Preparation method of sweet potato seedling and corn straw mixed silage

Abstract

The invention belongs to the field of feed processing, and particularly relates to a sweet potato seedling and corn straw mixed silage preparation method which comprises the following steps: S1, raw material pretreatment: respectively chopping sweet potato seedlings and corn straws; s2, mixing: the chopped sweet potato seedlings and corn straws are weighed, an additive is added, the mixture is uniformly mixed, the additive is a mixed lactic acid bacteria additive, and the addition amount is 0.1 g / kg; s3, loading into a silage container, compacting and sealing; s4, storage: the fermentation temperature range is 15-28 DEG C, preferably 25 + / -1 DEG C. According to comprehensive evaluation, the sweet potato seedlings and the corn straw are mixed and ensiled according to the proportion of 1: 1, and the comprehensive value is the highest. The proportion can effectively balance dry substances and moisture of the two raw materials, and the silage which is excellent in smell, color and texture, complete in nutrition preservation and excellent in fermentation quality can be obtained after the mixed lactic acid bacteria additive is added for ensiling for 60 days.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of feed processing, and particularly relates to a preparation method of mixed silage of sweet potato sprouts and corn stalks. BACKGROUND

[0002] With the continuous development of the livestock breeding industry in China, the demand for high-quality roughage is increasing, but the contradiction between human and livestock for food is highlighted, and the shortage of high-quality forage resources has become a bottleneck restricting the quality and efficiency of the industry. At the same time, a large amount of agricultural by-products cannot be efficiently utilized, among which the stems and leaves of sweet potato after tuber harvesting are rich in protein and vitamins and have good palatability. Conventional treatment methods are mostly field stacking and airing, but the high water content makes them prone to spoilage and deterioration, resulting in not only resource waste but also environmental pollution. On the other hand, corn stalks are the main source of roughage for ruminants, and the processing method is mostly yellow silage, which is mainly based on natural fermentation. However, the fermentation quality is unstable, the acid detergent fiber content is high, the digestibility is low, and the palatability is poor, which cannot meet the demand of the modern breeding industry for high-quality feed. Therefore, how to scientifically match the sweet potato sprouts with good feeding value but prone to spoilage and waste with the corn stalks with large quantity but poor fiber quality, and realize the complementary nutrition and quality improvement through innovative silage technology, has become a key breakthrough in the industry. Developing an efficient preparation method of mixed silage of sweet potato sprouts and corn stalks can not only convert the two agricultural wastes into high-quality feed to alleviate the shortage of roughage, but also significantly improve the nutritional value and utilization efficiency of existing straw feed, which has great practical significance for promoting agricultural circular economy and realizing cost reduction, quality improvement and efficiency increase in the breeding industry. SUMMARY

[0003] In order to solve the problems existing in the prior art, the application provides a preparation method and application of mixed silage of sweet potato sprouts and corn stalks, which solves the problems of spoilage and difficulty in preservation of sweet potato sprouts, and limited feed utilization, and improves the quality of corn stalk yellow silage. The prepared silage feed is stable in quality and balanced in nutrition, and an optimized feeding combination scheme is provided, which provides a reliable technical approach for the feed utilization of the two agricultural by-products.

[0004] The specific technical scheme adopted by the application is: A preparation method of mixed silage of sweet potato sprouts and corn stalks, comprising the following steps: S1. Raw material pretreatment: cutting the sweet potato sprouts and corn stalks respectively; S2. Mixing: according to the designed mixing ratio, the cut sweet potato sprouts and corn stalks are weighed and mixed uniformly after adding additives; S3. Filling: filling the uniformly mixed raw materials into a silage bag, compacting and excluding air; after filling, vacuum sealing machine is used to extract vacuum and seal; S4. Storage: the fermentation temperature ranges from 15-28℃, preferably 25±1℃.

[0005] The length of the cut sweet potato vine and corn stalk is 1-2 cm.

[0006] The design mixing ratio of the sweet potato vine and corn stalk is 1:1.

