The storage of hay and silage is very important since the goal of mechanically harvesting forage is to have a high-quality feed available for winter when pastures are not producing lush forages. Storing hay basically entails preventing deterioration of the hay which can come from mold, rot, or fungi.

Gathering Silage

Silage storage is more complicated than hay storage. Determining the type of storage system for silage should be based on the following factors: type of silage (species), herd size, available labor, capital investment, access to equipment, feeding management, and future needs. Silage is a good feed because the nutrients are kept in the fermentation process within a sealed container. However, when the silo is opened, the feed value begins to decrease, so the rate at which the silage is fed is important. The rate at which silage is fed to livestock should determine the size and type of the silo.

Horizontal silos are commonly used when a large amount of silage is used. They can be filled and emptied with conventional farm equipment and require less energy to move the forage. Tower silos allow greater mechanization during filling and removal (feedout). They have a smaller surface area exposed to the elements and therefore less spoilage than horizontal silos. 

Plastic bags can be used as a flexible storage system. Managers can use as many as is needed. Round bales (balage) offer the advantage of lower capital investment and lower labor and fuel requirements compared to other systems in which the forage is chopped. This system can be a good alternative to haymaking, when weather conditions do not allow field-wilting. The stack system has the greatest loss of dry matter during storage, which can approach 30-35% of the total forage harvested. These losses are associated with the large amount of surface area exposed to the air and also the stack cannot be packed as densely to exclude oxygen. The key factors in minimizing losses during storage are to ensile the crop at the correct dry matter and prevent infiltration of air. The horizontal silos tend to have the greatest losses of dry matter, while concrete and oxygen-limiting towers have the least. As the capacity of the silo increases, there is relatively less surface area exposed and, as a result, less loss of dry matter. (See Diagram)

The costs associated with the common silage storage systems are difficult to compare because initial investment can vary greatly among locations. However, generally, concrete bunker and bagger options provide the least expensive storage systems. It is important to note that the storage costs decline rapidly the more times the silo structure is used each year.

Forage managers interested in storing silage must be familiar with the capacities of their storage systems. Forages should be moved from the site of harvest to the silo and packed as quickly as possible. The forage mass must become anaerobic and excluding air with continuous packing speeds this process. 

Packing in horizontal silos with a wheel tractor is preferred to a "bull dozer", as the wheel tractor will compact the mass more densely. When making round bale silage, forming a tight, dense bale minimizes losses during fermentation and feedout. In addition, round bales which are tight and dense are easier to stack and more convenient to handle and store. The typical size (diameter) and weight of round bale silage harvested at 65% moisture (35% DM) are: 4 ft, 1,000 to 1,250 lbs: 5 ft, 1,500 to 2,000 lbs, and 6 ft, 2,800 to 3,500 pounds. It is desirable to move round bale silage and place in bags within 8 hours after harvest. This will insure a satisfactory fermentation throughout the bale and minimize air infiltration.

After the ensiled material has been properly packed, it is important to provide a good seal to exclude air infiltration into the silage mass. Horizontal silos (bunkers, trenches, and stacks) should be covered with plastic that is weighted down. Used tires closely placed across the surface will hold the plastic in place and prevent whipping and tearing of the material by the wind. Bagged and round bale silage bags should be inspected prior to use to insure that no holes exist. Any holes that are found should be sealed with a good adhesive tape. Occasional evaluation of the bags during the storage period is important, because rodents, birds, and other animals can puncture the plastic and allow entry of air which will result in spoiled silage. Horizontal silos can lose from 4 to 32% of their dry matter compared to covered silage.