Recent regulations may change how some U.S. producers weigh down their silage covers. Yet, the benefits to properly covering silage bunkers or piles continue to provide returns.
“The additional time and expense to comply with waste tire regulations may cause producers to question the need for covering piles at all,” notes Renato Schmidt, Ph.D., Technical Services – Silage, Lallemand Animal Nutrition. “Covering piles saves money, conserves important nutrients in the silage, reduces dry matter (DM) losses and improves the hygienic quality of the feed. It’s still worth the effort to cover silage piles.”Dr. Renato Schmidt
Covering piles helps create an anaerobic environment required for the silage. As a result, the quality of the fermentation process is improved compared to uncovered piles. During storage, well-maintained plastic covers help prevent oxygen ingress, which can cause spoilage.
For example, sealing and covering a 40-foot by 100-foot bunker returns approximately $2,000 in improved silage DM recovery when filled with corn silage. Plus, feeding spoiled silage from an uncovered silo can reduce feed intake and digestibility.
A combination of high-quality plastic and adequate weighting help prevent losses. Use plastic that is at least five millimeters thick and dual layer — black inner and white outer — to resist deterioration. Also, consider using plastic film with an increased oxygen barrier, Dr. Schmidt advises.
Weighing the plastic down prevents air from seeping underneath the covering. Full-casing waste tires have been the standard for anchoring bunk silo covers for years, but they are heavy to move and bulky to store. Standing water in a full-casing tire can be a breeding ground for mosquitoes. With the increasing concern around West Nile virus (WNV) — and state regulations — producers may be searching for new options, such as:
- Modifying tires by leaving tires on the rims, removing tire sidewalls, drilling holes in the tire sidewalls or cutting tires in half
- Covering tires with plastic to reduce standing water
- Treating tires with a mosquito larvicide, which requires a certified pesticide applicator
- Replacing tires with sidewall disks
- Using heavy equipment tire beads
- Finding alternatives to tires, such as gravel or sand bags
Dr. Schmidt advises producers to choose an option that maintains the integrity of the plastic. Tears or holes reduce the effectiveness of the covering and allow oxygen into the pile.
“Covering and sealing silage bunkers makes economic sense,” Dr. Schmidt says. “There are options for producers looking for alternative ways to weigh down covers. Don’t change a best practice that pencils out in the long run.”Dr. Renato Schmidt