Pig fattening feed based on sweet potato residues and preparation method thereof

Abstract

The invention discloses a pig fattening feed based on sweet potato residues and a preparation method thereof, and belongs to the technical field of feeds. The preparation method of the pig fattening feed based on the sweet potato residues comprises the following steps: inoculating the sweet potato residues with a complex microbial inoculant, fermenting, compounding the sweet potato residues obtained by fermentation with soybean meal, corn flour and wheat bran, and adding a premix and an enzyme preparation to obtain the pig fattening feed based on the sweet potato residues, wherein the complex microbial inoculant is obtained by mixing aspergillus niger, lactic acid bacteria and saccharomycetes according to the mass ratio of 3: 2: 1. According to the invention, the sweet potato residues are fermented by using the complex microbial inoculant and are matched with other components, so that the sweet potato residues are successfully converted into the pig fattening feed with high additional value, and the pig breeding cost is reduced. The pig fattening feed based on the sweet potato residues provided by the invention is low in cost and high in nutritional value, successfully solves the problems of poor palatability, difficult storage and unbalanced nutrition when the sweet potato residues are used as feed, has good market potential, and is suitable for large-scale pig farms.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of feed, and particularly relates to a pig fattening feed based on sweet potato residue and a preparation method thereof. BACKGROUND

[0002] The sweet potato residue is a main by-product of sweet potato starch processing, and is high in water content (70-80%), rich in crude fiber (15-25%) and a small amount of starch (5-10%), but low in protein content (2-4%). Directly used as feed, the sweet potato residue has problems such as poor palatability (low digestibility due to high fiber content, insufficient animal feed intake), easy spoilage (difficult storage due to high moisture, easy mold), and unbalanced nutrition (difficult to meet the energy, protein and amino acid requirements of pigs in the fattening stage). SUMMARY

[0003] The application aims to provide a pig fattening feed based on sweet potato residue and a preparation method thereof. The crude fiber of the sweet potato residue is degraded, and antibacterial small molecule sugar is generated and bacterial protein is provided by solid-state fermentation of the sweet potato residue with a compound microbial agent, and a low-cost, high-nutritional-value pig fattening feed is developed by combining with a nutritionally balanced formula design, so as to solve the problems of poor palatability, difficult storage and unbalanced nutrition of the sweet potato residue as feed.

[0004] To achieve the above-mentioned purpose, the application provides the following technical scheme:

[0005] One of the technical schemes of the application: a preparation method of a pig fattening feed based on sweet potato residue is provided, comprising the following steps:

[0006] The sweet potato residue is inoculated with a compound microbial agent and then fermented, and the obtained sweet potato residue is compounded with soybean meal, corn flour and wheat bran, and premix and enzyme preparation are added to obtain the pig fattening feed based on sweet potato residue.

[0007] The compound microbial agent is obtained by mixing Aspergillus niger, lactic acid bacteria and yeast bacteria at a mass ratio of 3:2:1.

[0008] The compound microbial agent of mixed Aspergillus niger, lactic acid bacteria and yeast bacteria is used to ferment the sweet potato residue, which not only degrades the crude fiber of the sweet potato residue and provides bacterial protein, but also decomposes the sweet potato polysaccharide without antibacterial effect into small molecule sugar with antibacterial function. The soybean meal, corn and wheat bran in the pig fattening feed formula can balance the energy-protein ratio; the added premix can supplement amino acids and minerals; and the enzyme preparation can further improve the digestibility of the feed and reduce fecal pollution.

[0009] Preferably, the water content of the sweet potato residue is 55-60 wt.%, and the particle size is not more than 2 mm.

[0010] Preferably, the inoculation amount of the compound microbial agent is 5-10% of the weight of the sweet potato residue.

[0011] Preferably, the fermentation is solid-state fermentation, the fermentation temperature is 30-35℃, and the fermentation time is 48-72h.

[0012] Compared with liquid fermentation, solid-state fermentation is relatively rough, does not need strict sterile conditions, needs simple equipment structure, has low investment and energy consumption, is easy to operate, has simple post-processing, has less pollution, and basically has no waste water discharge.

