High moisture or dry corn: What do the numbers say? (Dr. Michelle Windle)

By Dr. Michelle Windle, Vita Plus forage products & dairy technical service specialist
Fermentation breaks down the starch-binding proteins within the corn kernel.  As a result, high moisture corn (HMC) can feed better than dry corn due to an increase in starch availability in the rumen.

However, HMC often spoils quickly upon exposure to air, so it is best to treat HMC with L. buchneri 40788, an inoculant which can inhibit spoilage.  Although this treatment adds up-front costs, economic analysis reveals that storage of corn as HMC is usually more profitable than storage as dry corn.

Many factors were considered in this analysis.  For the production of HMC, we included the following costs:

• Corn processor
• Bagger/blower/pack tractors
• Fuel (which would cost less if storing as HMC as the corn needs to be driven to the farm, which is presumably closer than a drying/storage facility)
• Silo/bag/plastic
• Storage unit (if storing in a bunker, drive-over pile or upright silo)
• Fermentation shrink
• Treatment with L. buchneri 40788.

When in doubt, during calculations and assumptions, we erred on the side of expense for HMC.  The costs associated with storage as dry corn included fuel costs, drying charges, storage charges, grinding charges, processing shrink, and delivery charges.

Crunching the numbers
Assuming 50,000 bushels of corn were harvested in both scenarios and stored as either dry corn or HMC in a bag, storing the corn as L. buchneri-treated HMC had an advantage of $6,610 ($0.1322/bu) compared to dry corn.  If the HMC was stored in an upright silo, this advantage became $4,862, and if the corn was stored in a bunker (which would require additional labor and tractors), this advantage became $5,970.

In actuality, the advantage of storage of corn as L. buchneri-treated HMC would probably be even greater than quoted above, as this analysis assumed the best-case scenario for dry corn, and worst-case scenarios for HMC.

One assumption was that dry corn was harvested at 18 percent moisture and dried to 15 percent.  Obviously, the cost of drying would increase (resulting in an even greater advantage of storage as HMC) if the corn was harvested wetter.  For example, if corn was harvested at 25 percent moisture and stored in the same bag conditions as mentioned above, then the advantage of storage as L. buchneri-treated HMC shoots up to $20,611.

Processing and storage considerations
To maximize your investment in HMC, it is best to process (roll or grind) HMC before it goes into the storage unit.  This will improve starch availability for the microorganisms in the rumen and it will also improve the natural increase in starch digestibility that occurs with ensiling.  Treatment with L. buchneri 40788 will protect your investment by preventing spoilage; a separate economic analysis shows the advantage of treatment with L. buchneri 40788 versus untreated HMC as it significantly decreases shrink associated with storage.  For help calculating the advantage of storage as L. buchneri-treated HMC versus dry corn on your farm, contact your Vita Plus consultant or enter your own numbers in the Vita Plus Inoculant Decision Maker spreadsheet.

Other cost/savings factors
Some cost/benefit factors are difficult to measure with a spreadsheet. As herds reach higher production levels, 365-day-a-year consistency in the grain source is a priority for nutritionists, producers and ultimately the dairy cow.  For that reason, dry corn every day of the year – or a combination of dry corn and high moisture corn – is recommended by some nutritionists.  This avoids a transition between a supply of high moisture corn running out and moving to all dry corn late in the year. So when decisions are made regarding the advantages and disadvantages of various grain feeding and storage strategies, you may have to look beyond immediate economics.