A method for improving the quality of yellow silage feed from rice straw

Abstract

The present invention relates to the technical field of agriculture and relates to a method for improving the nutritional quality of ensiled rice straw feed. The processing method of the present invention cuts the mature rice straw, adds Lactobacillus rhamnosus LG608 to the cut straw, and ferments it at room temperature for 60 days under sealing. The present invention changes the traditional ensiling method of rice straw, uses a microbial additive to treat the rice straw, and adjusts the appropriate water content. The ensiled rice straw feed processed thereby reduces the loss rates of crude protein and soluble carbohydrates, reduces the contents of acid detergent fiber and neutral detergent fiber, significantly reduces the contents of propionic acid, acetic acid and butyric acid, and increases the feed intake of beef cattle for the ensiled rice straw feed, and is suitable for popularization and application in forage processing.

Description

Technical Field

[0001] The present invention relates to the field of agriculture, and specifically to a method for improving the nutritional quality of ensiled rice straw feed. Background Art

[0002] Rice is an important food crop in China. After harvesting rice every year, a large amount of straw is produced. Its unreasonable utilization will cause serious waste of resources and environmental pollution. Reasonably using rice straw resources for ruminant feeding can not only alleviate environmental pollution problems, but also contribute to the sustainable development of China's ruminant breeding industry. However, in the hot and humid climate environment of the southwestern region, it is not easy to prepare hay from rice straw. Therefore, ensiling is an ideal storage method.

[0003] However, the raw material of rice straw has a high fiber content and poor palatability. The ensiled rice straw feed obtained by conventional ensiling also has the problem of high fiber content, and livestock do not like to eat it. At the same time, during the natural fermentation process of rice straw ensiling, due to the small amount of Lactobacillus rhamnosus attached to the straw itself, there are often harmful microorganisms competing with Lactobacillus for substrates, resulting in inhibited growth and reproduction, slow decline in pH, and consumption of more nutrients. This makes the quality of rice straw ensiling low and the palatability poor. In the hot and humid environment, the growth activities of fungi or bacteria such as yeasts and Escherichia coli in the ensiled rice straw feed are vigorous and difficult to inhibit, leading to easy mildew, which affects the health of livestock. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a method for improving the nutritional quality of ensiled rice straw feed, which can effectively increase the crude protein content of ensiled rice straw feed, inhibit the growth of yeasts and Escherichia coli, improve the palatability of ensiled rice straw feed, and thus improve the fermentation quality of ensiled rice straw feed. The processed ensiled rice straw feed has higher nutritional quality. It is mainly manifested in being able to increase the crude protein content of the feed, improve the nutritional quality, improve the palatability of rice straw feed, and can inhibit the growth of yeasts and Escherichia coli in the hot and humid environment.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] In the first aspect, the present invention provides a method for improving the nutritional quality of ensiled rice straw feed, which harvests and cuts the rice straw at the mature stage, then sprays Lactobacillus rhamnosus LG608 for ensiling, and ferments at room temperature with sealing for 60 days.

[0007] Preferably, the rice straw is obtained after threshing the mature rice.

[0008] Preferably, the water content of the rice straw is 60% - 65%.

[0009] Preferably, the addition amount of Lactobacillus rhamnosus LG608 accounts for 1×10 6 cfu·g -1 .

[0010] Preferably, the method is specifically: the method of Lactobacillus rhamnosus LG608 in improving the fermentation quality of rice straw silage feed. More preferably, the fermentation quality specifically refers to any one or more of reducing the pH value of silage, reducing the ammonium nitrogen content, increasing the lactic acid content, and reducing the organic acid content.

[0011] Preferably, the nutritional quality specifically refers to improving the crude protein content and soluble carbohydrates.

[0012] Preferably, the method is specifically the method of Lactobacillus rhamnosus LG608 in improving the palatability of rice straw silage feed.

[0013] Preferably, the method is specifically to inhibit the growth of Escherichia coli and yeast in rice straw silage feed.

[0014] Preferably, the method specifically includes the following steps:

[0015] Apply Lactobacillus rhamnosus LG608 to the raw materials of rice straw silage and ferment. The fermentation product is the rice straw silage feed; Lactobacillus rhamnosus LG608 is preserved in the China General Microbiological Culture Collection Center, located at No. 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, with the preservation number of CGMCC 1.60089 and the preservation date of January 6, 2023.

[0016] Preferably, in the preparation method, the addition amount of Lactobacillus rhamnosus LG608 accounts for 1×10 6 cfu·g -1 .

[0017] In the second aspect, the present invention provides the rice straw silage feed prepared by the above method.

