A shortage of cattle feed, and the high cost of the feed that is available, is forcing producers to scramble for alternatives this year. Grazing cornstalks is a good option that should be considered, says Aaron Stalker, a range systems specialist at the University of Nebraska’s (UNL) West Central Research and Extension Center in North Platte.
“A lot of folks don’t realize the great and underutilized cattle feed resource cornstalks are. That's particularly true in Nebraska where 70% of corn gets at least some irrigation water, but only 25% of the available cornstalks are grazed. It's not a high-quality feed, but a mature, non-lactating cow will gain body condition under an appropriate stocking rate," he says.
In fact, Stalker says recent research conducted at UNL's Gudmundsen Sandhills Laboratory research facility compared the performance of cows wintered solely on cornstalks, with cows wintered on native winter range in the Sandhills and supplemented with a 32% protein supplement.
"At a stocking rate on cornstalks of 1½ animal unit months/acre, or 45 grazing days/acre, the cows on cornstalks gained the same amount of body condition without supplement as did the supplemented cattle grazing pretty good native range in the Sandhills," Stalker says.
$1/cow/day in savings
Bruce Anderson, UNL forage specialist, says winter grazing corn stalks can save over $1/day/cow compared to feeding expensive hay.
"But the way you manage grazing of stalks by your cattle can have a big effect on its success. For instance, maybe you have a goal of feeding as little protein supplement as possible while winter grazing. You must make sure you have enough acres so your stocking level can be light enough to allow cattle to select just the higher-quality plant parts to eat. When the grain, husks and leaves are gone, move to a fresh field," he says.
He says cornstalks can also be utilized as "filler" while limit-feeding corn, distiller’s grains, or other more nutrient-dense cattle feeds. In that case, high stocking levels and unrestricted access might be best.
Whatever your strategy, consider carefully the level of nutrition the animals are getting from the stalk pasture so you neither underfeed nor overfeed expensive supplements, Anderson adds.
Stalker concurs that the first and foremost consideration in grazing corn stalks for cattle feed is stocking rate.
“Different parts of a corn plant vary widely in their nutrient content. When turned into a cornfield, the first thing cows seek out is the downed ears. Next, in order of cattle's preference, are the husks, followed by the leaves.”
The husks are more digestible and nutrient-dense than leaves but make up only about 12% of the residue left in a field. Meanwhile, the leaves are capable of allowing a mature, non-lactating cow to maintain her body weight. Because the stalks and cobs are of poorer quality, cows forced to eat them will lose body condition.
“That’s why stocking rate is so important. If you move the cows to a new field as soon as they finish eating all the husks and leaves, they’ll perform really well during the winter,” Stalker says.
Because trucking is potentially a major cost of grazing cornstalks, a rancher can greatly spread out his fixed costs by staying in the cornfields longer. And since grazing cornstalks is so much less expensive than a lot of other cattle feed options this year, there’s incentive to stay in the cornfields as long as possible.
“Obviously, if a producer is paying by the day, it’s to his advantage to have the cows moved to a new field more often, because the cows will perform better. However, if he doesn’t have an unlimited amount of acres rented, or if he’s paying by the acre, then there’s an optimum stocking rate,” Stalker says.
A decision support tool has been developed by UNL to help producers determine the optimum stocking rate by estimating the costs and returns associated with grazing cornstalks. Find it by going to beef.unl.edu and searching for "Cornstalk Grazing Calculator."
No effect on crop production
Stalker says a common misconception about cornstalk grazing is its effect on subsequent crop production. “For the majority of corn fields, there are no negatives to grazing. In fact, on high-yielding fields, removing a little of the residue actually increases subsequent yield," he says.
Dryland fields might be a different matter. If water is limiting, the residue cover can help prevent soil-moisture evaporation. It's also effective in minimizing water runoff and capturing snow, as well as minimizing erosion on highly erodible cropland.
