Special silage additive for high-moisture corn

Abstract

The invention relates to a special silage additive for high-moisture corn. Adding chestnut involucral polyphenol extract to the corn silage additive can enhance silage effect, improve aerobic stability of high-moisture corn, improve fermentation quality, and better preserve nutrients in the high-moisture corn.

Description

Technical Field

[0001] The invention relates to the technical field of bulk feed, in particular to a special silage additive for high-moisture corn containing a chestnut involucral polyphenol extract. Background Art

[0002] Corn is the main food crop in my country and the main source of energy feed for livestock and poultry. Corn is rich in starch and soluble sugars, has strong hygroscopicity, and has a high moisture content when harvested. It is very easy to mold during drying and storage. Not only is the nutrient content seriously lost, but the mycotoxins produced can also cause poisoning of livestock and poultry. In order to prevent corn from mold and deterioration during storage, preparing high-moisture corn is an effective way. High-moisture corn (scientific name: High-moisture Corn, abbreviated as HMC) refers to a high-starch energy feed made from kernel corn, cob corn or whole-ear corn with a moisture content between 20% and 40%, which is crushed, pressed in a cellar or wrapped, and fermented. High-moisture corn silage is regarded as a concentrated feed with high feeding value, characterized by high starch content and high digestibility. In the production of high-moisture corn, special silage additives that can improve the aerobic stability and fermentation quality of high-moisture corn are needed.

[0003] Plant polyphenols are natural products widely found in plants and are secondary metabolites of plants. They possess unique physiological activities and medicinal value. Polyphenols possess strong biological activities such as free radical scavenging, antioxidant, and anti-aging properties. Studies have shown that extracts from chestnut kernels, flowers, leaves, and fruits possess strong antioxidant capacity. Chestnut polyphenols can significantly increase the proportion of rumen-passing protein, reduce ammonia production in the rumen of dairy cows, and also reduce the loss of non-protein nitrogen (NPN) and dry matter in the feed.

[0004] High-moisture corn, due to its relatively low moisture content (compared to other silages) and high starch content, is prone to oxidative deterioration. Currently, there are no dedicated high-moisture corn silage additives. Commonly used whole-plant corn silage additives result in unstable high-moisture corn quality. Therefore, improving the oxygen stability of high-moisture corn silage, reducing nutrient loss, and enhancing fermentation quality are key research areas for those skilled in the art.

[0005] The information disclosed in this background technology section is only intended to deepen the understanding of the overall background technology of the present application, and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art. Summary of the Invention

[0006] The purpose of the present invention is to provide a special silage additive for high-moisture corn to solve the technical problems existing in the prior art.

[0007] In order to solve the above technical problems, the present invention provides a special silage additive for high-moisture corn, and chestnut polyphenols are added to the whole-plant corn silage additive.

[0008] Furthermore, the corn silage additive contains 1‰-2‰ chestnut bract polyphenol extract by weight.

[0009] Furthermore, the corn silage additive is added with chestnut bract polyphenol extract containing 1.5‰ by weight.

[0010] Furthermore, the corn silage additive is a mixed bacterial strain additive composed of Lactobacillus plantarum, Lactobacillus buchneri and Enterococcus faecium in a weight ratio of 1:1:1.

[0011] Furthermore, the weight ratio of the mixed bacterial additive to chestnut polyphenol is 1:5.

[0012] By adopting the above technical solution, the present invention has the following beneficial effects:

[0013] Because chestnut involucral polyphenols have high antibacterial and antioxidant activities, adding chestnut involucral polyphenol extract to whole-plant corn silage additives significantly increases the lactic acid and acetic acid content and aerobic stability of high-moisture corn, thereby better preserving the nutrients in the high-moisture corn.

[0014] The chestnut involucral polyphenol extract as a silage additive enhancer improves the quality of corn including: physical sensory score of high-moisture corn, silage fermentation quality and changes in nutritional components after ensiling.

