This feeding strategy has been validated through recent studies conducted at Iowa State University and the University of Nebraska.
After shelling the corn, windrow the stalks, add hydrated lime, chop the stalks and store the feed in an oxygen-free container, which typically is a plastic “ag bag” or a bunker, for at least a week.
A 1,200-pound stover bale can be treated with approximately 50 pounds of calcium hydroxide. The solution loosens the chemical bonds between the stover’s less-digestible lignins and its more digestible components. Relaxing these bonds allows natural enzymes to digest the stover.
While research on hydrated lime was done with corn, the same treatment process should make wheat and late-harvested Conservation Reserve Program hays more digestible to ruminants as well. However, application equipment is not readily available.
Hydrated lime is similar to quick lime but releases only a fraction of the heat, so you are not likely to start a fire.
Limited reports note that once the stover is collected and baled, you need to check the moisture content and then grind it in a tub grinder, preferably one with a 3-inch screen. After it is ground, put the stover into a feed wagon with a scale, add a 5 percent treatment of calcium oxide and bring up the moisture content to 50 percent.
For example, for 1,000 pounds of dry stover, a 5 percent treatment would require 50 pounds of calcium oxide. If the bale started with 20 percent moisture content, the bale would weigh 1,250 pounds (1,000 pounds of dry stover, 250 pounds of moisture and 50 pounds of calcium oxide).
The next step is to add enough water to bring the mixture to 50 percent moisture content. In this case, you would add 800 pounds of water. So in the end, you would have 1,050 pounds of dry matter and 1,050 pounds of moisture. It’s a 50/50 mixture, very similar to corn silage.
Another important aspect to the treatment is the pH. The pH of the stover before treatment is usually in the 6.5 to 8.5 range. After the calcium oxide is added, the pH is raised to 12.5. Check the pH in several areas of the mixture to ensure the calcium oxide is mixed in evenly.
After that, dump the mixture onto the ground or in a bunk. Within five minutes, you should see a dramatic change in color; it will turn green. This indicates the lignin, cellulose and hemi-cellulose have begun to break down. This mixture must sit for five to seven days for the chemical reaction to continue. After that, it can be fed to cattle.