阅读说明：本技术 一种楚雄南苜蓿拉伸膜裹包青贮饲料及其制备方法 (South alfalfa tensile film wrapped silage and preparation method thereof ) 是由 张美艳 薛世明 匡崇义 高月娥 罗鑫 徐驰 侯洁琼 于 2020-12-31 设计创作，主要内容包括：本发明提供了一种楚雄南苜蓿拉伸膜裹包青贮饲料及其制备方法,其特征在于,采用开花期的楚雄南苜蓿通过晾晒、挤丝、揉搓、打捆和包膜制备而成,包括如下步骤：将收获的开花期楚雄南苜蓿,经过晾晒风干后,采用秸秆揉丝机对牧草进行挤丝、揉搓软化成条；将步骤1处理后的楚雄南苜蓿用青贮圆捆机高密度压实打捆成草捆；利用圆捆包膜机将塑料拉伸膜紧紧地将步骤2打捆好的草捆裹包密封,制作完成后,妥善贮存。本发明具有较好的贮存条件、贮存利用时间和拉伸膜裹包青贮贮藏利用的最大期限,对拉伸膜裹包青贮的广泛应用和推进,家畜饲料安全和南方草地畜牧业的可持续发展和起着重要的作用。(The invention provides a Chuxiong alfalfa tensile film wrapped silage and a preparation method thereof, and is characterized in that the Chuxiong alfalfa tensile film wrapped silage in a flowering period is prepared by airing, extruding, kneading, bundling and film wrapping, and the method comprises the following steps: airing and air-drying the harvested southern alfalfa in the flowering period, and extruding, kneading and softening the pasture into strips by using a straw kneading machine; compacting and bundling the south alfalfa processed in the step 1 into a straw bundle at high density by using a silage round baler; and (3) tightly wrapping the bales bundled in the step (2) by using a plastic stretch film through a round bale wrapping machine, and sealing, and after the production is finished, properly storing. The invention has better storage condition, storage and utilization time and the maximum storage and utilization period of the tensile film-wrapped silage, and plays an important role in the wide application and promotion of the tensile film-wrapped silage, the safety of livestock feed and the sustainable development and play of southern grassland animal husbandry.)

1. A preparation method of a Chuxiong alfalfa tensile film wrapped silage is characterized in that the Chuxiong alfalfa in a flowering period is prepared by airing, extruding, kneading, bundling and film wrapping, and comprises the following steps:

step 1, airing and air-drying harvested southern alfalfa in flowering period, and extruding, kneading and softening pasture into strips by using a straw kneading machine;

step 2, compacting and bundling the south alfalfa processed in the step 1 into a straw bundle at a high density by using a silage round baler;

and 3, tightly wrapping and sealing the bales bundled in the step 2 by using a plastic stretch film through a round bale wrapping machine, and storing properly after the manufacture is finished.

2. The preparation method of the south alfalfa stretch film wrapped silage according to claim 1, wherein the south alfalfa stretch film wrapped silage comprises the following steps: in the step 1, the water content of the south clover after airing and air drying is controlled to be 65-75%.

3. The preparation method of the south alfalfa stretch film wrapped silage according to claim 1, wherein the south alfalfa stretch film wrapped silage comprises the following steps: in the step 1, the rotating speed of the straw rubbing machine is 2280 r/min.

4. The preparation method of the south alfalfa stretch film wrapped silage according to claim 1, wherein the south alfalfa stretch film wrapped silage comprises the following steps: in step 2, the size specification of the bales bundled by the ensiling round baler is as follows: the length X width X height is 520mm X520 mm.

5. The preparation method of the south alfalfa stretch film wrapped silage according to claim 1, wherein the south alfalfa stretch film wrapped silage comprises the following steps: in step 3, the length of the envelope size of the round bale film wrapping machine is 520mm by 520 mm.

6. The preparation method of the south alfalfa stretch film wrapped silage according to claim 1, wherein the south alfalfa stretch film wrapped silage comprises the following steps: in step 3, the round bale film wrapping machine at least adopts 4 layers of plastic stretch films for wrapping.

7. The preparation method of the south alfalfa stretch film wrapped silage according to claim 1, wherein the south alfalfa stretch film wrapped silage comprises the following steps: and in the step 3, the round bale film wrapping machine adopts 4-6 layers of plastic stretch films for wrapping.

