Cornstalk bale quality differs from grazing cornfields, may require supplementationWritten by Gayle Smith
Many producers assume baled cornstalks are equal in value to grazing a cornfield, but the two are vastly different, explained Aaron Berger, Extension Educator in Nebraska. When grazing a field of cornstalks, the cows get a higher quality diet early on because they go through and eat all the downed corn, leaves and husks, which are of higher feed value and leave the low-quality stalks for last.
When eating a cornstalk bale, the stalks are in the bale with the husks and leaves, so the cattle are consuming a lower quality forage to start with. In fact, Berger said a cornstalk bale isn’t of much higher quality than feeding cattle wheat straw.
Test the bale
“Cornstalk bales need to be tested just like any other hay,” according to Berger.
The bales can be sampled using a hay probe, but it is important to get a good, representative sample.
“A good bale probe, when it’s sampled, should give you a fairly accurate representation of what’s in the bale,” Berger said. “I think if you have 50 bales, I would try to get a good core sample from at least a third of them. Mix those core samples together thoroughly and send them in for analysis.”
Berger recommends having cornstalk bales analyzed by a lab using the wet chemistry method, rather than an NIR. A wet chemistry analysis determines the actual crude protein, energy and total digestible nutrients.
He also stressed the importance of having the sample analyzed for nitrates.
“It will cost about $12 more, but it is important information to have. There is the potential for higher nitrate levels this year, than we would normally have, because of the drought,” he said.
Twelve dollars would seem relatively inexpensive if you don’t have it tested and a cow gets sick or dies from nitrate poisoning.
Each laboratory has different procedures for reporting nitrate levels, but typically they provide a range, and let the producer know where the sample ranks.
“Bales high in nitrates can be managed,” Berger said. “You have to be careful with pregnant cows, but weaned calves or replacement heifers that aren’t pregnant can utilize a little higher nitrate feed, adjust to it and still be okay. It can also be blended with other feeds.”
Improving the quality
“The most effective way to feed a cornstalk bale is by grinding it or mixing it with some other feed,” Berger explained.
The quality of grinding is also important. If the stalks are finely ground or pulverized, the cattle will consume more, and there will be less waste. In some instances, Berger said farmers may take the spreader off the combine when harvesting the corn, so what is baled up is leaves and husks. But most of the time, the bales will also contain the stalks.
The trick of feeding cornstalk bales is getting the cow to consume as much of the bale as possible. Berger estimates the cow will waste nearly a third of the bale, most of which will be uneaten stalks. By grinding the bale and feeding it with a supplement like alfalfa, distiller’s grains or some corn, producers can provide the cows with the additional energy and protein they need, beyond what the cornstalk bale can provide.
Balance the ration
If producers are considering cornstalk bales, Berger cautions them to make sure the cow is receiving a balanced ration.
“You can’t just feed a cow cornstalk bales, especially just prior to calving, and expect her to hold herself together. You need to feed a supplement to go along with it,” he said. “What supplement a producer feeds is going to vary with the quality of the cornstalk bale, the nutrient requirements of the cow, and what stage of production she is in. April to May and May to June calving cows may not need much supplement if they are in good body condition,” he explained. “However, if the cows will calve in January or February, they will need a pretty good supplement to go with the cornstalk bales, in order to maintain their body condition.”
“Once the bales have been tested, I would encourage producers to work with an Extension person experienced in formulating rations or a feed dealer to formulate a ration that will meet their goals, especially if they are feeding something they aren’t familiar with,” he said.
Cornstalks may be in abundant supply
University of Nebraska Extension Educator Aaron Berger estimates that in Nebraska alone, 10 million acres of corn will be harvested this fall. Some researchers estimate in past years, only 25 percent of the available cornstalks in Nebraska were utilized.
“That is a lot of corn residue that could be a potential source of feed for the cows during a year when we don’t have anything else,” he said. “It provides ranchers an opportunity to find something to feed their cattle. Distiller’s grains are expensive, but if they are combined with cornstalk bales, it will get the cow through the winter months.”
Although most producers prefer to graze a cornfield, some have to bring cornstalk bales to the cow if there is no access to water, fences are difficult to put up, or the farmer won’t allow cattle to graze the cornfield.