[0007] The additive is a mixed lactic acid bacteria additive, and the addition amount is 0.1 g / kg.

[0008] The mixed lactic acid bacteria additive includes 1×10 8 CFU / g of Lactobacillus plantarum, 1×10 8 CFU / g of Lactobacillus buchneri and 1×10 9 CFU / g of Pediococcus pentosaceus.

[0009] The design storage time is 60 days.

[0010] The beneficial effects of the present application are: Through comprehensive evaluation, the sweet potato vine and corn stalk are mixed in a ratio of 1:1 for silage, and the comprehensive value is the highest. This ratio can effectively balance the dry matter of the two raw materials, and when silage is performed for 60 days, silage feed with excellent smell, color and texture, complete nutrient preservation and excellent fermentation quality can be obtained.

[0011] The present application also provides the most suitable silage additive: for the silage of 1:1 of the sweet potato vine and corn stalk, the addition of 0.1 g / kg of the mixed lactic acid bacteria additive can most effectively promote lactic acid fermentation, significantly reduce the pH value to 3.94, improve the crude protein preservation rate, reduce the fiber content, and obtain the optimal comprehensive membership degree score. DETAILED DESCRIPTION

[0012] The present application will be further described below in combination with specific examples: The present application is a preparation method of mixed silage of sweet potato vine and corn stalk, comprising the following steps: S1. Raw material pretreatment: cut the sweet potato vine and corn stalk respectively; S2. Mixing: according to the design mixing ratio, the cut sweet potato vine and corn stalk are weighed and mixed uniformly after adding an additive; S3. Filling: the uniformly mixed raw materials are filled into a silage bag, compacted and air excluded; after filling, a vacuum sealing machine is used to extract vacuum and seal; S4. Storage: the fermentation temperature ranges from 15-28℃, preferably 25±1℃.

[0013] The present application determines the mixing ratio of the sweet potato vine and corn stalk through a test method, and determines the suitable additive through a comparative test, and the specific test steps are as follows: 1 Test material Sweet potato vines were harvested 1-2 days before the harvest of sweet potatoes (dry matter 15-18%) and corn stalks were harvested at the same time (dry matter 40-45%). The stalks were cut to 2-3 cm and packed into silage bags. After compaction, the bags were sealed (compaction density about 676 kg / m 3 ).

[0014] 2 Mixing ratio and ensiling time The sweet potato vines and corn stalks were mixed in the ratio of 1:0, 3:1, 1:1, 1:3 and 0:1 and placed in vacuum bags. Each combination was repeated 6 times, with 3 bags per repeat. After ensiling for different times (0, 3, 7, 15, 30, 60 and 90 days), sensory evaluation was performed and the conventional nutritional quality and fermentation quality were determined.

[0015] 3 Suitable additive for mixed ensiling Based on the suitable mixing ratio and ensiling time of sweet potato vines and corn stalks determined in the previous stage, 0.1 g / kg of lactic acid bacteria additive (Lactobacillus plantarum, Lactobacillus buchneri, mixed lactic acid bacteria, among which the mixed lactic acid bacteria includes 1 x 10 8 CFU / g of Lactobacillus plantarum, 1 x 10 8 CFU / g of Lactobacillus buchneri and 1 x 10 9 CFU / g of Pediococcus pentosaceus) was added. By evaluating the sensory state, nutritional and fermentation quality of mixed ensiling with different additives, the suitable lactic acid bacteria additive for different mixed ensiling was determined.

[0016] 4 Silage preparation steps: 4.1 Raw material pretreatment: sweet potato vines were harvested 1-2 days before the harvest of sweet potatoes, and mature corn stalks were harvested at the same time. The sweet potato vines and corn stalks were cut to 1-2 cm in length, respectively.

[0017] 4.2 Mixing: according to the test design ratio, the cut raw materials were accurately weighed and the corresponding additive was added, and then mixed evenly.

[0018] 4.3 Packing and sealing: the mixed raw materials were quickly packed into the silage container, and each part was compacted and sealed after the air was removed.

