Late-harvested Corn Lacks Nutrition
Ear and cob rots in late-harvested corn won't make dairy cows sick, but they won't help their performance either, say Ohio State specialists.
Rots are are common in this year's corn because it was planted late and had high moisture levels at harvest, says plant pathologist Pat Lipps. He says the most common fungi are Cladosporium, a black to green-black mold, and Trichoderma, a green mold.
These molds don't produce harmful mycotoxins, he says. "Most corn escaped infection by Fusarium, a pink mold, the ear rot fungus that produces various important, harmful, mycotoxins," he says.
However, dairy nutritionist Bill Weiss says farmers probably will have a feed quality problem with the moldy corn. In extreme cases, cattle will turn up their noses and refuse to eat it, he says.
"They don't like the taste of it," Weiss says.
Weiss says corn rots can throw a diet off balance. The molds metabolize the grain starch, leaving relatively higher levels of other nutrients, such as fiber and protein. Farmers who suspect a problem should balance the ration with higher quality feed, or they need to feed more total grain relative to forage, he says.
Weiss says farmers usually don't have grains tested for nutri- tional value, but he suggests that now is a good time to do so at OSU's Research/Extension Analytical Laboratory (REAL) or at any other reputable laboratory.
REAL will test corn as part of the standard feed analysis package, known as F-PACK1, says director Maurice Watson. For a $20 fee, the analysis will give total crude protein, dry matter, levels of important minerals, and the neutral-detergent fiber test. For an additional fee, farmers can have an available crude protein test.
With thenecessary herd information, REAL can do a ration analysis to help farmers balance the diet. Test kits and instructions are available at Extension offices or by calling REAL, (330) 263-3760.
Lipps says fungi can grow when grain moisture levels are above 18 percent and field temperatures are above freezing. Farmers should harvest any standing corn to avoid further grain deterioration. Grain will no longer lose moisture in the field at this point.
Farmers should artificially dry corn down to 14 percent moisture if they want to store it, Lipps says. "Damaged corn will be more difficult to store," he says. "Aerate the grain frequently to keep moisture as low as possible, especially during warm periods."