Silage

Good Silage Equals Good Grain

(but good grain doesn’t always equal good silage)

Selecting the appropriate hybrids for corn silage means achieving the proper balance between yield, defensive traits and nutritional traits. However, agronomic traits such as drought tolerance, disease and insect resistance, and herbicide options must come first because they influence both yield and quality.

“A good grain hybrid likely will be a good silage hybrid if it delivers adequate tonnage and acceptable fiber digestibility,” says Bill Mahanna, Ph.D., Pioneer nutritional sciences manager. “But not all grain hybrids make good silage hybrids. Differences do exist among commercial silage corn hybrids for digestibility and neutral deterrent fiber (NDF) digestibility.”

Silage hybrids should have high forage yields, high digestibility, low fiber levels and highly digestible stover, Mahanna says. The best silage hybrids have high grain yields because grain is so highly digestible and account for almost 65 percent of the energy in corn silage.

The rankings for top-yielding hybrids used for silage may vary, however, based on difference in fiber digestibility and grain-to-stover ration,” Mahanna notes.

Joe Lauer, Ph.D., University of Wisconsin corn agronomist, suggests growers should begin corn silage hybrid selection by first identifying a group of hybrids adapted to the growing environment, along with standability, disease resistance and drought tolerance needs unique to the grower’s conditions. Then evaluate this group of agronomically adapted hybrids for silage yield performance.

Many studies show grain yield is a good general indicator of whole-plant yield; that is, high grain-yielding hybrids tend to have high silage yield,” Lauer says. “However, within the high grain-yielding group there can be differences in whole-plant yield and fiber digestibility.” This reinforces the need to have silage data available on these hybrids.

The final consideration for hybrid evaluation, “Lauer says, “should be quality.”

Evaluating silage data

Mahanna suggests using an analytical approach to selecting your silage hybrids. “Work with your nutritionist to define which traits are important to your operation,” he suggest. “Then work with seed companies that can deliver the information needed on agronomics, silage tonnage, neutral detergent fiber digestibility, starch, milk per ton and milk per acre.”

Given the genetic variation in silage traits, Mahanna suggests scoring the hybrids that meet those trait and maturity needs using the following 100-point system.

• 60 to 70 points on silage yield: Yield is a reliably measured trait. There can be 7-to 10-ton per acre variation among hybrids.
• 20 to 25 points on starch content: Percent starch is easily measured, and there can be considerable variation between hybrids.
• 15 to 20 points on fiber digestibility: The lower weighting on fiber digestibility is because growing conditions affect this trait much more than genetics.

Hybrids