Standing Corn Grazer

Low grain prices encourage some ranchers to bring the herd to the corn.

Doug Sieck says successfully grazing a cow herd on a corn field takes detailed planning and daily management, Image by Dawn Sahli

Doug Sieck learned about grazing standing corn 10 years ago, but it wasn’t until prices reached break-even levels in 2016 that he decided it was time for him to try feeding corn right from the field.

The rancher works a 3,000-acre operation in north-central South Dakota, where recent years have seen him convert about 600 acres of cropland back to grass for cattle. Sieck prefers cattle to crops, though he still raises corn, soybeans and hay across about 1,000 acres.

The rancher’s decision to let the herd graze standing corn goes back to a grassland workshop he attended at the University of Nebraska. Today, Sieck jokes it only took him a decade to put the strategies he learned into practice.

CORN YIELD CALCULATION. When corn prices are low, grazing a standing crop is an economical way to feed cows. Sieck calculates he’s able to feed his 300-head cow herd for $1 per head per day. That’s based on grazing corn that yields between 100 and 120 bushels per acre.

“My cows do fine on 10 pounds of corn plus 10 pounds of corn fodder per day,” Sieck says. “In a field producing 100 to 120 bushels of grain per acre, corn stover amounts would range from 3 to 4.5 dry tons per acre.”

Before Sieck started feeding standing corn, he systematically calculated what it would take to support his cow herd. He harvested all but 30 acres of his corn crop, looked at overall yields and calculated paddock size needed to provide 10 pounds of corn (plus 10 pounds of stover) each day for each cow. With that figure in mind, Sieck used his combine to create a checkerboard pattern across the 30 acres.

“Across the length of the field, I combined six rows and left 28,” Sieck says. “Then, I went across the field, combining a path for fences every 80 or 90 yards. That created 60 paddocks with alleyways that separated the paddocks and left room for fencing. I rotated cattle through those paddocks, moving them every day, over a period of two months.”

The practice was so successful and kept winter feed costs so low, Sieck has continued to use the practice. Before he started grazing standing corn, the producer notes he fed his cows about 10 large bales of hay a day at a cost of $480 per day. Having those same 300 cows on a half-acre of 107-bushel corn and adding a couple of bales of alfalfa to maintain nutritional levels, he estimates he spends around $262 per day, equaling a savings of some $218 each day he’s feeding.

VISIBLE FENCING. Bruce Anderson, agronomist and Extension forage specialist at the University of Nebraska, agrees grazing standing corn is an economical way to feed cattle and add value to the crop--especially when commodity prices are low. He recommends taking some precautions, however, to ensure cattle don’t break out of a paddock and gain access to too much corn at one time.

“Fencing needs to be visible to cows, especially when there’s very tempting material on the other side,” Anderson says. “One method some producers have found effective is the use of electric tape rather than electric wire, or electric tape with electric wire. The tape greatly increases overall visibility of the fence. You can also tie flags on the fence to make it more visible.”

Volume of volts delivered to either (polytape or high-tensile wire) depends on the charger used. Both can deliver the same voltage, and cost is comparable. The greatest benefit of the tape, Anderson says, is its visibility; although in areas with frequent high winds, it’s more susceptible to wind damage.

“In grazing standing corn, it’s key to restrict the amount of corn allotted to the cattle at one time,” he stresses. “You don’t want the cattle to trample a large amount of the corn, wasting it.”

GRAIN OVERLOAD. Paddocks not only help preserve standing corn from waste, they help avoid rumen acidosis or grain overload. If cows are moved from a pasture setting to standing corn, it’s important to restrict the amount of corn consumed those first few grazing days to prevent acidosis.

Rumen acidosis occurs when ruminants have a sudden shift in diet from high-fiber roughage (grass or hay) to low-fiber, high-carb grain (corn, barley, wheat). More mature corn crops increase the risk, as kernels are more easily dislodged, and the whole cob is less likely to be eaten. More mature kernels also have more starch, another contributor to acidosis.

It’s important producers monitor cows grazing standing corn to spot problems early. Signs of acidosis may include wandering, panting, excessive salivation, diarrhea, falling, kicking at the belly, etc. To avoid acidosis, move cows frequently, every day to two days, to backgraze stalks or hay.

It may also be important to provide a protein supplement when grazing cornstalks. Anderson says while cows will get plenty of energy from grazing standing corn, they may or may not be getting adequate protein. The only way to know for sure is to check nutrient levels and supplement accordingly.

When cows are first moved from an all-you-can-eat forage system, they often need a few days to adjust to eating less volume of feed. They essentially find a new satiety point when feeding on grain. Producers shouldn’t be surprised if cattle in this scenario are somewhat restless the first few days. Anderson notes in some cases, there is a higher risk of cows breaking out of a paddock if they’ve never grazed corn stalks.

RUN THE NUMBERS. Beef producers considering grazing standing corn should thoroughly calculate every economic aspect of the practice before trying it. Anderson adds that if the primary goal is to avoid a break-even year on corn production, lowering input costs may be an effective strategy, too.

“Use of bin-run corn or non-GMO corn as a seed source can greatly reduce corn production costs,” Anderson explains. “Yields are lower with this type seed, and if corn is intended for grazing, it could be a significant way to further minimize costs.”

As a cost comparison, for 2017, the University of Missouri Extension Service estimates non-GMO seed cost at $61.25 per acre, GMO seed at $96.25 per acre.

Anderson says Sieck’s long-term planning and detailed management for cows grazing standing corn is the right approach. Monitoring cows during their time in these paddocks helps determine how long it takes to clean up a paddock and whether paddocks should be larger or smaller. Those are the kinds of details that can help refine a program, making it even more cost effective.

While monitoring and moving cattle in standing corn involves daily labor during winter, there’s no need to harvest, transport or store the corn. And, there’s no manure to haul out of a feedlot. The nutrients cattle deposit on paddocks are considered another benefit in the practice of grazing standing corn.

Sieck, who’s used to moving cattle through paddocks all year, sees the system as a positive trade-off.

“There are years when cattle are just break-even, too,” he says. “But, if I have to be in a break-even situation, I’d rather do it with cattle than with crops.”


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