Ammonia treatment of low-quality roughage stretches feed supplies
The availability of economical roughage sources that can support acceptable cattle performance is a concern this year because of the widespread drought conditions. One tool that's available to cattle producers that might be a possible solution is using anhydrous ammonia to treat low-quality roughages, according to South Dakota State University Extension.
When low-quality (less than 5 percent crude protein) roughages are treated with anhydrous ammonia, the ammonia combines with the moisture in the forage to produce ammonium hydroxide. The ammonium hydroxide will chemically react with the cellulose in the roughage to partially break down some of the chemical bonds. Because of the changes in the cell wall components, the digestibility of the roughage improves, plus the dry matter intake of the roughage increases after ammoniation. As a result of these changes, the feeding value of the roughage improves to be roughly equivalent to prairie hay. Ammoniating roughage will cost roughly $30 per ton, which may be feasible given the current hay market.
Straw is the feedstuff most commonly associated with ammoniation. However, other low-quality roughages such as corn stalks or low-quality, mature CRP hay may also be suitable candidates for treatment. One thing to keep in mind is that at least 10 percent moisture is required for the ammonia treatment to be successful; in some cases this year's CRP may be too dry. On the other hand, corn stalks are notorious for being more difficult to completely dry down. Ammonia will act as a fungicide and can help inhibit mold growth if the corn stalks were baled at moisture contents over 20 percent.
The actual procedure involves covering the stack of bales with plastic and sealing all of the edges to prevent any ammonia from escaping. Any holes or tears need to be sealed as well. A pipe or hose connected to the anhydrous ammonia tank is placed as close as possible to the center of the stack. The ammonia is allowed to flow into the stack at a rate of 3 percent on a dry matter basis, or 60 pounds per ton. After the correct amount of ammonia has been applied, the hose or pipe is removed and the stack re-sealed.
Working with anhydrous ammonia can be very hazardous. Be sure to have protective equipment on hand such as goggles and gloves and have an ample supply of water nearby.
The length of time that the stack needs to be sealed depends on the outside temperature. At temperature from 40 to 60 degrees F, the process will take from four to eight weeks. More time will be required if the temperatures are colder.
The greatest benefit to ammoniating forages is the changes seen in digestibility and intake. Many research results point to 20 percent greater intake and a 10 percent improvement in digestibility with ammoniated forages. Crude protein concentrations will also increase because of ammoniation, usually an additional 6 to 7 percentage points. However, only about 50 percent of the increased CP is available to the animal, because non-protein nitrogen is poorly utilized in lower energy roughage diets. For instance, if straw that originally contained 4 percent CP tested at 10 percent CP after treatment, then the usable crude protein would be considered to be about 7 percent (one-half of the 6 percent additional crude protein, plus the 4 percent originally found in the straw). If the cattle required a diet containing more than 7 percent CP, that additional protein should be supplied from all-natural sources.