Critical control points for the production of whole-plant corn silage

Whole-plant corn silage is the silage of whole plant corn with ears at the waxy ripening stage (when the weight of corn seeds accounts for more than 45%). Silage has obvious advantages: aromatic flavor, soft and juicy; can improve the palatability of cattle and feed digestibility; large storage capacity per unit volume, convenient for long-term storage in large quantities, can be supplied all the year round; less nutrient loss, nutrient loss is generally about 10%, can effectively maintain the green state of green feed. The key control points of whole plant corn silage production are as follows.

I. Budget for silage corn requirements

Taking dairy farms as an example, each cow is 12~25 kg/day, and the average size of cattle is 18~20 kg/day, that is, about 7 tons per year, which can effectively guarantee the supply of silage corn (generally, the loss is controlled within 15%).

II. Preparation of silage facilities

There are many kinds of silage facilities, mainly silage cellar, tower, pool, bag, box, trench and flat silage. The requirements for silage facilities: (1) air impermeable;(2) impermeable;(3) the wall should be straight and the corners of the wall should be smooth;(4) it should have a certain depth, 2.5~3 meters deep, 2~10 meters wide, and the length should be determined according to the silage amount;(5) it can freeze;(6) the trench wall should have 1/10 inclination to prevent collapse, and the section should be inverted trapezoidal.

Silage cellars are divided into above-ground, underground and semi-underground types, generally 20~40 meters long, 5.5~6 meters wide, 4.5~5.5 meters wide and 2.5~3.5 meters deep. It can also be stored on the ground, that is, with 1 mm thick polyethylene film, stored on the ground, the scale can reach 20~50 tons. The capacity of general whole plant corn silage per cubic meter is 650~750 kg. Silage cellars should be disinfected 3 days before silage production. Clean it first. If it is sunny, it can be exposed to the sun for 3 days. If it cannot be exposed to the sun, it can be sprayed with 1%~2% bleaching powder solution or 0.3% peracetic acid solution 3 days in advance. Silage walls should be covered with plastic film. The width of the membrane is equal to pit height +1/2 pit width +3 meters, and the length of the membrane is more than or equal to 15 meters.

III. Appropriate harvest time

The best harvest time of silage corn is in the late milk ripening and early wax ripening, the dry matter content is between 28% and 40%, and the dry matter content should not be lower than 25%.

IV. Chopping Silage Corn

The stubble height of corn harvest should be at least 15 cm, preferably 20~25 cm, so as to avoid poor silage fermentation caused by contamination of miscellaneous bacteria on the ground. Silage corn should be chopped to the right length and corn seeds crushed. Whole-plant corn silage generally requires a cutting length of 0.63~1.25 cm (foreign), the United States requires a maximum length of no more than 19 mm; domestic reports cut the length of 0.90~1.70 cm. If a kneader is used, the length of the chop should be controlled at 1.0~2.0 cm; if a shredder is used, it should be controlled at 0.5~1.3 cm. Corn dry matter content is less than 27%, recommended cutting length is 17 mm; dry matter content is 28%~31%, recommended cutting length is 11 mm; dry matter content is 32%~35%; recommended cutting length is 9 mm; dry matter content is greater than 36%, recommended cutting length is 5 mm.

Crushing corn kernels can make starch flow out quickly, promote fermentation, and also improve corn digestibility and starch utilization in the rumen, so crushing is also critical. The optimum diameter of broken grain is 4.75 mm. To test the degree of fragmentation, pour 1 liter of silage corn (volume, not weight) into a bucket of water, remove the corn stalks, and then count the number of whole grains that sink to the bottom of the bucket, never more than 5.

V. Filling and compaction

Before filling, the cellar bottom can be paved with a layer of 10~15 cm cut straw and other soft grass to absorb silage juice; the best time from harvesting to cellar entry is controlled within 4 hours.(within 200km), the limit of time for entering the cellar is 8 hours, otherwise the raw materials are easy to oxidize and deteriorate; after unloading the materials, the vehicles shall be pushed up immediately, otherwise they are easy to deteriorate, and the deterioration is faster than that piled on the vehicles; during the filling process, avoid exposing the grass to the air for more than 4 days; pay attention to compaction when loading raw materials, with a layer of 15cm and 4~5 minutes for each ton of raw materials; Heavy tractors should be used for compaction, the running speed of tractors should be slow, tires should not slip, and the surrounding parts should be compacted; the compaction of silage should be detected regularly, and the density of silage should be ≥750 kg/m3.

(1)First, pour the first car of materials 10 meters away from the cellar head (2 times the cellar height), ensure that the angle from the unloading position of the first car to the top of the cellar wall is within 30~35°, the shovel plate of the 50 loader is about 10 cm away from the ground, slowly push forward, lay flat on the cellar surface, and only when the bottom is compacted can the upper part be compacted better. When apportioning the raw materials, the raw materials distributed to the edges should be higher than the middle position of the cellar. When the vehicle is pressed sideways, it will tilt toward the middle of the cellar, so that the raw materials at the edges can be compacted.

(2)Laying layer by layer, compaction layer by layer, each layer is 15~ 30cm; the cellar head is gradually raised to form a slope of about 30~35°, and the materials are poured backward in turn, and the inclined surface is pressed into the cellar.

(3)Do not crush the top too much, otherwise it will lead to more serious top spoilage, because plant cells rupture, nutrients and water outflow, will accelerate the growth of aerobic spoilage microorganisms.

When checking the compaction degree, select 5 points on the pressed surface separately, drill holes with coarse material sampler, take out silage corn and weigh it, then put a large soft plastic bag in the hole, add water to the plastic bag to the level of silage surface, then pick up the plastic bag, measure the volume of water with measuring cylinder, and calculate the density of silage corn by taking out silage corn and water volume.