Feed formula for improving weight gain efficiency of fattening pigs

Abstract

The invention relates to the technical field of animal nutrition and feed processing, and discloses a feed formula for improving the weight gain efficiency of fattening pigs, and the feed formula comprises the following components by weight: 55-68% of corn; 18-25% of soybean meal; 5-8% of wheat bran; 3-5% of a compound premix; 2-4% of puffed soybeans; 0.1-0.3% of a compound enzyme preparation; 0.08 to 0.12% of a microecological preparation; 0.01 to 0.03 percent of slow release type organic zinc; the compound enzyme preparation comprises xylanase and protease which are compounded according to the proportion of 2: 1-3: 1, the components are subjected to double-screw extrusion puffing treatment, the puffing temperature is 135-145 DEG C, and the die head pressure is 3.5-4.2 MPa. Through innovative combination of a dynamic nutrition model and an enzyme-bacterium synergistic degradation system, the feed nutrient utilization rate is remarkably increased, and precise adaptation in the growth stage is achieved; meanwhile, based on a processing technology of directional modification and a slow release technology, the pollution risk of the breeding environment is effectively reduced while the stability of the feed is enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of animal nutrition and feed processing, and in particular to a feed formula for improving the weight gain efficiency of fattening pigs. Background Art

[0002] During the pig fattening stage, feed costs account for more than 70% of the total breeding costs, and traditional feed formulas generally have problems such as low nutrient utilization efficiency and extensive supply at different stages. The current industry mostly adopts a fixed three-stage feeding model, which fails to fully consider the individual growth differences of pigs and the impact of environmental factors on metabolic needs, resulting in large fluctuations in daily weight gain and high feed-to-meat ratio in actual production.

[0003] In the prior art, the simple combination of enzyme preparations and probiotics often leads to limited synergistic effects due to the uncoordinated action sequence, and the conventional puffing process is not efficient enough in removing anti-nutritional factors from raw materials, which can easily cause intestinal immune stress. At the same time, trace elements are generally added in the form of inorganic salts, which have the disadvantages of low bioavailability and high environmental emissions. The static nutrition model is difficult to dynamically respond to changes in the health status of the pig herd, which restricts the realization of precise nutrition regulation. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a feed formula for improving the weight gain efficiency of fattening pigs, which solves the problems in the prior art of mismatch between nutrient supply and growth curve in fattening pig feeds, high residual rate of anti-nutritional factors and low metabolic efficiency of trace elements.

[0005] To achieve the above object, the present invention is implemented by the following technical scheme: a feed formula for improving the weight gain efficiency of fattening pigs, comprising the following components in percentage by weight:

[0006] Corn 55-68%;

[0007] Soybean meal 18-25%;

[0008] Wheat bran 5-8%;

[0009] Composite premix 3-5%;

[0010] Expanded soybeans 2-4%;

[0011] Complex enzyme preparation 0.1-0.3%;

[0012] Probiotics 0.08-0.12%;

[0013] Sustained release organic zinc 0.01-0.03%;

[0014] 0.02 - 0.05% of tea tree oil extract, wherein the complex enzyme preparation comprises xylanase and protease compounded in a ratio of 2:1 - 3:1, and the components are processed by twin - screw extrusion and puffing, with the puffing temperature of 135 - 145°C and the die head pressure of 3.5 - 4.2 MPa.

[0015] Preferably, the probiotic preparation is composed of Bacillus subtilis and Enterococcus faecalis in a ratio of 3:1 - 5:1, and the CFU / g is the final viable bacteria content in the feed.

[0016] Preferably, the slow - release organic zinc is compounded by zinc methionine and zinc glycinate in a ratio of 1:0.5 - 1:2, and the zinc element content is 8 - 12%.

[0017] Preferably, the compound premix contains 8000 - 12000 IU / kg of vitamin A, 2000 - 3000 IU / kg of vitamin D3, 30 - 50 mg / kg of vitamin E, 20 - 30 mg / kg of niacin, and 10 - 15 mg / kg of calcium pantothenate.

