Bacteria-enzyme combined step-by-step fermented grain residue feed as well as preparation method and application thereof

Abstract

The invention relates to the technical field of feed preparation, in particular to a bacterium-enzyme combined step-by-step fermentation residue feed and a preparation method and application thereof.The preparation method of the residue feed comprises the steps that fermentation raw materials, bran and soybean meal are mixed according to the mass ratio of 7.5-8.5: 1-1.5: 0.5-1, and a fermentation culture medium is obtained; the method comprises the following steps: mixing a fermentation culture medium with water, firstly adding a compound enzyme to degrade dietary fibers for 2-4 hours, and then adding compound bacteria to ferment for 72-96 hours so as to convert a dietary fiber degradation product into crude protein, thereby obtaining the grain residue feed, the mass ratio of the fermentation culture medium to the compound enzyme to the compound bacteria is 1000: (0.5-1.5): (0.5-2.5). Compared with a one-step fermentation method, the vinasse feed obtained by a two-step method through combination of bacteria and enzymes has the advantages that crude fibers are reduced by 19.65% and crude proteins are improved by 18.98% after 72 hours of fermentation, so that the fattening effect of beef cattle and sheep can be promoted.

Description

Technical Field

[0001] The invention relates to the technical field of feed preparation, and in particular to a dregs feed produced by bacterial and enzyme combined step-by-step fermentation, a preparation method and an application thereof. Background Art

[0002] Apple pomace has a high dietary fiber content, and its nutritional value can be improved by preparing it into fermented feed through biological fermentation. At present, the microorganisms used in fermenting apple pomace are mainly Aspergillus niger, which produces high-yield digestive enzymes such as cellulase and xylanase. Complex digestive enzymes such as cellulase, hemicellulase and xylanase can also be directly added to hydrolyze the dietary fiber in apple pomace into small molecular monosaccharides; at the same time, yeast and lactic acid bacteria can be added for synergistic fermentation to convert small molecular monosaccharides into bacterial proteins, improve the flavor of the fermentation product, and improve the nutritional value and palatability of apple pomace feed.

[0003] The dietary fiber content in apple pomace is close to 80% of its mass number. The prior art generally adopts a one-step fermentation method, that is, adding compound enzymes and compound bacteria to the apple pomace for fermentation. Due to the inconsistent fermentation conditions of the compound enzymes and compound bacteria, the method cannot effectively exert the digestion effect of the compound enzymes on the dietary fiber in the apple pomace, and thus the enzymatic hydrolysis of the apple pomace is insufficient, making it difficult to promote the subsequent fermentation process of the compound bacteria. Therefore, the nutritional value of the feed obtained by fermenting apple pomace using the one-step method is low. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a residue fermented feed and a preparation method and application thereof, which can improve the fermentation effect of apple residue, fully enzymatically hydrolyze the apple residue and promote the fermentation of microorganisms.

[0005] To achieve the above-mentioned object of the invention, the technical solution of the present invention is specifically as follows.

[0006] The first aspect of the present invention provides a method for preparing a fermented feed from dregs, comprising the following steps:

[0007] The fermentation raw material, bran and soybean meal are mixed in a mass ratio of 7.5-8.5:1-1.5:0.5-1 to obtain a fermentation medium; wherein the fermentation raw material is obtained by mixing apple pomace and potato pomace in a mass ratio of 1-3:1;

[0008] After mixing the fermentation medium with water at a solid-liquid ratio of 1:2.5-3, adding a composite enzyme to degrade the dietary fiber for 2h-4h, and then adding a composite bacteria to ferment for 72h-96h to convert the dietary fiber degradation product into crude protein to obtain the dregs feed;

[0009] The mass ratio of the fermentation medium, the compound enzyme and the compound bacteria is 1000: 0.5-1.5: 0.5-2.5.

