Method for researching feeding value of harvested straws of fresh corn

Abstract

The invention discloses a method for researching the feeding value of harvested straws of fresh corn. The method comprises the following steps: selecting an experimental material, collecting a sample, determining the feeding quality content of the sample, changing the index content of the straws, and determining the feeding quality content. According to the straw feeding value research method after harvesting of fresh corn, variety selection covers multiple types, random block test design is adopted, interference of environmental factors such as soil fertility difference and marginal effect on experimental results is reduced to the maximum extent through strict and normative planting layout, and the method is suitable for popularization and application. The device can dynamically monitor the feed quality change of the straw along with time lapse, unify the sampling standard, accurately convert the dry matter content and other key indexes, comprehensively acquire data, comprehensively evaluate the feed applicability of the straw, provide multi-dimensional data support for subsequent screening of high-quality feed straw varieties, and improve the feed quality of the straw. The accuracy of a measurement result is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of corn stalk feeding, and in particular to a method for studying the feeding value of harvested fresh corn stalks. Background Art

[0002] Corn, as a major food and feed crop in my country, plays an important role in the field of food security. Fresh corn refers to special corn harvested during the milky stage of corn. It is rich in calcium, magnesium, selenium, glutathione, fatty acids, riboflavin and other nutritional and health substances. Compared with rice, fresh corn has higher content of vitamin A, vitamin B1 and vitamin B2, and its lysine content is also higher than that of ordinary corn. It also has a higher digestibility and absorption rate. As the public's demand for healthy diet continues to increase, these excellent characteristics of fresh corn have been favored by more and more consumers. The planting area of ​​fresh corn has also continued to increase, and the fresh corn processing industry chain has been fully developed. However, since ordinary consumers only need cobs, with the development of the fresh corn industry, the problem of fresh corn straw treatment after harvest will become more and more obvious in the future. my country's corn straw production accounts for 56.6% of the national straw production (including rice, corn, wheat, etc.). The rational development and utilization of straw as a feed source can provide a material basis for herbivorous livestock [5]. If fresh corn straw can be treated reasonably and effectively, it can not only improve the economic benefits of fresh corn planting, but also avoid environmental problems caused by straw burning.

[0003] As the public's demand for healthy diet continues to increase, fresh corn is increasingly favored by consumers due to its excellent nutritional characteristics. The planting area of ​​fresh corn is also expanding, and the related processing industry chain has also been fully developed. However, ordinary consumers mainly demand corn ears, which makes the treatment of fresh corn straw after harvesting more and more prominent. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a method for studying the feeding value of fresh corn straw after harvest, with the aim of providing a method for rationally developing and utilizing corn straw as feed to provide an important food source for herbivorous livestock. Effective processing of fresh corn straw will help improve the economic benefits of corn planting and reduce environmental problems caused by straw burning.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0006] A method for studying the feeding value of harvested fresh corn stalks comprises the following steps:

[0007] S1: Experimental materials were selected, including 5 varieties of fresh corn and one variety of silage corn. A randomized block experiment was designed with 6 rows and 2 replications. The row length was 20 m, the row spacing was 60 cm, the plant spacing was 31 cm, and 4 rows of protection rows were set around. The density was 52,500 plants / hectare. The fertilizer in the planting area was diammonium phosphate, and the application rate was 40 kg / mu.

[0008] S2: Sample collection: sampling started after the fresh corn ears were harvested. Five stalks of the same growth state were harvested from each variety on the third, seventh, sixteenth, twenty-third, and thirtieth days after harvesting. The stalks were cut from 15 cm above the ground, and the fresh weight of the whole plant was recorded. Then, the stalks were withered at 120°C for 30 minutes and dried at 85°C to constant weight.

[0009] At harvest, the plant height, ear height, number of leaves on the whole plant, stem thickness at the ear end, and stem thickness at the widest point in the middle of the third internode of the aboveground part were investigated in the field. All samples were dried and ground into powder, passed through a 40-mesh sieve, sealed in plastic bags, and stored in a dry and cool place until various nutritional indicators were determined;

[0010] S3: Determination of sample feeding quality content, including crude protein content, crude ash content, NDF and ADF content;

[0011] S4: Changes in straw index content, including comparison of plant height / ear height at harvest between different fresh corn varieties and silage, comparison of stem diameter between different fresh corn varieties and silage, comparison of green leaf numbers between different fresh corn varieties and silage, and comparison of fresh weight, dry matter, and water content between different fresh corn varieties and silage;

[0012] S5: Feed quality content determination, including crude protein content analysis, crude ash content analysis, neutral detergent fiber NDF and acid detergent fiber ADF content analysis.