[0018] A method for preparing a feed for improving the weight - gain efficiency of fattening pigs, comprising the following steps:

[0019] (1) Raw material pretreatment: Corn and soybean meal are subjected to twin - screw extrusion and puffing at 135 - 145°C for a residence time of 25 - 35 seconds;

[0020] (2) Solid - state fermentation: The puffed raw materials are inoculated with Aspergillus niger and fermented at 38 - 42°C for 44 - 52 hours. The humidity is 40 - 45% in the first 24 hours and adjusted to 35 - 38% in the later stage;

[0021] (3) Enzyme preparation activation: The complex enzyme preparation is pre - activated in a pH 6.0 - 6.5 phosphate buffer at 40 - 45°C for 20 - 30 minutes;

[0022] (4) Mixing process: Each component is put into a double - shaft paddle mixer according to the ratio of claim 1, first dry - mixed for 80 - 100 seconds, and then the liquid components are added for wet - mixing for 200 - 250 seconds, and the coefficient of variation (CV) value of the mixing uniformity is ≤5%;

[0023] (5) Pelleting control: The ring die compression ratio is 1:6 - 1:8, the steam pressure is 0.15 - 0.25 MPa, and the discharge temperature is 75 - 85°C.

[0024] Preferably, in the step (4): The liquid components include 0.1 - 0.3% of liquid methionine and 0.05 - 0.1% of compound acidifier by mass fraction.

[0025] A feeding method for a feed formula for improving the feed intake of fattening pigs, comprising the following steps:

[0026] (a) Stage division: Feed in five stages according to body weights of 25 - 35 kg, 35 - 60 kg, 60 - 90 kg, 90 - 115 kg, and 115 - 130 kg. The stage division is based on the Gompertz growth model with model parameters A = 130 - 140 kg and k = 0.016 - 0.018 day -1 ;

[0027] (b) Dynamic adjustment: Based on the daily weight gain data, when the deviation from the target value is ±5% for three consecutive days, adjust the net energy density by 15 - 20 kcal / kg for each 1% deviation. The target value is calculated according to the Gompertz equation, and the reference value of the net energy density is 2400 - 2600 kcal / kg;

[0028] (c) Environmental compensation: Reduce the net energy density by 8 - 10 kcal / kg for every 1°C increase in temperature, and increase the microecological preparation by 0.02 - 0.03% when the humidity exceeds 70%.

[0029] Preferably, the specific form of the Gompertz equation is:

[0030] W(t) = A·exp(-exp(-k(t - t0)));

[0031] where A = 130 - 140 kg, k = 0.016 - 0.018 day -1 , t0 = 95 - 100 days old.

[0032] Preferably, in step (b), the UHFRFID individual identification system is adopted, the data sampling frequency ≥ 0.2 Hz, and it is connected to the dynamic adjustment module in real - time. The feeding data recording frequency of each pig is ≥ 5 times / minute, and an alarm is triggered when the data deviation exceeds ±8%.

[0033] The present invention provides a feed formula for improving the weight - gain efficiency of fattening pigs. It has the following beneficial effects:

[0034] 1. By optimizing the synergistic effect of enzyme preparations and microecological preparations, the present invention significantly enhances the decomposition ability of fiber and protein in the feed. A specific ratio of enzyme combinations effectively destroys the plant cell wall structure, releases more digestible nutrients, and at the same time, the precise regulation of probiotics promotes the absorption of nutrients by the intestine and reduces the loss of ineffective metabolism.

[0035] 2. Based on the stage - division technology of the dynamic growth model, the present invention realizes the precise matching of nutrient supply and the physiological needs of fattening pigs. By real - time monitoring of individual growth data and dynamically adjusting the formula, it effectively solves the problems of lag or excess of nutrient supply caused by traditional fixed - stage feeding.

[0036] 3. The innovative extrusion and fermentation synergistic process of the present invention significantly improves the structural modification of raw materials and the elimination effect of anti-nutritional factors. While ensuring the retention of key nutrients, this process enhances the physical durability of feed pellets and reduces the risk of quality deterioration during transportation and storage.

[0037] 4. By combining the slow-release trace element system with the directed fermentation technology, the present invention reduces the emission of heavy metals and the generation of harmful gases such as ammonia. By optimizing the nutritional metabolism pathway, the utilization rate of elements such as nitrogen and phosphorus is improved, alleviating the environmental pollution problem in the aquaculture industry from the source. Brief Description of the Drawings

[0038] Figure 1 It is a flowchart of the method steps of the present invention. Detailed Embodiments

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0040] Please refer to the attached Figure 1 , the embodiment of the present invention provides a feed formula for improving the weight gain efficiency of fattening pigs, including the following components by weight percentage:

[0041] Corn 55 - 68%;

[0042] Soybean meal 18 - 25%;

