 4 kg rice bran, 1.5 kg fish meal, 1.0 kg limestone powder, 0.7 kg dicalcium phosphate, 0.4 kg salt, 0.3 kg amino acid premix, 0.15 kg vitamin premix, and 0.05 kg compound enzyme preparation. Among these, the mass ratio of fermented peanut meal to fermented sesame meal is 1.25:1, the proportion of soybean meal as a co-substitute is 78.9%, and the crude protein content of the feed is 17.2%.

[0055] 2. Preparation of fermentation raw materials:

[0056] 21. Strain activation: Bacillus subtilis and Saccharomyces cerevisiae were mixed at a mass ratio of 2:1 and inoculated into LB medium. The mixture was incubated at 31℃ with shaking at 190 rpm for 21 h to obtain a strain concentration of 3 × 10⁻⁶. 8 CFU / mL;

[0057] 22. Raw material pretreatment: Grind peanut meal and sesame meal into 90 mesh to remove impurities, add 22% of their own weight of water to each, stir evenly, and adjust the moisture content to 52%;

[0058] 23. Fermentation treatment: Spray the inoculum solution at a ratio of 4% of the total mass of raw materials onto the pretreated peanut meal and sesame meal respectively, stir evenly, and then put them into a fermentation tank. Ferment at a constant temperature of 32℃ for 60 hours, stirring once every 12 hours. After fermentation, dry at 62℃ until the moisture content is 10%, and then crush for later use. After testing, the phytic acid removal rate of peanut meal after fermentation was 82%, and the tannin removal rate of sesame meal was 78%.

[0059] 3. Preparation of finished product: Mix the above components according to the formula ratio, add the compound enzyme preparation, wherein the mass ratio of cellulase, phytase and protease is 1:2:3, stir thoroughly and evenly, grind to 70 mesh, press into pellet feed with a diameter of 4mm using a pellet feed machine, dry to a moisture content of ≤12%, and seal and package for later use.

[0060] Example 2

[0061] Growth performance and meat quality indicators testing:

[0062] 1. Experimental design: 120 healthy Songliao black pigs weighing 60±2kg were randomly divided into 2 groups, with 60 pigs in each group and 3 replicates per group, with 20 pigs in each replicate. The control group was fed with traditional whole soybean meal feed (17.0% crude protein), while the experimental group was fed with the feed prepared in this embodiment. The two groups had the same breeding environment and feeding method, with free access to feed and water, and were fed 3 times a day for 40 days.

[0063] 2. Testing indicators: At the beginning (day 0) and end (day 40) of the experiment, the weight of each pig in each group was measured on an empty stomach, the daily feed consumption was recorded, and the average daily weight gain, feed conversion ratio and survival rate were calculated; where average daily weight gain = (final weight - initial weight) / number of feeding days, and feed conversion ratio = total feed consumption / total weight gain.

[0064] 3. Growth performance test results: The experimental group had an average daily weight gain of 795g, a feed conversion ratio of 2.82:1, and a survival rate of 98.3%; the control group had an average daily weight gain of 780g, a feed conversion ratio of 3.05:1, and a survival rate of 98.0%. There was no significant difference in survival rate between the two groups (P>0.05). The average daily weight gain of the experimental group was 1.9% higher than that of the control group, and the feed conversion ratio was 7.5% lower, indicating that the feed of the present invention can optimize the growth efficiency of Songliao black pigs (see Table 2).

[0065] 4. Meat quality index test results: The shear force of the longissimus dorsi muscle in the experimental group was 30.20 N, which was significantly lower than that in the control group (38.87 N) by 22.3%. The intramuscular fat content in the experimental group was 4.12%, which was significantly higher than that in the control group (3.28%) by 25.7%. The meat color brightness (L value) of the experimental group was 52.30, which was higher than that in the control group (47.33) by 10.50%. The meat color redness (a value) was 14.60, which was higher than that in the control group (12.99) by 12.3%. The inosinic acid content in the experimental group was 3.85 mg / g, which was significantly higher than that in the control group (3.26 mg / g) by 18.2%. Fermented miscellaneous meal can optimize the meat quality characteristics of Songliao black pigs from multiple dimensions such as tenderness, fat deposition, meat color and flavor substances, as shown in Table 3.