[0019] 4.4 Storage: the sealed silage container was stored at 15-28℃, preferably at 25±1℃.

[0020] 5 Test indicators and methods 5.1 Sensory evaluation: according to the German DLG silage feed sensory evaluation standard, sensory evaluation was performed from the aspects of odor, texture and color.

[0021] 5.2 Routine nutritional indicators: Dry matter (DM): determined by oven drying method; Crude protein (CP): determined by Kjeldahl method; Crude ash: determined by high temperature ashing method; Crude fat (EE): determined by Soxhlet extraction method; Neutral detergent fiber (NDF) and acid detergent fiber (ADF): determined by Van Soest detergent fiber method; Soluble sugar (WSC) determined by anthrone-sulfuric acid colorimetric method; Calcium (Ca): determined by potassium permanganate titration method; Phosphorus (P): determined by vanadium ammonium molybdate colorimetric method.

[0022] 5.3 Silage fermentation quality: According to the "Silage Quality Evaluation Standard (Trial)", the extract was prepared, the pH value of the silage was determined by pH meter, and the ammonia nitrogen (NH3-N) content was determined by phenol-hypochlorous acid colorimetric method; the high performance liquid chromatograph (Agilent 1200) was used to determine the contents of lactic acid (LA), acetic acid (AA) and propionic acid (PA).

[0023] 5.4 Aerobic stability evaluation: After the completion of ensiling, 1 kg of mixed silage was placed in a polyethylene silage tank with a volume of 1 kg, the tank opening was covered with two layers of gauze to prevent the silage from evaporating too quickly and foreign matter from falling in, and was placed in room temperature conditions. The USB data temperature and humidity recorder was used to record the temperature at the center of the silage, and two other temperature observation points were set up in the room to record the indoor temperature, which was automatically recorded every 30 minutes. After 6 days, the thermometer was taken out, and when the silage temperature was 2 ℃ higher than the outside temperature, it was considered that the silage began to deteriorate and ferment.

[0024] 5.5 Study on the combination effect of mixed silage Different proportions of design (mixed silage: yellow silage: concentrate) were used to record the gas production at 2, 4, 6, 8, 12, 24, 36, 48, 60, 72 h by in vitro gas production method, and the SAS 9.4 NLIN program was used to fit the gas production kinetic equation to calculate the kinetic parameters. After incubation, the residual was collected by nylon bag filtration method, dried at 105 ℃ to constant weight, and the dry matter degradation rate (DMD) was calculated. The fermentation broth was collected, and the pH value, ammonia nitrogen (NH3-N) and total nitrogen (TN) contents of the fermentation broth were determined, and the NH3-N / TN ratio was calculated. The fermentation characteristics were comprehensively evaluated, and the optimal combination ratio was selected to provide data support for later application.

[0025] 5.6 Calculation of membership function value Eleven core indicators (DM, CP, NDF, ADF, WSC, starch, pH, LA, AA, PA, aerobic stability) were selected for membership function analysis. DM, CP, WSC, starch, LA content and aerobic stability were positive indicators, and NDF, ADF, pH, AA, PA content were negative indicators. The total membership degree of each mixed silage was calculated, and the total membership degree value was used as the basis for ranking the comprehensive value of mixed silage (the larger the total membership degree value, the higher the comprehensive value).

[0026] The results showed that the sensory evaluation and conventional nutritional quality of mixed silage of sweet potato vine and corn straw in different proportions were analyzed. The ash content (10.32%) and crude protein content (7.59%) of single silage of sweet potato vine were slightly higher than those of other mixed silage, the neutral detergent fiber (47.12%) and acid detergent fiber content (23.98%) were significantly lower than those of other mixed silage, but the dry matter content was too low (15.77%), which was not suitable for silage. When the ratio of sweet potato vine to corn straw was 1:1 and 1:3, and the silage time was 60 days, the color, smell and texture of mixed silage had the highest comprehensive score, and the crude protein content was slightly higher and the fiber content was slightly lower, which was better than single silage.