[0043] Wheat bran 5 - 8%;

[0044] Compound premix 3 - 5%;

[0045] Extruded soybean 2 - 4%;

[0046] Compound enzyme preparation 0.1 - 0.3%;

[0047] Microecological preparation 0.08 - 0.12%;

[0048] Slow-release organic zinc 0.01 - 0.03%;

[0049] Tea tree oil extract 0.02 - 0.05%, wherein the compound enzyme preparation contains xylanase and protease compounded in a ratio of 2:1 - 3:1, and the components are processed by twin-screw extrusion expansion, with an expansion temperature of 135 - 145°C and a die head pressure of 3.5 - 4.2 MPa.

[0050] Composition of Example 1 formula:

[0051] 62 kg of corn, 20 kg of soybean meal, 6.5 kg of wheat bran, 4.2 kg of compound premix, 3.2 kg of extruded soybean, 0.25 kg of compound enzyme preparation (xylanase: protease = 2.5:1, with activities of 17,500 U / g and 5,500 U / g respectively), 0.1 kg of probiotic preparation (Bacillus subtilis: Enterococcus faecalis = 4:1, with viable counts of 3.5×10^9 CFU / g and 1.2×10^9 CFU / g respectively), 0.025 kg of slow-release organic zinc (zinc methionine: zinc glycinate = 1:1, zinc content 10%), 0.035 kg of tea tree oil extract.

[0052] Preparation steps:

[0053] Raw material pretreatment: Corn and soybean meal are processed by a twin-screw extrusion expander at a temperature of 140°C, a die head pressure of 3.8 MPa, and a residence time of 30 seconds;

[0054] Solid-state fermentation: The expanded raw materials are inoculated with Aspergillus niger (1.1×10^6 CFU / g) and fermented at 40°C for 48 hours, with a humidity of 43% in the first 24 hours and 37% in the last 24 hours;

[0055] Enzyme activation: The compound enzyme preparation is pre-activated in a pH 6.3 phosphate buffer at 43°C for 25 minutes;

[0056] Mixing process: After dry mixing for 90 seconds, 0.25 kg of liquid methionine and 0.075 kg of compound acidifier are added, and then wet mixing is carried out for 220 seconds;

[0057] Pelleting control: The ring die compression ratio is 1:7, the steam pressure is 0.2 MPa, and the discharge temperature is 80°C.

[0058] Example 2

[0059] Formulation composition:

[0060] 55 kg of corn, 25 kg of soybean meal, 5 kg of wheat bran, 3 kg of compound premix, 2 kg of extruded soybean, 0.1 kg of compound enzyme preparation (xylanase: protease = 2:1, with activities of 15,000 U / g and 4,000 U / g respectively), 0.08 kg of probiotic preparation (Bacillus subtilis: Enterococcus faecalis = 3:1, with viable counts of 1×10^9 CFU / g and 5×10^8 CFU / g respectively), 0.01 kg of slow-release organic zinc (zinc methionine: zinc glycinate = 1:0.5, zinc content 8%), 0.02 kg of tea tree oil extract.

[0061] Preparation steps:

[0062] Raw material pretreatment: Temperature 135°C, die head pressure 3.5 MPa, residence time 25 seconds;

[0063] Solid-state fermentation: inoculation amount 1.0×10^6 CFU / g, ferment at 38°C for 44 hours, humidity 40% in the first 24 hours and 35% in the next 24 hours;

[0064] Enzyme activation: pH6.0 buffer solution, pre-activate at 40°C for 20 minutes;

[0065] Mixing process: dry mix for 80 seconds, add 0.1 kg of liquid methionine and 0.05 kg of compound acidifier, wet mix for 200 seconds;

[0066] Pelleting control: ring die compression ratio 1:6, steam pressure 0.15 MPa, discharge temperature 75°C.

[0067] Example 3

[0068] Formula composition:

[0069] 68 kg of corn, 18 kg of soybean meal, 8 kg of wheat bran, 5 kg of compound premix, 4 kg of expanded soybean, 0.3 kg of compound enzyme preparation (xylanase: protease = 3:1, activities 20000 U / g and 6000 U / g), 0.12 kg of microecological preparation (Bacillus subtilis: Enterococcus faecalis = 5:1, viable counts are 5×10^9 CFU / g and 2×10^9 CFU / g respectively), 0.03 kg of slow-release organic zinc (zinc methionine: zinc glycinate = 1:2, zinc content 12%), 0.05 kg of tea tree oil extract.

