These upright silos – sometimes called “silent sentinels on the horizon” – have been in use on dairy farms since the late 1800s. Dairy farmers stored feed such as chopped whole-plant corn, grasses and legumes in upright silos, where it is preserved through fermentation. This technique transformed dairy farming in northern climates by allowing animals to be fed green fodder year-round, which encouraged cows to give milk through the winter.
The use of silos grew rapidly – from fewer than 100 in 1882, to as many as 500,000 by 1903, according to the U.S. Department of Agriculture. They were built in a variety of colors and using different materials. Older silos were made of wood, some of field stone, and some of brick, tile, metal and concrete. Blue steel, glass-lined sealed silos called Harvestores were introduced by Milwaukee-based AO Smith Company by 1950, and are still a familiar sight to Midwesterners.
But farmers are constantly improving their practices, and one of the areas that continually changes is the method of storing feed. Removing the feed, called silage, from upright silos each day was relatively slow, and required constant monitoring to be sure it didn’t spoil. Neglect could lead to unnecessary waste and worse: the potential for fire due to a build-up of methane gas in the tall structure.
That’s why today, many modern farms are moving to more efficient and environmentally-beneficial storage methods such as bunker silos and silage bags – the long, white bags you see snaking along near the cow barns. These bags are filled with a nutritious mix of feed and allow for easy removal and less spoilage. In fact, one California farmer estimates that moving to silage bags has reduced spoilage by as much as 15 percent.
So while it’s a little sad to find out upright silos are standing unused or being torn down, take heart. It’s just another sign of progress by farmers who are committed to providing you with dairy foods and beverages that are good for you and good for the environment.