The 2012 growing season has been anything but typical. Despite variable crop conditions, farmers should still harvest corn silage based on whole-plant dry matter.
Whole-plant dry matter is the best predictor of when to harvest, not kernel milk line. Ideally, corn silage should be harvested between 60 to 68 percent moisture (32 to 40 percent dry matter).
Digestibility of neutral detergent fiber (NDF) and starch are more closely linked with whole-plant moisture than with kernel milk line. Whole-plant dry matter between 30 to 35 percent indicates the digestibility of NDF and starch is optimal. It is important to harvest when NDF digestibility is high because a 1 percentage unit increase in NDF digestibility is associated with an increase of 0.55 pounds of 4 percent fat-corrected milk... more here.