Those caveats aside, Stalker says grazing corn stalks as a cattle feed is all positive. And, while some worry about compaction, research shows it's not a real concern. Plus, the manure deposited on the field in a grazing situation is a big attribute.
Jon Holzfaster, a farmer-feeder near Paxton, NE, attests to the benefits of grazing stalks. His family feeds out 1,000 to 1,500 head of cattle annually, relying significantly on ethanol byproducts available in the area. They also cash farm thousands of acres under center pivots, about 3,500 corn acres of which are grazed by area cow-calf producers on a contract basis once fall harvest is complete.
"For the last 15-18 years, we've brought in bred cows to utilize cornstalks as winter pasture. We use temporary electric fence and make sure they have water; the older cows really do well on stalks," he says.
"It’s a win-win; it allows us to reduce some of our residue so that our strip-tillage works better with the Roundup-ready varieties we plant. And the cattle do a great job of eliminating volunteer corn because they pick up those stray kernels. It’s become part of our normal operation."
Holzfaster's staff does the fencing, water and moving of the cattle, and put out salt and mineral provided by the rancher, but the workload differs by the contract. "We have different arrangements whereby the rancher might do a flat cash rent on the circle and do all the fencing, watering and management himself. Or anything in between, whatever the relationship is between us," he says.
The Holzfasters have developed long-term relationships with several ranchers, an arrangement that benefits both parties. "They're comfortable with what we do and how we do it," he says. He jokes that the only drawback is "not being able to put your feet up and drink a cup of coffee when the weather turns bad in the winter."
Cattle can go on residue anytime after harvest, but Holzfaster generally waits until the neighborhood harvest is completed. "Temporary electric fence can fail and we sure don’t want to get cows wandering into neighbor’s standing crop," he explains.
He says they've begun grazing as late as January, but with this year's early harvest, he anticipates an early- to mid-November start. The cattle generally are off the field by mid March, in time for fieldwork to begin.
Holzfaster says his day-to-day familiarity with the land is a big factor in determining stocking rates and movement patterns.
"We don’t like to pasture too terribly heavy because we feel there's value to maintaining some residue on the field for erosion control and nutrient breakdown. Our rule of thumb is that for 130 acres, 100 cows for 30 days is a pretty light stocking rate. So you just multiply that by the number of head or how hard you want the ground worked.
"On sandier ground, you might not want it pastured quite as hard. But with the yields increasing how they are – some of it is 200+ bu. corn – there’s a lot more residue out there, so you can stock it a little heavier." As mentioned before, UNL’s Cornstalk Grazing Calculator is a helpful tool for determining the appropriate stocking rate.
Holzfaster says residue grazing works best for older cows because they tend to be more effective and aggressive at foraging.
"Younger cows – first-and second-calf heifers – haven’t figured out how to make it work yet. And bulls are just too lazy to go out and hunt. So younger cows and bulls aren’t always the best fit for cornstalks, but it does work; you just have to take a little more intensive management approach and make sure they have enough supplement. They can fall behind pretty quick."
Holzfaster says he realizes drought is forcing more producers this year to investigate residues as a source of cattle feed. He's a firm believer in cornstalk grazing.
"I’d encourage anyone who hasn’t done it before to try it. I think they will enjoy how it works, particularly if they can lock in a long-term relationship," he says.
• The Nebraska Corn Board (NCB) is working with the University of Nebraska (UNL) to generate greater interest among corn producers to bale and graze crop residue for use as beef cattle feed. Kelly Brunkhorst, NCB director of research, says UNL Extension personnel are recording videos detailing various aspects of grazing, stover removal and its use in beef rations. NCB's role is to reach out to corn growers on stover removal’s potential benefits. The spots began airing in September on "Market Journal" (marketjournal.unl.edu/).
• In addition, the UNL is offering a webinar, entitled “Cornstalk Grazing – Understanding the Value to Cattle Producers and Corn Farmers,” on Oct. 2, from 12:30-1:10 p.m. Learn more here.
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