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Own this year’s silage harvest

John Goeser for Progressive Dairy Published on 21 August 2019
Silage Packing

When asked for several years what I viewed as “normal” in production agriculture, the reply was often something to the effect, “Extreme volatility in dairy and beef margins (per hundredweight) is our normal.”

Yet, for a variety of factors the past few years’ margins have unfortunately appeared to stabilize in slim to negative territory for prolonged periods. We’re in a market now where we need to find health and production efficiency opportunities. Producing more milk and meat isn’t the aim, but the goal has shifted to doing so more efficiently. Alas, volatility hasn’t disappeared though, as it’s reappeared in a different aspect and one that is also outside of our control. 



The volatility previously recognized in dairy and beef futures looks to have come on strongly with the growing environment through extreme weather conditions. Turbulent weather patterns are more the norm the past few growing seasons, leaving producers and advisors to manage extreme variations in germination, plant growth, health, harvest timing and ultimately forage nutritive quality and hygiene.

There has been one consistent recommendation in this new normal of weather obstacles: Scout fields proactively. The recommendation holds true throughout the growing and harvest season, regardless of crop. For corn, scouting for plant disease during V6 to R2 stages (around silking and tasseling) and then continuing to scout as plants near half milk-layer stage and harvest for corn silage is proving critical, in addition to scouting near harvest for crop health reasons.

Scouting as harvest nears is not a novel recommendation; however, scouting objectives and checkpoints are changing for various reasons. Walking fields and checking whole-plant moisture is no longer sufficient to consistently and successfully master the corn silage crop timing because kernel maturity has disconnected from whole plant moisture (or dry matter) in some cases. While we’ve historically assumed whole-plant dry matter and kernel maturity are tightly linked, and have used whole-plant dry matter to time chopping and harvest, plant genetic and health advances (stay green) along with weather challenges have contributed to grain maturing at faster rates than whole-plant dry matter would suggest. 

With the potential for moisture and kernel maturity disconnects, both whole-plant dry matter and kernel maturity are important to scout and evaluate. Kernel maturity and whole-plant moisture is important for silage quality due to the following reasons:

1. Kernel maturity


• Tightly tied to rumen and total tract starch digestibility and total digestible nutrients (TDN) – more mature and harder kernels are harder to digest

• The goal is harvesting at half milk-layer

2. Whole-plant moisture

Related to fermentation efficiency and quality

a. Extremely wet silage (less than 30% to 32% dry matter) will leach and/or inefficiently ferment, leading to greater dry matter losses.

b. Drier silage (greater than 38% to 40% dry matter) will be more fluffy, not pack as well and will be more prone to spoilage when feeding out (yeast, mold and bacteria).


• The goal is harvesting around 35% dry matter for most storage structures. 

Start scouting cornfields around 40 days after silking date to plan for harvest. If silking dates weren’t recorded, there are a number of online growing degree day tools to help, assuming planting date and plant maturity are known.

  • Check the following link for a tool from the Midwest Regional Climate Center.
  • The InField Updates tool is another helpful (and free) option to view regional results for freshly chopped corn whole-plant moistures, fiber and starch levels. The app based reporting tool allows users to view regional chopped corn results and graphs, using a crowd-sourced information approach. This tool is akin to what many regional university extension groups offer; however, it is more broadly available to any user across the U.S. that downloads the FeedScan smartphone app. Details on the InField Updates tool are available online

Then as kernel maturity (half milk-line is the goal) and whole-plant dry matter (35% DM) come near, if your crop scouting team recognizes a kernel maturity and moisture disconnect, pick a harvest date that most closely balances achieving these two goals.

Avoid grossly missing both of these quality goals with stepped-up crop scouting and set your farm up for a consistent year of silage to follow. As always, work as a team. Consult with both your agronomist and nutritionist to add their input to the game plan for another potentially variable corn chopping season this year.  end mark

John Goeser earned a Ph.D. in animal nutrition from the University of Wisconsin – Madison where he currently serves as an adjunct professor in the dairy science department. He also directs animal nutrition, research and innovation efforts at Rock River Lab Inc. based in Watertown, Wisconsin.

PHOTO: Extremely wet silage (less than 30% to 32% dry matter) can leach and results in too much dry matter loss; drier silage (greater than 38% to 40% dry matter) doesn't pack well, also creating dry matter loss with increased oxygen exposure. Shoot for 35% dry matter at harvest to achieve optimal packing. Staff photo.

John Goeser
  • John Goeser

  • Director of Nutritional Research & Innovation
  • Rock River Laboratories
  • Email John Goeser