[0066] Example 3

[0067] Blood biochemical indicators:

[0068] 1. Sample Collection: After the feeding trial period, samples were collected after a 12-hour fast (feeding was prohibited, but water was allowed freely) to eliminate the transient effects of feed digestion and absorption on serum biochemical indicators and ensure the comparability of data between groups. The experimental pigs were restrained, and the skin at the blood collection site in the anterior vena cava was repeatedly wiped with alcohol swabs for aseptic disinfection. The lancet was inserted into the blood vessel at a 30-45° angle. After blood flow was observed, the other end of the lancet was connected to a vacuum blood collection tube, and blood was collected using vacuum negative pressure. 4-5 mL of blood was collected from each pig. After collection, the blood collection site was immediately pressed with hemostatic cotton for 5-10 minutes until bleeding stopped, and the pigs were reassured. The collected blood sample was gently inverted and mixed 3-5 times to ensure sufficient contact between the blood and the coagulant. The blood collection tube was then placed vertically in a 4°C incubator and sent to the laboratory for processing within 2 hours. Violent shaking of the blood sample was avoided throughout the process. In the laboratory, blood samples are left to stand at room temperature for 30-60 minutes until the blood has completely coagulated before centrifugation. A refrigerated centrifuge is used with the parameters set to 4℃, 3500r / min, and centrifugation for 15 minutes. After centrifugation, the upper pale yellow serum layer is carefully aspirated with a pipette, avoiding aspirating the lower layer of blood cells and blood clots. The serum is then aliquoted into 1.5mL sterile centrifuge tubes, labeled, and immediately stored in an ultra-low temperature freezer at -80℃ for testing. If testing is to be conducted within 72 hours, the serum can be stored in a freezer at -20℃, avoiding repeated freeze-thaw cycles.

[0069] 2. Serum index determination: The fully automated biochemical analyzer was used with a dedicated reagent kit (total protein, albumin, globulin, total cholesterol, triglycerides, alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, creatinine). All reagents were within their expiration date and stored at 2-8℃. Before use, the reagents were brought to room temperature and mixed well.

[0070] 3. Experimental results: Compared with the control group, the serum total protein, albumin and globulin in the experimental group were slightly increased, while the total cholesterol and triglycerides were significantly increased. There were no significant differences in alanine aminotransferase, aspartate aminotransferase and creatinine with the control group. Urea nitrogen was significantly reduced. This indicates that fermented miscellaneous meal provides a good basis for lipid metabolism in Songliao black pigs, can promote protein absorption, improve immune level and ensure stable physiological function (see Table 4).

[0071] Example 4

[0072] Detection of gut microbiota and metabolites:

[0073] 1. Sample collection: After the feeding cycle, 6 pigs were randomly selected from each group and slaughtered on an empty stomach. The contents of the ileum and cecum were collected aseptically. One part was stored in a -80℃ refrigerator for intestinal flora detection; the other part was centrifuged (8000r / min, 4℃, 10min), and the supernatant was filtered through a 0.22μm filter membrane for metabolite detection.

[0074] 2. Intestinal flora detection:

[0075] 21. Total DNA extraction: Using a fecal DNA extraction kit, total microbial DNA was extracted from the contents of the ileum and cecum, and the purity and integrity of the DNA were tested.

[0076] 22. PCR amplification: Design specific primers targeting the V3-V4 region of the 16S rRNA gene for PCR amplification;

[0077] 23. High-throughput sequencing and analysis: After purifying and quantifying the amplification products, a sequencing library was constructed, and sequencing was performed using the Illumina MiSeq platform. Bioinformatics analysis was used to analyze the bacterial community diversity, species composition, and differential bacterial communities.

[0078] 3. Detection of intestinal metabolites: Metabolites in cecal contents, including short-chain fatty acids (acetic acid, propionic acid, butyric acid, etc.), amino acids, lipids and flavonoids, were detected using LC-MS / MS technology; differentially expressed metabolites were screened through multivariate statistical analysis and metabolic pathway enrichment analysis was performed.

