Proper hay storage is fundamental for preserving the investment made in harvesting forage. The primary goal is to minimize dry matter loss and maintain the hay’s nutritional profile until it is fed to livestock. Unmanaged hay experiences significant quality degradation and spoilage, leading to economic losses. Understanding the best storage techniques ensures the feed maintains its quality for the long term.
Ensuring Hay is Ready for Storage
The most significant factor determining successful storage is the hay’s moisture content at baling. High moisture levels create an ideal environment for microbial activity, which causes spoilage and, in severe cases, fire. For small square bales, moisture content should be kept at or below 20% for safe storage. Denser large round or square bales require lower levels, ideally between 12% and 16%.
When moisture levels climb above this threshold, bacteria and fungi metabolize plant sugars, releasing heat. This heat leads to rapid quality decline as the hay molds, resulting in loss of palatability and digestible nutrients. Producers often use an electronic probe meter, inserted into the bale, to accurately assess moisture content. A simpler, tactile method involves the “feel test,” where damp hay feels cool to the touch or shows visible condensation. This assessment is a prerequisite before moving any bale into storage.
Indoor vs. Outdoor Storage Options
Storing hay indoors, such as in a covered barn or shed, offers the highest protection and the lowest dry matter loss, often less than 5%. Even covered storage requires attention to prevent moisture wicking from the ground or concrete floor. Bales must be elevated off the floor using wooden pallets, discarded tires, or a layer of crushed rock to allow air circulation and eliminate ground contact.
For storage structures with dirt or concrete floors, installing a vapor barrier, such as heavy-gauge plastic sheeting (e.g., 6 mil polyethylene), underneath the bottom layer prevents moisture from rising. When hay must be stored outside, losses up to 30% can be expected without protection, but these are reduced substantially with proper management. Outdoor bales should be placed on a well-drained site, elevated on gravel or pallets, and covered with a secured tarp or plastic wrap to shed precipitation.
Proper Stacking Techniques for Airflow and Stability
The arrangement of bales is crucial for structural stability and adequate air circulation. For small square bales, stability is achieved through an interlocking pattern, often called crisscrossing or brick-stacking. In this technique, each layer is rotated 90 degrees relative to the layer below it, tying the stack together and preventing collapse. For optimal airflow and to prevent moisture accumulation, the bottom layer should be stacked on its side, allowing the cut edges to face up.
Round bales stored outdoors should be placed flat side down, end-to-end, in long rows to minimize the surface area exposed to rain and snow. Leave at least a three-foot space between these rows to promote sun penetration and maximize air movement, aiding in drying the outer layer after precipitation. Pyramid stacking of round bales is only recommended when the entire stack is fully covered, as exposed pyramid stacks trap moisture and maximize spoilage. Regardless of the bale type, leaving a gap of one to two feet between the stack and any fixed walls or ceilings facilitates air exchange and prevents moisture condensation.
Monitoring and Mitigating Storage Risks
Ongoing management focuses primarily on fire prevention, as spontaneous combustion presents a serious hazard, especially within the first six weeks after baling. Microbial activity, fueled by excess moisture, generates heat that elevates the internal temperature of a bale. A temperature reading of 150°F (65°C) is a warning sign, while temperatures approaching 170°F (77°C) signal a high risk of ignition.
Monitoring should be done using a long-stemmed temperature probe inserted deep into the stack, checking multiple sites regularly during the initial high-risk period. The storage area must maintain a safe distance from heat sources and electrical equipment, with a minimum clearance of 10 feet from overhead power lines. Pest control is also important, as rodents and insects can contaminate the feed and compromise structural integrity. This is best managed through physical exclusion, such as sealing building entry points, maintaining a clean storage area free of debris and spilled feed, and using tamper-resistant bait stations placed along walls.