[0015] The chestnut involucral polyphenol extract as a silage additive significantly improves the physical sensory scores of high-moisture corn, including smell, texture, color and grade.

[0016] The chestnut involucral polyphenol extract as a silage additive significantly increases the starch and dry matter DM content of high-moisture corn, wherein the nutritional value evaluation includes dry matter DM, neutral detergent fiber NDF, acid detergent fiber ADF, crude protein CP and starch.

[0017] The chestnut involucral polyphenol extract increases the lactic acid and acetic acid contents, lowers the pH, inhibits the growth and reproduction of harmful bacteria such as yeast, and reduces the ammonia nitrogen level. The relevant evaluation indicators include pH, lactic acid, acetic acid, propionic acid and ammonia nitrogen content. DETAILED DESCRIPTION

[0018] The following table clearly and completely describes the technical solution of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0019] The following is a detailed description of the specific embodiments of the present invention in conjunction with the table. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0020] Example: Study on the effect of chestnut bract polyphenol extract as silage additive on the fermentation quality of high-humidity corn

[0021] 1. Test materials and methods

[0022] High-humidity corn: The materials used in the experiment were corn Ruipu 909 (including corn seeds and corn cobs) grown on an experimental farm of Shanxi Academy of Agricultural Sciences in China. The corn was fully mature when harvested.

[0023] Chestnut involucral polyphenol extract: Chestnut involucral bracts were obtained from the Chestnut Experimental Station in Huairou District, Beijing. They were crushed using a grinder, passed through an 80-mesh sieve, and stored at -18°C in the dark until ready for use. Extraction method: ethanol concentration of 30% by volume, extraction temperature of 80°C, extraction time of 140 min, and liquid-to-solid ratio of 18:1 (mL:g). Under these conditions, the polyphenol yield from chestnut involucral bracts was 22.61%, and the polyphenol content in the extract was 51.23%.

[0024] Experimental method: The cob-containing corn was crushed and mixed using a crusher (FWJ-20, China Minye) and then divided into four treatment groups: control group, treatment group 1, treatment group 2 and treatment group 3.

[0025] Control group: mixed bacterial strain additives were added, but chestnut involucral polyphenol extract was not added.

[0026] Treatment group 1: chestnut involucral polyphenol extract and mixed bacterial strain additives containing 1‰ by weight were added, and the weight ratio of the two was 10:3.

[0027] Treatment group 2: 1.5‰ weight of chestnut involucral polyphenol extract and mixed bacterial strain additive were added, with the weight ratio of the two being 5:1.

[0028] Treatment group 3: 2‰ weight of chestnut involucral polyphenol extract and mixed bacterial strain additive were added, with the weight ratio of the two being 20:3.

[0029] The mixed bacterial strain additives used in the four treatment groups were composed of Lactobacillus plantarum, Lactobacillus buchneri and Streptococcus faecium (1:1:1 weight ratio), and the bacterial strain concentration was adjusted to ≥0.5×107 cfu / g and added equally to each treatment group at a concentration of 300 mg / kg.

[0030] The moisture content and fermentation time of high-moisture corn were determined. Water was added to adjust the moisture content to 47.5% by weight for each of the four treatment groups. The corn was then placed in fermentation bags (20 × 30 cm; Deli Group, China) and sealed using a vacuum sealer (Deli 14886, Deli Group, USA). Ten replicates were performed for each treatment, and the corn was silaged at room temperature (21–25°C) for 180 days.

[0031] A total of 40 silage samples (10 replicates × 4 treatment groups) were prepared for this experiment. Physical sensory scores, nutritional values, and fermentation indices of high-moisture corn silage were obtained. The data were analyzed using Excel 2019 software and analyzed using one-way analysis of variance (ANOVA) using SPSS 20.0 (SPSS Inc., Chicago, IL, USA). Data were expressed as mean values, and multiple comparisons were performed using LSD and Duncan's method. Differences were considered significant when P < 0.05.