[0013] Furthermore, in step S3, the crude protein content is determined by using the Dumas combustion method and a RapidNcube nitrogen analyzer detector.

[0014] Furthermore, in step S3, the crude ash content is determined by a dry ashing method (525±25° C.) using a Thermo high-temperature muffle furnace.

[0015]

[0016] In the formula,

[0017] W0-----Mass of empty crucible with constant weight (g)

[0018] W1-----Total weight of crucible and sample (g)

[0019] W2-----Total weight of crucible plus ash after sample ashing (g).

[0020] Furthermore, in step S3, the NDF and ADF contents are determined by using the Van Soest method and an ANKOMA 200i semi-automatic fiber analyzer to determine the neutral detergent fiber (NDF) and acid detergent fiber (ADF);

[0021] NDF calculation formula:

[0022] NDF%=(W3-W1*C1)*00 / W2

[0023] W1 = filter bag mass, W2 = sample mass, W3 = dry weight of filter bag after digestion

[0024] C1 = ash content blank filter bag factor (blank value of ignition weight loss / original blank value)

[0025] ADF calculation formula:

[0026] ADF%=(m2-m1*C1)*100 / m

[0027] m1 = empty bag mass, m = sample mass, m2 = dry weight of filter bag after digestion

[0028] C1 = correction factor for blank bag (mass after drying / original mass).

[0029] The beneficial effects of the present invention are:

[0030] The method for studying the feeding value of the straw of fresh corn after harvest of the present invention comprises the following aspects: variety selection covers various types, randomized block test design is adopted, and strict and standardized planting layout minimizes the interference of environmental factors such as soil fertility difference and marginal effect on the experimental results, ensures that each variety grows under relatively consistent conditions, makes the data more reliable, and can truly reflect the feeding potential of corn straw of different varieties; the density is precisely controlled to provide stable and suitable nutrient supply and growth space for corn growth; sampling at multiple time points completely covers different growth stages of the straw after ear picking, can dynamically monitor the changes in feeding quality of the straw over time, unifies the sampling standards, can accurately convert key indicators such as dry matter content, comprehensively collects data, and comprehensively considers the feeding applicability of the straw, which can provide multi-dimensional data support for the subsequent screening of high-quality feeding straw varieties, and ensures the accuracy of the measurement results.

[0031] By comparing the plant height / ear height, stem diameter, number of green leaves, fresh weight, dry matter, and water content of different fresh corn varieties and silage corn at the harvest period, we can intuitively show the similarities and differences between fresh corn stalks and silage corn from multiple angles such as plant appearance, biomass accumulation, and moisture status, helping breeders, feed processing companies, etc. to intuitively judge the feasibility and potential advantages of replacing silage corn with fresh corn stalks.

[0032] Comprehensive analysis of feeding quality: covers analysis of multiple feeding quality contents such as crude protein, crude ash, NDF and ADF, comprehensively evaluates key feeding characteristics of the straw, such as its nutritional supply capacity and digestibility, and combines the previous comparison of varieties, morphology and growth stages to form a complete fresh corn straw feeding value assessment system, providing solid theoretical and practical guidance for the resource utilization of agricultural waste and the development of new feeds.

[0033] The method for studying the feeding value of the fresh corn stalks after harvest of the present invention provides a strong guarantee for in-depth exploration of the feeding value of the fresh corn stalks after harvest through rigorous experimental design, standardized sample collection, accurate indicator determination and comprehensive comparative analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram comparing plant height and ear height of different varieties of fresh corn and silage corn at harvest time of the present invention;

[0035] Figure 2 It is a schematic diagram comparing the stem diameters of different varieties of fresh corn and silage corn of the present invention;

[0036] Figure 3 It is a schematic diagram comparing the number of green leaves of different varieties of fresh corn and silage corn of the present invention;

[0037] Figure 4 It is a schematic diagram comparing the fresh weights of different varieties of fresh corn and silage corn of the present invention;

