Now is the time to do corn chopper maintenance, giving you time to order new parts if needed.

“To ensure the entire chopper is in good condition, replace nicked knives and the shear bar if the edges are smooth,” Michelle Jones, with the University of Kentucky. “If the rollers are showing signs of wear, replace them.”

Rollers typically have a life span of about 60,000 tons of corn silage, she says. “Irregular wear of the roller teeth can prevent the narrowing of the roller gap, resulting in insufficient damage to the kernel which can lead to reduced starch digestibility for the cow.”

The ideal roller gap is 1 to 2 millimeters, and a quick way to check proper gapping is to use a dime. A dime is 1.2 mm thick. “Place the dime between the rollers and if excessive space is found, the tighten the roller gap,” she says.

Once in the field, you can check if processing is correct by scooping a sample of silage into a 32-ounce cup, explains Donna Amaral-Phillips, a dairy nutritionist with the University of Kentucky. Spread the sample on the ground and count the number of whole or half kernels. If you have less than two whole or half kernels per cup, processing is ideal. Two to four whole or half kernels per sample suggests processing is adequate, but more than 5 whole or half kernels means adjustments to the roller should be done.

To ensure the samples are representative, take sample from three different loads. At a bare minimum, take three samples at the end of each day.

“If the results of kernel processing are not monitored during harvest, starch digestibility may be reduced,” says Amaral-Phillips. “Once the silage is chopped and stored, fixing mistakes made during harvest is difficult.”

You can read more about chopper maintenance and adjustments here.