[0032] 2. Effect of chestnut involucral polyphenol extract on physical sensory scores of high-humidity corn

[0033] According to the group standard "Guidelines for Quality Grading of High-Moisture Corn with Shaft", the color of high-moisture corn is divided into three types: yellow (original color of corn), dull color, dull, brown, and partially black-brown.

[0034] The odor of high-humidity corn is divided into three types: sour aroma, fruity acid smell, slight ethanol smell, and obvious sour smell.

[0035] The texture of high-moisture corn is divided into three types: tight structure, non-sticky, loose structure, non-sticky, soft, and sticky.

[0036] Table 1 On-site rapid assessment standard for high-moisture corn quality

[0037]

[0038] Evaluation standards for high-humidity corn silage: a total score of 15 to 12 points is excellent, 11 to 8 points is good, 7 to 4 points is medium, and below 4 points is poor quality.

[0039] According to the above evaluation standards, a standard table for rapid on-site evaluation of high-moisture corn quality was prepared, as shown in Table 1.

[0040] The high-moisture corn was evaluated by observing its color, smell, and texture. The results are shown in Table 2.

[0041] The results showed that the odor, color, and structural compactness of high-moisture corn silage improved with increasing chestnut involucral polyphenol extract addition rates. When chestnut involucral polyphenol extract concentrations were 1.5‰ and 2.0‰, the sensory evaluation of high-moisture corn silage was excellent, with the 1.5‰ concentration giving the highest physical sensory score.

[0042] Table 2 Effects of different proportions of chestnut involucral polyphenol extract additives on sensory scores of high-humidity corn silage

[0043]

[0044] 3. Effect of chestnut bract polyphenol extract on the nutritional components of high-humidity corn

[0045] After opening the bag, about 200 g of sample was taken from each group of silage and dried in an oven at 65 °C for 48 h for determination of dry matter (DM).

[0046] The starch content of the dried samples was determined by the sulfuric acid-anthrone colorimetric method.

[0047] The crude protein (CP) content was determined by the Kjeldahl method.

[0048] The Van Soest method was used to determine the neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents.

[0049] The results are shown in Table 3. The addition rate of chestnut involucral polyphenol extract significantly affected the dry matter, crude protein, and starch contents of high-moisture corn silage (P < 0.05). Compared with the control group, the addition of chestnut involucral polyphenol extract significantly increased the nutrient content of high-moisture corn silage. High-moisture corn silage supplemented with chestnut involucral polyphenol extract at a concentration of 1.5‰ had significantly higher dry matter and starch contents than the other treatment groups (P < 0.05).

[0050] Table 3 Effects of different proportions of chestnut involucral polyphenol extract additives on the nutrient content of high-humidity corn silage

[0051]

[0052] 4. Effect of chestnut bract polyphenol extract on improving the fermentation quality of high-humidity corn

[0053] On the 180th day of fermentation, after mixing each bag of samples, randomly take 20g of silage and add 180ml of distilled water, crush it with a wall breaker for 1min, filter the residue through four layers of gauze, and then filter the supernatant with qualitative filter paper into a 250ml sterilized conical flask and mix well.

[0054] Take 100 mL of the extract into a 250 mL beaker and measure the pH using a pH-100A pH meter.

[0055] Another 15 mL of the extract was placed in a 25 mL centrifuge tube and stored at -20°C for determination of lactic acid, acetic acid, propionic acid and ammonia nitrogen contents.

[0056] The lactic acid content was determined by the p-hydroxybiphenyl colorimetric method.

[0057] The acetic acid and propionic acid contents were determined using an Agilent 6890N gas chromatograph with an injection volume of 1 μL, a capillary column (30.00 m×0.32 mmx0.25 μm), a flow rate of 1.5 mL / min, nitrogen (N2) as the carrier gas, a column pressure of 81.36 kPa, a column temperature starting at 150 °C, maintained for 1 min, then increased to 220 °C at 6 °C / min and maintained for 15 min, the injection port was in split mode, and the split ratio was 5:1.