[0013] Preferably, the weight parts of each component in the sweet potato residue-based pig fattening feed are as follows: the fermented sweet potato residue 38-42 parts, the soybean meal 13-18 parts, the corn flour 25-35 parts, the wheat bran 8-10 parts, the premix 4-6 parts, and the enzyme preparation 0.1-0.2 parts.

[0014] Preferably, the premix contains lysine, methionine and trace elements, the content of the lysine is 0.5% of the mass of the premix, the mass of the methionine is 0.2% of the mass of the premix, and the mass of the trace elements is 2% of the mass of the premix.

[0015] Preferably, the enzyme preparation is composed of cellulase and phytase at a mass ratio of 1:1.

[0016] The second technical scheme of the present application provides a sweet potato residue-based pig fattening feed prepared according to the preparation method of the sweet potato residue-based pig fattening feed.

[0017] The beneficial technical effects of the present application are as follows:

[0018] The present application uses a compound microbial agent to ferment sweet potato residue, and successfully converts the sweet potato residue into a high-value pig fattening feed by cooperating with other components, thereby reducing the pig breeding cost. The production process provided by the present application does not need complex conditions such as high temperature, and is green and environmentally friendly. The sweet potato residue-based pig fattening feed provided by the present application has low cost and high nutritional value, successfully solves the problems of poor palatability, storage difficulty and unbalanced nutrition of sweet potato residue as feed, has good market potential, and is suitable for large-scale pig farms. DETAILED DESCRIPTION

[0019] The various exemplary embodiments of the present application will now be described in detail, which should not be considered as limiting the present application, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present application. It should be understood that the terms described in the present application are only for describing the particular embodiments, and are not used to limit the present application.

[0020] It should be noted that the parts not described in detail in the present application are all conventional operating means in the art, and are not the focus of the present application.

[0021] In addition, for numerical ranges in the present application, it is to be understood that every intermediate value of the upper and lower limits of the range is also specifically disclosed. Each intermediate value of any stated value or intermediate value in a stated range, and any other stated value or intermediate value in the stated range, is also included in the present application. The upper and lower limits of these smaller ranges can independently be included or excluded in the ranges.

[0022] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as those of ordinary skill in the art to which the application relates. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application, the preferred methods and materials are described.

[0023] As used herein, the terms "comprise", "comprising", "include", "including", "have", "having" and the like are open-ended terms that are intended to mean including, but not limited to.

[0024] The raw material of sweet potato residue used in the examples and comparative examples of the present application is fresh sweet potato residue with a moisture content of 75 wt.%, which is dewatered by pressure filtration to a moisture content of 60 wt.% and then crushed to a particle size of ≤2 mm to serve as the fermentation sweet potato residue.

[0025] The Aspergillus niger, lactic acid bacteria and yeast used for inoculation in the examples of the present application are all commercially available inoculants, wherein the effective viable count of the Aspergillus niger inoculant is ≥5×10 9 The lactic acid bacteria used specifically are Lactococcus lactis inoculants, and the effective viable count is ≥2.3×10 8 The yeast used specifically is Candida yeast inoculants, and the effective viable count is ≥1.5×10 10

[0026] Example 1

[0027] Preparation of fermented sweet potato residue:

[0028] The complex inoculant obtained by mixing Aspergillus niger, lactic acid bacteria and yeast at a mass ratio of 3:2:1 is inoculated into the sweet potato residue, and the inoculation amount of the complex inoculant is 6% of the mass of the sweet potato residue; solid-state fermentation is carried out at 30°C, and the fermentation time is 48 h to obtain fermented sweet potato residue.

[0029] Example 2

[0030] Preparation of pig fattening feed based on sweet potato residue:

[0031] Prepare each raw material according to the formula in Table 1, and then mix the raw materials uniformly to obtain the pig fattening feed based on sweet potato residue.

