WEST LAFAYETTE, Ind. — The moldy corn that is coming out of some Indiana fields presents challenges to growers and livestock producers, but cattlemen may be able to take advantage of this unfortunate opportunity, according Purdue University beef and dairy specialists.
The rumen is an organ that allows beef and dairy cattle to detoxify anything they might eat, said Ron Lemenager, Purdue Extension beef management specialist.
However, he said growers should be cautious because the rumen does have its limitations.
“The concern that I have, as a nutritionist, in feeding moldy corn is for the replacement heifer,” Lemenager said. “It’s in those diets that we feed a little more corn to help them reach the target 65 percent of mature weight by the time they enter the breeding season next year.
“We know the toxin zearalenone has the potential to cause negative effects on conception rates and fertility in these breeding females.”
Tamilee Nennich, Purdue Extension dairy cattle nutrition specialist, said lactating cattle are more sensitive to zearalenone than beef cattle because of their increased feed intake and milk production.
Nennich said growers should keep in mind how much corn the animals get as a percentage of their diet versus the single ingredient.
“In a typical diet, corn probably makes up about 20 percent, but it depends on the feeds available in the area and costs,” she said. “This does cause a dilution effect.”
Ideally as a part of the total diet, deoxynivalenol levels should be 300-500 parts per billion or less and zearalenone should be 200-300 parts per billion or less, Nennich said.
However, short-term research studies have found no side effects from feeding higher levels, up to 6 parts per million, she said.
Nennich and Lemenager both recommend that growers work with their nutritionist to identify a diet with the resources available that meets the nutritional needs of their livestock.
Add a binding agent
One thing growers can do is to add a binding agent to the diet, which has been shown to have a positive effect on milk production, Nennich said.
Cattle going off feed, reduced milk production and weight loss are all signs toxin levels are too high for the rumen to detoxify.
“If you notice any of these signs, the best option is to remove the feed and replace it with a new source,” Nennich said. “If that’s not possible, consider diluting it with other feeds and adding binders.”
Moldy corn can be diluted with good corn, soybean hulls, hay and other feed sources.
Lemenager and Nennich agree that dried distillers grains with solubles is a good feed source, but there could be issues if the corn taken to the ethanol facilities has mycotoxins.
“The fermentation process might destroy the molds, but it doesn’t remove mycotoxins,” Lemenager said. “In fact, it multiplies them threefold.”
The ideal thing, he said, would be if producers can get an indication of what the levels are before purchasing or feeding, which would allow a diet to be formulated around it.
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