frequent rains, heavy dew and overcast days make curing hay difficult. By the time Mother Nature decides to cooperate with hay production, cool-season forages can be too mature and lower in quality.
Compounding this problem is that as the forage lies curing, a rain event in any season can contribute to the diminished quality of the forage by essentially washing away the water-soluble proteins and carbohydrates.
These factors increase the appeal of baleage technology. But what if the weather, or other conditions outside our locus of control, prevents us from wrapping silage in a timely manner as prescribed by research?
Dr. Wayne Coblentz, research scientist at the U.S. Dairy Forage Research Center in Marshfield, Wisconsin, conducted research to answer the question, “What happens to fermentation when silage bale wrapping is delayed by one, two or three days?”
Silage bales allow producers to store high-quality harvested forage without extended curing time in the field. Typical baleage is wrapped either in individual bale bags or long tubes that contain bales stacked in a row as one unit.
The equipment needed for baleage includes a mower and mower-conditioner, a large round baler, bale-moving equipment that prevents bag puncturing, raking equipment and a bale wrapper.
Thus, the only extra equipment most forage producers need to ensile bales is a silage wrapper, making silage bale technology particularly attractive to small producers compared to precision-chopped silage.
Another benefit of baleage is the decreased storage loss when compared to traditional hay stored outside. Losses of hay stored outside can range from 20 to 50 percent, while typical losses from baleage are less than 5 percent. Round bale silage can greatly improve the timeliness of harvest, which can in turn improve the quality of harvested forage.
When processed properly, baled silage is often higher in quality than similar hay because of reduced leaf loss in legumes, shorter curing time, reduced spontaneous heating and less weather exposure in silage.
Research at the Southwest Research and Extension Center in Hope, Arkansas, indicates that dry matter yield is doubled when cool-season annuals are harvested at the hard dough stage of maturity but decreases crude protein by 6 percent compared to harvest at the boot stage.
Wheat harvested at the boot stage and stored as round bale silage resulted in a product that was 17 percent crude protein and 60 percent total digestible nutrients. Boot-stage wheat that was allowed to cure for hay for 10 days to dry down and was rained on twice, resulted in a small loss of crude protein, down to 15 percent, but large increases in fiber, decreasing total digestible nutrients to 53 percent.
Ideally, baled silage should be wrapped within two hours of baling. The recommended moisture content for ensiling baled forage crops is 45 to 55 percent. Bales are wrapped in one mil (0.001 inch) thick plastic. A roll of plastic wrap usually covers 25 to 30 bales. Four layers of wrap are recommended with a 50 percent overlap.
During storage, periodically inspect bales for holes in the plastic and repair with polyethylene tape to exclude exposure to air and prevent spoilage.
Anaerobiosis, or an oxygen-free environment, is required to produce a well-preserved silage. Oxygen trapped in the bale at wrapping is removed through respiration of the harvested plant cells, and new oxygen is prevented from entering the environment by good bale wrapping.
Simply put, silage is a process of increasing good bacteria (lactic acid bacteria) and eliminating bad bacteria (clostridia, enterobacteria) by excluding oxygen. Plants with higher water-soluble carbohydrates (WSC) tend to make better silage.
Another factor that contributes to quality is the buffering capacity of the forage. Clostridial fermentation causes the formation of butyric acid and ammonia, both of which contribute to the bad smell associated with poor fermentation.
Clostridial fermentation can be caused by moisture over 60 percent, high contamination with dirt and manure, low WSC in the plant, high buffering capacity of some plants, high protein, excessive legumes and not wilting the forage prior to ensiling.
When silage is exposed to air, either from poor wrapping or not having the bale rolled tightly, the bales go through a heat process and the plant sugars are converted to CO2, which causes a loss in dry matter and decrease in total digestible nutrients (TDN).
Cody Askew of southwest Arkansas has been baling silage for five years. His baleage system consists of ryegrass and clover. Askew says the biggest benefit is getting the hay out of the field without having to waste time waiting for it to cure properly, thereby allowing his summer grasses to break dormancy without competing with the mature cool-season forages.
Askew feeds the baled silage free-choice to both his fall- and spring-calving cows and occasionally to his yearlings.
Askew says, “I have a lot of ground to cover and if the ryegrass and clover dry out too much, I will wrap what I can and bale the rest as a dry hay.”
Dr. John Jennings, animal science professor with University of Arkansas, proposes the additional benefits of forage testing, labeling, inventorying and storing silage bales so they can be matched with the nutrient requirements of the different stages of beef cattle production.
But what if your equipment breaks down, or you have an unavoidable delay in wrapping your baleage? In Coblentz’s delayed wrapping study, large alfalfa round bales were wrapped at four hours after baling or after delays of one, two and three days to compare the effects on fermentation and forage quality.
The internal temperatures of all bales were collected at wrapping and bales were sampled after being stored for 97 days. The internal temperature at baling was higher in all bales with delayed wrapping, but increased with longer delays. Peak temperatures during the 97-day storage period likewise increased as the wrapping delay increased.
The water-soluble carbohydrate content decreased with increasing delayed wrapping, which was related to the increased temperatures during storage. The total silage fermentation acids were higher for the bales that were wrapped immediately and these levels also declined with longer delays in wrapping.
In summary, wrapping delays did inhibit fermentation and decreased the nutritive value of the silage after the 24-hour mark, but there appears to be more forgiveness in that first 24-hour period than previously perceived.
The disadvantages to baleage include the cost of bale wrapping (upwards of $8 per bale) and the extra steps of handling the bales for wrapping at the time of baling. Additionally, the plastic used to wrap bales is susceptible to being punctured either by equipment or animals and should be examined for damage periodically during storage.
Richard Wilson, a forage grower in southeastern Oklahoma says, “The biggest problem I have with baled silage is keeping the coyotes and other predators from tearing into the plastic to get after small rodents; when you get holes, you start to get spoilage.”
Another consideration is the waste associated with baled silage, as the plastic cannot be reused and recycling isn’t a good option due to the residues of dirt and low demand for recycling the material.
Round bale silage offers forage producers another method to produce high-quality, low-maturity forage. When, however, circumstances prevent the immediate wrapping of silage bales, producers can inventory those lower-quality bales and use them to feed livestock with lower nutritional requirements.
Also, producers have about 24 hours to wrap bales in order to get good fermentation and a high-quality end product. 
Melissa Beck is a freelance writer based in Arkansas.
PHOTO 1: Ryegrass bales are ready for wrapping near Hope, Arkansas.
PHOTO 2: Baleage wrapping at the Southwest Research and Extension Center at Hope results in higher leaf retention in legumes and shorter curing time, among other benefits. Photos by Melissa Beck.
