October 18, 2001

Specialist Offers Tips for Feeding High Moisture Corn

As acres devoted to production of corn for grain continue to increase in the region, high moisture corn is becoming a more popular feed for the area’s livestock producers.

"That’s to be expected," says J.W. Schroeder, a dairy specialist with the North Dakota State University Extension Service. "High moisture corn has many advantages and few disadvantages when properly managed."

High moisture corn can be harvested earlier with no artificial drying. As a result field losses and weather risks are reduced and time for harvesting is increased. High moisture corn often has less storage loss, pest damage and dust. There are fewer nutritional problems when feeding the crop and rations can maximize dry matter intake. Harvest and handling are easily accomplished with equipment, reducing labor. Producers can use later-maturing hybrids that often yield more. The crop is easy to process and usually produces more milk per acre for dairy producers.

The crop does have some disadvantages, Schroeder notes. High-moisture corn can only be used as a livestock feed. Although some of the stored grain is sold as feed, it cannot be readily marketed like dry corn.

"High moisture corn from this year’s harvest can be a good fit for feed and economic efficiency," Schroeder says. Some general recommendations include:

• High moisture grain results in a faster rate of digestion, which may cause greater problems with acidosis and erratic intake; monitor starch levels closely.
• Blending a more slowly digested form of corn (dry rolled or whole shelled) with the wet high moisture corn will alleviate some of the problems of excessive moisture.
• Feeding additional roughage will stimulate saliva production and lessen ruminal acid accumulation.
• More frequent feeding may provide assistance in reducing acid load.
• Total mixed rations will help ensure that adequate forage intake is achieved by each animal.
• Bunk management is important. Frequent feeding and cleaning will alleviate potential problems.

"Producers need to alter some of their management practices to make the most of this feed," Schroeder says. "They need to learn about the crop and how best to use it in their operations."

Schroeder says some feedout procedures need to be altered with wet high moisture corn. High moisture corn that contains less dry matter is less stable. Therefore, spoilage will begin sooner at the exposed surfaces. About 3 to 4 inches of grain must be removed from the exposed surface per day to prevent spoilage. This is particularly true in mild weather when temperatures are 70F or greater. "At colder temperatures typical of what we see in this region in the winter, the risk of spoilage is minimal," he says.

Blending high moisture corn with dry corn or other dry feeds before ensiling can be an excellent strategy, Schroeder says. "Dry ground corn blended with whole wet corn would pack and ensile properly. In addition, the blended product would provide an excellent feed resource. It may be possible to add dry grain screenings or dry beet byproducts to the wet corn as well." If mycotoxins are a potential problem, he advises against using grain screenings unless they are first analyzed for mycotoxin content.

Schroeder notes that producers may need to manage feeds carefully to avoid acidosis and bloat. "The potential for digestive disorders is greater with more rapidly degraded substrates such as grain starch," he says. "In the case of high moisture corn, the immature kernels and greater amount of fines increase the rate of starch digestion. Consequently, digestive disorders are a potential risk." Add more roughage to diets or blend dry corn with the ration to reduce the risk. Frequent feeding may also reduce the problem, he says.

Livestock producers need to remember that harvesting immature corn in the shelled form can result in low test weights. Research from Minnesota suggests energy value of corn increases with maturity. Starch and lipid content increases while cell wall and protein tend to decrease as a percentage of the dry matter. "Diets need to be adjusted accordingly," Schroeder says.

Wet corn and temperatures greater than 40F conditions are favorable for Fusarium mold growth, Schroeder notes. Fusarium molds can produce mycotoxins such as vomitoxin (DON-deoxynivalenol) and zearalenone. These mycotoxins can depress dry matter intake and animal performance. Aspergillus mold, the source of aflatoxin, does not grow under these conditions. "A good indicator for potential mycotoxin problems is an unexplained decrease in dry matter intake," he says.

"It is thought that the cob portion is the major site where molds grow and the toxins are produced," he says. "So, harvesting as shelled corn rather than ear corn should reduce the potential for high mycotoxin concentrations."

If you suspect mycotoxins are present in high moisture corn, obtain a lab analysis to determine which mycotoxins are present and respective concentrations recommended. Take care to collect a representative grain sample.

###

Source: J.W. Schroeder, (701) 231-7663, jschroed@ndsuext.nodak.edu
Editor: Tom Jirik, (701) 231-9629, tjirik@ndsuext.nodak.edu

Click here for a printable PDF version of this graphic. (5KB b&w graph)
Click here for a printable EPS version of this graphic. (76KB b&w graph)