“It's not a sow's ear; we can still make a silk purse out of it.” That's what University of Illinois dairy nutritionist Mike Hutjens says of the immature corn crop that's expected to be harvested for silage in the Upper Midwest.

Barring a late killing frost, not much corn in Minnesota, Wisconsin and other Northern states will reach maturity, according to forage specialists in the region. Yet, says Hutjens: “It will make fine feed. It won't have much grain, but will make a fair amount of tonnage — and additional nutrients will be in the plant.”

Even so, Northern growers and dairymen will have some challenges harvesting and feeding this year's corn silage crop.

The first, says Hutjens, is deciding when to harvest the immature crop that was grown in abnormally cool weather.

“How many days do you wait until that crop will be at a more optimum moisture level?” Hutjens asks. Even if it looks dry, the stalks will probably be too high in moisture to make good silage.

So let corn dry to 65-70% to prevent poor fermentation and seepage, even if that means the crop will be hit by another frost, Hutjens says.

“If you have to harvest it really immature, before there is much cob formation, it's going to feed more like a sorghum-sudangrass or other grass-type silage or forage source,” Hutjens points out.

“But it could feed more like corn silage depending on what type of ear formation and what caused the producer to have to chop the crop.”

Besides having patience, growers should have silage nutrient content analyzed. “Then go to a nutritionist and say, ‘Look, I've got feed that's got 10% protein, only 5-10% starch and 55-60% fiber digestibility. What do I do with it?’”

Grainless corn silage can be higher in protein — 9.6% vs. 8% for normal corn silage. It's lower in starch; normal corn silage contains about 30%. It's also lower in energy — 65% TDN vs. 70% TDN in normal corn silage, Hutjens says.

“If it's more grass-like, it's going to be fairly lower in fiber than if it's more stover-like. And I would expect the digestibility would be fairly good if it's not becoming too stalk-like.”

Hutjens says immature corn silage could be an inexpensive forage for livestock producers who need to buy it. “It's going to be much better than that low-quality first-cutting hay that got rained on and delayed. In some situations, this could be a very economical forage diluter for some of that plain-Jane first crop.”

The bottom line, Hutjens says, is that immature corn silage is still a good feed resource. “If it's chopped at the right length of chop and at the right moisture levels so it will ferment properly, inoculate it and try to push that fermentation. Then test it and build the ration around it.”

For more information on harvesting frost-damaged and immature crops, visit the following Web sites.

Minnesota: www.extension.umn.edu/frostdamage;

Wisconsin: www.uwex.edu/ces/crops/uwforage/uwforage.htm;

North Dakota: www.ext.nodak.edu/extnews/newsrelease/2004/current/01index.htm;

South Dakota: sdces.sdstate.edu. Click on “Crops.”