[0010] The present invention is fermented by a two-step method, that is, a composite enzyme is first added to degrade dietary fibers such as cellulose, hemicellulose and pectin in the fermentation medium into small molecules, such as glucose and galacturonic acid, and then composite bacteria are added. The small molecules produced by the early enzymatic hydrolysis can effectively promote the fermentation process of the microorganism, produce abundant bacterial protein and flavor substances, and can further reduce the content of crude fiber by the two-step fermentation method, improve the level of crude protein in the fermentation product, and effectively improve the efficiency of the composite enzyme and the composite bacteria. In addition, apple pomace and potato pomace are mixed, and the starch contained in the potato pomace provides a carbon source for the growth of microorganisms in the initial stage of fermentation, making up for the high dietary fiber content of apple pomace and the difficulty of fermenting alone. The method of the present invention can make full use of apple pomace, so that the obtained dregs feed has higher nutritional value.

[0011] In another preferred embodiment, the composite bacteria is obtained by mixing lactic acid bacteria, bacillus and yeast in a mass ratio of 1-2:1-2:0.5-1;

[0012] The complex enzyme is prepared by compounding xylanase, cellulase, pectinase and acidic protease; in the complex enzyme, the concentration of xylanase is 10U / g-15U / g, the concentration of cellulase is 10U / g-20U / g, the concentration of pectinase is 5U / g-10U / g, and the concentration of acidic protease is 3U / g-5U / g.

[0013] Digestive enzymes such as cellulase, xylanase, pectinase and protease in the complex enzyme replace the digestion of Aspergillus to simplify the fermentation steps and improve the digestion efficiency. By inoculating lactic acid bacteria, yeast and Bacillus subtilis, the apple pomace is fermented by multiple strains to promote the degradation of cellulose in the apple pomace and increase the crude protein content in the fermentation product.

[0014] In another preferred embodiment, the enzymatic hydrolysis temperature is 50°C to 55°C, and the pH value is 5 to 5.5.

[0015] In another preferred embodiment, the fermentation temperature is 28°C to 30°C, and the pH value is 6 to 6.5.

[0016] In another preferred embodiment, the viable counts of the lactic acid bacteria, the Bacillus and the yeast are all 1×10 5 CFU / g~4×10 5 CFU / g.

[0017] The second aspect of the present invention provides the dregs feed.

[0018] The third aspect of the present invention provides the use of the dregs feed in preparing livestock feed, wherein the livestock is beef cattle or sheep.

[0019] The fourth aspect of the present invention provides the use of the dregs feed in promoting the growth of livestock.

[0020] In another preferred embodiment, the growth promotion refers to increasing the daily weight gain, average daily feed intake and reducing the feed-to-weight ratio of livestock.

[0021] Compared with the prior art, the present invention has the following beneficial effects.

[0022] (1) The present invention first adds a composite enzyme and then adds a composite bacteria in a two-step process, whereby dietary fiber is degraded by enzymatic hydrolysis in the early stage, and the degradation products of dietary fiber are converted into crude protein by microbial fermentation in the later stage, thereby increasing the content of crude protein and effectively increasing the nutritional value of the fermented feed. Then, apple pomace and potato pomace are mixed. As a kind of agricultural and sideline product, potato pomace contains starch and protein, which can provide nutrition for the growth and reproduction of microorganisms in the early stage of fermentation, and is beneficial to the fermentation of microorganisms. By utilizing the starch in potato pomace to provide the necessary carbon source in the early stage of fermentation, the deficiency of apple pomace that is difficult to ferment due to the high dietary fiber content is compensated, and fermentation is further promoted to improve the fermentation efficiency.

[0023] (2) The composite enzyme compounded with cellulase, xylanase, pectinase and protease of the present invention can effectively improve the digestion efficiency compared with Aspergillus niger; the composite bacteria compounded with lactic acid bacteria, yeast and Bacillus subtilis can promote the degradation of cellulose in apple pomace and increase the crude protein content in the fermentation product. According to the different fermentation conditions of the composite enzyme and the composite bacteria, the pH value and temperature are controlled, the digestion effect of the composite enzyme on the dietary fiber in the apple pomace is fully exerted, the apple pomace is fully enzymatically hydrolyzed, the fermentation process of the composite bacteria is promoted, and the nutritional value of the feed is effectively improved.

