Silage that is baled or bagged offers a flexible storage system, especially for producers who lack space to build bunker/silo or drive-over piles. If used correctly, these systems can produce quality forage.
The dry matter at time of harvest has an enormous impact on how bales need to be managed. The net and plastic of the bale are designed for the weight/pressure of a single bale, and although stacking of bales is possible, it is not recommended unless the bales are of 40% dry matter (DM) or higher. If the forage is wetter than this, it can cause the plastic to slip, increasing air ingress through reduced seal integrity, leading to significant increases in DM and digestibility (D) losses of the silage. Although expensive to produce in terms of labour and wrapping, if managed appropriately, well wrapped and stored bales can see DM losses as low 2 – 3%.
It is essential to define the goals of baling and understand the farm limits, such as where and how many bales be safely stored. Ensure the baler is set up appropriately for the wrap that will be used (check stretch by wrapping a straw bale and meet manufacturer recommendations). Pre-stretch units on balers should be thoroughly overhauled (de-grease and replace springs as necessary).
The type, tack, stretch and color of the plastic used all impact the quality of the silage that is produced. Even in colder conditions, dark coloured plastic can lead to a temperature rise of 6°c in the temperature of the baled forage. If stored in hotter climates the need to use light coloured plastic increases (increased temperature of the bale leads to higher losses, cooking of the protein and sugars, thus making them unavailable to the animal).
Wrapping of the bale should ideally be undertaken through the use of an appropriate 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 care should be taken to ensure the plastic is not damaged with the field stubble. Care must be taken when handling bales (even soft hands can lead to plastic damage) and bales should be carefully re-located to their final storage point within 8 hours of production.
Stacking of Bales
Stacking of low DM bales leads to the lower bales becoming misshapen and the plastic around the bale slipping, leading to a significant increase the DM and feed losses of the bale and associated spoilage and losses.
For the best results, bales are best stored unstacked, on their ends on a well compacted aggregate base that will not damage the plastic.
Bales can be subject to ‘bird damage’ immediately they are produced and this by itself impacts the choice of storage location.
The storage location should be:
- Away from trees and watercourses
- Level and well-drained
- Baited against vermin
- On a heavy gauge plastic base or compacted sand
- Protected from farm animals if necessary
- Regularly inspected for damage and repairs made as appropriate