Silage is a valuable feed and a convenient storage method for holding grain or pasture forage for months at a time. However, it’s not without its challenges and pitfalls. A well-meaning farmer can set out with all the right techniques and equipment and still end up losing an average of 20% of the fodder to spoilage during their first few attempts. Narrowing down your issues by troubleshooting your silage production process will help you bring your spoilage to as close to 0% as possible.
Labor for Covering and Uncover Bunkers
First, the majority of small to medium silage piles and bunkers are covered by hand rather than heavy equipment. Even when tractors are used for filling and compacting the pile, they’re not always the best choice for dragging the covers back and forth. Even tough, reinforced geomembranes should be handled with care or with automated roller systems. Don’t discount the labor needed, even if it’s just for operating heavy equipment or activating rollers.
Costs for Turning, Testing, and Covering
Most silage piles only need compaction and covering after they’ve been harvested. However, some high moisture fodder materials need an additional turning or two before they’re ready to cover. Turning can add a surprising amount of cost to the total silage production. Testing services need to be performed by a trained professional, either that you employ or hire as a contractor. The covers don’t just have labor costs either, but also upfront material costs as well.
Planning Volume, Planting, and Harvesting
Calculating the right amount of silage crop to plant, harvest, process, and store is never easy. Cattle producers often have unexpected good or bad luck with new calves, resulting in either too little or too much feed stored for their weaning. Losses of steers or heifers to unforeseen emergencies, or reductions in pasture availability due to flooding or drought, also interfere with estimation. Check in with the agricultural extension for your area to get recommendations on how much to store of each forage material based on your herd size.
Risks of Silage Going Bad
If silage spoils due to high moisture levels or yeast contamination, the risks are greater than just losses of valuable feed. Silage is often fed to delicate and valuable livestock while it’s contaminated with dangerous mycotoxins, bacteria, and other microorganisms. Even mildly spoiled silage interrupts the natural rumen balance and slows growth and weight gain in young cattle. Dairy cattle can lose production or develop off-flavors if fed low quality and contaminated silage. Additionally, mold growing on the surface of feed increases the risk of respiratory illnesses.
Maintaining the Right Moisture Levels and Temperature
Drying down and wilting the chopped silage before it’s packed and covered is the best way to reach the desired moisture level. Yet, water can still enter the pile if the cover is damaged or permeable from the start. Failing to use an impermeable barrier on the bottom of the silo also increases the likelihood of water rising up through the soil and causing rot where the silage and soil meet. Temperature is harder to control because many forage materials generate 20 degrees F or more in heat while fermenting, especially in stage 2. Light colored cover materials are a good choice when overheating or fires are a concern, while dark covers work better to maintain warmth in cold climates.
Controlling Oxygen Levels
Oxygen exposure is the number one cause of decomposition and nutrient loss during fermentation and storage. An impermeable cover is also the most important way to control oxygen levels over the entire lifespan of the silage pile. Yet, applying a cover quickly after harvest isn’t the only necessary step to maintain low oxygen levels. It’s also important to prevent damage to the cover and minimize exposure during testing. If you don’t maintain an even layer of weight over the cover material, gas production will lift it and eventually let oxygen enter. Make sure the weights themselves don’t have sharp or rough edges that could tear or scrape the cover and make a weak point for air intrusion.
Collapse and Injury Risks
Each year, a few dozen farmhands and silage specialists die while testing the open and exposed faces of silage piles that collapse on them. Even if someone isn’t killed by a full-sized face collapse, a small slide can still cause property damage and serious injuries. Keep piles wider rather than tall, never stacking material more than a foot high for every three feet of width. Never let anyone approach the pile on foot at any of the front faces, especially after silage removal and shaving begins. The active face is particularly prone to collapse and should be trimmed carefully to avoid injuries to workers operating heavy equipment. If a sample must be taken from the front for testing, have a tractor retrieve the material and bring it back to a safe distance.
General Quality Concerns
Even if nothing significant goes wrong during fermentation, some silage just doesn’t turn into a high-quality feed. Fiber content is often too high for good rumen health or rapid growth in corn silage, if it’s harvested close to the ground and late in the season. Nutrition is also lower for high moisture feeds that weren’t wilted and in haylage. Vitamin D levels, in general, are lower for all forms of bulk silage than hay or haylage. Feeding a mix of hay and silage from your own fields or nearby suppliers will help cover a full range of nutritional needs.
Access for Testing and Adjustments
Accessing the silage pile for testing its temperature, oxygen level, fermentation stage, and pH level isn’t just a safety risk once the pile is open. It’s also difficult to accomplish while the pile is still tightly covered and sensitive to oxygen exposure. Some farmers deal with this issue by avoiding testing until the last two stages of silage processing. Others install small ports in the cover material that seal tightly after each sample is taken. If the cover is installed with the right weighting system, it’s possible to lift back all of the sides to take samples from different parts of the pile without disturbing it.
Finally, the sheer size of many silage piles makes them difficult to manage. Tasks that are easier to achieve by hand due to the delicate nature of taking a sample or spreading a cover material often require heavy machinery for large bunkers. Yet, trying to generate large amounts of silage in multiple, small piles also multiples the amount of labor needed from your farmhands. Large scale silage piles can be safer than smaller ones by reducing the need for human interaction, but only if they’re designed to restrict collapse.
These challenges aren’t insurmountable when you’re dedicated to finding solutions. Silage is worth the effort of identifying issues and addressing them with a few upgrades to your system. New, impermeable, geomembrane covers are always a good way to improve the quality of the finished silage.