[0058] Ammoniacal nitrogen content was determined by phenol-sodium hypochlorite colorimetry.

[0059] The measurement results are shown in Table 3. The addition of chestnut bract polyphenol extract significantly affects the pH, lactic acid, acetic acid and ammonia nitrogen content of high-moisture corn silage (P<0.05). The content of lactic acid and acetic acid in silage can accurately evaluate the anaerobic stabilization stage of fermented feed, and appropriate lactic acid and acetic acid content helps to improve the fermentation quality. The level of ammonia nitrogen content can usually be used as an important indicator of the degree of protein and amino acid degradation in silage. In the present invention, the lactic acid content of treatment group 2 (1.5‰ chestnut bract polyphenol extract) was significantly higher than that of the control group and other treatment groups (P<0.05), and the pH and ammonia nitrogen content were significantly lower than those of the control group (P<0.05). The above results show that 1.5‰ chestnut bract polyphenol extract as a silage additive significantly improves the fermentation quality of high-moisture corn.

[0060] Data were analyzed using LSD and Duncan's method for multiple comparisons, and P values ​​were calculated. The results are shown in the following table:

[0061] Table 4 Effects of different proportions of chestnut bract polyphenol extract additives on high-humidity corn silage fermentation parameters

[0062]

[0063] 5. Effect of chestnut bract polyphenol extract on improving the aerobic stability of high-humidity corn

[0064] After 180 days of fermentation, one bag of sample was taken from each group and placed in a 1.5L polyethylene silage tank. The probe of a temperature recorder (SMOWO MDL-1048A) was placed in the center of the silage fermentation tank. A probe was also placed in an empty silage tank to measure the ambient temperature. The aerobic stability of the silage was assessed by the time it took for the silage temperature to differ by 2°C from the ambient temperature.

[0065] The results are shown in Table 5. The addition of chestnut involucral polyphenol extract significantly impacted the aerobic stability of high-moisture corn (P < 0.05). The aerobic storage time of treatment group 2 (1.5‰ chestnut involucral polyphenol extract) was significantly longer than that of the control group and the other treatment groups (P < 0.05). These results further demonstrate that 1.5‰ chestnut involucral polyphenol extract, as an silage additive, significantly improves the aerobic storage time of high-moisture corn.

[0066] Table 5 Effects of different proportions of chestnut involucral polyphenol extract additives on the aerobic stability of high-humidity corn

[0067]

[0068] The above results show that chestnut involucral polyphenol extract can be used as a silage additive to improve the aerobic stability of high-moisture corn, improve fermentation quality and better preserve the nutrients in high-moisture corn, and the effect is better when the concentration is 1.5‰ chestnut involucral polyphenol extract (the weight ratio of mixed strain additive and chestnut involucral polyphenol extract is 1:5, that is, the weight ratio of Lactobacillus plantarum: Lactobacillus buchneri: Enterococcus faecium: chestnut involucral polyphenol extract is 1:1:1:5).

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A special silage additive for high-moisture corn, characterized in that: Adding chestnut involucral polyphenol extract to a corn silage additive; the corn silage additive is a mixed bacterial strain additive composed of Lactobacillus plantarum, Lactobacillus buchneri, and Streptococcus faecium in a weight ratio of 1:1:1; the weight ratio of the mixed bacterial strain additive to the chestnut involucral polyphenol extract is 1:5; Preparation method of chestnut involucral polyphenol extract: chestnut involucral was crushed with a grinder and passed through an 80-mesh sieve, and stored in the dark at -18°C until use; ethanol extraction method was used: ethanol volume concentration 30%, extraction temperature 80°C, extraction time 140 min, and liquid-to-solid ratio 18mL:1g.

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