Although large round bales reduce labor requirement when putting up hay, storage losses with them generally are much higher than with small rectangular bales, particularly when stored outdoors.
This indicates a lot of large round bales might have some nutrient loss from precipitation combined with air temperature and humidity. Much of the dry matter loss with outdoor storage is associated with microbial respiration under optimal moisture, temperature, and nutrient condition for microbes.
The following are ways to minimize large round bale loss stored outside:
Increase bale density
One of the most important ways to reduce round bale loss is to tighten the outer layer of the bale. If the bale is not tight enough, microbes are going to use oxygen to break down the bale using moisture and nutrients. If you can depress the surface more than a half inch, the round bale could experience significant loss when placed outside and unprotected. It’s recommended to have a minimum density of 10 pounds of hay per cubic foot.
Round bales stored outside and covered with either plastic or canvas generally experience much less deterioration than unprotected bales. Weathering can reduce forage quality of round bale hay, particularly digestibility. Plastic wrap, net wrap, reusable tarps or plastic twine can be used to prevent the loss from weathering. Plastic wrap or net wrap will result in less loss than twine.
Select a good storage site
Selecting a good storage site is another important consideration in reducing bale loss with little cost involvement. First of all, the storage site should not be shaded and should have good air circulation, which will enhance drying conditions.
The storage site also should be well drained to reduce moisture absorption into the bottom side of the round bales. A well-drained, 4- to 6-inch coarse rock base would help minimize bottom spoilage of a large round bale. Bale storage loss can be reduced by elevating the bales rather than placing them on the ground. Ground contact can account for over half of the total dry matter loss. To elevate the bales from the ground use racks, fence posts, discarded pallets, railroad ties, used tires, or a layer of crushed rock about 4 to 6 inches deep to have good drainage.
Orient rows of bales to promote good drying
It’s recommended to stack large round bales in rows, butt end-to-end, give three feet between rows, and orient the rows in a north-south direction. This will allow the area to dry faster after a rain by having good sunlight and air flow. Vegetation between rows should be mowed to allow good air flow.
Environment makes a difference
Storage loss coincides with precipitation amount. Storage loss in eastern Oklahoma is much greater than in western Oklahoma. Bales can be stored outside in the western part of the state for a couple of years before much significant loss will occur, but storage loss can be significant on the east side of the state after just one year of outside storage. Rarely would indoor storage pay for itself in western Oklahoma, but storing high quality/high value forage in eastern Oklahoma might justify the expense of storing hay under cover.
Nelson is Oklahoma Cooperative Extension Service ag educator for Garfield County.