[0070] Preparation steps:

[0071] Raw material pretreatment: temperature 145°C, die head pressure 4.2 MPa, residence time 35 seconds;

[0072] Solid-state fermentation: inoculation amount 1.2×10^6 CFU / g, ferment at 42°C for 52 hours, humidity 45% in the first 24 hours and 38% in the next 24 hours;

[0073] Enzyme activation: pH6.5 buffer solution, pre-activate at 45°C for 30 minutes;

[0074] Mixing process: dry mix for 100 seconds, add 0.3 kg of liquid methionine and 0.1 kg of compound acidifier, wet mix for 250 seconds;

[0075] Pelleting control: ring die compression ratio 1:8, steam pressure 0.25 MPa, discharge temperature 85°C.

[0076] Design of comparative examples

[0077] Comparative example 1 (lack of enzyme synergy)

[0078] Compared with Example 1, the difference is:

[0079] The compound enzyme preparation only contains xylanase (activity 17,500 U / g) and does not contain protease. The addition amount of xylanase is adjusted to 0.2 kg (the total amount of enzyme preparation remains unchanged).

[0080] The other components and the preparation process are the same as those in Example 1.

[0081] Comparative Example 2 (Insufficient Probiotic Preparation)

[0082] Compared with Example 1, the differences are as follows:

[0083] The addition amount of the probiotic preparation is changed to 0.05 kg (accounting for 0.05% of the total feed amount).

[0084] The ratio of Bacillus subtilis to Enterococcus faecalis remains 4:1

[0085] The other components and the preparation process are the same as those in Example 1.

[0086] Comparative Example 3 (Destruction of Zinc Composite System)

[0087] Compared with Example 1, the differences are as follows:

[0088] Only methionine zinc is used for the slow-release organic zinc (glycine zinc is not added).

[0089] The zinc element content is adjusted to 6% (lower than the range of 8 - 12% in Claim 3).

[0090] The total addition amount remains 0.02 kg

[0091] The other components and the preparation process are the same as those in Example 1.

[0092] Comparative Example 4 (Raw Materials Not Extruded)

[0093] Compared with Example 1, the differences are as follows:

[0094] Corn and soybean meal are directly crushed to a fineness of 2.0 mm (without twin-screw extrusion and puffing), and the die head pressure control step is omitted.

[0095] The other preparation processes are the same as those in Example 1.

[0096] Comparative Example 5 (Lack of Fermentation Humidity Control)

[0097] Compared with Example 1, the differences are as follows:

[0098] The solid-state fermentation maintains a humidity of 40% throughout the process (without two-stage regulation).

[0099] The fermentation time is still 48 hours

[0100] The other preparation processes are the same as those in Example 1.

[0101] Comparative Example 6 (Improper enzyme activation conditions)

[0102] Compared with Example 1, the differences are as follows:

[0103] The enzyme preparation was pre-activated with deionized water (without adding phosphate buffer solution).

[0104] The pH value naturally fluctuated within the range of 5.8 - 6.0.

[0105] The remaining preparation processes were the same as those in Example 1.

[0106] Comparative Example 7 (Missing stage division model)

[0107] Compared with Example 1, the differences are as follows:

[0108] The feeding stage adopted the traditional three-stage division: 25 - 60 kg, 60 - 90 kg, 90 - 130 kg

[0109] The Gompertz growth model was not used.

[0110] The remaining feeding control parameters were the same as those in Example 1.

[0111] Comparative Example 8 (Degraded data acquisition system)

[0112] Compared with Example 1, the differences are as follows:

[0113] The sampling frequency of the UHF RFID system was reduced to 0.1 Hz.

[0114] Simple moving average method was used for data fusion (Kalman filter was not used).

[0115] The lag compensation time constant τ = 2 h (outside the range of 4 ± 0.5 h in Claim 10). The remaining feeding methods were the same as those in Example 1.

[0116] Test Example 1: Explanation of enzyme synergistic effect verification experiment

[0117] Experimental steps

[0118] Construction of bionic digestive system

[0119] Configure simulated gastric juice (pH 2.0, containing pepsin) and intestinal juice (pH 6.8, containing pancreatin). Crush the feed sample through a 40-mesh sieve, and take 5.0 g of the sample to perform the following steps in sequence:

[0120] Gastric phase digestion: Oscillate at 37°C for 2 hours (rotation speed 120 rpm).

