Donna Amaral-Phillips, Jeff Lehmkuhler, and Chad Lee with the University of Kentucky College of Agriculture Department of Animal & Food Sciences would like farmers to consider the following seven tips when dealing with drought-stressed corn:
— If corn is going to be fed as green chop, grazed, or as hay, test for nitrates before harvest to be sure the crop will be safe to feed. For corn harvested properly as silage or baleage and which goes through a good fermentation, nitrate levels could decrease 30 to 50 percent and can be tested after fermentation and before being fed. If you need to decide which corn fields to harvest as silage or hay, testing before harvesting will allow one to determine which fields need to be harvested as silage (those higher in nitrates) and those with safe levels of nitrates which can be harvested as corn hay. For sorghums and sorghum-sudangrasses, nitrates should be tested before harvest to be safe for your harvest method.
— Check herbicide withdrawals to make sure the crop can be fed to livestock.
— Raise the cut high — nitrates are highest in the plant stem closer to the ground. This may be more difficult if using a disc mower or other hay equipment for the purpose of making hay or baleage.
— If at all possible, harvest as silage and let ferment for 4-6 weeks before feeding. You may want to consider using a silage inoculant. Again, test for nitrates before feeding.
— Immature corn will be more variable in nutrient content than “normal corn silage.” After harvest, test the forage for its nutrient content and develop and feed a balanced ration to your cattle.
— Watch the moisture content of the crop closely. A small amount can be chopped to determine the current moisture content. Corn is drying down quickly in parts of Kentucky. You will need to use a Koster tester or microwave to determine the actual moisture content. Silage and baleage need to be correct moisture to ferment properly and make good feed.
— Can you add enough water at the bagger or silo blower to increase the moisture content of the silage? For each 1 percent increase in moisture content, approximately 7 gallons of water is needed per ton. A typical garden hose delivers approximately 8-10 gallons per minute. Thus, it is nearly impossible to deliver enough water to make a difference. For example, to increase the moisture content from 45 percent moisture (55 percent dry matter) to 60 percent moisture (40 percent dry matter) for a wagon load of silage (4 ton capacity), you need to add 420 gallons of water — not feasible!