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University of Minnesota Extension

Storage of hay bales for livestock feed

Source: Allison Wright and Karen Johnson,  McLeod and Meeker County Extension University of Minnesota Extension, ande9495@umn.edu, McLeod: 320-484-4303, Meeker: 320-693-5275 

As the harvest of hay is well on its way, discussion around preserving and storing bales is worth talking about. Being able to preserve bales and store them accurately will have a big effect on the quality of the hay, which in the long term saves money. 

There are many ways you can store your bales: uncovered directly on the ground, covered with a tarp on the ground, wrapped, and in a shed with an earthen floor. In each case the quality of the hay can change with the temperature, time, and moisture the bales are experiencing before they are stacked, wrapped or waiting for use in storage. 

In each case, keeping the bales off the ground will help control moisture going into the bale which will reduce microorganism population. Noting the bottom six inches of the bale will lose relative feed value if stored on a not well-drained surface. Storing bales on gravel, old tires, or pallets are recommended rather than directly on the ground. Another recommendation is to keep a record of bale inventory. The value of using older bales versus newly baled ones is keeping feed waste to a minimum, and maximizing the resources on farm.  

Taking time to evaluate the temperature and moisture content of the bales is a worthwhile task. Temperature and moisture levels are the driving factors in the population growth of microorganisms including fungi like Aspergillus and Fusarium. Besides growing unwanted fungi with a high temperature or moisture content, the bales also run the risk of spontaneous combustion and starting a hay fire. 

Hay fires cost farmers millions of dollars from building and feed replacement costs, increased insurance rates, and lost revenue. An easy fix for minimizing your risk of having a hay fire is checking moisture guidelines at baling and taking an internal temperature of the bales before stacking them in a pile. These charts are located at the bottom of the article. 

Baleage is the alternative to storing dry hay. Baleage needs to be at the moisture content of 40 to 55 percent, making it the best choice when there are rainy periods during hay season. The downside of baleage is transporting the bales after they are wrapped and in place, any air that gets into the baleage will cause spoilage. Wrapping of the bales should be done within 24 hours of baling using 6- to 8- mil thick plastic. Waiting longer than 24 hours will cause the internal temperature to go over 130 degrees F. 

Moisture guidelines at the time of baling from the University of Minnesota Extension Educator Krishona Martinson.
Moisture % Comments
Less than 10 Hay may be brittle and dry.
10 - 15 Recommended moisture. Least risk of fire.
16 - 20 Could mold without preservatives. Slight fire risk.
21 - 25 Will likely mold without preservative. Moderate risk of fire.
Over 25 Severe heat damage. High fire risk.
Effects of internal bale temperature and fire potential from the University of Minnesota.
Temperature (F) Comments
Less than 130 Least risk of fire.
130 - 140 Little risk of fire. Keep checking.
150 Moderate risk of fire. Check often.
175 - 190 Fire is imminent. Contact the fire department.
Over 190 Use extreme caution. Bales may combust when moved.

For more information on storing bales or hay fires contact Karen Johnson, University of Minnesota Extension Educator in McLeod at 320-484-4303 and Meeker at  320-693-5275 or via email at ande9495@umn.edu.

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