Corn struggling in drought-stressed growing areas this season, may be a good option for cattle feed–providing at least some salvage value for affected acres. There are, however, a few cautionary notes.
Kansas State University beef systems specialist, Jaymelynn Farney, says silage is likely the best choice, but notes there are other considerations.
“Drought-stressed corn silage or baleage is often higher in protein than conventional corn silage, even though energy values are generally lower,” she notes. “Additionally, drought-stressed corn silage has less lignin than conventional silages.”
She says if property ensiled, nitrate concentration on drought-stressed corn will be reduced 30% to 60% after the ensiling process. Optimal moisture content for proper ensiling depends on storage method. Silage stored in a bunker, for example, should be harvested at 65% to 70% moisture; baleage can be 45% to 60% moisture.
“Putting up drought-stressed corn for hay,” she adds, “is the least recommended because even when we think it is very dry, it’s large stem generally isn’t. If putting up for hay, condition the stem to aid in drying.”
Farney points to a 2012 North Dakota State University study where corn was cut for hay and had to cure for 30 days to reach 16.2% moisture. Also nitrates are not reduced in hay, like they are during the ensiling process.
Another option to use drought-stressed corn would be in-field grazing. This would minimize nutrient removal from the field. Be aware there is potential for nitrate toxicity and acidosis. Nitrate toxicity potential is reduced if cattle don’t eat the stem and lower 8 inches. Acidosis can be a concern, depending on how much mature grain is in the field.
“To minimize issues with acidosis, strip graze and allow the cows only a couple of days in each strip,” she recommends. “Calf gains while grazing standing corn have been reported between 1.6 and 3.3 pounds per day.”
The energy value of drought-damaged silage can range from 75% to 95% that of regular silages. Farney says it’s important to test silage for nutrient content to help balance the ration. Limit feeding is best for this, as cows will voluntarily consume 2.5% of body weight on a dry matter basis of corn silage.