[0038] Figure 5 It is a schematic diagram comparing the dry weights of different varieties of fresh corn and silage corn of the present invention;

[0039] Figure 6 It is a schematic diagram comparing the moisture content of different varieties of fresh corn and silage corn of the present invention;

[0040] Figure 7 It is a schematic diagram comparing the crude protein content of different varieties of fresh corn and silage corn of the present invention;

[0041] Figure 8 It is a schematic diagram comparing the crude ash content of different varieties of fresh corn and silage corn of the present invention;

[0042] Fig. 9 It is a schematic diagram comparing the ADF content of different varieties of fresh corn varieties and silage corn varieties of the present invention;

[0043] Fig.10 This is a schematic diagram comparing the NDF content of different varieties of fresh corn and silage corn varieties of the present invention. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present invention are described clearly and completely below in conjunction with the accompanying drawings.

[0045] A method for studying the feeding value of harvested fresh corn stalks comprises the following steps:

[0046] The test materials are shown in Table 1:

[0047]

[0048] Table 1

[0049] The test site is located in Guzhuangzi Village, Liangtou Town, Jinghai District, Tianjin. Tianjin is located in the northeast of the North China Plain and has a warm temperate semi-humid monsoon climate. The annual average temperature is 12.7℃, the annual average precipitation is 124.9mm, and the annual average sunshine hours are 2699h.

[0050] Field experiment design, the field experiment design was carried out in 2023, using a randomized block design, the experiment selected 5 fresh corn varieties and one silage corn variety, according to the randomized block experiment design, 6 rows, 2 replications, row length 20m, row spacing 60cm, plant spacing 31cm, 4 rows of protection rows around, density of 52500 plants / hectare. Sowing on April 27, later according to the growth of each variety of thinning, seedlings and inter-row weeding. The fertilizer in the planting area is diammonium phosphate, the application rate is 40kg / mu, and other management measures are the same as the field.

[0051] Sample collection method: Sampling began after the fresh corn ears were harvested. For each variety, five stalks of the same growth state were harvested at five different times (cut from 15 cm above the ground) on the third day (3d), seventh day (7d), sixteenth day (16d), twenty-third day (23d), and thirtieth day (30d) after harvesting the ears. The fresh weight of the whole plant was recorded. The stalks were then withered at 120°C for 30 minutes and dried at 85°C to constant weight

[10] .

[0052] At harvest, the plant height, ear height, number of leaves on the whole plant, stem thickness at the ear end, and stem thickness at the widest point in the middle of the third internode of the aboveground part were investigated in the field. All samples were dried, ground into powder, passed through a 40-mesh sieve, sealed in plastic bags, and stored in a dry and cool place until various nutritional indicators were determined.

[0053] Sample feeding quality content determination method:

[0054] The crude protein content was determined using the Dumas combustion method and a RapidNcube nitrogen analyzer detector.

[0055] The crude ash content was determined by dry ashing method (525±25°C) using a Thermo high-temperature muffle furnace.

[0056]

[0057] In the formula,

[0058] W0-----Mass of empty crucible with constant weight (g)

[0059] W1-----Total weight of crucible and sample (g)

[0060] W2-----Total weight of crucible and ash after sample ashing (g)

[0061] 1.2.3.3 Determination of NDF and ADF content

[0062] Neutral detergent fiber (NDF) and acid detergent fiber (ADF) were determined by Van Soest method using ANKOMA200i semi-automatic fiber analyzer.

[0063] NDF calculation formula:

[0064] NDF%=(W3-(W1, C1))*00 / W2

[0065] W1 = filter bag mass, W2 = sample mass, W3 = dry weight of filter bag after digestion

[0066] C1 = ash content blank filter bag factor (blank value of ignition weight loss / original blank value)

[0067] ADF calculation formula:

[0068] ADF%=(m2-(m1*C1))*100 / m

[0069] m1 = empty bag mass, m = sample mass, m2 = dry weight of filter bag after digestion

[0070] C1 = blank bag correction factor (drying mass / original mass)

[0071] Comparison of changes in straw index content:

[0072] Comparison of plant height / ear height of different fresh corn varieties and Jinchu 100 at harvest time:

