Corn production has changed. More efficient combines lose less grain, and modern corn hybrids stand up better to pests and weather, avoiding ear drop. So, given these new realities, are your corn stalks providing all the nutrients your cows need? Bruce Anderson, University of Nebraska Extension forage specialist, offers the following advice.
“Ten to 15 years ago, about 4% of the corn grain was left in the field due to downed ears and combining losses. Today, it’s about half that, or about 1 lb. less grain/acre for the cows to consume for every bushel harvested,” he says.
The rule of thumb for initiating the feeding of protein supplements on corn stalks is when you no longer see grain in the manure. But with less grain in the field, protein is needed earlier, usually about ½ lb. of actual protein/cow/day, preferably from natural sources, he says.
Energy is a bit harder to judge, but as long as there’s grain, cows should be okay.
“The same holds true for the husks. Surprisingly, they are high in energy, between 65-70% total digestible nutrients (TDN). But once the husks have been eaten, trampled, or blown away, it gets iffy,” Anderson says. “Leaves tend to be in the mid-50s for TDN, which is about the same as what the cows require. But stalks themselves may be 10 points lower. So cows eating a fair amount of stalks will lose weight and body condition, even with protein supplements.”