Bales and tube lines afford a flexible storage system for the efficient fermentation and storage of many fermentable forages. Although expensive to produce in terms of labor and wrapping, if managed appropriately through harvest, wrapping and storage losses can be as low as 2 to 3 percent.
Dry matter (DM) at time of harvest has an enormous impact on the how the bales need to be managed. The net and plastic wrapping of the bale is only designed for the weight/pressure of a single bale and although stacking is possible, it is not recommended unless bales are of 40 percent DM or higher due to plastic slippage, air ingress through reduced seal integrity, and generally a doubling of both the DM and digestibility (D) losses of the baled forage.
During pre-season, it is important to define goals of baling and understand the farm limits. Pre-stretch units on balers should be thoroughly overhauled by degreasing and replace springs as necessary, and to ensure the baler is set up appropriately for the wrap that will be used by checking stretch by wrapping a straw bale and meet manufacturer recommendations.
The type, tack, stretch, and color of the plastic all impact the quality of the baleage that is produced. Even under cool British conditions dark colored plastic leads to a 6°C increase in the temperature of the baled forage, and as the ambient temperature rises the need to use light colored plastic increases. Elevated temperature of the bale leads to higher losses, essentially cooking the protein and sugars thus making them unavailable to the animal and open to yeast and mold outgrowth in the bale.
Wrapping of the bale should ideally be undertaken through the use of an inline bale-wrapper, but if this is not possible the bales should be wrapped at the site of storage within 8 hours of production.
If the bales are field wrapped it is important to be cautious of damaging the bale plastic with the field stubble, and great care must be taken when handling them. Again, bales should be re-located to their final storage point within 8 hours of production.
Research undertaken by the Institute of Grassland and Environmental Research (IGER) showed that six layers of plastic instead of four lead to an improved fermentation and reduced DM losses and spoilage, and there was no proven benefit in using 8 layers.
Stacking of bales
The stacking of low DM bales leads to misshapen form and slippage, providing a significant loss in DM and feedout of the baleage coupled with a variable feed value.
Additionally, in hotter climates, stacking of bales leads to reflection of ultra violet rays from the top bale and a “plastic burn” to the lower bale that lets air into the bale and associated spoilage and losses.
The chart to the left (Engormix) highlights the impact on losses of bales when stacked, while the chart to the right highlights the impact of the storage base on the DM losses. In total, bales are best stored unstacked, on their ends, on a well compacted aggregate base.
Bales are subject to “bird damage” immediately after they are produced, which greatly impacts the choice of storage location.
Storage location should be:
- Away from trees and water courses
- Level and well drained
- Baited against vermin
- On a heavy-gauged plastic base or on compacted sand
- Protected from farm animals if necessary
- Regularly inspected for damage and repairs made as appropriate