[0027] The fermentation quality results showed that when the silage time of mixed silage of sweet potato vine and corn straw was 60 days, and the mixing ratio was 1:1, the pH was 3.94, and the quality was the best. When the mixing ratio was 1:0, the pH of mixed silage was 3.55, which was prone to oxidation and spoilage, and was not suitable for silage. The lactic acid content and aerobic stability of mixed silage were the highest when the ratio of sweet potato vine to corn straw was 1:3, and the lowest when the ratio was 1:0.

[0028] Based on the results of conventional nutritional quality and fermentation quality, it was preliminarily inferred that the water content of sweet potato vine was high, which was not suitable for single silage. Eleven indicators were selected, including dry matter, crude fat, crude protein, soluble sugar, starch and lactic acid content, pH and aerobic stability, which were positively correlated with mixed silage quality, and crude ash, neutral detergent fiber and acid detergent fiber content, which were negatively correlated, were used as positive and negative indicators. The total membership degree of different proportions of mixed silage was calculated, and the total membership degree value was used as the basis for ranking the comprehensive value (the larger the total membership degree value, the higher the comprehensive value). The results showed that the comprehensive value of mixed silage of sweet potato vine and corn straw in different proportions was ranked as follows: 1:1 (6.34) > 1:3 (6.31) > 3:1 (5.86) > 1:0 (4.54) > 0:1 (3.55). The suitable ratio of mixed silage of corn straw and sweet potato vine was 1:1, and the best silage time was 60 days.

[0029] Determination of silage additives, sweet potato vine and corn straw 1:1 mixed, respectively, adding the same unit of 3 kinds of lactic acid bacteria additives (Lactobacillus plantarum, Lactobacillus buchneri, mixed lactic acid bacteria), evaluation of the nutritional and fermentation quality of each treatment of mixed silage. The results showed that the sensory score and starch content of Lactobacillus buchneri and mixed lactic acid bacteria treatment group were significantly improved; the crude protein content of mixed silage in the mixed lactic acid bacteria treatment group was higher than that in other groups, the neutral detergent fiber content was lower than that in other treatment groups, and the pH was 3.94, which was better than the control group, and met the pH standard of high-quality silage.

[0030] Select 11 indicators of conventional nutritional quality and fermentation quality, calculate the total membership degree of different treatment mixed silage, and sort the comprehensive value according to the numerical value of total membership degree (the larger the numerical value of total membership degree, the higher the comprehensive value). The results showed that when the mixing ratio of sweet potato vine and corn straw was 1:1, the order of different lactic acid bacteria additives was: mixed lactic acid bacteria (8.08) > Lactobacillus buchneri (5.16) > Lactobacillus plantarum (3.67) > control group (2.42). Therefore, mixed lactic acid bacteria is more conducive to the fermentation of 1:1 mixed silage of sweet potato vine and corn straw. By analyzing the conventional nutritional quality, fermentation quality and aerobic stability of mixed silage under different mixing ratios and different additives, the suitable mixing ratio of sweet potato vine and corn straw for mixed silage is 1:1, and the suitable additive is mixed lactic acid bacteria. After 60 days of mixed fermentation, the silage pH is between 3.9 and 4.0, the neutral and acid detergent fiber is about 56% and 31% respectively, reaching the standard of high-quality corn straw silage.