[0024] (3) The present invention combines potato residue with apple residue to obtain residue feed in a two-step method, which can significantly reduce the crude fiber level and increase the crude protein content in the fermentation product, thereby significantly improving the daily weight gain and feed intake of livestock and reducing the feed-to-weight ratio. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] Unless otherwise specified, the experimental methods described in the following examples are all conventional methods; the reagents and materials described are all commercially available unless otherwise specified.

[0027] In the following examples, Lactobacillus plantarum and Bacillus subtilis were purchased from Shandong Baolai Lilai Bioengineering Co., Ltd., and yeast was purchased from Angel Yeast.

[0028] Apple pomace was purchased from Shandong Linqu Yongduo Feed Factory, dried at 60°C to 65°C, crushed and passed through a 20-mesh sieve. Potato pomace was purchased from Shandong Linshu County Huabin Starch Business Department, dried at 60°C to 65°C, crushed and passed through a 20-mesh sieve.

[0029] Embodiment 1: A method for preparing dregs feed comprises the following steps.

[0030] S1. Mix 20-mesh apple pomace and potato pomace in a mass ratio of 2:1 to obtain a fermentation raw material.

[0031] S2. Mix the fermentation raw materials, bran and soybean meal in a mass ratio of 75:15:10 to obtain a fermentation medium, mix the fermentation medium with water in a solid-liquid ratio of 1:2.5, sterilize at high temperature at 121° C. for 30 minutes, and cool to room temperature to obtain a fermentation medium.

[0032] S3. Adjust the pH of the fermentation medium to 5, add complex enzyme, and perform enzymolysis at 50° C. for 2 hours to obtain an enzymolyzed fermentation medium; wherein the complex enzyme is a compound of xylanase, cellulase, pectinase and acid protease, and the content of xylanase in the complex enzyme is 15 U / g, the content of cellulase is 15 U / g, the content of pectinase is 5 U / g, and the content of acid protease is 5 U / g.

[0033] S4. The pH of the fermentation medium after enzymatic hydrolysis was adjusted to 6, and composite bacterial powder was added to ferment at 30°C for 48 hours to obtain dregs fermented feed; wherein the composite bacterial powder was obtained by mixing lactic acid bacteria powder, Bacillus powder and yeast powder in a mass ratio of 2:1:1, and the number of live lactic acid bacteria was 2×10 5 CFU / g, the addition amount of Bacillus and yeast was 1×10 5 CFU / g;

[0034] The mass ratio of the fermentation medium, the compound enzyme and the compound bacteria is 1000:1:1.5.

[0035] Embodiment 2: A method for preparing dregs feed comprises the following steps.

[0036] S1. Mix 20-mesh apple pomace and potato pomace in a mass ratio of 1:1 to obtain a fermentation raw material.

[0037] S2. Mix the fermentation raw materials, bran and soybean meal in a mass ratio of 80:15:5 to obtain a fermentation medium, mix the fermentation medium with water in a solid-liquid ratio of 1:3, sterilize at high temperature at 121°C for 30 minutes, and cool to room temperature to obtain a fermentation medium.

[0038] S3, adjusting the pH of the fermentation medium to 5.5, adding a composite enzyme, and performing enzymolysis at 55° C. for 3 hours to obtain an enzymolyzed fermentation medium; wherein the composite enzyme is a compound of xylanase, cellulase, pectinase and acid protease, with a xylanase content of 10 U / g, a cellulase content of 12 U / g, a pectinase content of 5 U / g, and an acid protease content of 3 U / g;

[0039] S4. The pH of the fermentation medium after enzymatic hydrolysis was adjusted to 6, and composite bacterial powder was added to ferment at 28°C for 72 hours to obtain a fermented feed of dregs; wherein the composite bacterial powder was mixed with lactic acid bacteria powder, Bacillus powder and yeast powder in a mass ratio of 1:1:1, and the number of live bacteria in the lactic acid bacteria powder, Bacillus powder and yeast powder was 1×10 5 CFU / g;

[0040] The mass ratio of the fermentation medium, the compound enzyme and the compound bacteria is 1000:0.5:1.

