Arm & Hammer Animal and Food Production
corn silage

Build resilience with high quality corn silage.

Posted August 29, 2022 by Dr. Ben Saylor, Dairy Technical Services Manager

As corn silage harvest season quickly approaches, the steps you take now will determine the consistency of the corn silage you put up—and whether your corn silage quality will help or hurt your herd’s overall resilience to challenges. Read on for recommendations on best practices to keep in mind as we get into harvest season.

Stage of Maturity

One of the most influential factors affecting the fermentation and overall quality of the corn silage you produce is the stage of maturity at harvest time. Careful monitoring of plant maturity and moisture concentration prior to harvest is essential to optimize both corn silage yield and quality.

It is recommended that corn silage be harvested between 30 and 40% DM (60 and 70% moisture). When harvested below this range starch concentrations may suffer, and the risk of effluent loss and undesirable fermentations increases.

When harvested above this range silage “packability” is reduced, risk of an incomplete fermentation and acidification is increased, starch and fiber digestibility are reduced, and kernel hardness increases which could limit your ability to successfully process kernels during harvest.

Length of Cut

Another important consideration is length of cut (LOC). Corn silage LOC is known to influence both fermentation in the silo and rumen function in the cow. A shorter LOC is easier to pack, an essential component of establishing an anaerobic environment in the silo, but silage with a longer LOC contains more physically effective fiber capable of stimulating rumination.

When considering LOC, remember corn silage should be harvested at a 3/8-inch to 3/4-inch LOC. In the absence of a kernel processor, corn silage should be harvested at a shorter LOC (3/8-inch to 5/8-inch).

A shorter LOC may help if silage is being harvested at a higher (>40%) DM concentration to optimize silo packing.

Kernel Processing

Extensive kernel processing is essential for maximizing starch digestibility of corn silage. Processed kernels are also known to experience greater increases in starch digestibility with storage than whole kernels.

Remember these key factors when considering kernel processing:

  • Kernel processing should be continuously monitored throughout harvest.
  • A 32 oz. sample of fresh corn silage should contain no more than 4 half (or larger) kernels.
  • If measured by a laboratory, at least 60% of the corn silage starch should be able to pass through a 4.75 mm sieve (kernel processing score).
  • If kernel processing is found to be lacking, immediately request that processing rolls in your self-propelled forage harvester be tightened down.
  • Processor roll gap width should be set to around 1 mm for optimal kernel processing.

Silage Inoculants

Silage inoculants supplement the native microbial population on corn plants at harvest with scientifically selected lactic acid-producing bacteria (LAB). This ensures that a more efficient, reliable fermentation occurs. Inoculants containing heterofermentative LAB (like L. buchneri) have been shown to improve the shelf-life of your silage and TMR by preventing spoilage and heating. Silage inoculants are one of the best “insurance policies” you can have to protect your valuable investment.

Remember to only use silage inoculants from reputable companies that have been research-proven to improve fermentation and/or aerobic stability. In corn silage prone to spoilage, it is highly recommended to use an inoculant containing L. buchneri.

Only use silage inoculants that provide a high level of LAB to your corn silage (at least 150,000 CFU/g of forage).

Silage Pile Construction

Silage piles should be constructed in a way that is safe to work with, optimizes packing density and allows for appropriate feed-out rates.

When constructing your pile, silage should be applied in layers that do not exceed 6 inches. Individual layers should be packed thoroughly before the next layer is applied. The pile should be constructed in a way that will allow you to remove at least 6 inches of silage per day during feed-out.

To determine the appropriate tractor weight needed to achieve proper packing density, use the Rule of 800:

tractor weight - tons of silage unloaded per hour

Silage should be packed to a density of 14 – 17 lbs. of DM per ft. to create a thoroughly anaerobic environment and to optimize fermentation. Piles should not be built higher than unloading equipment can reach during feed-out.

Immediately cover the pile with plastic and oxygen barrier film when the final pack is completed. Overlap seams in plastic by 4 – 10 ft. Thoroughly cover your pile with tires or tire sidewalls to eliminate air pockets and reduce spoilage.

Help your herd’s resilience.

These best practices for harvest management are critical to the success—or lack thereof—of your corn silage crop and your herd’s resilience. Contact your ARM & HAMMER representative to learn what other steps you can take to make sure your herd is prepared for even the toughest challenges.



About Dr. Ben Saylor

Dr. Saylor has extensive experience in ruminant nutrition including his current role as a dairy technical services manager at Arm & Hammer Animal and Food Production. Dr. Saylor earned his bachelor’s degree in animal sciences from the University of Arizona, a master’s degree in ruminant nutrition from Kansas State University and a Ph.D. in ruminant nutrition from the University of Wisconsin-Madison.



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