[0073] The ratio of plant height to ear height is an important indicator for measuring corn yield, quality and lodging rate. The difference in the ratio of plant height to ear height between different varieties has an important impact on corn yield. The ratio of plant height to ear height between different fresh corn varieties and silage corn at harvest time is as follows: Figure 1 As shown in the figure, the ratio of silage corn is 2.25, and the ratio of fresh corn varieties is between 1.50-3.50. Among them, the ratio of Meiyuhei 303 is 2.20, which is the same as the height of silage corn. According to the research of Feng Guang et al., the greater the ratio of plant height to ear height, the stronger its lodging resistance is. There are significant differences in the plant height / ear height ratio between Meiyu 27 and other varieties of corn, and the difference between it and Jinzuo 100 is the greatest. Among them, there is no significant difference between Meiyuhei 303 and Jinzuo 100, indicating that its lodging resistance is equivalent to that of Jinzuo 100.

[0074] Comparison of different fresh corn varieties and Tianjin storage corn stem diameter:

[0075] The global crop industry suffers serious losses due to plant lodging, and whether the internodes at the base of the plant are thick and short is an important indicator of the development of the corn root system and the healthy growth of the plant. Figure 2 By comparison, it can be seen that the diameter of the aboveground nodes of silage corn Jinzhu 100 is 32.73 mm, and that of Meiyuhei 303 is 30.24 mm, and there is no significant difference between the two; there is no significant difference in the diameter of the aboveground nodes of Huanaitiannuo 358 and Meiyu 27, but there is a large difference between them and Meiyuhei 303 and Jinzhu 100; this indicates that the root development ability of Huanaitiannuo 358 and Meiyu 27 is weaker than that of Huanaitiannuo 358, while the root development ability of Meiyuhei 303 and Jinzhu 100 is the same.

[0076] Comparison of green leaf numbers between different fresh corn varieties and silage corn:

[0077] Corn stay-green refers to the high proportion of green leaves in the total area of ​​the corn plant. Figure 3 It can be seen that the number of green leaves of each variety of fresh corn was higher than Jinsuo 100 at the beginning of harvest, but was basically lower than Jinsuo 100 in the later period, indicating that silage corn has better green retention and is better than fresh corn. On the 23rd day, the green retention of each variety of fresh corn showed a significant decline, indicating that nutrients have begun to be lost. Among them, Meiyu 27 had already declined significantly on the 16th day, indicating that its green retention was poor. Overall, the green retention of Huanai Tiannuo 358 and Meiyuhei 303 is relatively stable compared with other fresh corn varieties, and the green retention time is longer, indicating that they can retain nutrients for a longer time.

[0078] Comparison of fresh weight, dry matter and water content of different fresh corn varieties with Jinshu 100:

[0079] Crop fresh weight and dry matter are important indicators of crop biological yield, affecting the yield of livestock feed, while dry matter, as the main energy source of feed, is one of the components of feed nutritional value. In addition, appropriate moisture is the key to preparing high-quality silage.

[0080] The fresh weight of Jinchu 100 was 57.56%-108.33% higher than that of Meiyuhei 303, 139.94%-199.55% higher than that of Meiyu 27, and 129.40%-267.86% higher than that of Huanaitiannuo 358. The difference in water content between Huanaitiannuo 358 and Jinchu 100 was the greatest, and the difference in water content between Jinchu 100 and fresh corn was the greatest on the 23rd day after earing.

[0081] Depend on Figure 4 It is known that the fresh weight content of both silage corn stalks and fresh corn stalks decreases significantly from the 7th to the 16th day.

[0082] Depend on Figure 5 It can be seen that the dry matter content of several corn stalks is generally on an upward trend, and the dry matter content of silage corn stalks is still higher than that of several other fresh corn varieties. Figure 6 It can be seen that the moisture content of several corn varieties is continuously decreasing, and the decrease is most obvious from the 3rd to the 7th day, and gradually slows down in the later period. Figure 6 It can be seen that the moisture content of the straw of the four varieties of corn in this experiment was between 66% and 74% on the 30th day. The moisture content at this time was basically the same as the moisture content in the feed of the dairy farm tested by the CVAS Testing Center, indicating that the moisture content of the straw at this time reached the standard for silage.