[0031] Based on the previous determination of sweet potato vine and corn straw 1:1 mixed, adding mixed lactic acid bacteria and ensiling 60 days of the best technology, further study the combination effect of the mixed silage in the actual feeding. The in vitro gas production method was used to evaluate the effect of different proportions of concentrate supplement on the in vitro fermentation characteristics of mixed silage. Three different diet combinations (mixed silage: yellow silage: concentrate, dry matter basis) were designed: combination A (60:0:40): 60% optimal technology mixed silage + 40% concentrate; combination B (40:20:40): 40% optimal technology mixed silage + 20% corn straw yellow silage + 40% concentrate; combination C (20:40:40): 20% optimal technology mixed silage + 40% corn straw yellow silage + 40% concentrate. And 100% corn straw yellow silage + 40% concentrate was used as control group (control group (0:60:40)) for comparison. The results showed that the gas production kinetics parameters: the potential gas production (b) and the rapid degradation part gas production rate (c) of combination A were significantly higher than those of other combinations and the control group, indicating that it had higher fermentable substrate content and better fermentation rate. Dry matter degradation rate: the dry matter degradation rate of combination A was the highest, significantly higher than that of combination C and the control group, indicating that the nutrient utilization rate of this combination was the best. Fermentation end products: the fermentation liquid pH value of combination A was stable in the ideal range, and the ammonia nitrogen / total nitrogen ratio was the lowest, indicating that the protein degradation loss in the rumen was less, and the nitrogen utilization efficiency was higher.

[0032] The present application determines the optimal mixing ratio and ensiling time: through comprehensive evaluation, sweet potato vine and corn straw are mixed at a ratio of 1:1 for ensiling, which has the highest comprehensive value. This ratio can effectively balance the dry matter and moisture of the two raw materials, and when ensiling for 60 days, the silage feed with excellent odor, color and texture, complete nutrient preservation and excellent fermentation quality can be obtained.

[0033] The most suitable ensiling additive is screened out: for 1:1 mixed ensiling of sweet potato vine and corn straw, adding 0.1 g / kg of mixed lactic acid bacteria additive can most effectively promote lactic acid fermentation, significantly reduce the pH value (to 3.94), increase the crude protein preservation rate, reduce the fiber content, and obtain the optimal comprehensive membership degree score, which is the recommended additive of the present application.

[0034] The feed combination application scheme is clear: the feed combination effect study shows that the mixed silage prepared by the above optimal technology as the basic roughage, combined with concentrate supplement at a ratio of 60:40 (dry matter basis), can produce the best positive combination effect, significantly improve the in vitro fermentation gas production and dry matter degradation rate of rumen, and optimize the nitrogen utilization efficiency.

[0035] The core advantage of the present application is that the present application successfully provides an efficient method for mixed silage of high-moisture sweet potato seedlings and corn stalks, solves the problem of easy corruption of the single silage of sweet potato seedlings, the moisture of the sweet potato seedlings is absorbed by the corn stalks after vacuum packaging, the corruption of the sweet potato seedlings due to excessive moisture is avoided, the quality of the existing yellow silage of the corn stalks is improved (the previous quality can only be used for beef cattle), the prepared silage feed is stable in quality and balanced in nutrition, and an optimized feeding combination scheme is matched, and a reliable technical way is provided for the feed utilization of the two agricultural by-products.

Claims

1. A method for preparing a mixed silage of sweet potato seedlings and corn stalks, characterized by comprising the following steps: It comprises the following steps: ​ S1. Raw material pretreatment: cutting sweet potato vine and corn stalk respectively; S2. Mixing: according to the design mixing ratio, the cut sweet potato vine and corn stalk are weighed and mixed uniformly after adding additives; S3. Filling: the mixed raw materials are filled into the silo, compacted and sealed; S4. Storage fermentation, the storage temperature is 15-28℃.

2. The method according to claim 1, wherein the method is characterized by: The length of the cut sweet potato vine and corn stalk is 1-2 cm.

3. The method according to claim 1, wherein the method is characterized by: The design mixing ratio of the sweet potato vine and corn stalk is 1:

1.

4. The method according to claim 1, wherein the method is characterized by: The additive is mixed lactic acid bacteria additive, and the adding amount is 0.1 g / kg.

5. The method according to claim 1, wherein the method is characterized by: The mixed lactic acid bacteria additive comprises 1 x 10 8 CFU / g Lactobacillus plantarum, 1 x 10 8 CFU / g Lactobacillus buchneri and 1 x 10 9 CFU / g Pediococcus pentosaceus.

6. The method according to claim 1, wherein the method is characterized by: The design storage time is 60 days.

7. The method according to claim 1, wherein the method is characterized by: The storage temperature is 25±1℃.