8. The preparation method of the south alfalfa stretch film wrapped silage according to claim 1, wherein the south alfalfa stretch film wrapped silage comprises the following steps: in step 3, each bale of grass weighs 35 kg/bale.

9. A south alfalfa stretch film coated silage prepared by the method of making south alfalfa stretch film coated silage of any one of claims 1-8, wherein the south alfalfa stretch film coated silage is prepared by: the preparation method is adopted to prepare the bamboo charcoal fiber through airing, extruding, kneading, bundling and coating.

Technical Field

The invention relates to the technical field of forage grass storage, and particularly relates to silage wrapped by tensile films of Medicago hispida L.var.chu and a preparation method thereof.

Background

The method is a scientific and efficient ensiling mode, and has the characteristics of convenience, simplicity, no limitation of time and place and the like. The method for wrapping silage by using the stretch film in wrapping silage is one of the most advanced silage wrapping technologies in the world at present, is widely applied in countries such as Europe and America, is an effective way for promoting agricultural sustainable development in China, and is a form of high-moisture silage. After the alfalfa stretching film is wrapped and ensiled, the nutrient components of the fresh alfalfa are basically maintained, the loss of crude protein is little, and the content of medium and acid detergent fibers (NDF and ADF) is basically close to that of the fresh grass. The Yunnan is drought in spring, high in temperature and sufficient in sunshine, and is the best season for making green hay, grass bundles, pasture silage and other grass products which can be stored and transported for a long time.

The south Medicago sativa (Medicago hispida Gaertn cv. Chuxiong) has long planting time in Yunnan, wide application and rich yield. With the development of the breeding industry, the alfalfa ensiling technology is continuously developed and explored, and the quality relation of alfalfa ensiling nutrient substances influences the breeding cost due to the growth of animals. Alfalfa is usually exposed to rain in the harvest season and is easy to mildew, while alfalfa ensilage not only can keep the nutritive value of pasture greenish, but also improves the palatability and reduces the mildew degree, which plays an important role in relieving the insufficient supply and shortage of forage grass in the animal husbandry production. With the continuous improvement and improvement of silage technology and equipment, the evaluation of the nutritive value of the tensile film silage during storage has important guiding significance on the aspects of livestock nutrition balance and feed safety.

The south alfalfa of Chuxiong is a commonly used alfalfa of good annual pasture in Yunnan province, and the storage rule of the south alfalfa ensilage is rarely reported. Therefore, the storage rule of the semi-dry silage of the south Medicago hispida is searched, the optimal storage condition, the optimal storage utilization time and the maximum storage utilization period of the silage wrapped by the stretching film are found, and the storage rule plays an important role in the wide application and promotion of the silage wrapped by the stretching film, the safety of livestock feed and the sustainable development and play an important role in southern grassland animal husbandry.

Disclosure of Invention

Aiming at the problems, the invention provides the south alfalfa tensile film wrapped silage and the preparation method thereof, which have better storage conditions, storage and utilization time and the maximum storage and utilization period of the south alfalfa tensile film wrapped silage, and play an important role in the wide application and promotion of the south alfalfa tensile film wrapped silage, the safety of livestock feeds and the sustainable development of the southern grassland animal husbandry.

According to the purpose of the invention, the invention provides the following technical scheme:

a preparation method of a Chuxiong alfalfa tensile film wrapped silage is characterized in that the Chuxiong alfalfa in a flowering period is prepared by airing, extruding, kneading, bundling and film wrapping, and comprises the following steps:

step 1, airing and air-drying harvested southern alfalfa in flowering period, and extruding, kneading and softening pasture into strips by using a straw kneading machine;

step 2, compacting and bundling the south alfalfa processed in the step 1 into a straw bundle at a high density by using a silage round baler;

and 3, tightly wrapping and sealing the bales bundled in the step 2 by using a plastic stretch film through a round bale wrapping machine, and storing properly after the manufacture is finished.

Further, in the step 1, the water content of the south alfalfa in Chuxiong after airing and air drying is controlled to be 65-75%.

Further, in the step 1, the rotating speed of the straw rubbing machine is 2280 r/min.

