By Terry Kowalchuk, MSc. PAg., Provincial Specialists, Forage Crops, Regina
Soaking rain or repeated snow melt can result in significant losses in baled hay. Based on surface area, a six-foot wide, six-foot diameter bale can receive up to 22 gallons of water for each inch of precipitation. Just four inches of surface spoilage can result in a 25 per cent loss of feed (Figure 1).
Here are some tips to minimize storage losses:
- Bale size – Large round bales typically have a higher storage loss than rectangular bales. For round bales, the amounts of bale volume exposed to the elements per unit of surface area increases as bale size decreases. Everything else being equal, smaller round bales have greater losses than large diameter ones.
- Make a dense bale – A dense bale will sag less and have less surface area in contact with the ground. A dense surface layer will shed more precipitation and protect the inner part of the bale from weathering. Bale density should be at least 10 pounds per cubic foot to facilitate resistance to weathering. As bale density increases, the rate at which moisture and heat escape decreases. Therefore, it is critical that dense bales be baled at the proper moisture (18 to 20 per cent or less) so that the risk of spoilage and heating problems are reduced.
- Use net wrap – Net wrapped bales shed moisture better than twine bales (this benefit is lost if bales are not stored on a well-drained surface). Net wrap also reduces leaf loss during baling and speeds up the baling process which saves fuel and labour.
- Store bales on a well-drained location – Bales soak up moisture if placed on a wet or poorly-drained site, causing a large layer of spoiled hay on the bottom of the bale. The storage site should drain away in all directions. A well-drained, four to six-inch coarse rock base will minimize bottom spoilage. Rock base may need to be deeper depending on the weight of equipment used to store and retrieve bales as well as the soil type.
- Locate bale rows away from tree rows – To avoid accumulation of snow, contact with snow drifts and to allow wind to dry the hay after rain or snow, do not store bales under trees or other areas where drying is impaired.
- Store bales end to end – The arrangement of large round bales in outdoor storage can significantly influence the amount of storage loss. Under most conditions, position bales end to end in long lines. If more than one line of bales is needed, space adjacent lines at least 10 feet apart. This will minimize snow buildup between rows and allow the sun to reach the back row. Stacking large round bales usually increases losses. Stacking tends to trap moisture and limit drying action from exposure to the sun and wind.
- Store bales in rows which run up and down the slope with a north/south orientation – A southern exposure is best to promote rapid drying following precipitation.
If producers have further questions, they can contact their local Ministry of Agriculture regional office for further information.