Corn Silage

Originally written February 1, 2006 | Last updated August 21, 2014


Importance of Corn Silage to Wisconsin

Largest acreage and production among U.S. States

Used extensively in forage base for state dairy herds

Changing Wisconsin dairy production 'climate'

Wisconsin Corn Silage Consortium (Coors et al.)

Range for NDF and digestibility among commercial hybrids sold in Wisconsin is narrow.

Yield and quality differences among corn hybrids are repeatable.

Corn silage quality can be predicted using NIR

Corn Silage Compared to Other Forages


Palatable forage

High dry matter yield and energy content

Consistent quality

Less labor and machinery (one harvest). Lower cost per ton of dry matter

Manure management

Flexibility, dual purpose


Few established markets

Relatively low in protein

High transportation costs

Must be fed on or near farm

Expensive storage facilities

Limited production on erodible soils due to conservation requirements

What makes a good forage? (Carter et al., 1991)

High yield

High energy (high digestibility)

High intake potential (low fiber)

High protein

Proper moisture at harvest for storage

Ultimate test is animal performance - Milk2000 is our best predictor for performance (Schwab - Shaver equation)

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Hybrid Selection

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Criteria for Selecting Silage Hybrids

  • Grain yield: allows flexibility (dual purpose)
  • Whole plant silage yield
  • Relative maturity: 5-10 days later than grain hybrids
  • Standability: allows flexibility
  • Pest resistance
  • Silage quality

"Variation for silage yield and quality exists among commercial hybrids in Wisconsin."

"Dual Purpose" Hybrids versus Silage Specific

Other silage Hybrids

  • High sugar
  • Waxy
  • High-oil
  • Leafy Corn
  • Bmr Corn
  • Tropical
  • Sweet corn

Silage Quality

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Bt versus Conventional hybrids 

Management Guidelines for Corn Silage

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Silage yield and quality changes during corn growth and development

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Planting date response

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Plant density response

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Row spacing response

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Cutting height response

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When to Harvest

Harvest timing depends upon storage structure

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Environment drydown rate average = 0.5% per day

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Kernel milkline: use as a guide

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Predicting corn silage harvest date

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  • Planting date
  • Hybrid Relative Maturity
  • Silking date: add 42 to 47 days
  • Once kernel milkline begins to move measure whole-plant moisture and use drydown rate = 0.5% per day
  • Final check

Harvesting Stressed Corn

  • Frosted corn
  • Drought-stressed corn


Silage additives

Silage Preservation--The Role of Additives (A3544)

Storage structures

Further Reading

From Harvest to Feed: Understanding Silage Management Penn State University Circular (2003)

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