Corn Silage

As Wisconsin's number one field crop, corn is a major source of protein and fiber feed for our cows.

Corn is Wisconsin’s (and America’s) number one field crop. According to the United States Department of Agriculture, about 80 million acres of land in the U.S. are planted with corn, and the majority comes from the Midwest.

Did you know there are two ways to harvest corn? Most people know about harvesting corn for the kernel. Farmers use these kernels in grain mixes to feed to their cattle. But how many of you know about corn silage?

What’s corn silage? Corn silage is when a farmer takes the corn and its stalk and ferments it as a high-moisture feed. It is a popular forage for cows because it is high in energy and easily digested.

During the 2010 growing season, the plentiful rain and sunshine-nurtured corn crops, helping the corn grow and mature quickly. Consequently, Wisconsin farmers enjoyed a relatively early corn silage harvest that year.

It takes a lot to ensure an efficient and safe corn silage harvest. First, farmers check the condition of their equipment before they head to the fields. Also, they sharpen knives on choppers and set knives to chop corn at the correct particle size (chop length impacts corn silage palatability and cow health).

As harvest draws near, farmers and crop consultants also carefully evaluate if the corn is ready for harvest, checking the corn plant’s moisture content.

When the corn crop is ready to harvest, farmers use a forage chopper to cut stalks at a consistent, predetermined height (about one foot). They chop the entire corn plant (stalk, cob, husk and kernels). Then they place the contents in a wagon or truck so it can be delivered to a silo, which comes in a variety of styles, shapes and sizes (see Dairy Feed Storage article).

Some farmers use mechanical processing of whole-plant corn to improve silage quality. Whole-plant processing crushes the entire plant through rollers; this can be done in the field during harvest or at the silo. Or, it can be done after ensiling (which is the process of preserving green food for livestock in an undried condition in airtight conditions, either in a storage silo or in plastic wrapping) and just prior to feeding. Processing corn improves starch and fiber digestion in the cow.

During harvest, many farmers take representative corn silage samples to have its nutrient content analyzed. This information gets used to properly balance cow rations (cow meals) to ensure good cow health and maximize milk production.

Crop harvest often requires long work hours, with some tasks being extremely physical and some being very repetitive. Thus, it’s important for those involved in the process to do their best and follow safety guidelines. Farmers also need help from you during harvest–if you see large farm equipment traveling on a road, please use extreme caution when passing and/or sharing the road.