Corn silage is a valuable feedstuff, being a major source of feed energy on most farms.
With high producing cattle, it’s important to get as much energy out of the crop when fed as when it was growing in the field, therefore, harvesting only lasts a few days. Meaning, there is only one chance to get it right! If not done properly, a great deal of corn silage’s valuable energy can be lost.
For example, one of the laws of physics is that energy can neither be created nor destroyed, it can only be transferred or changed from one form to another. When silage ferments, energy is lost as heat. We want it to ferment quickly so minimal heat energy is lost. Packing well eliminates oxygen and shortens the aerobic phase of fermentation, and reduces energy lost as heat. Using an inoculant, such as 8377 Kent Silage Supreme® 3X – 200, speeds up the anaerobic phase of fermentation by more quickly lowering the silage’s pH. As the pH drops, fermentation slows, lactic acid levels rise and heat loss stops. We then have a stable silage that remains preserved until it is opened up and again exposed to oxygen.
Key management practices that will help get more of the 2025’s corn crop’s nutrients into the cattle herd are:
- Harvest at optimal dry matter (DM): If it is too dry, it’s difficult to pack and eliminate the oxygen from the forage. For bunk silos, it’s optimal to have 30-35% DM or 65-70% moisture. For tower silos, it’s optimal to have 33-38% DM or 62-67% moisture.
- Chop to a Theoretical Length of Cut (TLC): If unprocessed, chop to 0.25-0.50”. If processed, chop to 0.75”. A coarse chop promotes rumen health and takes less fuel to harvest.
- Process Correctly: The goal is to make the grain starch more digestible by breaking the hard seed coat of the kernel. If done properly, a 2-lb. sample shouldn’t be more than two whole or half kernels. This should be checked frequently, even within the field. Once it’s in the silo, it’s too late!
- Pack Well: Packing layer should be no more than 6″ deep. If delivery to the silo is too fast, there isn’t enough time to properly pack. If so, additional packing tractors may need to be added. The minimum packed density at 2/3 the height of the silo should be 15 pounds/ft3. However, closer to 20 pounds /ft3 is best.
- Cover ASAP After Filling: First, cover with low-permeable-oxygen barrier plastic. This thin layer is believed to stop more oxygen because it adheres to the silage. Second, cover with 5 ml. white/black plastic. Overlap seams 5 feet. Cover the entire surface tire to tire.
- Maximum Feed Value is not reached for many months. If possible, don’t open until Christmas.
It’s always important to get as much as possible out of the corn crop. The nutrients that are in the crop when harvested should end up in front of the cows. This is even more important in a marginal or poor crop year. Yes, it’s necessary to harvest quickly, but it’s also vital to pay attention to the details of good harvest management. Every year, there is only one chance to get it right.
For information on silage safety, the ever-present dangers when working around silage storage structures and how to re-enforce good practices to reduce risks, refer to this Basics of Silage Safety video. When working around silage, it’s important to be vigilant and aware of all the potential risks and how to minimize them.