There has been some movement toward harvesting drier corn silage, due to the high cost of corn grain, says Randy Shaver, University of Wisconsin-Madison extension dairy nutritionist.

Shaver shared data about this harvesting strategy during a presentation at the 2012 Tri-State Dairy Nutrition Conference, held last month in Fort Wayne, Ind.

The data show milk and fat-corrected milk production were not significantly affected when whole-plant dry matter content stays within the range of 30 percent up to 40 percent, he said, "but if you go to much drier material, black layer and beyond, we do see a significant drop in both milk and fat-corrected milk production."

This is particularly true if you don't do a good job of processing and chopping as the maturity of the corn silage increases.

"Keep that in mind if part of your strategy is to go for a drier corn silage to try to increase starch content," Shaver said.

The data showed no significant differences on the fat and protein content of milk. There also was no real evidence to show that a delayed harvest reduces neutral detergent fiber digestibility. If anything, Shaver said, the drier silage increased NDF digestibility. However, as the kernel becomes harder, there is a significant depression in total tract starch digestibility.

Read Shaver and co-author Luiz Ferraretto's paper from the Tri-State Conference proceedings.

View Shaver's Tri-State presentation here.