[0018] The beneficial effects of the present invention are:

[0019] The present invention applies Lactiplantibacillus rhamnosus LG608 to the yellow silage of rice straw for fermentation to obtain yellow silage feed of rice straw. The yellow silage rice straw treated with LG608 has a higher crude protein content, can effectively convert structural carbohydrates into water-soluble carbohydrates, better improve the palatability of rice straw, has a higher feed intake of beef cattle, and can inhibit the growth of Escherichia coli and yeast. It can make good use of the carbon source of rice straw for fermentation and has broad application prospects. LG608 can also quickly convert the sugar in the yellow silage feed, significantly reduce the pH value of the yellow silage, increase the organic acid content, reduce the ratio of ammoniacal nitrogen to total nitrogen content, and effectively improve the quality of the yellow silage feed. Description of the Drawings

[0020] Figure 1 For the feeding effect of beef cattle on yellow silage feed of rice straw with different treatments. Detailed Implementation Modes

[0021] In order to enable those skilled in the art to better understand the technical solutions of the invention, the present invention will be further described in detail below in combination with specific implementation modes.

[0022] The Lactiplantibacillus rhamnosus LG608 (Lactiplantibacillus.rhamnosus) described in the present invention is preserved in the China General Microbiological Culture Collection Center, with the address being No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences. The preservation number is CGMCC No. 1.60089, and the preservation date is January 6, 2023. The preservation certificate has been submitted in other inventions submitted on the same day.

[0023] Example 1 Preparation of Yellow Silage Feed of Rice Straw

[0024] 1. Test Materials and Design

[0025] Materials: The rice variety is "Chuankangyou 637".

[0026] Table 1 Chemical Composition of Rice Straw Raw Materials

[0027]

[0028]

[0029] Additives: Lactiplantibacillus rhamnosus (Lactiplantibacillus.rhamnosus, LG 608), a Lactiplantibacillus rhamnosus isolated and identified from the Yayu 8 maize silage stored in the modern agricultural base of Sichuan Agricultural University; commercial Lactiplantibacillus plantarum 550 (Lactiplantibacillus plantarum, LP 550), purchased from Gaofuji Biotechnology Co., Ltd., Chengdu, Sichuan Province.

[0030] This experiment adopted a single-factor randomized block design, namely three additive treatments: sterile water control (Control, CK), Lactobacillus rhamnosus 608 (LG 608), and commercial Lactobacillus plantarum 550 (LP 550), with 3 replicates for each treatment. The rice straw was obtained after threshing when the rice was mature, and the water content was adjusted and controlled at 60%-65%.

[0031] After chopping and shredding the rice straw harvested at the same time period, the additives diluted to 1×10 6 cfu·g –1 FW (cfu, colony-forming units; FW, fresh weight) were evenly sprayed on the raw materials for ensiling rice straw to obtain ensiled rice straw feed; an equal amount of sterile distilled water was used as the control, thoroughly mixed, the raw materials for ensiling with different treatments were compacted, bundled, and wrapped and sealed. Each treatment was repeated 3 times. After ensiling at room temperature for 60 days, samples were taken to measure the fermentation quality, nutritional quality, microbial quantity, and feed intake of beef cattle.

[0032] Example 2 Effects of Additives on the Fermentation Quality of Ensiled Rice Straw

[0033] The measured values of the nutritional components of the ensiled rice straw feed after 60 days of fermentation are shown in Table 2.

[0034] Detection method: After opening the ensiling bag, weigh 20 g of the ensiled sample, add 180 mL of deionized water, seal it and place it in a 4°C refrigerator for overnight extraction (>24 h). The treated extract was filtered with four layers of gauze, and the filtrate was used to measure the contents of pH, ammoniacal nitrogen (AN / TN), lactic acid (LA), acetic acid (AA), propionic acid (PA), and butyric acid (BA). The pH was measured with a Leici PHS-3C precision pH meter; the ammoniacal nitrogen content was measured by the phenol-sodium hypochlorite method; the organic acid content was analyzed with a SHIMADZE-10A high-performance liquid chromatograph. Detector: SPD-M10AVP, chromatographic column: Shodex Rspak KC-811S-DVB gel column 300 mm×8 mm, detection wavelength: 210 nm, mobile phase: 3 mmol / L perchloric acid solution, injection volume: 5 μL, flow rate: 1 mL / min, column temperature: 50°C.

[0035] Table 2 Effects of Different Additives on the Fermentation Quality of Rice Straw

[0036]

[0037] Note: Different capital letters indicate significant differences between different additive treatments (P<0.05), the same below.

[0038] Conclusion: Compared with the CK treatment group, the pH value of the LG608 treatment group of the present invention decreased significantly, and the ammonium nitrogen content was also significantly lower than that of the CK treatment group and the LP550 group, showing a better yellow silage effect. At the same time, the lactic acid content of the rice straw treated with LG608 was significantly higher than that of the LP550 treatment group, and the AN / TN value and BA content of the yellow silage feed treated with LG608 were lower, showing a good fermentation effect.

[0039] Example 3 Effects of Additives on Nutritional Quality and Palatability of Yellow Silage Feed from Rice Straw

[0040] The nutritional quality component values of the yellow silage feed from rice straw after fermentation with different additives for 60 days are shown in Table 3.

