Hay storage will impact how much hay is needed and the cost of the hay feeding program. Strategies to reduce storage loss will vary some based on annual rainfall.
In most environments, round bales stored outside should be stacked in long rows with the flat ends butted against each other. At least 3 feet should be left between rows to allow sunlight and wind to dry the bales out quicker after it rains. Hay should not be stacked under trees as this delays drying. Storage sites with well drain soils will help reduce loss on the bottom of bales.