Further, in step 2, the bale size specification of the ensiling round baler is as follows: the length X width X height is 520mm X520 mm.

Further, in step 3, the length of the envelope size of the round bale film wrapping machine is 520mm by 520 mm.

Further, in step 3, at least 4 layers of plastic stretch films are adopted for wrapping by the round bale film wrapping machine.

Further, in step 3, the round bale film wrapping machine adopts 4-6 layers of plastic stretch films for wrapping.

Further, in step 3, each of the bale of grass weighs 35 kg/bale.

A south alfalfa tensile film wrapped silage is prepared by the preparation method through airing, extruding, rubbing, bundling and film wrapping.

Compared with the prior art, the invention has the beneficial effects that:

the alfalfa tensile film wrapped silage and the preparation method thereof are prepared by airing, extruding, rubbing, bundling and coating, have good storage conditions, storage utilization time and the maximum storage utilization period of tensile film wrapped silage, are widely applied and promoted to tensile film wrapped silage, and play an important role in the safety of livestock feeds and the sustainable development of southern grassland animal husbandry.

Drawings

FIG. 1 is a graph showing the change in crude alfalfa silage protein and ammoniacal nitrogen/total nitrogen during storage according to the invention;

FIG. 2 is a graph of the change in pH and dry matter of Medicago ensilage during storage according to the invention;

FIG. 3 is a graph showing the change in NDF and ADF of Medicago ensilage during storage according to the invention;

FIG. 4 is a graph showing the change in moisture and crude fat in alfalfa silage during storage according to the invention;

FIG. 5 is a graph showing the change in the rate of mildew of Medicago ensilage during storage according to the invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described below clearly and completely in connection with the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

A preparation method of a Chuxiong alfalfa tensile film wrapped silage is characterized in that the Chuxiong alfalfa in a flowering period is prepared by airing, extruding, kneading, bundling and film wrapping, and comprises the following steps:

step 1, airing and air-drying harvested southern alfalfa in flowering period, controlling the water content to be 65% -75%, and extruding, kneading and softening the pasture into strips by using a straw kneading machine; the type of the straw rubbing machine is as follows: 9RSZ-6, the rotating speed is 2280 r/min.

Step 2, compacting and bundling the south alfalfa processed in the step 1 into a straw bundle at a high density by using a silage round baler; the model of the ensiling round baler is MK5050-G, and the size and the specification of the bales are as follows: the length X width X height is 520mm X520 mm.

And 3, tightly wrapping and sealing the bales bundled in the step 2 by using a plastic stretch film by using a round bale film wrapping machine, wherein the model of the round bale film wrapping machine is YBS-5050, and the length and the width of a wrapping film are 520 and 520 mm. The round bale film wrapping machine adopts 4 layers of plastic stretch films for wrapping. The weight of each bale of grass was 35 kg/bale. After the preparation is finished, the product is properly stored.

A south alfalfa tensile film wrapped silage is prepared by the preparation method through airing, extruding, rubbing, bundling and film wrapping.

Example 2

A preparation method of a Chuxiong alfalfa tensile film wrapped silage is characterized in that the Chuxiong alfalfa in a flowering period is prepared by airing, extruding, kneading, bundling and film wrapping, and comprises the following steps:

step 1, airing and air-drying harvested southern alfalfa in flowering period, controlling the water content to be 65% -75%, and extruding, kneading and softening the pasture into strips by using a straw kneading machine; the type of the straw rubbing machine is as follows: 9RSZ-6, the rotating speed is 2280 r/min.

Step 2, compacting and bundling the south alfalfa processed in the step 1 into a straw bundle at a high density by using a silage round baler; the model of the ensiling round baler is MK5050-G, and the size and the specification of the bales are as follows: the length X width X height is 520mm X520 mm.

And 3, tightly wrapping and sealing the bales bundled in the step 2 by using a plastic stretch film by using a round bale film wrapping machine, wherein the model of the round bale film wrapping machine is YBS-5050, and the length and the width of a wrapping film are 520 and 520 mm. The round bale film wrapping machine adopts 5 layers of plastic stretching films for wrapping. The weight of each bale of grass was 35 kg/bale. After the preparation is finished, the product is properly stored.

