In between our recent rainstorms, most farmers have been able to get their hay cut, dried, baled and stored.

For those who produce it for on-farm use, hay-making can be considered a necessary evil.

It is most certainly one of the most costly expenses on beef cattle operations, but in seasons where forages may be scarce, such as winter and summer, hay can be a precious commodity.

There are many important factors in hay production that impact the cost, such as fertilizer, weed management, equipment, and time. Hay storage is another cost that must be considered.

Regardless of how you store your hay, there will be a cost associated with it. You may not think so if you don’t have hay under an expensive storage barn, but even if your hay is sitting outside on the ground, that hay is costing you more and more every day due to loss of both nutritional value and dry matter.

Hay that is stored outside is subject to wetting and drying cycles that lead to the degradation and leaching of nutrients from the bales. Over time, this causes the fiber (indigestible) component of the forage to represent a larger proportion of the bales dry weight.

The loss of nutrients (Total Digestible Nutrients, or TDN) can often be as much as 15 to 20 percent in weathered bales.

The result is a fibrous, weathered layer that is very low in quality and unpalatable to livestock. Livestock can often be seen eating the middle out of these round bales leaving a “doughnut”-shaped bale.

 (Another item you might want to consider is the use of a preservative applicator for the baler. For a look at the costs and returns of this equipment, see Hay baler preservative applicators pay off quickly).

When bales are stored outside and uncovered, weathering may affect depths up to 12 inches. The depth will vary, based on factors such as bale tightness (i.e. density), storage on unprotected ground, storage under trees and more.

It is a general expectation, however, for a weathered layer of 4 to 6 inches for bales stored outside on the ground. This is important because the outer portions of bales make up for a disproportionate amount of the bale’s volume. Losses of only a few inches represent a substantial loss in terms of total bale volume. And, it determines what you can feed your animals.