[0041] Embodiment 3: A method for preparing dregs feed comprises the following steps.

[0042] S1. Mix 20-mesh apple pomace and potato pomace in a mass ratio of 3:1 to obtain a fermentation raw material.

[0043] S2. Mix the fermentation raw materials, bran and soybean meal in a mass ratio of 80:10:10 to obtain a fermentation medium, mix the fermentation medium with water in a solid-liquid ratio of 1:3, sterilize at high temperature at 121°C for 30 minutes, and cool to room temperature to obtain a fermentation medium.

[0044] S3. Adjust the pH of the fermentation medium to 6.5, add complex enzyme, and perform enzymolysis at 53° C. for 4 hours to obtain an enzymatically hydrolyzed fermentation medium; wherein the complex enzyme is a compound of xylanase, cellulase, pectinase and acid protease, wherein the content of xylanase is 15 U / g, the content of cellulase is 20 U / g, the content of pectinase is 10 U / g, and the content of acid protease is 5 U / g.

[0045] S4. The pH of the fermentation medium after enzymatic hydrolysis was adjusted to 6.5, and composite bacterial powder was added to ferment at 30°C for 72 hours to obtain dregs fermented feed; wherein the composite bacteria was obtained by mixing lactic acid bacteria powder, Bacillus powder and yeast powder in a mass ratio of 2:2:1, and the number of live lactic acid bacteria and Bacillus powder was 2×10 5CFU / g, the number of live yeast cells is 1×10 5 CFU / g;

[0046] The mass ratio of fermentation medium, compound enzyme and compound bacteria is 1000:1.5:2.

[0047] Comparative Example 1: A method for preparing dregs feed, comprising the following steps.

[0048] S1. Mix 20-mesh apple pomace and potato pomace in a mass ratio of 2:1 to obtain a fermentation raw material.

[0049] S2. Mix the fermentation raw materials, bran and soybean meal in a mass ratio of 75:15:10 to obtain a fermentation medium, mix the fermentation medium with water in a solid-liquid ratio of 1:2.5, sterilize at high temperature at 121° C. for 30 minutes, and cool to room temperature to obtain a fermentation medium.

[0050] S3. Adjust the pH of the fermentation medium to 5, dispense into fermentation bags, sterilize at 121°C for 30 minutes, cool to room temperature, add compound enzyme in the clean bench, and ferment in a 30°C incubator for 48 hours, 72 hours, and 96 hours, respectively. The compound enzyme is a compound of xylanase, cellulase, pectinase, and acid protease, and the content of xylanase in the compound enzyme is 15U / g, the content of cellulase is 15U / g, the content of pectinase is 5U / g, and the content of acid protease is 5U / g.

[0051] The mass ratio of the fermentation medium to the complex enzyme is 1000:1.

[0052] Comparative Example 2: A method for preparing dregs feed, comprising the following steps.

[0053] S1. Mix 20-mesh apple pomace and potato pomace in a mass ratio of 2:1 to obtain a fermentation raw material.

[0054] S2. Mix the fermentation raw materials, bran and soybean meal in a mass ratio of 75:15:10 to obtain a fermentation medium, mix the fermentation medium with water in a solid-liquid ratio of 1:2.5, sterilize at high temperature at 121° C. for 30 minutes, and cool to room temperature to obtain a fermentation medium.

[0055] S3. Adjust the pH of the fermentation medium to 5., divide it into fermentation bags, sterilize it at 121°C for 30 minutes, cool it to room temperature, adjust the pH of the fermentation medium to 6.0-6.5 in a clean bench, add composite bacterial powder, and ferment it in a 30°C incubator for 48h, 72h, and 96h respectively. The composite bacterial powder is obtained by mixing lactic acid bacteria powder, Bacillus powder, and yeast powder in a mass ratio of 2:1:1, and the number of viable lactic acid bacteria is 2×10 5CFU / g, the number of live bacteria of Bacillus and yeast was 1×10 5 CFU / g.