A south alfalfa tensile film wrapped silage is prepared by the preparation method through airing, extruding, rubbing, bundling and film wrapping.

Example 3

A preparation method of a Chuxiong alfalfa tensile film wrapped silage is characterized in that the Chuxiong alfalfa in a flowering period is prepared by airing, extruding, kneading, bundling and film wrapping, and comprises the following steps:

step 1, airing and air-drying harvested southern alfalfa in flowering period, controlling the water content to be 65% -75%, and extruding, kneading and softening the pasture into strips by using a straw kneading machine; the type of the straw rubbing machine is as follows: 9RSZ-6, the rotating speed is 2280 r/min.

Step 2, compacting and bundling the south alfalfa processed in the step 1 into a straw bundle at a high density by using a silage round baler; the model of the ensiling round baler is MK5050-G, and the size and the specification of the bales are as follows: the length X width X height is 520mm X520 mm.

And 3, tightly wrapping and sealing the bales bundled in the step 2 by using a plastic stretch film by using a round bale film wrapping machine, wherein the model of the round bale film wrapping machine is YBS-5050, and the length and the width of a wrapping film are 520 and 520 mm. The round bale film wrapping machine adopts 6 layers of plastic stretch films for wrapping. The weight of each bale of grass was 35 kg/bale. After the preparation is finished, the product is properly stored.

A south alfalfa tensile film wrapped silage is prepared by the preparation method through airing, extruding, rubbing, bundling and film wrapping.

Example 4 control experiment

Test site

The test is carried out in a beef cattle farm of modern agriculture development limited company of Chuxiong colorful cloud Zhenlufeng colorful cloud impression.

Test materials

And ensiling the south clover in Chuxiong and the alfalfa in Sandeli to prepare the semi-dry stretched film ensiling in the southern Chuxiong Yi nationality autonomous Doyun town in 2 months, 26 days to 3 months and 3 days in 2014. The specific method comprises the following steps: the harvested fresh alfalfa of the south alternifolia and the three-profit alfalfa (the south alternifolia is in the flowering period and the alfalfa is in the bud flowering period) is dried in the sun and air-dried to control the water content to be 65-75 percent, a straw rubbing machine (the model is 9RSZ-6, the rotating speed is 2280r/min) is used for extruding the pasture, kneading and softening the grass seeds into strips, compacting and bundling the strips at high density by using an ensiling round baler (type: MK5050-G, bale size: phi 520 multiplied by 520mm, and height 520mm), tightly wrapping and sealing the grass bundles by using a round bale film wrapping machine (type: YBS-5050, and wrapping size phi 520 multiplied by 520mm), wrapping by adopting 2 layers of plastic stretch films, making 1500 bags (about 35 kg/bag) for each grass seed, and transporting the grass seeds to a warehouse of a grassland animal science research institute in Yunnan province for proper storage after the completion of the making.

Test method

Sampling

Ensilage quality measurements were started at month 1 of storage (month 4 2014), with sampling measurements taken at 30-day intervals, and continued until month 10 of 2014. Sampling is carried out at the beginning of each month, 3 bags of the three-profit alfalfa and the four-male-south alfalfa are randomly selected for wrapping silage, mildew-free silage is selected, 3 bags of sample are taken for each bag, each bag is about 200g, and the silage is sealed by a self-sealing bag and sent to a laboratory for index determination.

Sample pretreatment

The retrieved samples were dried at 65 ℃ for 48h, then crushed, sieved through a 40 mesh sieve, and packed into self-sealing bags for determination of DM, CP, EE, pH, ammoniacal nitrogen, NDF and ADF.

Determination of the Dry Matter (DM) content: the fresh samples were dried, weighed and the dry content calculated.

Determination of the pH and the ammoniacal nitrogen: weighing 20g silage sample, adding 180ml distilled water, stirring uniformly, stirring for 1min with a tissue triturator, filtering the homogenate with qualitative filter paper, and measuring the pH value of the filtrate with a pH meter (pHS-3C precision acidity meter). After completion of the pH measurement, 15ml of the silage filtrate was taken and subjected to ammoniacal nitrogen measurement by a FOSS Kjeldahl apparatus.

