By Jason Evitts, UT Extension Agent

Hay season is here and farmers are itching to start harvesting hay any day now.

By the time this article hits the press, many will have started and more will be preparing to start hay harvest. Harvesting forage as round-baled hay is a necessity for any livestock producer and producers have learned the value of storing it properly to preserve storage losses. The most common and beneficial storage method is indoors in open-air hay barns. However, storing hay in large round bales inside has its dangers.

Photo courtesy of University of Kentucky

The danger with stored hay is from hay that may have been baled with more than 20 percent moisture. Bacteria in the hay baled over 20 percent can cause heating to occur if the temperature reaches 135-140 degrees Fahrenheit. Thermophilic (heat loving) bacteria can take over and cause the bale to heat to over 175 degrees. At that temperature, the hay can spontaneously combust and ignite the entire barn.

Farmers know the dangers, but with the recent weather patterns farmers always have hay that they try to bale before it rains, or a few spots that were a little green (high in moisture). The bales from these areas are of the most concern. Try to identify those bales and set them outside to go through the “sweat” for a few weeks prior to stacking.

Farmers can monitor their baled hay with a moisture/temperature tester and if the temperature continues to climb, move the hay & contact fire department if needed. Farmers can also use an inexpensive long probe/ compost thermometer to measure the temperature of the hay.

Producers should try to allow plenty of drying time before baling hay. If weather permits, allow hay to go through the initial “sweat” prior to storing and monitor any bales that may be questionable due to moisture levels. There would be nothing worse than a whole summer’s work, and a whole winter of feed, going up in smoke. So use caution when storing hay in the barn.