[0056] The mass ratio of the fermentation medium to the composite bacteria is 1000:1.5.

[0057] Comparative Example 3: A method for preparing dregs feed, comprising the following steps.

[0058] S1. Mix 20-mesh apple pomace and potato pomace in a mass ratio of 2:1 to obtain a fermentation raw material.

[0059] S2. Mix the fermentation raw materials, bran and soybean meal in a mass ratio of 75:15:10 to obtain a fermentation medium, mix the fermentation medium with water in a solid-liquid ratio of 1:2.5, sterilize at high temperature at 121° C. for 30 minutes, and cool to room temperature to obtain a fermentation medium.

[0060] S3, adjusting the pH of the fermentation medium to 6, adding compound enzymes and compound bacteria, and fermenting at 37° C. for 72 hours to obtain fermented feed;

[0061] The compound enzyme is a mixture of xylanase, cellulase, pectinase and acid protease. The content of xylanase in the compound enzyme is 15U / g, the content of cellulase is 15U / g, the content of pectinase is 5U / g, and the content of acid protease is 5U / g. The compound bacteria is obtained by mixing lactic acid bacteria, bacillus and yeast in a mass ratio of 2:1:1, and the number of viable lactic acid bacteria is 2×10 5 CFU / g, the number of live bacteria of Bacillus and yeast was 1×10 5 CFU / g.

[0062] The mass ratio of the fermentation medium, the compound enzyme and the compound bacteria is 1000:1:1.5.

[0063] 1. The impact of different fermentation methods on feed nutritional components.

[0064] The dregs feed obtained without adding the composite enzyme and the composite bacteria was used as the control group, and Example 1, Comparative Example 1, and Comparative Example 2 were used as the experimental groups, and the crude protein and crude fiber in the dregs feed obtained at different fermentation times were measured, and the results are shown in Tables 1 and 2. Among them, the fermentation time was 48h, 72h, and 96h.

[0065] Table 1 Crude protein content of feed fermented with dregs at different fermentation times (%)

[0066] Group 48h 72h 96h Control group <![CDATA[14.50±0.52 b ]]> <![CDATA[14.48±0.37 c ]]> <![CDATA[14.41±0.70 c ]]> Comparative Example 1 <![CDATA[14.35±0.38 b ]]> <![CDATA[14.52±0.75 c ]]> <![CDATA[14.16±0.51 c ]]> Comparative Example 2 <![CDATA[16.64±1.05 a ]]> <![CDATA[17.96±0.92 b ]]> <![CDATA[17.18±0.43 b ]]> Example 1 <![CDATA[18.54±0.42 a ]]> <![CDATA[20.49±0.36 a ]]> <![CDATA[19.75±0.29 a ]]>

[0067] Note: Data in the same column with the same letters on their shoulders indicate no significant difference (P>0.05), and data with different letters on their shoulders indicate significant difference (P<0.05), the same below.

[0068] Table 2 Crude fiber content of dregs fermented feed at different fermentation times (%)

[0069] Group 48h 72h 96h Control group 21.09±0.52 21.84±0.08 21.03±0.15 Comparative Example 1 15.07±0.1 14.52±0.09 14.22±0.12 Comparative Example 2 20.85±1.03 20.13±0.15 20.64±0.68 Example 1 16.54±0.22 15.54±0.16 15.04±0.42

[0070] After 48h, 72h and 96h of fermentation, the methods of Comparative Example 1, Comparative Example 2 and Example 1 can all increase the crude protein level in the fermented apple pomace compared with the control group. Among them, the fermentation effect of the dregs fermented feed obtained by Example 1 after 72h of fermentation was the best, followed by Comparative Example 2. Compared with the control group, the fermentation method in Comparative Example 2 can increase the crude protein content in the apple pomace by 24.03% (p<0.05), and the fermentation method in Example 1 can increase the crude protein content by 41.51% (p<0.05).