Crude Protein (CP) assay: kjeldahl method, sulfuric acid digestion. (FOSS8040 full-automatic Kjeldahl apparatus determination)

Crude fat (EE) assay: soxhlet extraction of petroleum ether (FOSS2050 full-automatic fat determination nitrogen instrument)

Acid scour fibers (ADF) and neutral scour fibers (NDF) measurements: a paradigm cellulose assay was used. (FOSS2023 sample bottle filtration method determination)

Determination of the mildew rate: the silage, which is dark green, brown or black, has obvious moldy taste, is held on the hand and has sticky feeling, is determined as a moldy part. And (3) independently and randomly selecting 3 silage bags for each grass seed for measurement, weighing the weight of each silage bag, opening the silage bags, taking out the mildewed part, weighing, calculating the weight of the mildewed part in the whole silage bag, and obtaining the mildewed rate of silage.

Data analysis

One-way ANOVA program in SPSS 19.0 statistical software was used for One-way variance analysis, and Duncan's method (P0.05) was used for multiple comparisons, and sigmaplot10.0 was used for mapping.

Results and analysis

Nutritional ingredients of Medicago before ensiling

TABLE 1 nutritional ingredients of Medicago before ensiling

Note: the yield of the alfalfa is only the yield in winter and spring, while the south alfalfa in Chuxiong is annual pasture which is the total yield in one growing season.

As can be seen from Table 1, the tested Medicago species has certain differences in nutritional ingredients, and the contents of crude protein and crude fat of the Medicago sativa are higher than those of the Medicago hispida, while the contents of the neutral detergent fiber and the acidic detergent fiber are lower than those of the Medicago hispida. The nutritional ingredients of the alfalfa are better than that of the southern alfalfa, but the hay yield and the crude protein yield of the southern alfalfa are obviously higher than those of the alfalfa, and are respectively 3.01 times of the hay yield and 2.31 times of the crude protein yield of the alfalfa. The south alternifolia is an important protein forage grass source in winter and spring in Yunnan, and compared with alfalfa, the south alternifolia has more advantages in forage grass supply in dry Yunnan.

Changes in crude alfalfa ensilage protein and ammoniacal nitrogen/total nitrogen during storage

As can be seen from FIG. 1, the crude protein changes in the semi-dry ensiling process of Medicago sativa and Medicago hispida both have the same trend, and both show the trend of increasing first and then decreasing then stabilizing. The silage is stored for 1 month, the crude protein content of the silage is higher than that of a fresh sample, and the silage obviously decreases after 2 months and then tends to be basically stable. The content of the alfalfa crude protein is between 23 and 27 percent; the crude protein content of the south medicago sativa is 18-21.4%. The crude protein content of the south Medicago hispida L.is slightly lower than that of the alfalfa as a whole, which may be related to the different growth periods of the south Medicago hispida L.and the growth period of the south Medicago hispida L.for preparing silage is more mature than that of the alfalfa. Shows that the content of crude protein is not greatly changed along with the prolonging of the storage time in the ensiling process of the alfalfa stretching film.

During the ensiling process, when the content of crude protein is reduced, the ratio of ammoniacal nitrogen to total nitrogen is increased, and certain negative correlation exists between the ammoniacal nitrogen and the total nitrogen. The ammonia nitrogen to total nitrogen ratios of the two alfalfa ensilages showed a trend of a curve with increasing storage time, but were all less than 5 as a whole, indicating that the two alfalfa semi-dry stretch film wrapped ensilages as a whole were successful in this study. Wherein, the ratio of ammoniacal nitrogen to total nitrogen of the southwestern alfalfa is higher than that of the alfalfa as a whole, which indicates that the protein decomposition of the southwestern alfalfa is faster than that of the alfalfa during the ensiling process, and the ensiling quality of the southwestern alfalfa is slightly lower than that of the alfalfa as a whole. (see FIG. 1).

Note: in the study, the alfalfa half-dry silage is seriously mildewed and rotted when observed at the 8 th month of storage, so that only the 7 th month of storage is observed.

