“Even after silage has been chopped and piled and packed correctly, it still can be damaged seriously by air and moisture slowly penetrating the outer 3-4 feet. In fact, good silage can lose 15-20% of its feed value from fermentation and spoilage under normal conditions,” says Bruce Anderson, University of Nebraska Extension forage specialist. “This loss can be cut in half, or even less, if covered well by a sheet of plastic.”
Before you say, “No kiddin’, we already do that,” read on.
Anderson recommends covering freshly chopped silage with black plastic immediately after filling the trench, bunker or pile. “Then cover the plastic with something to help hold it down,” he says.
Though old tires often are often used because they’re readily available and do a good job of keeping the plastic from blowing away, he says the tires only keep the plastic in direct contact with silage directly beneath the tire. In between the tires, air can circulate and cause some spoilage.
“An even better choice would be a solid cover, something like freshly chopped forage or weeds or maybe even a 3- to 4-in. layer of manure. Then, the entire surface of silage will be fully protected,” Anderson says. “You go to a lot of time and expense to make good silage. Isn't it worth it to spend just a little bit more to protect that investment?”
As for increasing fermentation via inoculants, Anderson says there’s no consistent, clear-cut way to predict when they will be most useful or cost effective.
Anderson explains fermentation starts and ends quicker with inoculation so more silage remains for feeding. “Typically, you save an extra 5%,” Anderson says. “Some inoculants can improve feeding value, although results are a bit inconsistent… Inoculants consistently improve wet silage, especially sorghum silage. If you start chopping early enough to prevent silage from being too dry at the end, inoculants should help.”
When you begin chopping, Anderson suggests grabbing a handful of silage and squeezing it tightly in your fist. If free juice squeezes from the forage, he says it’s wet enough to benefit from use of an inoculant.
“In the past, inoculants rarely improved properly made corn silage – silage at the right moisture, chopped fine, packed well, and sealed tight. Nor did they improve dry silage. But recently developed inoculants, with more effective strains of fermentation bacteria, are producing slightly better quality silage,” Anderson explains. “If you do use an inoculant, make sure it contains live bacteria. Also check to see that the inoculant provides at least 100,000 colony forming units per gram of wet forage when applied at the recommended rate. You need plenty of live bacteria for the inoculant to do you any good.”