[0071] After 48h, 72h and 96h of fermentation, the crude fiber level in apple pomace can be reduced in each treatment group compared with the control group. Among them, the treatment group of comparative example 1 has the most significant effect, and the crude fiber content in apple pomace can be reduced by 28.54%, 33.51% and 32.39% (p<0.05) at 48h, 72h and 96h, respectively; in addition, compared with comparative example 2, the fermentation of example 1 has a better effect on the degradation of crude fiber in apple pomace, among which the fermentation for 72h has the best effect, and the treatment group of example 1 can reduce crude fiber by 33.51% (p<0.05).

[0072] 2. Effect of two-step fermentation for 72 h on the pH and microbial count of apple pomace.

[0073] The results are shown in Table 3. The pH of Example 1, i.e., the bacterial-enzyme combined fermentation group, was the lowest, and the numbers of lactic acid bacteria, yeast and Bacillus in its fermentation products were 7.67 times, 2.82 times and 3.57 times of those in Comparative Example 2, i.e., the simple composite bacteria fermentation group, respectively. This is consistent with the lower pH value in the bacterial-enzyme combined fermentation apple pomace, and is also consistent with the fact that the bacterial-enzyme combined fermentation group has the highest crude protein content.

[0074] Table 3 Number of live bacteria and pH in two-step fermentation residue feed

[0075] index Control group Comparative Example 1 Comparative Example 2 Example 1 pH 6.15 5.89 4.05 3.33 Lactic acid bacteria — — <![CDATA[1.19×10 8 CFU / g]]> <![CDATA[9.13×10 8 CFU / g]]> Yeast — — <![CDATA[6.94×10 7 CFU / g]]> <![CDATA[1.96×10 8 CFU / g]]> Bacillus — — <![CDATA[1.83×10 6 CFU / g]]> <![CDATA[6.55×10 6 CFU / g]]>

[0076] Note: “—” means not detected, the same below.

[0077] 3. Effect of one-step fermentation on pH and microbial count of apple pomace.

[0078] The conventional one-step fermentation method, i.e., the method in comparative example 3, was used as the control group, and the feed obtained without adding the compound enzyme and compound bacteria was used as the experimental group. The crude protein and crude fiber in the fermented feed obtained under different fermentation times were measured, and the results are shown in Tables 4 and 5. The fermentation time was 48h, 72h, and 96h.

[0079] Table 4 Crude protein content in one-step fermentation dregs feed (%)

[0080] Group 48h 72h 96h Control group <![CDATA[14.58±0.11 b ]]> <![CDATA[14.48±0.13 b ]]> <![CDATA[14.44±0.06 b ]]> Complex enzyme <![CDATA[14.44±0.28 b ]]> <![CDATA[14.44±0.16 b ]]> <![CDATA[14.83±0.14 b ]]> Compound bacteria <![CDATA[16.07±0.19 b ]]> <![CDATA[16.24±0.47 b ]]> <![CDATA[16.11±0.16 a ]]> Comparative Example 3 <![CDATA[17.05±0.35 a ]]> <![CDATA[17.18±0.21 a ]]> <![CDATA[17.12±0.52 a ]]>

[0081] From the results in Table 4, it can be seen that the crude protein content in apple pomace of comparative example 3, i.e., fermentation with bacteria and enzymes, was the highest at 48h, 72h, and 96h, among which the crude protein content in apple pomace of fermentation with bacteria and enzymes at 48h and 72h was significantly higher than that of the compound bacteria fermentation group alone (p<0.05). In addition, the effect of fermentation at 72h was the best. Compared with the control group, the crude protein content in the fermentation with bacteria and enzymes group increased by 18.65%, and that in the compound bacteria group increased by 12.15%. Compared with the two-step fermentation, the crude protein content in apple pomace fermented by the one-step method was lower.

