Dairy producers are starting the silage season with empty silos this summer. Reagan Bluel, dairy specialist for the University of Missouri Extension, says farmers should inspect those silos for problems.
Producers turned to silage stockpiles this winter to feed cattle after the drought of 2018.
Tower silos, designed to store chopped fermented silage, are at risk because of age and use. Concrete and steel corrosion compromise the structural integrity of the silo.
“As a result, tower silos in disrepair may collapse because they can no longer carry the design loads caused by the stored forage,” MU Extension agricultural engineer Joe Zulovich says.
Empty silos are easier to inspect for structural damage than those being topped off, Bluel says.
“Now is the time to make a visual check on the entire exterior for cracks and settlement,” she says.
Where to look
Inspect interior sidewalls for cracks and degradation. “If you can see daylight through a tower silo wall,” Bluel says, “you have a tower silo that is likely structurally compromised.”
Pay close attention to any cracks or bulges on the sidewalls.
Check the silo discharge door, roof and wall openings for sagging, she adds. Roofs can receive damage from overfilling, vibrations and the environment. Check regularly.
Before any inspection, Bluel says dairy farmers should wear a mask to prevent breathing problems in the confined space.
Document all the silo faults and immediately make a repair plan. Consider treating surface problems to prevent collapse or using alternative storage for the 2019 silage crop. Perform regular preventive maintenance.
During her work with dairy farmers in southwestern Missouri, Bluel finds that leaning silos usually collapse within 24 hours. This puts lives and crops at risk. Proactive inspections reduce the likelihood of injury and costly cleanup. Zulovich notes that many silo failures are not included on insurance policies.
Prevent collapse
Be sure to harvest corn silage at the correct moisture, Bluel says. “If harvesting forage when it is juicier than ideal, as the feed ferments, the excess leachate containing acid from the silage will eat away at the concrete walls and foundation and weaken silo structure,” she says.
Make sure to train new workers on the correct way to blow silage or green fodder into the silo.
Silage should be blown in using a silo forage distributer to evenly spread forage or blow forage exactly into the center of the silo to evenly load silo walls. Uneven loads on a tower silo wall will likely cause the silo to collapse.
People should know how to properly unload the forage wagon and monitor the silo blower. Use fall protection and work with a partner, particularly during harvest season, Bluel adds.
Bluel recommends “Deterioration of Concrete Tower Silos,” a fact sheet from the Ontario Ministry of Agriculture, Food and Rural Affairs, available for download at omafra.gov.on.ca.