[0032] Table 1

[0033] Ingredients Content (wt. %) Fermented sweet potato residue prepared in Example 1 40 Soybean meal 15 Corn meal 30 Wheat bran 10 Premix 4.8 Enzyme preparation (cellulase + phytase) 0.2 ​

[0034] Note: Each kg of premix in Table 1 contains: lysine 5g, methionine 2g, iron 75mg, copper 25mg, zinc 75mg, manganese 75mg, iodine 0.8mg, selenium 0.4mg, vitamin A 0.4mg, vitamin B12mg, vitamin B2 0.05mg, vitamin D 0.08mg, vitamin E 22mg, sodium chloride 400g; the mass ratio of cellulase to phytase is 1:1.

[0035] Example 3

[0036] The feeding effect of the pig fattening feed based on sweet potato residue prepared in Example 2 was investigated:

[0037] Experimental design: 60 fattening pigs weighing 60 kg were randomly divided into a control group (the fermented sweet potato residue in the feed of Example 2 was replaced with sweet potato residue of equal mass) and a test group (the feed of Example 2), with 30 pigs in each group, and the test period was 60 days. After the test, the daily weight gain, feed-to-meat ratio, and diarrhea rate of the two groups were statistically analyzed. The statistical results are shown in Table 2.

[0038] Table 2

[0039] Control group Test group Daily gain 852g 967g Feed conversion ratio 3.2:1 2.8:1 Diarrhea rate 25％ 11％

[0040] The data in Table 2 show that the present invention uses the sweet potato residues subjected to solid-state fermentation to prepare pig fattening feed, which has a fast fattening speed, high feed utilization rate, and can also greatly reduce the diarrhea rate of fattening pigs.

[0041] Comparative Example 1

[0042] Preparation of fermented sweet potato residue:

[0043] Compared with Example 1, the only difference is that the inoculated composite bacterial agent is replaced by a composite bacterial agent obtained by mixing equal masses of Aspergillus niger and yeast at a mass ratio of 3:1.

[0044] Comparative Example 2

[0045] Preparation of fermented sweet potato residue:

[0046] Compared with Example 1, the only difference is that the inoculated composite bacterial agent is replaced by a composite bacterial agent in which equal masses of Aspergillus niger and lactic acid bacteria are mixed in a mass ratio of 3:2.

[0047] Example 4

[0048] Ultrasonic-assisted hot water extraction of sweet potato residue polysaccharides:

[0049] (1) Ultrasonic-assisted extraction

[0050] Take the fermented sweet potato residue or sweet potato residue of Example 1, Comparative Example 1~2 2.0g, add 60ml water for ultrasonic extraction (ultrasonic power 350w, ultrasonic time 60min), extract twice, 5000rpm centrifugal 3min after the upper liquid, reduced pressure concentration (70℃, 30min) after, add 4 times volume of anhydrous ethanol alcohol precipitation, placed in 4℃ refrigerator overnight. Then centrifugal (6000r / min, 5min), collect the precipitate.

[0051] (2) deproteinization

[0052] The precipitate was redissolved with deionized water (5ml, heating can promote dissolution), and the Sevage method was used to remove protein, which was repeated several times until the protein was completely removed. The water layer was again alcohol precipitated and centrifuged, and the crude sweet potato polysaccharide was obtained by vacuum drying and the extraction rate was calculated.

[0053] Note: Sevage method: mix the n-butanol and chloroform mixed solution (n-butanol: chloroform, V:V = 1:4) and the sample extraction liquid (m:V = 1:5) and shake well (2000r / min, 20min), no heating is required; centrifugal (6000r / min, 5min), until the interface between the liquid and the liquid is clear (upper layer: sugar liquid, middle layer: protein layer, lower layer: organic reagent layer), finally extract the upper layer sugar liquid.

[0054] (2) decolorization

[0055] According to the proportion of 1g polysaccharide corresponding to 20ml resin, activated AB-8 macroporous resin was added, and the solution was stirred at room temperature at low speed (150rpm) for 40min to prevent damage to the resin particles, then stood for 4h, and finally filtered to separate and collect the clear polysaccharide solution.

