Haylage, also known as round bale silage, is another approach to preserving forage in eastern North Carolina. Haylage is simply forage that is baled at a higher moisture content than dry hay and then stored in a sealed plastic wrap. Because of the high moisture level and air-tight environment, the forage ferments and is preserved by acid production during fermentation. This method has certain advantages and disadvantages over other forage harvesting and preservation systems.

Advantages

Decreased curing time needed from cutting to baling, which makes weather less of a factor in forage harvesting.
Potential for more timely harvest of large quantities of forage.
Decreased need for mechanical handling and time curing to dry the forage reduces the loss of leaves, the most digestible part of the plant.
Potential for higher feed quality bale through leaf preservation and possible nitrate reduction.
Disadvantages

Increased harvest cost per bale vs. conventional cured hay.
Disposal of used plastic wrap.
More likely to spoil as compared to silage in traditional silos.
Risk of forage spoilage if integrity of wrap is not maintained. Birds and rodents can puncture plastic and holes must be covered.
Transportation of bales is limited due to cost of moving high-moisture bales.
How is Haylage Made?
The forage is cut as if for hay-making but is baled at 50 – 60 percent moisture rather than at 18 – 20 percent moisture. Baling at the proper moisture content is the single most important variable. Baling haylage with too much moisture reduces the feed quality of the forage and reduces the amount of dry matter stored per bag, greatly increasing storage cost. Baling haylage with inadequate moisture reduces fermentation and increases mold production, greatly increasing storage losses.

Storage
Successful storage depends on many factors. The storage site should be cleared of stubble and sharp objects. Some people even place an old piece of plastic on the ground before placing the bales. Rodents can chew through the plastic wrap or bag, which will greatly increase storage losses. Spray the perimeter of the stack to kill weeds that harbor rodents and insects. Do not cover the bales with an extra layer of plastic because it makes an ideal nesting site for rodents. Find a shady area, preferably on a north facing slope, to avoid temperature fluctuations that can degrade both the haylage and the plastic.

If you find holes in the bagged bales, patch them as soon as possible. Wind causes loose plastic to billow out, providing an air exchange that usually spoils most of the outer layer of the bale. Bags are rarely reusable because of minor pinholes.

Effect of Ensiling on Nitrate Level
Ensiling forage as haylage can be a management strategy for high-nitrate grass. Scientific literature suggests an average of 50 percent reduction in nitrate in ensiled forages due to the de-nitrification process.

Research conducted by Karen Spivey and North Carolina State University in 1997 on bermudagrass harvested as haylage suggested that up to a 90 percent reduction in nitrate concentration could be achieved by ensiling bales at very high moisture levels (75 – 80 percent).

Feeding Haylage
Feeding haylage is similar to feeding large round bales of hay in that conventional feeding rings can be used. With the high investment in wrapping bales, it is essential to control feeding losses. Some studies have shown up to a 50 percent loss when large round silage bales are fed to cattle without being placed in a ring feeder. This loss can be reduced to 10 – 20 percent by using a simple ring feeder. The use of an elevated hay wagon can reduce feeding losses to below 10 percent.

Haylage can be safely fed to cattle, sheep, and goats. It is not recommended for horses because of the risk of mold. If the haylage is improperly harvested or the plastic is damaged during storage, mold and mycotoxins can form in the bale. This can be toxic to horses and haylage should therefore be avoided if possible.

The problem with feeding haylage to goats or sheep lies in reducing waste, as these small ruminants can get inside a typical ring feeder. When feeding individually wrapped haylage bales to any species, it is best to feed to a sufficient number of animals so they can eat an entire bale within one or two days. If multiple bales are ensiled in a plastic tube, the tube may be opened to remove individual bales and resealed without significant spoilage for up to two weeks