Proper harvesting techniques for ensiled corn and corn silage

1. Moisture
Moisture level of ensiled feeds is critical for several key reasons:

• When moisture levels are too high, ensiled feed will ferment poorly and also tend to lose valuable nutrients through runoff and seepage.

This runoff also has the potential to cause damage to silos and concrete storage areas as well as contaminate water supplies.

• When ensiled feeds are harvested too dry, they tend to be more difficult to pack, resulting in feed more prone to mold and spoilage.

• Corn silage harvested too dry also tends to be less digestible and contains less sugar as well.

To determine the moisture of corn silage in order to time harvesting, a common approach is to chop a sample at full dent stage, just as a milkline becomes visible and determine the moisture content of the silage. From this, a typical rate of drydown is 0.5 to 0.75 percentage units per day.

Particle size and length of cut
• Processed: 3/4-inch length with a 1- to 2-mm roller clearance
• Unprocessed: 3/8- to 1/2-inch depending on moisture

At 3/4-inch cut, 10 to 20 percent should be on the top screen, 50 to 70 percent on the middle screen and less than 30 percent on the bottom of the particle size separator.

At storage, kernels should be 95 percent broken, but do not have to be destroyed. Cobs should be broken.

Do not overprocess corn when making high-moisture shell and ear corn that is over the desired moisture level. Resulting feeds could lead to acidosis and decreased subsequent performance.

Proper storage techniques for corn and corn silage
1. Achieve a high density.
Pack, pack and pack the pile.

2. Harvest quickly.
Once harvesting has begun, make piles and fill silos as rapidly as possible until filled. Do this in order to minimize variation in packing density and prevent soft spots where spoilage is more likely to occur.

3. Use a forage treatment (inoculant or preservative).
Excessive oxygen, heating and low plant sugar levels can all cause undesirable fermentation. Forage treatments help enhance the fermentation process to ensure the proper preservation of ensiled feeds.

This is achieved through optimizing lactic acid production, lowering pH and minimizing oxygen in the silo.

4. Protect silage from weather.
• Use black and white 6 mil plastic.
• Overlap at least 6 feet between sheets
• Cover plastic with tire or cutouts.
• Keep plastic tight with no air pockets.
• Double up tires on seams.
• Seal around bottom with dirt or something heavy.
• Cover the pile if rain delays harvest.

5. Identify the right location and timing of feedout.
If storing corn in bags, keep them away from trees and long grass and keep snow away fromthe bags.

Use bagged corn during cooler months since rips, tears and punctures can cause rapid and widespread spoilage in the summer.

6. Manage the feedout face
• Corn silage – Feed 6 inches or more per day, 12 inches in hot weather.
• High-moisture ear and shell corn – Feed 3 to 4 inches per day; increase rate in warmer months.
• Shave top down, shave from side to side, evenly across the face.
• Feed all shaved silage before shaving more.

7. Discard spoiled ensiled feed.
Feeding rotten silage or ensiled grain reduces intake, depresses milk production and challenges overall cow health.  FG

References omitted due to space but are available upon request.
—Excerpts from Hubbard Ruminant Tech-Line newsletter