Answer provided by Mike Hutjens extension dairy specialist at the University of Illinois at Urbana-Champaign.
Q: If the corn crop does not mature, what alternatives are possible?
A: For dairy producers, corn silage is an excellent alternative for immature corn due to delaying spring plant due to rain and cool summer temperatures.
Allow the corn crop to grow and mature until a killing frost has occurred. Depending on ear fill, the quality and quantity of the corn silage will vary. A key point is to harvest at 30 to 35 percent (bunker or bag storage) or 33 to 37 percent (tower silos) dry matter to achieve optimal fermentation and minimize seepage). If the corn plant is too wet to harvest, wait for a killing frost to allow the plant moisture content to drop to 65 to 70 percent water (which may require three to seven days).
Adding an inoculant can improve forage quality, dry matter recovery, and fermentation profile.
If the dairy producer is purchasing the immature corn as silage, be sure to adjust for moisture content (do not buy water) and quality (based on the level of starch and neutral detergent fiber or NDF content).
Nitrate levels may increase in the frost-damaged plants, but ensiling and fermenting the corn silage will reduce nitrate levels 50 percent or more (below 4,500 parts per million or ppm). If nitrate content is a concern, test the silage after ensiling. Do not pasture immature corn after a killing frost, as animals may consume new re-growth high in nitrate risk. Green-chopping frosted corn can increase nitrate-toxicity risks.
High-moisture corn grain is another alternative if the corn grain is too wet and expensive to dry.
- Harvest high moisture shelled corn can be harvested at 26 to 30 percent dry matter.
- High moisture ear corn can harvested at 28 to 34 percent moisture.
- Snaplage (ear, husk, and some plant material) can be harvested at 35 to 40 percent moisture.
Adding an inoculant is recommended when storing high-moisture grain. If wet corn storage is in upright storage units, select the lower-moisture level. Bunkers or bags should be near the higher-moisture range.