In a race against weather, baleage gets the nod over dry hay.
Baleage combines baling with ensiling. Forage is baled at high moisture content and wrapped in plastic. Baleage offers the rewards of producing a high quality, highly palatable forage under weather conditions not conducive to dry hay production.
There are trade-offs comparing baleage to dry hay. Without a recycling system in place, disposal of the plastic used to wrap bales is a concern or at least a nuisance issue for most farms using baleage.
A University of Kentucky baleage survey found that the major barrier preventing producers from adopting baleage were the risks of botulism or listeriosis. When those organisms are present in baleage and fed unknowingly, livestock illness and death can result.
Management is key
The key to maximizing the rewards and avoiding the risks of botulism and listeriosis in a baleage production system is management. Attention to details is important. Specifically, producers need to focus on plant maturity at harvest, moisture content at baling, bale density, the time interval between baling and wrapping with plastic and the number of layers of plastic used to wrap the bale.
Risks associated with feeding suspect baleage can be reduced by using a fermentation analysis to guide feeding decisions. Properly ensiled forages, like baleage, are well accepted by livestock and have good palatability.
However, forage quality cannot be improved through fermentation. Forage quality, as defined by the percentage of protein, energy, minerals and fiber, is determined by the maturity stage at which the forage is mowed/harvested. Match forage maturity stage to livestock nutrient needs and plan the harvest accordingly.
The single most important factor that determines baleage quality is moisture content of the forage at baling. Baleage research at numerous land grant universities, including University of Wisconsin, Penn State and the University of Kentucky, has demonstrated that baleage quality is consistently best when forage is baled at 45-60% moisture. A moisture content of 50% is ideal.
Moisture contents above 65% have increased risk of the baleage undergoing clostridial fermentation. Clostridial fermentation is associated with the risk of botulism.
Moisture levels below 45% typically do not allow a complete fermentation and the risk of molds is increased. Although forage moisture is a critical component of producing high quality baleage, most producers use guesswork and estimation to determine the time of baling.
There are tools available to help make a more accurate determination of forage moisture. A recent edition of the Buckeye Dairy News had a good article on forage moisture determination. It is available online at go.osu.edu/determineforagemoisture.
In addition to moisture content, good forage fermentation is dependent upon eliminating air. Eliminating air minimizes the loss of plant sugars due to plant respiration and allows plant sugars to be converted to lactic and acetic acid by microbes that work in an anerobic environment.
The rapid production of lactic acid drives the forage pH down, inactivating and preventing harmful molds, yeasts and bacteria from becoming established.
In baleage production, it is essential to produce dense, tightly packed bales. Work at Penn State demonstrated that as bale density increased, baleage pH dropped. The goal in baleage is a pH below 5.0.
After baling, the next step is to wrap the bales in plastic. Both timing and the amount of plastic used to wrap bales is important. The goal is to reduce heating caused by plant respiration and get the bale into an anerobic condition as soon as possible.
Research at the University of Wisconsin showed that bales wrapped 24 or more hours after baling reached temperatures of 120 degrees or higher. At these temperatures, a portion of the protein is tied up due to the Maillard (caramelization) reaction.
Wrapping bales within 4-12 hours, or sooner, after baling with six or more layers of one mil plastic results in minimal bale heating and provides a favorable anerobic environment for the rapid conversion of plant sugars to lactic acid.
The baleage research project at the University of Kentucky identified red flags that indicate an increased risk of poor quality baleage that could show up in terms of decreased palatability, reduced bunk life and/or increased probability of a clostridial toxin (botulism) or a listeriosis organism.
High quality baleage routinely shows the following characteristics: a pH of 5.0 or lower, a lactic acid concentration of 3% or higher, a butyric acid content of 0.1% or less, an ash content of less than 11%, and the percent of total nitrogen as ammonia at 15% or less. A fermentation analysis provides this information.
Rancid or ammonia smelling baleage, forage baled at moisture content of greater than 68%, and/or baleage harvested from forage with soil on stems/leaves is suspect. Consider a fermentation analysis in these situations.
Risk management in baleage production involves understanding those factors that drive a good fermentation process. Attention to those details will result in a high-quality forage.
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