[0121] Intestinal phase digestion: Add bile salt solution and continue digestion for 4 hours.

[0122] Determination of crude fiber digestibility

[0123] Using the ANKOMA200 fiber analyzer

[0124] Calculation formula:

[0125]

[0126] Determining the apparent digestibility of crude protein by the total fecal collection method

[0127] Six healthy finishing pigs (body weight 60 ± 2 kg) were selected and divided into 3 groups

[0128] The pre-feeding period was 7 days, and the formal period was 5 days. The intake and excretion of nitrogen were determined by the total fecal collection Kjeldahl method

[0129] Collecting the ileal chyme for viscosity detection (sampling at slaughter)

[0130] Using a Brookfield DV2T viscometer (rotor CPE-40, shear rate 100 s -1 )

[0131] Measure three times at a constant temperature of 25 °C and take the average value

[0132] Experimental data

[0133] Table 1 Test results of key indicators of enzyme synergistic effect

[0134]

[0135] Crude fiber digestibility:

[0136] Example 1 (67 - 68%) was significantly higher than Comparative Example 1 (51 - 52%) and Comparative Example 6 (61 - 63%). In Comparative Example 6, the enzyme activity decreased partially due to the lack of buffer

[0137] Crude protein digestibility:

[0138] Example 1 (87 - 88%) was 13 - 14 percentage points higher than Comparative Example 1 (74 - 76%)

[0139] The lack of protease directly led to a decrease in protein digestibility in Comparative Example 1

[0140] Chyme viscosity:

[0141] Example 1 had the lowest viscosity (138 - 142 mPa·s), and Comparative Example 1 had the highest (218 - 225 mPa·s). Xylanase alone could not fully degrade NSP substances

[0142] Test Example 2: Description of the dose-effect verification experiment of probiotics

[0143] Experimental procedure

[0144] Sampling at the terminal ileum

[0145] On the morning of the 28th day of feeding, after 12 hours of fasting, the experimental pigs were anesthetized and sacrificed.

[0146] A 20-cm intestinal segment from the terminal ileum was intercepted, and the contents were rinsed with sterile saline and immediately placed in an anaerobic transport tank (stored at 4°C and processed within 2 hours).

[0147] Plate count of lactic acid bacteria

[0148] MRS agar medium (containing 0.3% bile salts) was used.

[0149] Serial dilution was performed to 10^-6, and anaerobic culture was carried out at 37°C for 48 hours.

[0150] The number of colonies within the range of 30 - 300 CFU was counted.

[0151] Measurement of ammonia emissions

[0152] Use a 1m 3 Feces were continuously collected for 24 hours using a metabolic cage.

[0153] A gas sampling pump was used to extract gas at a flow rate of 500 mL / min into a Tedlar gas bag.

[0154] Ion chromatography was used to determine the ammonia concentration (detection limit 0.1 ppm).

[0155] Clinical observation of diarrhea

[0156] The fecal morphology was observed regularly every day (using the Bristol Stool Scale).

[0157] Fecal scores ≤ 2 (liquid) were recorded as positive for diarrhea.

[0158] The weekly cumulative diarrhea incidence was calculated.

[0159] Experimental data

[0160] Table 2 Test results of the dose-effect of probiotics

[0161]

[0162] Colonization of lactic acid bacteria:

[0163] In Example 1, the lactic acid bacteria content in the terminal ileum was stable at 7.1 - 7.3 log CFU / g, while in Comparative Example 2 (with an addition amount of 0.05%), it decreased to 6.2 - 6.6 log CFU / g. Ammonia emissions:

[0164] In Comparative Example 2, the ammonia emissions increased by 38 - 45% compared to Example 1.

[0165] The data fluctuation was positively correlated with the fecal water content (r = 0.63).

[0166] Diarrhea control:

[0167] In Example 1, the diarrhea incidence rate was < 7%.

[0168] In Comparative Example 2, the incidence rate was > 12%, up to 16.2% at most.

[0169] The third week was the high-incidence period (accounting for 58% of the cumulative cases).

