The following information is a Web Extra from the pages of Farm Journal. It corresponds with the article "Test Cornstalks Twice." You can find the article in Farm Journal's November 2012 issue.
Sampling cornstalk bales is similar sampling hay bales, but forage probes should be sized appropriately for corn stalks, says Justin Sexten, University of Missouri Extension beef specialist.
With the brittleness of stalks and husks, he advises cattle producers to use a larger probe, ½" to ¾" wide, and one that is very sharp to cut through the corn. To prevent stalks or husks from sliding off the probe, cut at slower speeds than for hay bales.
There are lots of nutrient variability in cornstalk bales, says Rick Rasby, University of Nebraska-Lincoln Extension beef specialist. "Of any residue, cornstalks have the greatest potential as feed for cow-calf operations."
"Test for moisture, protein and energy in the form of total digestible nutrients (TDN), and test for nitrates and alfatoxins. Normally, nitrates not a major concern, but in extreme drought years, its best to test," Rasby says.
With high feed costs, farmers may think about grinding corn stalks to utilize the whole plant. "At that point, you’re not going to let cows select," Rasby says. "The smaller the screen you grind through, the less that the cows will sort—I suggest a 3" to 5" screen. When you are feeding the entire residue, a nutrient analysis as well as a nitrate test is really important."
Watch an video form University of Nebraska-Lincoln Extension featuring Rick Rasby, explaining how to sample corn stalk bales: