As you gear up to harvest corn for silage this fall, consider these tips from the experts at Pioneer Hi-Bred. Given the high price of feed and other inputs, it becomes increasingly important to use harvest and storage methods that optimize corn silage value.

  • More intensive management of corn silage harvest moisture can increase energy value and enhance profitability.
  • Pioneer Hi-Bred researcher Dr. Fred Owens has analyzed thousands of silage analyses from Pioneer and the University of Wisconsin. Dr. Owens quantified changes in quality as corn matures from 30 percent to 40 percent dry matter. The data reveals that, on average, a hybrid adds about 0.6 percentage points of starch per each additional point of DM.
  • Simultaneously, for each additional point of DM, corn loses less than 0.3 points of neutral detergent fiber (NDF), on average. Although NDF is important, the detrimental loss in digestibility is quite small relative to the beneficial gain in starch.
  • The degree of quality changes can vary depending upon the specific hybrid and overall plant health, but the general trend is clear. When plants are healthy, there is economic advantage to permitting corn silage percent DM to reach higher levels within the 30 to 40 percent DM range. For example, harvesting a typical corn crop at 35 percent DM instead of 30 percent DM could result in a nutritional analysis of 36.0 percent starch instead of 33.5 percent. In this same example, NDF may have only decreased from 59.0 to 57.5 percent. Since starch is also a major contributor to yield, harvestable tons would also be expected to increase with this modest delay in harvest.
  • Pioneer reminds producers to take caution when harvesting corn silage at higher DM levels. As whole-corn-plant DM approaches 40 percent DM, moisture may become limiting for adequate compaction and bacterial activity to support a desirable fermentation. Avoid permitting corn silage to exceed 37 percent DM.
  • High-starch hybrids add value to corn silage. Even a 1 percent increase in starch content can have a significant impact on improving your bottom line. Example: It would take 151 pounds per acre of corn grain to make up the difference between two hybrids (say 30 vs. 31 percent). Assuming 25 tons per acre and $4 per bushel corn grain, that equals $10.75 per acre.
  • Finally, Pioneer specialists say delaying feeding of corn silage until it has been in storage.
  • Intensive management of kernel processing during harvest is essential. Having adequately processed corn silage has been proven to reduce feeds costs and improve milk production. Yet, a summary of 446 research trials shows that that up to 29 percent of corn silage is under-processed.
  • All choppers should be able to do a good job of processing if managed correctly. Guidelines include:

1. Check roller mill wear; reset or replace as needed. Adjust teeth aggressiveness accordingly (# teeth/inch).

2. Check roller mill differential – typically prefer between 20 to 30 percent differential (in speed).

3. Set roller mill gap at 1 to 3 mm. Start at 3 mm and reduce as needed to get adequate kernel damage.

4. Dairy producers should target 19 mm (3/4”) as the longest TLC (theoretical length of cut). Anything more will compromise processor life, harvester capacity, silage compaction and fiber sorting.

5. If additional kernel damage is needed and you can afford to give up NDF, consider setting TLC at 17 mm. Attempt this only after optimizing roll clearance and differential speed. Important: make sure your nutritionist agrees that the shorter TLC will work well in your ration, as too little NDF in the ration can be very detrimental.

Throughout harvest, work together with your chopping operator to make sure an adequate job of processing is being done. Taking the time to do this during harvest has the potential to pay dividends all year long.

Have both a successful and safe harvest! Corn silage harvest generally goes at a fast pace and involves many people. Make sure all understand what will be happening and when, and what is expected of everyone. Especially, review how everyone can work together effectively to ensure a successful and safe harvest!