Successful high moisture corn harvest and storage – Jon Urness, Vita Plus

Posted on September 23, 2016 in Forage Foundations
By Jon Urness, Vita Plus national forage specialist
Dairy producers have successfully harvested, stored, and fed high moisture corn (HMC) for years, but problems can occur for the best producers.  Even with relatively low corn prices, HMC is still worth more than $100 per ton.  For the sake of cash flow, high production, and animal health, it pays huge dividends to get things done right, and it starts with harvesting at the correct moisture.
Low moisture = poor fermentation
Moisture is essential for fermentation.   Dry corn is stored at 15-percent moisture or less.  At that moisture level, the chances of yeast growth are greatly reduced, but fermentation won’t occur at such low moisture levels.
What moisture levels are reasonable to expect fermentation in a silo, bunker or bag?  Can we call corn stored at 20- or 25-percent moisture HMC?  Those numbers are on the lower end of the spectrum, and success often depends on the degree of processing and the integrity of the storage unit.  In a well-maintained, oxygen-limiting unit with a bottom unloader, this moisture range may be acceptable, but this is still a little on the dry side and too dry for bunkers, piles, or bags.  The University of Wisconsin Extension Team Grains offers these guidelines for target moisture content levels of HMC for different storage structures:
How about snaplage or earlage?
Additional challenges can come with snaplage.  Adding coarse material, like cob, husk and stover, increases porosity of the snaplage and makes it more difficult to achieve the proper packing density for fermentation and storage.  Moisture levels between 36 and 42 percent are optimal for snaplage.  To maintain adequate particle length and starch digestibility, set your chopper length between 0.25 and 0.375 inches, a processing roll gap of 1 to 2 mm, and a processing roll speed differential close to 40 percent.  Learn more about snaplage with this Vita Plus technical bulletin.
When aerobic stability is a concern
Whether the HMC is ground shell corn, ear corn or snaplage, it is a high-value, concentrated feed subject to aerobic stability challenges.  Minimum feedout rates from bunkers, bags and top unloading silos are often compromised.  Treatment with a preservative or inoculant can enhance aerobic stability. Propionic acid can also be effective, but it can get expensive when applied at the recommended rates.  For example, the UW-Extension recommends applying 15 to 20 pounds of propionic acid per ton of 25-percent moisture corn stored for 12 months.  That’s $12 to $16 per ton.  Crop-N-Rich Buchneri, applied at 3 grams per ton, has proven to be an effective and economic strategy to improve aerobic stability at a cost of $1.90 per ton, but proper moisture levels remain essential.  If you can’t achieve at least 25-percent moisture, your chances of success are greatly diminished and you may want to look at drying this corn.
Cost advantage goes to HMC
In the September 2014 Forage Foundations, Dr. Michelle Windle calculated all costs involved to either dry and store corn or harvest at high moisture and treat with Crop-N-Rich Buchneri.  The result: storing the corn as Crop-N-Rich Buchneri-treated HMC had a 13.2-cents-per-bushel advantage compared to dry corn.

Category: Feed quality and nutrition
Forage Foundations
Forage harvesting
Forage storage and management