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Storage of large round bales

John W. Worley Published on 07 August 2009

When large round hay balers first became popular in the 1970s, one of their strong selling points was the fact that you could store the bales in the field without covering them.

While it is true that losses from these bales is lower than from square bales, numerous studies and field demonstrations have proven that putting hay under a cover is cost- effective and results in a much higher-quality feed.

Storage in a barn has two primary benefits. It reduces the loss of dry matter caused by rot in the outer layer of hay. Studies have demonstrated losses of 30 to 65 percent in field-stored hay versus 0 to 5 percent for barn-stored hay. Barn storage also improves the digestibility and palatability of the dry matter that is left.

One study showed an improvement in digestibility from 45 percent for field-stored hay to 54 percent for barn-stored hay.

If you start with 100 pounds of dry matter at harvest and store it in the field with 50 percent dry matter loss and 45 percent digestibility, you wind up with 22.5 pounds of digestible dry matter at feeding.

That same hay stored in a barn with 3 percent loss and 54 percent digestibility will yield 52.4 pounds of digestible dry matter at feeding.

Storing good-quality hay in a barn is cost-effective. The savings will pay for the cost of owning the barn. But there are other, less costly alternatives.

One alternative (storage under a tarp) is not quite as effective at reducing losses (10 to 15 percent dry matter loss) and requires more labor, but it does require a significantly lower investment.

An additional benefit, especially when storing hay that is put up perhaps a little too wet, is that if the hay catches fire, losses are limited to a relatively small stack of hay and a tarp rather than a barn and all the hay in the barn.

Even with the clear advantage of storing hay in a barn, there are some legitimate reasons to store it outside (with or without a temporary cover.)

The hay may be grown on leased land where you don’t want to invest in a barn, and it is too far to haul back to your farm. You may not be financially able to invest in a barn at this time.

You may have a bumper crop of hay and simply have more hay than you had planned on. Whatever your reason, there are a number of factors to consider when storing hay outside, as well as when building a barn for storing round bales.

Factors affecting hay storage losses for field-stored hay

  • Tightness of the bale – A variable chamber baler will generally make a tighter bale than a fixed chamber baler.

  • The type of hay – (Leafy hays like alfalfa are more susceptible than grassy hays.)

  • Adequate twine wrap (or net wrap). With twine wrappers, producers are often tempted to save time (and twine) by cutting back on the amount of twine applied. Adequate wrap will help shed water and hold the edges tightly together.

  • Size of bale – Typically, the outer 6” of the bale is lost to rot. That represents 44 percent of a 4-foot bale, but only 30 percent of a 6-foot bale.

  • Duration of storage and the weather during storage

Some of the above factors are out of your control, but the factors you can control in this list can make a significant impact on the quality and amount of hay you have to sell or feed after storage. If you do decide to store some hay in the field, consider the following recommendations.

Recommendations for storing hay in the field

  • Try to store only the last cutting and feed it first to minimize storage time.

  • Store bales on a high, well-drained location to prevent standing water from rotting the hay. Elevating the hay on some type of support will also help, but may create problems in loading and unloading.

  • Store in an open, sunny area to promote rapid drying of hay when wet.

  • Store bales in rows with the flat edges touching (to reduce exposure to sun and rain) and the round edges separated by 2 to 3 feet to allow the sun and air to quickly dry the hay when wet.

    Of course, if the hay is tarped, it will need to be stored in a triangle of either 3 or 6 bales in order to maximize the tarp coverage and shed rain from the stack.

  • Orient the rows north/south to allow the sun to reach all sides of the bales.

  • Orient the rows down slope, not across slope to promote rapid drainage.

If you are considering building a barn, consider the following recommendations.

Factors to consider if you build a barn

  • Make sure the hay is dry enough – otherwise store it outside or under a tarp.

  • If possible, orient the long axis of the barn east-west to minimize sun penetration and damage to the hay. (This is for an open-sided barn.)

  • Make sure roof height is adequate to store the number of levels of bales you wish to store (typically 3-high). Nothing is more frustrating than trying to get that top row of bales into a tight space.

  • Storing bales on their flat side will increase the capacity of the barn by about 10-15 percent.

  • Provide adequate ventilation. Good hay is typically stored at 15 to 16 percent moisture and cures to 12-13 percent. For every 10 tons stored, 600 pounds of water must be removed by ventilation.

    Lack of ventilation can cause condensation on the metal roof, ruin the hay and cause damage to the barn. Make sure gable ends are vented (or better yet, open) and ridge vents will give additional benefits.

It is not always practical to do everything in the ideal way, but if you will consider the above recommendations and utilize the ones that make sense for you, you will wind up with more and better- quality hay at feeding time and hopefully more on the bottom line at the end of the year.  FG

John W. Worley
Associate Professor
University of Georgia