[0083] Feed quality content determination:

[0084] Crude protein content analysis:

[0085] The significance analysis of the effects of varieties and days on crude protein content is shown in Table 2:

[0086]

[0087] Table 2

[0088] As shown in Table 2, the effect of variety on the crude protein content of corn stalks was not significant (P=0.23>0.05); the effect of sampling time after ear picking on the crude protein content of corn stalks was extremely significant (P=0.00<0.01); the combined effect of variety and sampling time after ear picking on the crude protein content of corn stalks was significant (P=0.01<0.05).

[0089] Corn stalks have the highest crude protein content in their leaves, so the number of leaves will also affect the crude protein content of the stalks. Figure 7 It can be seen that the crude protein content of Jinchu 100 is generally on a downward trend, while Meiyuhei 303, Huanaitiannuo 358, and Meiyu 27 are generally on an upward trend. After the 23rd day, the crude protein content of fresh corn is stably higher than that of Jinchu 100. Among them, the crude protein content of Meiyuhei 303 is higher than that of fresh corn varieties, and the nutrients are relatively rich.

[0090] Crude ash content analysis:

[0091] The significance analysis of the effects of variety and days on crude ash content is shown in Table 3:

[0092]

[0093] Table 3

[0094] As can be seen from Table 3, the effect of variety on the crude ash content of corn straw is extremely significant (P=0.00<0.01); the effect of sampling time after ear picking on the crude ash content of corn straw is not significant (P=0.12>0.05); the combined effect of variety and sampling time after ear picking on the crude ash content of corn straw is not significant (P=0.10>0.05).

[0095] Crude ash plays an important role in the nutritional content of animal feed. Figure 8 It can be seen that the crude ash content of each variety of straw is generally on a downward trend, and Meiyuhei 303, Huanaitiannuo 358, and Meiyu 27 are generally the same. After the 16th day, the crude ash content of fresh corn is stably higher than that of Jinchu 100. The level of crude ash content can reflect the quality of the feed and can also indirectly affect the nutritional balance of the feed. Generally speaking, the lower the crude ash content, the higher the purity of the feed. At the same time, by controlling the crude ash content, the unnecessary mineral intake of animals can also be avoided. Figure 8 It is known that the crude ash content of fresh corn stalks is higher than that of Jinchu 100. Among several fresh corn varieties, Huanai Tiannuo 358 has the lowest crude ash content. However, the crude ash content of Jinchu 100 began to drop below 4.00% after the 16th day. This shows that the crude ash content of fresh corn is higher than that of silage corn. Therefore, when using fresh corn stalks as supplementary feed or ordinary feed, its crude ash content should be treated to reduce its content, or the intake of minerals should be appropriately reduced when using feed made from it.

[0096] Neutral detergent fiber NDF and acid detergent fiber ADF content analysis:

[0097] As shown in Table 4, for NDF, the influence of variety on the NDF content of corn stalks was extremely significant (P=0.00<0.01); the influence of sampling time after ear picking on the NDF content of corn stalks was extremely significant (P=0.00<0.01); the combined effect of variety and sampling time after ear picking on the NDF content of corn stalks was extremely significant (P=0.00<0.01). For ADF, the influence of variety on the ADF content of corn stalks was extremely significant (P=0.00<0.01); the influence of sampling time after ear picking on the crude protein content of corn stalks was not significant (P=0.16>0.05); the combined effect of variety and sampling time after ear picking on the crude protein content of corn stalks was not significant (P=0.22>0.05).

[0098] The significance between NDF and ADF content and variety days is shown in Table 4:

[0099]

[0100] The ADF content in Jinchu 100 showed a downward trend as a whole. Fig. 9 As shown, all of them are lower than the content of fresh corn stalks. Among the fresh corns, Meiyuhei 303, Huanaitiannuo 358, and Meiyu 27 are generally the same, without significant changes. Starting from the 7th day after earing, the ADF content of the three varieties of fresh corn is basically 43.77% to 159.35% higher than that of Jinchu 100, indicating that the crude fiber content of fresh corn stalks is higher than that of silage corn. Overall, the ADF content of fresh corn Zhonghuanaitiannuo 358 is the lowest.

[0101] from Fig.10 It can be seen that the ADF content of Jinchu 100 is generally decreasing, and is lower than that of fresh corn stalks. Although the four varieties of fresh corn are generally flat, they are still decreasing overall. And from 7 days on, the NDF content of the three varieties of fresh corn is basically 24.69% to 118.62% higher than that of Jinchu 100, indicating that the crude fiber content of fresh corn stalks is higher than that of silage corn. Overall, the NDF content of Meiyu 27 among fresh corn is relatively low.