[0082] Table 5 Crude fiber content in one-step fermentation dregs feed (%)

[0083] Group 48h 72h 96h Comparison 21.74±0.35 21.68±0.59 21.81±0.54 Complex enzyme 19.01±1.21 18.89±0.12 18.93±1.03 Compound bacteria 20.71±0.46 20.33±0.31 20.95±0.32 Comparative Example 3 19.85±0.17 19.34±0.05 19.38±0.03

[0084] From the results in Table 5, it can be seen that after 48h of fermentation, the crude fiber content in the apple pomace of each treatment group decreased compared with the control group. Among them, the effect of fermentation for 72h was the best. Compared with the control group, the crude fiber content of the complex enzyme group decreased by 12.86%, the complex bacteria group decreased by 6.22%, and the comparative example 3, i.e., the combined fermentation of bacteria and enzymes, decreased by 10.79%; after 96h of fermentation, the crude fiber content in the fermented apple pomace did not change much compared with that of 72h. In addition, the effect of combined fermentation of bacteria and enzymes at each time point was better than that of the combined fermentation of bacteria and enzymes. Compared with the combined fermentation of bacteria and enzymes at 48h, 72h and 96h, the crude fiber of the combined fermentation of bacteria and enzymes decreased by 4.30%, 4.87% and 7.49% respectively. Compared with the two-step fermentation, the one-step fermentation has a weaker ability to degrade crude fiber in apple pomace.

[0085] The pH and viable count of the product of the one-step fermentation of apple pomace after 72 hours of fermentation are shown in Table 6. Consistent with the two-step fermentation, the pH of the comparative example 3, i.e., the combined fermentation of bacteria and enzymes, was the lowest, which was 11.16% lower than that of the compound fermentation group, and the viable counts of lactic acid bacteria, yeast and bacillus were significantly higher than those of the compound fermentation group. However, compared with the one-step fermentation, the pH of the two-step fermentation product was lower, and the number of lactic acid bacteria, yeast and bacillus in the product was 6.34 times, 4.54 times and 2.54 times that of the one-step fermentation.

[0086] Table 6 pH and number of viable bacteria in one-step fermentation residue feed

[0087]

[0088]

[0089] From the above results, it can be seen that the two-step fermentation has a better effect than the one-step fermentation. Among them, the content of crude protein in the fermented apple pomace was the highest when the bacterial enzyme combined with the two-step fermentation was 72 hours, which was 41.51% higher than that of the control group. In addition, compared with other groups, the yeast and lactic acid bacteria content in the apple pomace fermented by the bacterial enzyme combined with the two-step fermentation was the highest, which was consistent with the crude protein level.

[0090] 4. Application in the fattening period of beef cattle and sheep.

[0091] 1) Application in beef cattle fattening period: Simmental cattle about 6 months old were selected for feeding test. The experimental group was added with fermented dregs feed in Example 1 at 0.5%, 1%, 2% and 4% of the complete feed. The experimental beef cattle were vaccinated according to the conventional immunization program. The pre-test period was 3 days, and the formal test period was 57 days. The fasting weight was weighed at 0d and 60d at the beginning of the test. The feed intake of each group was recorded, and the average daily weight gain, average daily feed intake and feed-to-weight ratio were calculated. The results are shown in Table 7.

[0092] The complete feed is obtained by mixing roughage and concentrate in a mass ratio of 7:3. The concentrate is composed of the following raw materials by mass percentage: 65% corn, 25% soybean meal, 5% bran, 1% salt, 1% baking soda, 1% oil, and 4% beef premix. The roughage is composed of the following raw materials by mass percentage: 70% silage corn straw and 30% distiller's grains.

[0093] Table 7 Results of average daily weight gain, average daily feed intake and feed-to-weight ratio of beef cattle

[0094]

[0095] The results showed that adding different levels of fermented pomace could increase daily weight gain and reduce feed-to-weight ratio. The daily weight gain of 1%, 2% and 4% fermented pomace increased by 221.73 g / d, 277.81 g / d and 289.67 g / d respectively compared with the control group, with significant differences (P<0.05); the daily weight gain of 1%, 2% and 4% fermented pomace decreased by 19.97%, 19.35% and 19.03% respectively compared with the control group, with significant differences (P<0.05).

