By Severson, Dan
Baleage is made in round-bale and big-square hay packages so some people assume it is very similar to making dry hay. Others assume because the end product of baleage is a fermented wet silage that it is just like making haylage. According to Dr. Wayne Coblentz, from the USDA Dairy Forage Research Center in Marshfield, Wisconsin, making baleage is different in some significant ways than other forage harvesting practices and farmers need to understand those differences if they are to make better quality forage from baleage.
Coblentz spoke in August at the Michigan State University’s Ag Innovation Day in Lake City, Michigan. He highlighted the great advantages of making baleage which include: fewer weather delays, less wilting time required, reduced respiration of plant sugars resulting in better feed quality, reduced dry matter losses in the field compared to dry hay, less storage loss and oftentimes reduced feeding losses compared to hay. Also he added that baleage requires less expensive equipment and offers more flexibility for feeding than does a traditional haylage system. However, he also explained that there are some major differences that forage producers need to understand about baleage to be more successful in making it.
These differences include:
- Baleage takes longer to ferment than chopped haylage. One reason for this is that the long plant stems in baleage do not release plant sugars as quickly to fuel fermentation as shorter, chopped haylage particles.
- Baleage usually is not packed as tightly as haylage. This permits more oxygen to be trapped within the bale, allowing extended respiration that further slows fermentation.
- Baleage is usually drier than chopped silages, which inherently restricts fermentation. Normally, the production of fermentation acids increases with higher forage moisture.
For these and other reasons, baleage goes through a slower and more incomplete fermentation than most chopped silages. This slower process usually allows the forage to remain above a pH of 5.0, and shifts even more emphasis towards maintaining anaerobic (oxygen free) conditions in order to preserve the silage. Air exclusion is then the key to making stable baleage and it is accomplished by wrapping the bales in air tight plastic. This is especially important with drier baled silages (less than 40 percent moisture) that are more permeable to air and are at risk for spoilage should holes in the plastic wrap occur during storage. Baleage that is too wet (greater than 60 percent moisture) can undergo a secondary fermentation that produces butyric acid and ammonia, which can cause depressed animal feed consumption. These clostridial-type of fermentations are more likely to occur in difficult to ensile crops, such as alfalfa, that have high buffering capacity and have very limited amounts of sugar. Cool-season grasses are usually more forgiving in this respect.
To make the highest quality baleage, and to avoid the feeding of a lower quality product Coblentz recommends the following:
- Make baleage from forages that are harvested at the proper stage of maturity and are of good quality. Do not assume that baled silage techniques will magically improve poor-quality forage.
- Harvest baleage in the moisture range of 45 – 55 percent. The bales will be lighter to handle, will optimize intake and performance, and will prohibit clostridial activity during fermentation and storage.
- Make bales that are packed tightly with high density. Excluding as much air as possible from the bale is important. Maximize revolutions within the baler for each bale by slowing ground speed, maintaining appropriate engine rpm, and by baling only moderately sized windrows.
- Wrap bales with six or more layers of plastic as soon as possible after baling; significant damage may occur after 24-hour or longer delays. Consider using a lactic-acid producing inoculant from a reputable manufacturer anytime conditions are less than optimum.
The key to making high quality baleage is to make a bale within the recommended moisture range that is as dense as possible (> 10 lbs DM/ft3), and wrap it in plastic as quickly as possible. This will allow oxygen depletion to occur rapidly inside the plastic. Once oxygen depletion is complete, fermentation will occur, but because of the slow and limited fermentation within baled silages, maintaining anaerobic conditions is absolutely critical. As such, plastic should be monitored closely for damage, and patched promptly when holes or leaks are discovered.
Some farms are successfully baling very dry silages (25 – 40 percent moisture), and preserving the forage in plastic. Coblentz says these bales typically will not ferment aggressively, and preservation is largely achieved by limiting air access. However, in the absence of air, preservation can be accomplished, provided the producers are diligent about maintaining the integrity of the silage plastic. As forages become drier, there may be increased risk of internal puncturing of the plastic as these drier plant stems become more rigid. This often occurs along the junction of the flat and circumferential sides of the round bale. A small investment in additional plastic layers may be appropriate for these very dry silages.
Baleage has many advantages and continues to grow in popularity. When done right it can make high quality forage that can optimize animal performance.