With Missouri's drought of 2003 taking on dramatic proportions, many farmers in the state are wondering what to feed their livestock. The answer lies in the tall grass, a University of Missouri forage specialist said.
Tall fescue treated with anhydrous ammonia is “the ideal feed alternative for the drought of 2003,” MU agronomist Craig Roberts said. “If you make tall fescue silage and feed it to livestock, you'll have all those toxicosis problems. But if you ammoniate it, it's like endophyte-free fescue or orchardgrass.”
Most tall fescue in Missouri pastures is infected with an endophyte that releases alkaloid toxins, which sicken the livestock that feed on it. When Roberts and MU agronomist Rob Kallenbach treated baled tall fescue with ammonia gas, they found that “the endophyte toxins almost disappear,” Roberts said. “The toxins fall well below the thresholds necessary to cause fescue toxicosis.”
He said the wet spring of 2003 led to an abundant tall fescue supply. “It just rained and rained this spring. We ended up with a bunch of tall fescue, and it was fully mature. The people who put it up as hay may think it's worthless, stemmy stuff — and it is. But it becomes valuable if you treat it.”
Ammonia breaks down the cell walls in low-quality plant material like stems and straw, Roberts explained. “You'll sometimes see people ammoniating wheat straw and crop stubble to feed their animals in very dry years. “When you do that with tall fescue, it's got a double whammy,” he said. “It not only makes it easily digestible — a nutritional function — but it performs a toxicological function by destroying or deactivating the endophyte toxins.”
The ammoniation process takes about two weeks and costs about $12 per 1,000-pound bale — half for the ammonia and half for the plastic to cover the bales.
Typically, farmers ammoniate hay or other forages by covering stacked large round bales with heavy plastic, and sealing the plastic at the bottom with a berm of dirt. A web of ropes, attached to old tires, concrete blocks or other weights can be used to secure the plastic in windy conditions.
Anhydrous ammonia gas, normally used for crop fertilizer, is injected into the stack and allowed to permeate the bales overnight. Previous MU research recommends injecting 3 percent of the forage's dry matter weight, or 30 pounds of anhydrous ammonia per 1,000-pound bale. Wear proper safety equipment when handling anhydrous ammonia.
“At $12 a bale, it's not free, but it's well worth it,” Roberts said. “This is really the best alternative for the 2003 drought.”
He said the practice has not been commonly recommended, but the recent research results from MU should change that. “I'd do it every year,” he said. “You can never count on cutting your hay on time in Missouri because of the uncertain weather. So, why not let it mature fully, cut it so you have a whole bunch, then treat it to make it into good hay?
“It's a really good idea in a drought like we have this year,” Roberts said. “Producers who are short of feed should be doing it now.”
Forrest Rose is an Extension and ag information specialist with the University of Missouri.