[0170] Test Example 3: Explanation of the zinc release kinetics verification experiment

[0171] Experimental procedures

[0172] In vitro simulated digestion

[0173] Prepare three-stage digestive juices:

[0174] Oral phase (pH 6.8, α-amylase)

[0175] Gastric phase (pH 2.5, pepsin)

[0176] Intestinal phase (pH 7.2, pancreatin + bile salts)

[0177] Sampling at regular intervals (0.5 / 2 / 4 hours) to detect the zinc release amount

[0178] Serum zinc concentration detection

[0179] Collect blood from the anterior vena cava in the morning (anticoagulated with EDTA)

[0180] Centrifuge to separate plasma (3000 rpm × 10 min)

[0181] Determine by atomic absorption spectrometry (wavelength 213.9 nm)

[0182] Hoof shell hardness test

[0183] Cut the sole horny layer of the hoof (thickness 2.0 ± 0.2 mm)

[0184] Press vertically with a Shore hardness tester (Type D) until complete contact

[0185] Read the instantaneous hardness value after stabilizing for 5 seconds

[0186] Experimental data

[0187] Table 3 Zinc metabolism kinetics test results

[0188]

[0189] Zinc release curve:

[0190] Example 1: Gastric phase release rate is 38 - 42%, which is smoother than that of Comparative Example 3 (65 - 72%). Intestinal phase 4-hour cumulative release rate: In Example 1, it reaches 92 - 95%, while in Comparative Example 3, it is only 81 - 84%. Serum zinc homeostasis:

[0191] In Example 1, the serum zinc concentration is stable at 89 - 93 μg / dL (daily fluctuation < 5%)

[0192] In Comparative Example 3, there is a morning low (the lowest is 75.3 μg / dL)

[0193] Hoof health:

[0194] The hoof shell hardness in Example 1 (70 - 72 HD) is significantly higher than that in Comparative Example 3 (58 - 63 HD). The hardness value is positively correlated with the serum zinc concentration (r = 0.78). Test Example 4: Verification experiment on the necessity of the extrusion process Instructions

[0195] Experimental procedure

[0196] Raw material crushing and extrusion treatment

[0197] Mix corn and soybean meal in proportion and crush them to 2.0 mm

[0198] For the experimental group, perform twin-screw extrusion. Operating conditions:

[0199] Screw speed: 250 rpm

[0200] Die temperature: 130 °C

[0201] Treatment time: 60 seconds

[0202] For the control group, do not perform extrusion. Directly use the crushed mixture for testing the residual amount of antigen protein

[0203] Use the ELISA method to detect the antigen protein content in the mixture. Take samples 3 times for each group and repeat the measurement to ensure data consistency. Determine the change in the residual amount of antigen protein in the control group and the experimental group

[0204] Starch gelatinization degree test

[0205] Heat the raw materials using the water bath method, keep at 95 °C for 15 minutes, and detect the gelatinization degree of the samples through a viscometer

[0206] Gelatinization degree calculation formula:

[0207]

[0208] Determination of the powder content of pellet feed

[0209] Sieve the samples using a standard sieve (aperture 0.5 mm) and calculate the proportion (percentage) of the undersize in the total sample

[0210] Calculate the average value for each set of three measurements

[0211] Experimental data

[0212] Table 4 Test results of the necessity of the puffing process

[0213]

[0214] Residual amount of antigen protein:

[0215] The residual amount of antigen protein in Example 1 is relatively low (4.7 - 4.9 ng / g), which is significantly better than that in Comparative Example 4 (11.8 - 13.1 ng / g)

[0216] Puffing treatment significantly reduces the residual amount of antigen protein

[0217] Degree of starch gelatinization:

[0218] The gelatinization degree in Example 1 is relatively high (92.5 - 94.3%), and that in Comparative Example 4 is significantly lower than this range (53.6 - 57.2%)

[0219] Puffing treatment enhances the hydrolysis potential of starch

[0220] Powder content of pellet feed:

[0221] The powder content of the pellets in Comparative Example 4 is significantly higher (16.9 - 19.2%), proving that the raw materials without puffing treatment have a larger degree of pulverization

[0222] The puffing process reduces powder generation and maintains the integrity of the pellets

[0223] Test Example 5: Description of the fermentation control verification experiment

[0224] Experimental procedure

[0225] Sampling of fermentation products

[0226] Two hours before the end of fermentation, collect the central point sample of the fermentation material under sterile conditions

[0227] Immediately place it in liquid nitrogen for quick freezing and store it at -80°C for testing

[0228] Determination of citric acid content

[0229] Use HPLC (C18 chromatographic column, mobile phase 0.1% phosphoric acid aqueous solution)

