Corn Silage

Originally written February 1, 2006 | Last updated February 03, 2014

Backgroundestamp" endspan i-checksum="37950" -->


  • 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)

Silage2.gif (17724 bytes)

Hybrid Selection

Silage1.gif (13682 bytes) Silage7.gif (18737 bytes) Silage8.gif (18740 bytes) Silage9.gif (25939 bytes) Silage10.gif (12975 bytes) wpeB.gif (9750 bytes)

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

wpe9.jpg (111386 bytes) bmrCorn.jpg (40458 bytes)

Bt versus Conventional hybrids 

Management Guidelines for Corn Silage

 wpe1.gif (11975 bytes) 

Silage yield and quality changes during corn growth and development

Silage18.gif (14037 bytes)

Planting date response

Silage16.gif (13501 bytes)

Plant density response

Silage17.gif (10900 bytes) Silage19.gif (11566 bytes) Silage20.gif (12090 bytes)

Row spacing response

CornSilageChopper.jpg (131431 bytes) Silage21.gif (15506 bytes)

Cutting height response

wpe3.gif (13643 bytes)

When to Harvest

Harvest timing depends upon storage structure

Silage15.gif (15290 bytes)

Environment drydown rate average = 0.5% per day

wpe2F.gif (14702 bytes)

Kernel milkline: use as a guide

ISU48R5EarCrossSection.gif (108098 bytes) ISU48R5StarchLineDevelopment.gif (84825 bytes) Silage13.gif (26581 bytes)  

Predicting corn silage harvest date

wpe5.gif (10205 bytes) wpe7.gif (16003 bytes)

  • 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)

University of Wisconsin, 1575 Linden Drive - Agronomy, Madison WI  53706    (608) 262-1390
If you would like to subscribe (or unsubscribe) to updates during the growing season, click here.
For a list of website updates, click here. Send comments about this website to Joe Lauer.
©  1994-2014 Board of Regents of the University of Wisconsin, Division of Cooperative Extension of UWEX.