As silage can represent up to 50% of a dairy cow’s diet, it’s vital that the silage produced is high quality. Quality silage aids producers as it allows them to control feed costs and gives them more flexibility with regards to managing their feedstocks.
Producing the best quality silage possible requires a multi-faceted approach, including best silage management practices and planning (such as silo design). Each year, tonnes of corn/maize silage is wasted due to poor silaging practices resulting in significant DM losses. The large proportion of this wastage is due to poorly compacted silo’s which result in aerobically unstable silages. Silo density is a critical aspect of silage making, and the recommended density for corn/maize silage is 240 kg DM/m3 (Bolsen, 2010).
A major multi-analysis audit1 from 149 dairy farms located across France, Italy and Greece, showed that 64% of the silos had a density below the recommended value. Further, 60% of all silos showed sign of heating and poor aerobic stability.
There are some silage management steps which can help producers improve the consolidation in the silo and reach the recommended 240 kg DM/m3.
Improving silo compaction (Density)
- Slow the delivery rate of silage being dropped into the silo, this will increase the packing time per tonne of forage.
- Pack the forage using horizontal layers to maximize the compaction
- Decrease the thickness of each layer. This requires less rolling to achieve the same density (pack thin layers <15cm)
- Increase the time the tractor rolls between each layer, if possible use more than one tractor.
- Increase the weight of the tractors if possible and use thin wheels to increase the pressure on the silo (for higher compaction)
- Don’t fill in the bunker above the wall, when forage is above the wall it is very difficult to compact properly and it’s highly dangerous for the staff.
- Pay particular attention to the sides of the silo. These areas are more difficult to consolidate.
- When filling a bunker start off by filling in a U shape this will allow compaction of the sides, if creating a drive over pile have a maximum run to rise ratio of 3 to 1 so the tractors can compact the sides of the pile properly and safely
- Do not leave the silo exposed overnight. Air will ingress back into the silo and the forage will decompress. Cover with good quality plastic or an Oxygen barrier plastic immediately after filling.
Andrieu & Demey, XVII International Silage Conference, July 1-3, 2015, Piracicaba, Sao Paulo, Brazil