[0079] 4. Test Results:

[0080] 41. Intestinal flora diversity: The Shannon index of the cecal contents in the experimental group increased by 12.3% and 10.8% respectively compared with the control group, while the Simpson index decreased by 8.5% and 7.2% respectively, indicating that the feed of this invention can significantly improve the intestinal flora diversity of Songliao black pigs (P<0.05). Figure 1 As shown;

[0081] 42. Species Composition: In the experimental group, the relative abundance of beneficial bacteria (Bifidobacterium and Lactobacillus) in the cecum increased by 45.2% and 38.7% respectively compared to the control group, while the relative abundance of harmful bacteria (Escherichia coli and Salmonella) decreased by 32.1% and 29.5% respectively. Figure 2 As shown;

[0082] 43. Metabolite Changes: Compared with the control group, the levels of butyric acid and propionic acid in the intestines of the experimental group increased by 30.5% and 25.3%, respectively; the levels of flavor-related amino acids such as glutamic acid and aspartic acid increased by 18.6%-22.4%; and the content of unsaturated fatty acids in lipid metabolites increased by 21.3%. The differentially metabolites were mainly enriched in amino acid metabolism, lipid metabolism, and short-chain fatty acid synthesis pathways, forming a synergistic effect with the improvement in meat quality. Figure 3 and Figure 4 As shown.

[0083] The nutritional composition of fermented miscellaneous meal feed is shown in Table 1. The effects of fermented miscellaneous meal feed on the production performance of Songliao Black Pigs are shown in Table 2. The effects of fermented miscellaneous meal feed on the meat quality indicators of Songliao Black Pigs are shown in Table 3. The effects of fermented miscellaneous meal feed on the blood biochemical indicators of Songliao Black Pigs are shown in Table 4.

[0084] Table 1:

[0085] Raw material name Amount added (kg) Percentage (%) corn 62.0 62.00 Fermented peanut meal 10.0 10.00 Fermented sesame meal 8.0 8.00 soybean meal 4.0 4.00 bran 5.0 5.00 rice bran 4.0 4.00 fish meal 1.5 1.50 stone powder 1.0 1.00 Calcium hydrogen phosphate 0.7 0.70 salt 0.4 0.40 amino acid premix 0.3 0.30 Vitamin premix 0.15 0.15 Compound enzyme preparations 0.05 0.05 total 100.0 100.00

[0086] Table 2:

[0087] Group Average daily weight gain Material weight ratio Survival rate (%) control group 780 3.05:1 98.0 experimental group 795 2.82:1 98.3

[0088] Table 3:

[0089] Measurement indicators control group experimental group Percentage of difference Shear force (N) of the longissimus dorsi muscle 38.87 30.20 -22.3% Intramuscular fat content (%) 3.28 4.12 +25.7% Flesh color brightness (L* value) 47.33 52.30 +10.50% flesh-colored redness (a* value) 12.99 14.60 +12.3% Inosinic acid content (mg / g) 3.26 3.85 +18.2%

[0090] Table 4:

[0091] Measurement indicators control group experimental group Percentage of difference Total protein (TP, g / L) 68.25 71.32 +4.5% Albumin (ALB, g / L) 35.18 37.26 +5.9% Globulin (GLO, g / L) 33.07 34.06 +3.0% Albumin / Globulin (A / G) 1.06 1.10 +3.8% Total cholesterol (TC, mmol / L) 2.86 3.15 +10.1% Triglycerides (TG, mmol / L) 0.82 0.95 +15.9% Alanine aminotransferase (ALT, U / L) 28.35 27.82 -1.9% Aspartate aminotransferase (AST, U / L) 36.62 34.98 -1.8% Blood urea nitrogen (BUN, mmol / L) 4.25 3.86 -9.2% Creatinine (CRE, μmol / L) 85.36 84.92 -0.5%