[0096] 2) Application in the fattening period of mutton sheep: Boer male goats of about 6 months old were selected for feeding test. The experimental group was added with the fermented feed of the residue in Example 1 at 0.5%, 1%, 2% and 4% of the complete feed. The experimental sheep were vaccinated according to the conventional immunization program. The pre-test period was 3 days, and the formal test period was 57 days. The fasting weight was weighed at 0d and 60d at the beginning of the test, and the feed intake of each group of mutton sheep was recorded, and the average daily weight gain, average daily feed intake and feed-to-weight ratio were calculated.

[0097] The complete feed was obtained by mixing roughage and concentrate feed in a mass ratio of 7:3. The concentrate feed was purchased from Shandong Hemeihua Agriculture and Animal Husbandry Group, and the roughage was corn stalks.

[0098] Table 8 Results of average daily weight gain, average daily feed intake and feed-to-weight ratio of mutton sheep

[0099]

[0100] The results showed that compared with the control group, each experimental group could increase daily weight gain and reduce feed-to-weight ratio. Adding 0.5% fermented pomace could increase the final weight of mutton sheep and reduce the feed-to-weight ratio, but the difference was not significant compared with the control group. The group adding 2% fermented pomace had the best effect. The final weight and average daily weight gain of mutton sheep increased by 8.27% and 21.7% respectively compared with the control group (P<0.05), and the feed weight decreased by 19.58% compared with the control group (P<0.05).

[0101] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing dregs feed by combined fermentation of bacteria and enzymes in steps, characterized in that: The following steps are involved: The fermentation raw material, bran and soybean meal are mixed in a mass ratio of 7.5-8.5:1-1.5:0.5-1 to obtain a fermentation medium; wherein the fermentation raw material is obtained by mixing apple pomace and potato pomace in a mass ratio of 1-3:1; After mixing the fermentation medium with water at a solid-liquid ratio of 1:2.5-3, adding a composite enzyme to degrade the dietary fiber for 2h-4h, and then adding a composite bacteria to ferment for 72h-96h to convert the degradation product of the dietary fiber into crude protein to obtain the dregs feed; The mass ratio of the fermentation medium, the compound enzyme and the compound bacteria is 1000: 0.5-1.5: 0.5-2.

5.

2. The preparation method according to claim 1, characterized in that: The composite bacteria is obtained by mixing lactic acid bacteria, bacillus and yeast in a mass ratio of 1-2:1-2:0.5-1; The complex enzyme is prepared by compounding xylanase, cellulase, pectinase and acidic protease; in the complex enzyme, the concentration of xylanase is 10U / g-15U / g, the concentration of cellulase is 10U / g-20U / g, the concentration of pectinase is 5U / g-10U / g, and the concentration of acidic protease is 3U / g-5U / g.

3. The preparation method according to claim 2, characterized in that: The temperature of the enzymatic hydrolysis is 50° C. to 55° C., and the pH value is 5 to 5.

5.

4. The preparation method according to claim 2, characterized in that: The fermentation temperature is 28°C to 30°C, and the pH value is 6 to 6.

5.

5. The method for preparing fermented feed from dregs according to claim 2, characterized in that: The viable counts of the lactic acid bacteria, the bacillus and the yeast were all 1×10 5 CFU / g~4×10 5 CFU / g.

6. A dregs feed prepared by the preparation method according to any one of claims 1 to 5.

7. Use of the dregs feed according to claim 6 in preparing livestock feed, characterized in that: The livestock are beef cattle or sheep.

8. Use of the dregs feed according to claim 6 in promoting the growth of livestock.

9. The use of the dregs feed in promoting livestock growth according to claim 8, characterized in that: The growth promotion refers to increasing the daily weight gain and average daily feed intake of livestock and reducing the feed-to-weight ratio.

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