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Protecting your hay investment

Vanessa Corriher-Olson for Progressive Forage Published on 30 October 2019

Most of the hay produced in the Southeast for feeding livestock is packaged as large, round bales. During the winter, hay becomes a valuable commodity to provide nutrients to livestock.

How we store our hay, whether we harvested it or we purchased it, can have a major impact on dry matter loss, nutritive value loss and waste at feeding.

Losses of hay during storage are often high, particularly with round bales stored outside in high rainfall areas, such as the southeastern United States. When you fertilize according to soil test recommendations, harvest forage at the appropriate stage of maturity, and carefully cure and bale your hay, it ends up being an expensive commodity worth protecting from the elements.

Hay stored outside can lose significant dry matter and nutritive value in a relatively short period of time. Even a 4-inch band on the outer surface of a 6-foot-diameter round bale can represent a 21% loss of dry matter and nutritive value. Typically, hay bales stored outside for several months develop at least 5 or 6 inches of outer surface which has no feed value and which animals will refuse (Table 1).

Effect of storage system on dry matter loss of ryegrass hay stored for seven months

The extent of weather damage during outside storage varies mainly with climatic conditions and with forage species.

Round hay bales can be stored outside, but losses will be significant compared to storage under a roof. To reduce losses, hay can be stored under tarps specifically designed for this task. When using a tarp to cover bales, stack hay in a pyramid formation. Do not place the plastic underneath the bales because water could pool inside the tarp. Bales stored outside on the ground without cover increases sharply in moisture content during storage. This is especially true for the outer 2 to 3 inches of the bale in which moisture may increase by as much as 120%.

Weathering begins slowly, but then accelerates because weathered hay is more easily penetrated by rain and does not dry as rapidly. Weathering is visually associated with a change in color and deterioration of the outer layers of hay following exposure to rainfall, sunlight and other factors during storage. Weathered hay is greatly reduced in quality and is often refused by livestock due to very low palatability when whole bales are fed.

In general, the denser or more tightly hay is baled, the lower the amount of spoilage that will occur (assuming hay moisture at baling is 18% to 20% or lower). Bale density is affected greatly by the type of baler being used. Some fine-stemmed hays such as bermudagrass naturally tend to produce a tight bale which sheds water much more so than coarse-stemmed hays such as johnsongrass, pearl millet or sorghum-sudangrass. Having well-formed, tight bales is an important factor in reducing storage losses.

A majority of the storage losses associated with outside storage occur at the bottom of the bale. Dry hay touching damp soil draws moisture into the bale. Hence, if hay and soil are in contact, large weathering losses occur on the bottoms of bales even when they are stored on a well-drained site. As a bale begins to weather on the bottom, it will flatten and allow for even more hay-to-soil contact as well as creating a flattened top surface, each of which increases the amount and rate of weathering. Round bales can be stored on gravel, pallets, old telephone poles, cross ties, or tires to minimize dry matter losses, but be aware that tires may hold water.

Well-drained upland storage sites are best. Bottom areas should generally be avoided as they tend to be heavier soils. Hay-to-soil contact should be avoided if possible, but if hay must touch the soil, a sandy, well-drained area is greatly preferred.

The flat ends of bales should be firmly butted against one another. This conserves space and may help protect the bottoms of bales from water flowing down the slope. Rows should run north and south to allow for maximum exposure of the rounded sides to the sun. This increases drying of the rounded surface of bales during the day. At least 3 feet should be left between bale rows to ensure sunlight penetration and allow good air circulation.

Moisture can be trapped where bales touch on the rounded sides, and this trapped moisture delays drying and thus results in greater weathering during storage. A gently sloping site will allow water to quickly drain away from the hay. Bales should be oriented up and down the slope so they will not create a dam for surface water and be placed near the top of the slope to minimize the amount of water flowing around the hay.

Hay can be stored in enclosed barns or roofed, open buildings, also called pole barns. Barn storage is considered to be a consistently highly effective method of storing hay. When the typical dry matter storage loss of dry hay during inside storage (usually around 5%) is compared to the 30% or more common with hay stored outside in the humid portions of the U.S., it isn’t difficult to see reduced losses can often provide payback on barn construction within a few years. The cost of the structure can increase the cost of hay storage considerably. There are several factors which must be considered in justifying the cost of providing protection. These factors include hay value, projected in-storage losses, environmental conditions and where the hay will be used.  end mark

References omitted but are available upon request. Click here to email an editor.

Vanessa Corriher-Olson
  • Vanessa Corriher-Olson

  • Associate Professor and Extension Forage Specialist
  • Texas A&M AgriLife Research and Extension Center
  • Email Vanessa Corriher-Olson