[0041] Detection method: Weigh 200 g of the yellow silage feed after opening the bag, dry it in an oven at 65 °C for 72 h, cool it to room temperature in a desiccator and then weigh it to calculate the dry matter (DM); then use a plant crusher to crush the dried sample and pass it through a 40-mesh sieve for determining the nutritional components. Crude protein (CP) is determined by the Kjeldahl method; soluble carbohydrate (WSC) is determined by the anthrone colorimetric method; acid detergent fiber (ADF) and neutral detergent fiber (NDF) are determined by the Van Soest fiber method; determination of average daily feed intake: For the yellow silage rice straw obtained from different treatments, each beef cattle is fed 4 kg of yellow silage rice straw per day, three beef cattle are fed for each treatment for 15 days, and the weight of the remaining rice straw is weighed after each feeding until the beef cattle finish eating, so as to calculate the weight of the straw eaten by each beef cattle per day.

[0042] Table 3 Effects of Different Additives on Nutritional Quality of Rice Straw

[0043]

[0044] Note: Different capital letters indicate significant differences between different additive treatments (P<0.05), the same below.

[0045] Conclusion: Compared with the CK treatment and LP550 treatment, the LG608 treatment group preserved more soluble carbohydrates in the feed, indicating that LG608 can effectively convert structural carbohydrates into water-soluble carbohydrates, better improving the palatability of ensiled rice straw feed. The average daily feed intake of the LG608 treatment group was also significantly higher than that of other groups. To further understand the palatability of ensiled rice straw feed, a beef cattle feeding experiment was conducted. See Figure 1 , it can be seen that during the experiment, the daily feed intake of rice straw by beef cattle in the LP608 treatment group was significantly higher than that in the LP550 and CK treatment groups. At the same time, LG608 of the present invention also significantly increased the crude protein content in the feed. The NDF (neutral detergent fiber) content of the LG608 treatment group was significantly lower than that of the CK treatment group and the LP550 treatment group, reflecting the better nutritional quality of the present invention.

[0046] Example 4 Effect of Additives on the Microbial Community of Ensiled Rice Straw Feed

[0047] The microbial counts of ensiled rice straw feed after 60 days of fermentation with different additives are shown in Table 3.

[0048] Detection method: Using the plate counting method, the numbers of lactic acid bacteria, yeast, and coliform bacteria in the ensiled materials were determined. Weigh 20 g of the sample and immerse it in 180 mL of sterile normal saline (0.85% NaCl). Seal it with a microbial sealing film and shake it on a shaker at 4 °C for 1 h. Use this solution to prepare a series of gradient dilutions (10 -1 ~10 -5 ). For lactic acid bacteria, use agar medium (MRS), and culture it anaerobically (seal the culture dish with sealing gum) at 37 °C for 48 h, then count the colony numbers; for yeast, use potato dextrose agar (PDA), and culture it aerobically at 25 °C for 72 h. For coliform bacteria, use violet red neutral red bile salt agar medium (VRBA), and culture it aerobically at 37 °C for 24 h, then count. Count according to the morphological characteristics of coliform bacteria and yeast respectively; the culture media were all purchased from Beijing Road and Bridge Company. The measurement results are shown in Table 4.

[0049] Table 4 Effect of Different Additives on the Microbial Counts of Rice Straw

[0050]

[0051] Note: Different capital letters indicate significant differences between different additive treatments (P<0.05), ND: not detected

[0052] Conclusion: As can be seen from Table 4, the lactic acid bacteria content in the LG608 treatment group was significantly higher than that in other groups. After adding LG608 to the rice straw, Escherichia coli was significantly inhibited, and no Escherichia coli was detected in the feed, ensuring the safety of the silage feed. At the same time, LG608 significantly inhibited the production of yeasts, effectively improving the preservation of the silage feed.

[0053] The above are only the preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as limiting the present invention, and the protection scope of the present invention should be subject to the scope defined by the claims. For those of ordinary skill in the art, without departing from the spirit and scope of the present invention, several improvements and refinements can also be made, and these improvements and refinements should also be regarded as within the protection scope of the present invention.

Claims

1. A method for improving the nutritional quality of ensiled rice straw, characterized in that, Harvest and chop the rice straw at the mature stage, then spray Lactobacillus rhamnosus LG608 for yellow silage, and ferment it airtight at room temperature for 60 days; the method is specifically a method of Lactobacillus rhamnosus LG608 in improving the palatability of yellow silage of rice straw, and the preservation number of the Lactobacillus rhamnosus LG608 is CGMCC1.60089.

2. The method according to claim 1, wherein The water content of the rice straw is 60% - 65%.

3. The method according to claim 1, wherein The method is specifically a method of inhibiting the growth of Escherichia coli and yeast in the yellow silage of rice straw.

4. The method according to claim 1, wherein The nutritional quality is specifically in terms of improving the crude protein content and soluble carbohydrates.

5. The method according to claim 1, wherein The method of Lactobacillus rhamnosus LG608 in improving the fermentation quality of yellow silage of rice straw.

6. The method according to claim 1, wherein The addition amount of Lactobacillus rhamnosus LG608 accounts for a proportion of 1×10 6 cfu·g -1 .

7. The yellow silage of rice straw prepared by the method according to claim 1.

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