Making Fermented Forages

For proper fermentation to occur, several processes must take place. Initially, forage should be removed from exposure to oxygen. Secondly, bacteria must convert plant sugars into organic acids, lowering the pH to a point of forage stability. Always consider the fact that when forage is heating, energy value is being depleted. Additionally, heating does not only occur in the silo, but it also can be observed during filling and feedout. The faster the forage is ensiled, the less loss due to heating. Multiple factors effect forage fermentation:

  • Maturity at Harvest
  • Sugar Content
  • Moisture of Crop
  • Length of Chop
  • Filling Rate
  • Packing Density
  • Bacterial Inoculant
  • Cover
  • Feed Out Rate

Haylage Baleage in a Day Makes More Milk

Practicing wide swath management can decrease moisture levels fast enough to make hay in a day. The benefit of this practice is silage that contains more NSC (sugar and starch), which makes additional milk per ton of feed. Freshly cut forage exposed to sun continues to make sugar (photosynthesis) until the plant is wilted to 60% moisture. The faster this crop is dried to this point and harvested, the less sugar and starch is lost in the field due to respiration (cells using energy). Wide swathing increases surface area of forage exposed to sun and allows the stomata (pores in the leaves) to stay open for faster drying and increased sugar production, resulting in forage that produces more milk or meat.

Basic Principles:

  • Swath must be at least 80% of cutting width
  • Leaving 3 to 4 inches of stubble allows air to flow through swath better
  • Best cutting time is between late evening and late morning
  • Crop must be raked or merged before it is too dry
  • Harvest at the appropriate moisture levels

Specific Storage Methods:


Baleage must be harvested as the crop reaches 50% moisture (40 – 60% acceptable). Bales must be made as tight as possible and they must be wrapped immediately. Plenty of plastic must be used during wrapping, with consideration to fact that tears and rips may occur during handling. Any damage that penetrates the plastic wrap must be repaired with plastic tape, as any exposure to air will increase forage spoilage in the bag.

Top Unloading Silo

In this type of system, forage must be stored at the highest moisture possible without causing seepage. Typically, around 65% moisture is appropriate. Matching the size of the silo with the feeding requirement also becomes important when you are trying to feed out faster than heating occurs. If you struggle with with heating, consider utilizing a buchneri based inoculant (AgMaster LB) that is specifically designed to reduce heating and extend bunk life.


While bunkers can be very effective for storing a high volume of feed, losses can be significant. Proper sizing, adequate packing and face management of bunkers are critical. A goal of 40 to 50 lbs of wet weight per cubic foot is ideal. Covering with a tough plastic material and weight is also critical. Ideal corn silage moisture at point of storage is 70%, for best milk production. For haylage, 60 to 65% moisture is ideal. As in the silo, if heating is a foreseen issue or becomes an issue, consider utilizing a buchneri based inoculant (AgMaster LB)

Ag Bags

Ag bags offer an alternative to a bunker that produces similar results. For silage and haylage a packing machine is needed to fill a bag with forage. These bags are then placed on a workable surface (concrete slab), and all damage (rips and tears) must be repaired immediately. Moisture levels for storing in ag bags should be similar to bunkers. Proper sizing and face management should also be considered to prevent heating and value loss.