Why you should ammoniate wheat straw

Jun 21, 2013
by WLJ

Forage availability is much lower this year than we would like. But soon there will be a source of forage that ranchers can use to extend their forage supplies, give pastures some rest, and maybe avoid selling cows if pastures don’t perform well this year. Here’s how:

Anhydrous ammonia can be added to poorer-quality forage to increase protein and improve digestibility. Research during several years and at several locations shows that protein can be increased by as much as 250 percent with digestibility increases of nearly 25 percent for wheat straw with ammoniation. Intake of ammoniated forages improves as well. Follow certain practices to get the most improvement possible. Moisture content should be above 10 percent for best results.

First know how much forage you will be ammoniating. You will be adding 60 pounds of anhydrous ammonia per ton of dry matter. Next build a triangular row of bales with a pipe inserted near the center bottom of the stack. Cover the stack with 6-8 mil plastic leaving 2 feet of surplus plastic on the ground. You then will seal this plastic and the stack with sand.

Add anhydrous to the stack via the pipe. Don’t add the ammonia so rapidly that the plastic balloons. Check for leaks and repair with duct tape. Remove the pipe and seal the hole. Let the stack stand for at least one week, or longer if temperatures are cool. The stack must stand for a time so that the conversion process completes. Temperatures near 40 degrees will take eight weeks, while warmer temperatures can take as little as two weeks. Open the plastic three to five days before feeding to release any remaining ammonia gas.

A recent analysis calculated ammoniation cost to be just below $50 per ton of dry matter. Low-quality forage such as wheat straw bought at $85 per ton would provide 1 pound of protein at 78 cents per pound and 1 pound of TDN at 16 cents per pound after treatment.

Many different types of forage can be ammoniated. Wheat straw can be used as well as CRP hay. Check moisture before ammoniating in case it is too low. It is best to treat soon after harvest so that moisture does not drop. Other forages we will have access to very soon are dry bean and soybean straw. These can be treated as well.

A few precautions exist when ammoniating forage. Only ammoniate low-quality mature forage. Anhydrous ammonia can be dangerous to handle so be cautious. Use chemical resistant goggles and gloves. Wear heavy long sleeve shirts or coveralls. Avoid feeding ammoniated forage to cows with young calves at their side. Calf toxicity can occur through milk.

Not all of the added protein is useable so discount the increase by 50 percent. Ammoniation works best at higher temperatures.

More information about the ammoniation process is located at beef.unl.edu under the drought tab. — Robert Tigner, SW4 Extension Educator