[0230] Detection wavelength 210 nm, column temperature 30°C, flow rate 1.0 mL / min

[0231] Quantify by external standard method (citric acid standard 0.1 - 10 mg / mL)

[0232] Analysis of neutral detergent fiber degradation rate

[0233] Treat the sample according to the Van Soest method and use an ANKOM fiber analyzer

[0234] Calculation formula:

[0235]

[0236] Volatile fatty acid detection

[0237] Take 1 g of the sample, add 2 mL of ultrapure water, vortex and centrifuge (12000 rpm × 10 min)

[0238] Filter the supernatant through a 0.22 μm filter membrane and analyze by GC-MS (DB-FFAP chromatographic column)

[0239] Calculate the proportions of acetic acid, propionic acid, and butyric acid by the internal standard method

[0240] Experimental data

[0241] Table 5 Test results of fermentation control effect

[0242]

[0243] Accumulation of metabolites:

[0244] The citric acid content in Example 1 (8.7 - 9.2 mg / g) was significantly higher than that in Comparative Example 5 (4.9 - 5.6 mg / g). Two-stage humidity control promoted the secondary metabolism of Aspergillus niger

[0245] Fiber degradation effect:

[0246] The neutral detergent fiber degradation rate in Example 1 reached 39 - 41%, which was about 30% higher than that in Comparative Example 5 (26 - 31%). The data fluctuation was related to the porosity of the material (r = 0.59)

[0247] Fatty acid composition:

[0248] The proportion of propionic acid in Example 1 (25 - 27%) was significantly higher than that in Comparative Example 5 (16 - 20%)

[0249] The proportion of butyric acid increased to 13 - 15% (only 11 - 12% in Comparative Example 5)

[0250] The decrease in the proportion of acetic acid was beneficial to reducing intestinal acidification stress

[0251] Test Example 6: Experimental description for verifying the structural stability of carrier particles

[0252] Experimental steps

[0253] Test the wet disintegration resistance of the particles

[0254] Place the particle sample in a constant temperature and humidity chamber (relative humidity 85%, temperature 30°C)

[0255] Samples were taken every 12 hours and placed in 300 mL of distilled water to observe disintegration, and the time point of the start of disintegration was recorded (with the obvious rupture of the particle structure as the judgment criterion).

[0256] Transport simulation seismic test

[0257] A vibration test bench (ISO2247 standard) was used to simulate road transportation.

[0258] Test parameters: frequency 5 Hz, amplitude 25 mm, time 6 hours

[0259] Determine the particle pulverization rate: Pass the sample through a 0.5 mm sieve mesh and calculate the proportion of the mass of the material under the sieve.

[0260] Water stability test

[0261] Put the particles into water at 40 °C and let them stand for 2 hours. Observe the integrity of the particles, recover and dry the samples through a filter mesh, measure the remaining mass and calculate the retention rate.

[0262] Retention rate = (mass of residual particles after drying / original dry mass) × 100%

[0263] Experimental data

[0264] Table 6 Test results of the structural stability of carrier particles

[0265]

[0266]

[0267] Humidity tolerance:

[0268] The particles of Example 1 began to disintegrate after 48 hours in a high-humidity environment, while obvious structural collapse occurred in Comparative Example 6 within 24 hours.

[0269] It shows that the optimization of the structural density and hydrophobic materials effectively delays the intrusion of moisture.

[0270] Seismic stability:

[0271] The pulverization rate of Example 1 was less than 7%, while that of Comparative Example 6 reached 15 - 18%, showing a significant difference.

[0272] A high pulverization rate directly affects the physical integrity during the particle feeding process.

[0273] Retention rate in water:

[0274] The retention rate of the particles of Example 1 exceeded 85% after soaking in water, which was significantly better than that of Comparative Example 6 (the lowest was 68.7%).

[0275] It helps to improve the release stability of the payload in the aquatic environment.

[0276] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A feed formula for improving the weight gain efficiency of fattening pigs, characterized in that, It includes the following components by weight percentage: Corn 55 - 68%; Soybean meal 18 - 25%; Wheat bran 5 - 8%; Compound premix 3 - 5%; Extruded soybean 2 - 4%; Compound enzyme preparation 0.1 - 0.3%; Microecological preparation 0.08 - 0.12%; Slow - release organic zinc 0.01 - 0.03%; Tea tree oil extract 0.02 - 0.05%, wherein the compound enzyme preparation contains xylanase and protease compounded in a ratio of 2:1 - 3:1, and the above - mentioned components are treated by twin - screw extrusion expansion, the expansion temperature is 135 - 145 °C, and the die head pressure is 3.5 - 4.2 MPa.

