Corn Silage Harvest Reminders

By:  Allan Vyhnalek

High-quality corn silage often is an economical substitute for some of the grain in finishing and in dairy rations, and it can be an important winter feed for cow-calf producers. All too often, though, silage isn't harvested at the best time for ultimate feed value.

Timing needs to be based on moisture content of the silage. Silage chopped too early and wetter than 70% moisture can run or seep and it often produces a sour, less palatable fermentation. We often get this wet silage when we rush to salvage hail or wind damaged corn. Live and green stalks, leaves, and husks almost always are more than 80% moisture, so be patient and wait until these tissues start to dry before chopping.

Normal corn though is often chopped for silage too dry, below 60% moisture. Then it's difficult to pack the silage adequately to force out air.  The silage heats, energy and protein digestibility declines, and spoilage increases. If your silage is warm or steams during winter, it probably was too dry when chopped.
Many corn hybrids are at the ideal 60%-70% moisture as corn kernels reach the one-half milkline.  This guide isn't perfect for all hybrids so check your own fields independently.

Corn kernels in silage between half milkline and black layer are more digestible.  Drier, more mature corn grain tends to pass through the animal more often without digesting unless processed.  Also, older leaves and stalks are less digestible.
Remember, chopping your silage at the proper moisture level can mean better feed and better profits.

The second management tip for Corn Silage harvest relates to storage with plastic.  Plastic is one of those things you forget how useful and valuable it can be.  You will invest time and money to store good feed for your livestock.  However, when feeding your silage you can find that the top couple foot have an off color, smells bad, or has spoiled.

Even after silage has been chopped, piled and packed correctly, it still can be damaged seriously by air and moisture slowly penetrating the outer three to four feet.  In fact, good silage can lose 15 to 20 percent of its feed value from fermentation and spoilage under normal conditions.  This loss can be cut in half, or even less, if covered well by a sheet of plastic.

Cover freshly chopped silage with black plastic immediately after you finish filling the trench, bunker, or pile.  Then cover the plastic with something to help hold it down.  Old tires often are used because they are readily available and do a good job of keeping the plastic from blowing away.  But tires only keep the plastic in direct contact with the silage directly under the tire.  In between the tires, air can circulate and cause some spoilage.  A better choice would be a solid cover, something like freshly chopped forage or weeds or maybe even a 6-inch layer of manure. Then the entire surface of silage will be fully protected.

Dr. Bruce Anderson, UNL Forage Specialist, provided most of the information used in this week’s column. 

For more information or assistance, please contact Allan Vyhnalek, Extension Educator, University of Nebraska-Lincoln, Extension in Platte County.  Phone: 402-563-4901 or e-mail

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People : Allan VyhnalekBruce Anderson