[0102] RFV and GI are widely used roughage quality assessment indicators in my country. RFV includes two important indicators, NDF and ADF, and is the most commonly used parameter for assessing the nutritional value of roughage. The larger the values ​​of RFV and GI, the higher the feed quality.

[0103] Table 5 Quality evaluation of roughage

[0104]

[0105]

[0106] From Table 6, the RFV values ​​of all varieties reached standard 1, and the RFV values ​​of Jinzuo 100 reached the special grade standard on the 7th, 16th and 23rd days of sampling; while the GI values ​​of fresh corn varieties performed poorly, reaching only the 2nd grade standard at most, and the GI value of Jinzuo 100 reached the special grade standard on the 30th day of sampling. Overall, the roughage quality grade of Meiyu 27 was the highest among the fresh corn varieties in the trial, followed by Meiyuhei 303.

[0107] Table 6 RFV and GI values ​​of corn stalks of various varieties

[0108]

[0109] Corn straw production in my country is high, accounting for the majority of corn straw production in my country. Feeding corn straw is one of the effective ways to solve the problem of straw leaving the field and straw burning pollution. Yield and nutritional value are important indicators for judging whether feed crops are good. Compared with the data provided by the CVAS Feed Testing Center for silage testing (crude protein 7.90%, crude ash 3.82%, NDF 34.4%, ADF 22.9%), the crude protein content of fresh corn straw is higher than that of silage corn, and the nutritional value is also high, but the fiber content of fresh corn is higher than that of silage corn, and the palatability is worse.

[0110] Based on the comparison of the contents of fresh corn and silage corn in various nutritional indicators, this research method shows that the stalks of fresh corn stalks after earing can be made into roughage or supplementary feed, but there is still a difference in nutritional value between them and silage corn. However, the purchase price of fresh corn stalks can be appropriately reduced to help farmers increase their income and reduce straw waste.

[0111] Plant height and ear height are highly correlated with corn yield and also affect the lodging resistance of corn plants. The appropriate plant height / ear height ratio is of great significance to corn yield per plant

[22] and lodging resistance. According to field growth conditions, Meiyuhei 303 and Jinchu 100 have similar lodging resistance. Stem diameter is an important indicator of corn stalk lodging resistance. Meiyuhei 303 has the largest stem diameter among fresh corn varieties, slightly lower than Jinchu 100. It has excellent lodging resistance in the field. Chlorophyll in the leaves maintains the photosynthesis of the leaves. The green retention of the leaves reflects the preservation of nutrients in the corn plant. However, among the fresh corn varieties, Meiyuhei 303 has the best green retention. Biomass will be affected by changes in water content. The loss of water will cause the nutrients in the stalk to be lost. The water loss rate of Jinchu 100 and other fresh corn varieties is not much different, indicating that they have similar water retention capabilities.

[0112] Crude protein is the main nutrient in animal feed, and its content in straw is relatively low. The protein content in the straw of fresh corn in the experiment is basically lower than that of Jinzuo 100, and the decline rate of Jinzuo 100 is also slightly lower than that of fresh corn varieties. The protein content of Meiyuhei 303 and Meiyu 27 in fresh corn is close to and higher, and the decline rate is relatively stable, among which the protein content of Meiyuhei 303 is closer to that of Jinzuo 100. The higher the content of crude ash in feed, the lower the organic matter, and thus the poorer the feed quality. In this experiment, the crude ash content of Jinzuo 100 is lower than that of fresh corn, and the crude ash content of Meiyu 27 and Huanaitiannuo 358 in fresh corn is even lower. Neutral detergent fiber and acid detergent fiber are important indicators for measuring the nutritional value of feed. The lower their content, the higher the feed quality and the higher the palatability of the feed. The NDF and ADF content of Jinzuo 100 is lower than that of fresh corn. The ADF and NDF contents of several fresh corn varieties are relatively close. Therefore, the palatability of feed made from fresh corn is slightly lower than that of Jinzuo 100.

