For many northern corn silage growers, it can be challenging to determine the optimum whole plant moisture level needed for a successful harvest. Harvesting silage too dry decreases yield, causes mold to develop, lowers digestibility and reduces protein and vitamins A and E. Harvesting when the corn is too wet also reduces yield and causes souring and seepage, which can lower intake by dairy and beef cattle.
“When timing corn silage harvest, growers should consider maximizing and optimizing the amount of starch deposition in the kernels,” said Dann Bolinger, a Pioneer Dairy Specialist in Michigan. “This increases the starch content of our final feed as well as increases tonnage potential. By capitalizing on that maximum kernel maturity and putting an emphasis on healthy plants, growers better maintain fiber digestibility and moisture for packing and fermentation in the silo.”
Monitoring maturity stages, grain moisture and crop condition during the drydown period are useful tools in making the best possible harvest timing decisions. While ideal whole plant moisture for ensiling varies, proper moisture must be obtained for correct fermentation to occur and to preserve silage quality.
To help growers balance optimizing starch content while maintaining digestibility and moisture, consider the milk line or progression of the kernels. To determine the milk line, growers can break an ear of corn in half and visually see where the milk line is located on the kernel. For the best possible corn silage harvest, the milk line should be 1/3 to 1/2. It is very important for growers to spend some time walking fields, pulling whole plant samples, looking at the milk line and evaluating the maturity of the plant to maximize the feed quality and tonnage.