[0092] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A fermented mixed meal synergistically replacing soybean meal to improve the quality of Songliao black pork, characterized in that, Based on a total feed weight of 100 parts, the feed consists of the following components: 60-65 parts corn, 8-12 parts fermented peanut meal, 6-10 parts fermented sesame meal, 3-5 parts soybean meal, 4-6 parts wheat bran, 3-5 parts rice bran, 1-2 parts fish meal, 0.8-1.2 parts limestone powder, 0.6-0.9 parts dicalcium phosphate, 0.3-0.5 parts salt, 0.2-0.4 parts amino acid premix, 0.1-0.2 parts vitamin premix, 0.1-0.2 parts mineral premix, and 0.05-0.1 parts compound enzyme preparation. The mass ratio of fermented peanut meal to fermented sesame meal is 1.0-1.5:1, and the two synergistically replace 70%-85% of soybean meal, ensuring that the crude protein content of the feed is maintained at 16%-18%, which meets the protein requirements of Songliao black pigs during the fattening period.

2. The application of the fermented mixed meal synergistically replacing soybean meal to improve the quality of Songliao black pork according to claim 1, characterized in that: The application of large-scale feeding during the fattening period of Songliao Black Pigs to improve the quality of Songliao Black Pig meat.

3. The application of the fermented mixed meal synergistically replacing soybean meal to improve the quality of Songliao black pork according to claim 2, characterized in that, Includes the following steps: S1. Preparation of fermented peanut meal and fermented sesame meal: S11. Strain activation: Bacillus subtilis and Saccharomyces cerevisiae are mixed at a mass ratio of 2:1 and inoculated into LB medium. The medium is then cultured with shaking for 18-24 hours to obtain an activated strain solution with a concentration of 1×10⁻⁶. 8 -5×10 8 CFU / mL; S12. Raw material pretreatment: Crush peanut meal and sesame meal into 80-100 mesh respectively to remove impurities, then add 20%-25% of their respective weights of water, stir evenly, and adjust the moisture content to 50%-55%; S13. Fermentation treatment: Spray the activated inoculum solution into the pretreated peanut meal and sesame meal at a ratio of 3%-5% of the total mass of the raw materials, stir evenly, and then put them into a fermentation tank. Ferment at a constant temperature of 30-35℃ for 48-72 hours. After fermentation, dry at 60-65℃ until the moisture content is ≤12%, crush and set aside. The phytic acid removal rate after fermentation is ≥80%, and the tannin removal rate is ≥75%. S14. Mixing and blending: Mix fermented peanut meal, fermented sesame meal, corn, remaining soybean meal, wheat bran and other components according to the formula ratio, add compound enzyme preparation, stir thoroughly and evenly, grind to 60-80 mesh, and make into pellet feed with a pellet diameter of 3-5 mm. S2. Feeding: During the fattening period of Songliao Black Pigs, they are fed with free access to feed and water, 3-4 times a day, with each feeding amount being 2.5%-3.0% of the pig's body weight. The feeding cycle is 30-45 days, until the pigs reach a weight of 110-120kg and are ready for slaughter.

4. The application of the fermented mixed meal synergistically replacing soybean meal to improve the quality of Songliao black pork according to claim 3, characterized in that: Step S11: Incubate at 30-32℃ with shaking at 180-200 r / min.

5. The application of the fermented mixed meal synergistically replacing soybean meal to improve the quality of Songliao black pork according to claim 3, characterized in that: Step S13: Stir once every 12 hours during constant temperature fermentation.

6. The application of the fermented mixed meal synergistically replacing soybean meal to improve the quality of Songliao black pork according to claim 3, characterized in that: Step S14: The compound enzyme preparation is a mixture of cellulase, phytase and protease in a mass ratio of 1:2:

3.

7. The application of the fermented mixed meal synergistically replacing soybean meal to improve the quality of Songliao black pork according to claim 3, characterized in that: Step S2: The weight of the Songliao black pigs fed is 60-110kg.

8. The application of the fermented mixed meal synergistically replacing soybean meal to improve the quality of Songliao black pork according to claim 3, characterized in that: Step S2: During the feeding period, control the temperature of the breeding environment to 18-22℃ and the humidity to 60%-70%. Ventilate 2-3 times a day for 30-60 minutes each time. Clean up the feces regularly and keep the breeding environment clean.

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