What You Should be Thinking About When Beginning to Chop Corn Silage

Back to school, state fair and corn silage harvest. This is a busy time of year and there are many things consuming our thoughts; however, there are a few key items that we should be thinking about to make sure the corn silage we harvest today will yield high quality feed for the year to come.


Maturity. There is probably no bigger question than when to start chopping and, assuming weather cooperates, the optimal time is dependent on plant maturity. Generally speaking the energy content of a corn plant increases up to about 2/3 milkline, and beyond this point, we see decreased stover (fiber) digestibility and kernels (starch) that are resistant to digestion. Research from University of Wisconsin has shown that the digestibility of fiber is highest when whole plant dry matter ranges from 35 – 40 % DM, which is the optimal range to have corn silage


Kernel processing. Kernel processing usually increases starch digestibility, and this effect is likely greatest in mature corn plants. Recommendations from University of Wisconsin suggest that producers should target 0.75 inch theoretical length of cut (TLC) with an initial processor roll clearance of 0.12 inches; however, producers should inspect chopped material and make sure that kernel breakage is adequate and potentially make necessary adjustments. In general the kernel should be well damaged not simply “scuffed” or “nicked.”  If there is plugging at the processor rolls the TLC should be reduced.


Take measures now to control losses later.  Dr. Keith Bolson, Professor Emeritus of Kansas State University, notes that proper packing and sealing has the potential to decrease dry matter losses by 5 – 10 %. He recommends that the proper silage density is 15 – 16 lbs per ft3 (44 – 48 lbs fresh weight bulk density ft3).


Safety. When the frenzy of chopping begins is critically important that saftey remains a priority. Dr. Bolsen outlines several precaustions that must be taken when harvesting corn silage.

  • Use tractors with roll-over protection structures (ROPS) and seatbelts.
  • Use low-clearance, wide front end tractors equipped with well-lugged tires with added front and back weights.
  • Never fill higher than the sidewall.
  • Use lights if filling the silage structures at night.
  • Form a  progressive  wedge  of  forage when filling bunkers or piles this provides a slope for packing, and a 1 to 3 slope, or shallower.
  • Backing up a slope can prevent rollbacks on steep slopes.
  • If using dump trucks make sure they are on a stable surface s and remember they are less stable when the bed is raised.