[0056] (4) dialysis

[0057] A dialysis bag with a molecular weight cutoff of 3500Da was used to dialyze the polysaccharide solution with pure water for 3 days (water was changed regularly, such as every 2 hours, or directly with running water). After dialysis, freeze-drying was performed to obtain sweet potato residue polysaccharide, which was stored in a desiccator for future use.

[0058] Example 5

[0059] The antibacterial ability of different sweet potato residue polysaccharides extracted in Example 4 was investigated:

[0060] The agar diffusion method was used to detect the antibacterial circle of different sweet potato residue polysaccharides (0.5~2.0mg / mL) on Escherichia coli and Staphylococcus aureus. The sweet potato residue polysaccharides were dissolved in distilled water to different concentrations (0.5, 1.0 and 2.0mg / mL, respectively), and filtered with a 0.22μm filter. 15ml of nutrient agar was added to each glass plate and solidified, then 100μl of bacterial suspension (10 6The CFU / mL) was coated on the surface of agar plate and filter paper disc (diameter 6mm, thickness 1mm), and finally 30 μL sweet potato residue polysaccharide sample was placed in the center of the plate. Incubation at 37℃ for 24h, the control group was the bacterial suspension without polysaccharide sample. The antibacterial ring diameter was measured with vernier caliper, and the antibacterial activity was evaluated. The test results are shown in Table 3 and Table 4.

[0061] Table 3 Inhibition effect of different sweet potato residue polysaccharides on Escherichia coli

[0062]

[0063] Table 4 Inhibition effect of different sweet potato residue polysaccharides on Staphylococcus aureus

[0064]

[0065] The results of Table 3 and Table 4 show that Escherichia coli and Staphylococcus aureus are sensitive to the sweet potato residue polysaccharide extracted from the fermented sweet potato residue of Example 1, indicating that the small molecule sugar obtained by fermentation through the comprehensive action of the complex microbial agent has strong bacteriostatic effect.

[0066] The above-described examples are only to describe the preferred modes of the present application, and do not limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements to the technical solutions of the present application made by those skilled in the art shall fall within the protection scope determined by the claims of the present application.

Claims

1. A method for preparing pig fattening feed based on sweet potato residue, characterized in that: The following steps are involved: The sweet potato residue is inoculated with a composite bacterial agent and then fermented, and the fermented sweet potato residue is compounded with soybean meal, corn flour and wheat bran, and a premix and an enzyme preparation are added to obtain the pig fattening feed based on the sweet potato residue; The composite bacterial agent is obtained by mixing Aspergillus niger, lactic acid bacteria and yeast in a mass ratio of 3:2:

1.

2. The method for preparing the pig fattening feed based on sweet potato residue according to claim 1, wherein The sweet potato residue has a moisture content of 55-60 wt.%, and a particle size of no more than 2 mm.

3. The method for preparing the pig fattening feed based on sweet potato residue according to claim 1, wherein The inoculation amount of the composite bacterial agent is 5-10% of the weight of the sweet potato residue.

4. The method for preparing the pig fattening feed based on sweet potato residue according to claim 1, wherein The fermentation is solid-state fermentation, with a fermentation temperature of 30-35° C. and a fermentation time of 48-72 hours.

5. The method for preparing the pig fattening feed based on sweet potato residue according to claim 1, wherein The weight proportions of the components in the sweet potato residue-based pig fattening feed are as follows: 38 to 42 parts of the fermented sweet potato residue, 13 to 18 parts of the soybean meal, 25 to 35 parts of the corn flour, 8 to 10 parts of the wheat bran, 4 to 6 parts of the premix, and 0.1 to 0.2 parts of the enzyme preparation.

6. The method for preparing the pig fattening feed based on sweet potato residue according to claim 1, characterized in that: The premix contains lysine and methionine, wherein the content of lysine is 0.5% of the mass of the premix, and the content of methionine is 0.2% of the mass of the premix.

7. The method for preparing pig fattening feed based on sweet potato residue according to claim 1, characterized in that: The enzyme preparation consists of cellulase and phytase in a mass ratio of 1:

1.

8. A pig fattening feed based on sweet potato residue prepared according to the method for preparing a pig fattening feed based on sweet potato residue according to any one of claims 1 to 7.

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