Thinking of grazing standing corn?

If your corn's cooked, you've got your indemnity payments lined up and you've got cattle to feed, why not graze your standing corn?

This eliminates a lot of costs, experts say, from harvest and storage to feed processing and handling. But, before you let your cattle loose on your drought-damaged corn, make sure they're ready for it.

"After a brief learning period, cattle will preferentially graze corn ears if any have developed. Drought-damaged corn may not have many ears, but if much grain has developed, the cattle first need to adapt to a higher grain diet before grazing corn begins," says University of Nebraska Extension forage specialist Bruce Anderson. "Otherwise, acidosis or other digestive disorders could develop."

Even though you can cut back on those costs associated with normal harvest and feeding of corn or silage, there are still costs and labor involved. Don't just let a few head out on a field without controlling the amount of corn and forage to which the animals have access. You can effectively do this by cross-fencing or grazing in controlled strips.

"Cross-fencing and strip-grazing is needed to minimize trampling waste. Give cattle access to no more than a two-day supply of fresh corn at a time; a one-day supply is even better, especially for younger, growing cattle," Anderson says. "Dry cows might do fine if moved just twice each week."

So, how do you determine what 2 days' worth of feed is? There are a few basic rules of thumb. "As a starting guide, each acre of standing corn that is about 6 feet tall and tasseled should provide enough grazing for about 100 cows for one day. In other words, provide 435 square feet of standing corn for each cow for each day of grazing in the first strip," Anderson says. "Observe animal behavior and amount of grazable corn available each day, as well as in-field variation, to determine whether to increase or decrease the area allotted with each new grazing strip. Do not bother with back fences to simplify animal travel back to water."

How many acres is required also depends a lot on the animals you're grazing; the nutrient load in standing corn can be harmful to dry cows, for example.

"Dry cows may become fat and over-conditioned grazing standing corn, especially if grain is present. Even without grain, barren stalks can be surprisingly high in nutrient concentration because protein and energy that normally would have been transferred to the grain has instead been stored in the stalk and leaves. Diets containing crude protein exceeding 8% and TDN of 55% are usually expected," Anderson says. "Standing corn can be limit-fed to stretch the supply and/or to minimize over-conditioning by reducing the area allotted to the cows and forcing them to eat more of the lower quality stalks. However, nitrate concentration may be high in the lower portion of the corn stalks. Before forcing animals to consume this part of the plant, test the stalks for nitrates and then manage accordingly."

Those are all reasons to keep a close eye on your cattle grazing standing corn and be quick to make adjustments when needed. "Limit-feeding can cause animals to remain hungry even when they have consumed sufficient protein and energy to meet their needs," says Anderson. "Behavior problems can occur, including increased pressure on fences. More strands of wire, higher electric voltage, or providing free choice access to poor quality hay or straw may be needed to avoid problems."

If these reasons compel you to instead windrow your drought-damaged corn, then let the cattle out on it, you could cut some of your labor but it may not have all the benefits of a more disciplined strip-grazing system.

"This may simplify construction of fences and determination of area to be allotted. Trampling waste also can be reduced. However, if cattle do not utilize all of the corn in the windrows, the remaining residue might cause problems for planting crops next spring," Anderson says. "Also, residue remaining after grazing will be concentrated in the windrows, which may not meet residue requirements for conservation purposes, compared to grazing standing corn."