Changes in pH and dry matter of Medicago ensilage during storage

As can be seen in fig. 2, the pH of the semi-dry alfalfa silage varied less consistently with increasing storage time, with the alfalfa silage bales showing a tendency to increase after a slow decline and a minimum of 3.71 at 6 months of storage. While the south clover exhibits a tendency to change in "M" shape, the pH was almost entirely lower than that of alfalfa 5 months prior to storage. The storage time of the semi-dry ensilage of the alfalfa is 0 to 6 months; the storage time of the south Medicago hispida is within 5 months. When the alfalfa is stored for 4 months, the dry matter content is reduced, but the dry matter content of the south Chuxiong alfalfa is not obviously changed.

Changes in NDF and ADF of Medicago ensilage during storage

As can be seen from fig. 3, the NDF content in the two semi-dry bales of alfalfa grass exhibited a less consistent trend with longer storage times. Wherein, the alfalfa NDF shows the variation trend of the shape of M and reaches a lower value at 1 month and 5 months of storage; while the south Medicago hispida NDF showed a tendency of "n" deformation, the NDF reached a lower value at month 5 of storage and then tended to plateau. The ADF content of the two semi-dry grass silage grains shows the change trend of an M shape along with the prolonging of the storage time, wherein the ADF content shows a peak value when the grass forage grains are stored for 2 months and 6 months, and shows a low value when the grass forage grains are stored for 5 months and 7 months, but the whole change range is not large. And both NDF and ADF are lower than that of the alfalfa in south China, wherein the ADF of the alfalfa is 19-25.4%, and the NDF is 26.6-30.2%; while the ADF of the south Medicago sativa L.is 21.5-31.7% and the NDF is 32.3-39.2%. This may be due to the fact that south Medicago hispanica made silage is slightly more mature than alfalfa. Compared with the alfalfa or the south alfalfa before ensiling, the NDF and the ADF after the ensiling is wrapped have no significant change, which shows that the wrapped ensiling has no significant influence on the cellulose content of the medicago.

Changes in water and crude fat in alfalfa silage during storage

As can be seen from fig. 4, the trend of the change in the moisture content of the semi-dry silage of alfalfa and chongxiong alfalfa was less consistent with the increase in the storage time. Wherein, the water content of the alfalfa shows a rising trend, the water content changes more stably in 3 months before storage, and then slowly rises. While the south clover shows the trend of curve change, but the change amplitude is smaller. The indication shows that the water content of the alfalfa semi-dry silage changes little in the storage stage, and particularly in the early storage stage, the water content basically tends to be stable.

The change trend of the crude fat of the semi-dried silage of the two medicago pastures is not consistent with the prolonging of the storage time. Wherein, the south medicago sativa shows a relatively stable change trend, the change amplitude is very small, but the content of the fat is obviously higher than that of crude fat before ensiling; the crude fat content of the alfalfa shows a rising trend along with the prolonging of the storage time, after the alfalfa is stored for 7 months, the crude fat content reaches 3.40 percent, is nearly 1 percent higher than the crude fat content when the alfalfa is stored for 1 month, and is increased by 1.38 percent higher than the crude fat content before the alfalfa is stored for 1 month. This indicates that there is some interspecific difference in crude fat during storage of semi-dry silage from different alfalfa species. After ensiling, the crude fat content of both alfalfa and chongxiong alfalfa was higher than before ensiling, indicating that ensiling has some effect on the crude fat content of medicago (see figure 4 and table 1).

Changes in the rate of mildew of Medicago ensilage during storage

As can be seen from FIG. 5, the mildew rate of the semi-dried silage of both Medicago grasses showed an increasing trend with increasing storage time. In the 4 month period before storage, the overall mildew rate of the alfalfa is lower than that of the alfalfa in south Chuxiong, and is within 9 percent; while the south medicago sativa in the same size as the standard medicago sativa has a low mildew rate within 2 months before storage, the mildew rate is within 6%, the mildew rate is remarkably increased after 2 months, and the mildew rate is as high as 58.8% after 7 months of storage. The mildew rate of the alfalfa is high, and the alfalfa is possibly related to the phenomena that the compaction degree is not enough before the sample is wrapped, and the silage stretch film leaks air in the storage process. The semi-dry ensiling, compacting, wrapping and stretching film selection of the alfalfa grass are all very critical links. The ensiling bag is not suitable for being stored for too long time, and is preferably fed within half a year, and the phenomenon of severe mildew and rot can occur after half a year.

