Hay waste can occur during both storage and feeding. Research has shown outdoor hay storage losses of round bales can range from 5% to 35% depending on precipitation, storage site and original condition of the bale. For example, the outer 4" layer of a 6' diameter round bale contains about 25% of the total bale volume, and it is most likely to be damaged by weather if stored improperly or unprotected. There are a number of techniques that minimize outdoor storage losses of round bales:
- Bale (or buy) a dense bale as the bales will sag less and have less surface area in contact with the ground.
- Use plastic wrap, net wrap, or plastic twine. Research has shown that net wrapped bales reduced grass hay dry matter losses by 32% compared with twine bales when stored outside.
- Store bales on a well‐drained surface. A well‐drained, 4 to 6" coarse rock base will minimize bottom spoilage, as well as using wood pallets.
- Never store round‐bales under trees.
- Store round‐bales end‐to‐end when storing outside.
- Position round‐bales as tightly as possible in long lines on a well‐drained site. If more than one line of bales is needed, space adjacent lines at least 3’ apart. This will increase airflow and allows sunlight to penetrate the bales.
- In a South Dakota study, dry matter losses of round bales were 4% for round‐bales stacked individually and less than 1% for round bales stacked end to end.
- When storing round bales outside without cover, never stack round bales in a pyramid. Stacking tends to trap moisture and limits drying action from sunlight and wind.
- A South Dakota study reported dry matter losses of round‐bales stacked in pyramids at more than 10% after one year of storage.
- Storage losses are usually reduced by approximately two‐thirds with indoor storage and by one‐half with good plastic covering (i.e., a tarp) outdoors.
This article was written by Krishona Martinson, PhD, University of Minnesota. You can subscribe to the university's horse newsletter on this page.