The main advantage to kernel-processed corn silage is improved starch utilization and, therefore, improved milk production.
Corn harvested for silage at greater than 32 percent dry matter (DM) is a good candidate for using a kernel processor or shredder processor at harvest. A processor simply helps break the kernels into pieces prior to ensiling.
To achieve production benefits, producers should pay close attention to their particle size. After analyzing more than 1,000 forage samples, Cornell University found only 7 percent were optimally processed.1
Kernel-processed corn should be chopped at 0.75 inches (19 mm) theoretical length of cut (TLC). In addition, the roll clearance should usually be set at 2 to 3 mm. The specific clearance depends on both the equipment and the maturity and variety of the crop. Increasingly, some producers and custom operators are setting their roll clearance to 1 to 2 mm to improve kernel processing scores (KPS), especially with hard kernel varieties and/or plant at higher DM levels.
Processor maintenance is critical since worn rolls can result in many unbroken kernels. If the corn is properly processed, all the kernels should be broken, nicked or damaged, and there should be no cob fragments larger than 0.25 inches. One general rule of thumb is that in a quart of kernel-processed corn silage, there should be no more than one whole or two half kernels.
1 Ishler VA. Corn Silage Kernel Processing, Fact or Fiction? PennState Extension. March 15, 2017. Accessed June 22, 2017. Available at http://extension.psu.edu/animals/dairy/news/2017/CS%20processing%20score.