Discussion of the related Art

Rate of mold change and degree of compaction in wrapped silage

In some areas in the south, the ripe mowing period of alfalfa is mostly rainy and muggy seasons, and silage is easy to mildew in warm and humid storage environments. The mold is spore-spread, the spread speed is very fast, and the longer the storage time is, the higher the mold rate is. Ensiling mycotoxin contamination is multifaceted, and if weather temperature changes greatly, mildew becomes more prominent and mildew rate becomes higher. The compaction degree is an important factor causing the loss of silage surface layer materials and the change of silage nutrition quality, the low compaction degree is one of the main causes of silage mildew and silage quality, and researches such as Baichunsheng show that the silage mildew rate of 4-6 layers of wrapping is low and the nutrition quality is better under the condition of the same water content. The film has insufficient thickness, is easily penetrated by oxygen in the long-term storage process, and is easily punctured by sharp stems of leguminous grass in the transportation and carrying processes, so that physical damage is caused, and the quality is deteriorated. In the research, a small part of samples of the alfalfa in south of Chuxiong and alfalfa stretch films are not kneaded, the compaction degree in the wrapping process is not enough, and in addition, the samples are wrapped by three layers of films, so that the phenomenon that part of silage bags are seriously mildewed occurs. It has been proposed to date that in the manufacture of semi-dry baled silage of the medicago genus, care must be taken to compact the material and to wrap it with more than 4 layers of stretch film. In the research, the alfalfa and the Chuxiong alfalfa wrapped and stored in the green package are seriously mildewed after being stored for 7 months, and the mildewing rate exceeds 50 percent, which is consistent with the research conclusion of Yuzhu and the like. Indicating that the validity period of alfalfa stretch film wrapped silage in Yunnan and southern areas is generally half a year.

Crude fat

Crude fat is a highly caloric substance and an important nutrient component in plant feeds, and in general, silage is mainly a feed that provides high fibrous nutrient content to ruminants, with relatively low crude fat content. Studies such as Shielyuanhua show that the higher the number of alfalfa molds, the faster the crude fat decreases, which is inconsistent with the findings of this study. This study showed that the coarse fat content of alfalfa semi-dry stretch film silage bales increases with storage time. This may be related to the date of storage and the experimental conditions. They designed the experimental scheme that the storage time is finished in a short period of 16 days, and under the constant temperature experimental condition, our storage time is long, and under the natural condition, the air temperature changes greatly. And the study on the Liugui important and the like shows that the corn straw bottled silage lasts for 50 days, and the crude fat is slowly increased in the whole silage process, which is similar to the experiment. The crude fat increases with the increase of the ensiling time, and may be related to microorganisms participating in activities and actions in the ensiling process, and the specific reasons are still to be proved by further experiments.

Relationship between crude protein and ammoniacal nitrogen

In the early stage of fermentation of the alfalfa ensilage, the content of crude protein is detected to be increased to some extent in comparison with that of a fresh sample in the first month, after the second month, the alfalfa ensilage begins to mildew, the content of crude protein is reduced by 2-3 percentage points, and the content of crude protein tends to be flat in the next months. The result is similar to the study of the staphylia formosana, and shows that the content of crude protein at the initial stage of the ensiling is increased and is probably caused by microbial protein, and the later-stage mould is largely decomposed, and the crude protein is reduced along with the decomposition of the microbes. Ammonia nitrogen is an important index for measuring the decomposition and corruption degree of protein, and is a substance generated by decomposing crude protein into NPN (negative-positive-negative) due to the increase of activities of acid protein degrading enzyme, metalloprotease, carboxypeptidase and the like in the alfalfa ensiling process, so that the content of the crude protein is reduced when the content of the ammonia nitrogen is increased. The ratio of ammoniacal nitrogen to total nitrogen reflects the degree of decomposition of protein and amino acid in the silage, the smaller the ratio, the better the silage quality, and the larger the ratio, the worse the silage quality is. The ratio of ammoniacal nitrogen to total nitrogen in the research is less than 5, and the better quality of the alfalfa wrapped silage is obtained according to an ammoniacal nitrogen grading method provided by McDonald and the like.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.