[0113] From the comprehensive perspective of the plant height, stem thickness, number of green leaves, water content and other indicators of each variety of straw, Meiyuhei 303 performed significantly better than other fresh corn varieties, and the values ​​of its various indicators were basically the same as those of Jinchu 100. From the perspective of feeding quality, the NDF content of straw feed of each variety was between 14.69% and 67.67%; the ADF content was between 11.16% and 37.11%; the crude ash content was between 2.30% and 7.30%; the crude protein content was between 6.38% and 9.12%; the RFV value was between 14.69% and 67.67%. 82.71%~261.88%; GI value is between 1.23~7.5MJ; Meiyuhei 303 and Meiyu27 have higher crude protein content in straw after earing, averaging 7.9% and 7.7% respectively; Meiyu27 has lower fiber materials such as NDF and ADF that affect animal feeding than the other two fresh corn varieties, at 28.146%, among which Meiyuhei 303 has higher; Meiyu27 also has lower crude ash content, at 5.93%; RFV is level 2, GI is level 5, indicating that its feeding grade is higher. In summary, referring to the high crude protein content, low crude ash, NDF and ADF content, good green retention, strong lodging resistance, and slow water evaporation, Meiyu27 among fresh corn is not as good as Meiyuhei 303 in characterization performance, but has the highest comprehensive feeding quality performance, so its straw has the highest comprehensive feeding value after earing.

[0114] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for studying the feeding value of fresh corn stalks after harvest, characterized in that: The following steps are involved: S1: Experimental materials were selected, including 5 varieties of fresh corn and one variety of silage corn. A randomized block experiment was designed with 6 rows and 2 replications. The row length was 20 m, the row spacing was 60 cm, the plant spacing was 31 cm, and 4 rows of protection rows were set around. The density was 52,500 plants / hectare. The fertilizer in the planting area was diammonium phosphate, and the application rate was 40 kg / mu. S2: Sample collection: sampling started after the fresh corn ears were harvested. Five stalks of the same growth state were harvested from each variety on the third, seventh, sixteenth, twenty-third, and thirtieth days after harvesting. The stalks were cut from 15 cm above the ground, and the fresh weight of the whole plant was recorded. Then, the stalks were withered at 120°C for 30 minutes and dried at 85°C to constant weight. At harvest, the plant height, ear height, number of leaves on the whole plant, stem thickness at the ear end, and stem thickness at the widest point in the middle of the third internode of the aboveground part were investigated in the field. All samples were dried and ground into powder, passed through a 40-mesh sieve, sealed in plastic bags, and stored in a dry and cool place until various nutritional indicators were determined; S3: Determination of sample feeding quality content, including crude protein content, crude ash content, NDF and ADF content; S4: Changes in straw index content, including comparison of plant height / ear height at harvest between different fresh corn varieties and silage, comparison of stem diameter between different fresh corn varieties and silage, comparison of green leaf numbers between different fresh corn varieties and silage, and comparison of fresh weight, dry matter, and water content between different fresh corn varieties and silage; S5: Feed quality content determination, including crude protein content analysis, crude ash content analysis, neutral detergent fiber NDF and acid detergent fiber ADF content analysis.

2. The method for studying the feeding value of harvested fresh corn stalks according to claim 1, characterized in that: In step S3, the crude protein content is determined by using the Dumas combustion method and a RapidNcube nitrogen analyzer detector.

3. The method for studying the feeding value of harvested fresh corn stalks according to claim 1, characterized in that: In the step S3, the crude ash content is determined by a dry ashing method (525±25° C.) using a Thermo high-temperature muffle furnace. In the formula, W0-----Mass of empty crucible with constant weight (g) W1-----Total weight of crucible and sample (g) W2-----Total weight of crucible and ash after sample ashing (g).

4. The method for studying the feeding value of harvested fresh corn stalks according to claim 1, characterized in that: In the step S3, the NDF and ADF contents are measured, and the neutral detergent fiber (NDF) and acid detergent fiber (ADF) are measured by the Van Soest method using an ANKOMA200i semi-automatic fiber analyzer; NDF calculation formula: NDF%=(W3-(W1*C1))*00 / W2 W1 = filter bag mass, W2 = sample mass, W3 = dry weight of filter bag after digestion C1 = ash content blank filter bag factor (blank value of ignition weight loss / original blank value) ADF calculation formula: ADF%=(m2-(m1*C1))*100 / m m1 = empty bag mass, m = sample mass, m2 = dry weight of filter bag after digestion C1 = correction factor for blank bag (mass after drying / original mass).

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