What do we do with low-moisture corn silage?

Posted on February 20, 2017 in Dairy Performance
By Dr. Darin Bremmer
We knew fields were wetter than normal heading into fall harvest, but we didn’t expect the season’s heavy rains.

Corn also matured quicker this year, resulting in drier-than-normal corn silage.  It dried even more as farmers waited out the rain to get back in the field.  To properly harvest and feed this dry corn silage, it came down to adjusting the basics, including kernel processing, chopping height, packing, and good fermentation.

Kernel processing
Kernel processing has improved in recent years, allowing corn to mature longer and improve corn silage starch quality.  As this year’s crop had plenty of time to mature, we had to monitor kernel processing closely throughout harvest.  When processing dry corn silage, it is best to shorten the length of cut to ensure good kernel processing.

Chopping height
Raising the chopping height also helped this year.  Chopping at heights between 12 to 20 inches helped compensate for the decline in fiber digestibility associated with harvesting corn at a later stage of maturity.

This resulted in a 5-percent increase in the amount of fiber digestibility and starch because the lowest portion of the stalk contains the least-digestible fiber.

Pack, pack, pack!
Packing is emphasized every year, but it was especially important this year because drier corn silage is harder to pack and squeeze out the air.

During ideal chopping conditions, pack tractors can become overwhelmed with too much silage at a time.  With the rain this year, that was not a big issue.  While trucks and wagons had to wait to get out into the fields, packing tractors had plenty of time to push and pack properly.

Although research has not proven it, I believe a Shredlage®-type material could pack easier because of the vertical shredding versus conventional, horizontal cutting.  While conventionally cut silage will return to its original shape after compression, a shredded stalk does not have as much ability to expand after compression, which reduces oxygen levels.

Keep fermentation in mind
For fermentation to occur, it is critical to remove as much oxygen as possible.  This can be accomplished with good packing.

Once all oxygen is removed, lactic acid-producing bacteria become active to reduce pH and preserve the silage.  This can’t be accomplished without moisture.  Although it is more critical with dry corn silage, we recommend adding a reputable lactic acid-producing inoculant each year to reduce spoilage risk as much as possible and give the best opportunity for stable silage.

How will it feed?
The answer depends on how well you accomplished the previous points.  It is important to watch manure starch levels and molds, yeasts, and mycotoxins in this year’s corn silage.  High manure starch levels could indicate poor kernel processing and lead to digestive upsets.  The longer the crop stood in the field, the more opportunity yeasts and molds had to grow, which can also lead to negative impacts on cow health.

It is important to take off enough of the face of all storage units.  Dry corn silage could have stability issues due to yeasts and molds if too little is removed from the face.  It will help if you don’t remove excess plastic at the face and keep a sand bag or row of tires on the edge to prevent oxygen from getting under the plastic.

Lastly, stay safe. With the difficulty to pack dry corn silage this year, chances are greater for a collapse.

Contact your Vita Plus consultant if you have questions about this year’s crop.

This article was originally written for the January 10, 2017 issue of Hoard’s Dairyman.  A full version of the article can be found in the magazine.

About the author:  Dr. Darin Bremmer grew up on a farm in Shannon, Illinois. Af­ter high school, he attended the University of Wisconsin-Platteville and received a bachelor’s degree in animal science in 1993. From 1993 to 1995, he attended the University of Illinois and received a master’s in animal science with an em­phasis in ruminant nutrition. Bremmer then completed a Ph.D. in nutritional sciences with an emphasis in animal nutrition and a minor in dairy science from UW-Madison in De­cember 1999. In Dr. Grummer’s labora­tory at UW-Madison, Bremmer’s research focused on transition cows, studying ketosis and fatty liver. After completing his Ph.D., Bremmer worked for a major feed company as a dairy nutritionist and technical services manager in Wisconsin. In March 2003, he joined Vita Plus as part of the dairy nutrition and technical services team based in central Wisconsin.

Category: Dairy Performance
Feed quality and nutrition
Forage storage and management