2. The feed formula for improving the weight gain efficiency of fattening pigs according to claim 1, characterized in that The microecological preparation is composed of Bacillus subtilis and Enterococcus faecalis in a ratio of 3:1 - 5:1, and the CFU / g is the final viable bacteria content in the feed.

3. A feed formula for improving the weight gain efficiency of fattening pigs according to claim 1, characterized in that, The slow - release organic zinc is a compound of methionine zinc and glycine zinc in a ratio of 1:0.5 - 1:2, and the zinc element content is 8 - 12%.

4. A feed formula for improving the weight gain efficiency of fattening pigs according to claim 1, characterized in that, The compound premix contains vitamin A 8000 - 12000 IU / kg, vitamin D3 2000 - 3000 IU / kg, vitamin E 30 - 50 mg / kg, niacin 20 - 30 mg / kg, and calcium pantothenate 10 - 15 mg / kg.

5. A method for preparing a feed for improving the weight gain efficiency of fattening pigs, which is used for a feed formula for improving the weight gain efficiency of fattening pigs according to any one of claims 1-4, characterized in that, It includes the following steps: (1) Raw material pretreatment: Corn and soybean meal are subjected to twin - screw extrusion expansion at 135 - 145 °C, and the residence time is 25 - 35 seconds; (2) Solid - state fermentation: The expanded raw materials are inoculated with Aspergillus niger and fermented at 38 - 42 °C for 44 - 52 hours. The humidity is 40 - 45% in the first 24 hours and adjusted to 35 - 38% in the later stage; (3) Enzyme preparation activation: The compound enzyme preparation is pre - activated in a pH 6.0 - 6.5 phosphate buffer at 40 - 45 °C for 20 - 30 minutes; (4) Mixing process: Each component is put into a double - shaft paddle mixer according to the ratio of claim 1. First, dry - mix for 80 - 100 seconds, and then add liquid components for wet - mix for 200 - 250 seconds. The coefficient of variation (CV) value of the mixing uniformity is ≤5%; (5) Pelleting control: The ring die compression ratio is 1:6 - 1:8, the steam pressure is 0.15 - 0.25 MPa, and the discharge temperature is 75 - 85 °C.

6. The feed preparation method for improving the weight gain efficiency of fattening pigs according to claim 5, characterized in that, In the step (4): The liquid components include liquid methionine with a mass fraction of 0.1 - 0.3% and a compound acidifier with a mass fraction of 0.05 - 0.1%.

7. A feeding method for a feed formula for improving the weight gain of fattening pigs. According to the feed formula for improving the weight gain efficiency of fattening pigs described in any one of claims 1-4, it is characterized in that, It includes the following steps: (a) Stage division: Feed in five stages according to body weights of 25 - 35 kg, 35 - 60 kg, 60 - 90 kg, 90 - 115 kg, and 115 - 130 kg. The stage division is based on the Gompertz growth model with model parameters A = 130 - 140 kg and k = 0.016 - 0.018 day -1 ; (b) Dynamic adjustment: Based on the daily weight gain data, when it deviates from the target value by ±5% for 3 consecutive days, adjust the net energy density by 15 - 20 kcal / kg per 1% deviation. The target value is calculated according to the Gompertz equation, and the reference value of the net energy density is 2400 - 2600 kcal / kg; (c) Environmental compensation: When the temperature rises by 1 °C, reduce the net energy density by 8 - 10 kcal / kg. When the humidity exceeds 70%, increase the microecological preparation by 0.02 - 0.03%.

8. A feed formula for improving the weight gain efficiency of fattening pigs according to claim 7, characterized in that The specific form of the Gompertz equation is: W(t) = A·exp(-exp(-k(t - t0))); where A = 130 - 140 kg, k = 0.016 - 0.018 day -1 , and t0 = 95 - 100 days old.

9. A feed formula for improving the weight gain efficiency of fattening pigs according to claim 7, characterized in that, In the step (b), a UHF RFID individual identification system is adopted, the data sampling frequency is ≥0.2 Hz, and it is connected to the dynamic adjustment module in real time. The feeding data recording frequency of each pig is ≥5 times per minute, and an alarm is triggered when the data deviation exceeds ±8%.

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