The best way to utilize cornstalks is to graze them. Cattle graze selectively, looking for the more palatable feedstuffs. The more palatable parts of the plant are also more nutritious. Cattle first eat the remaining corn grain, then husks, then leaves, and finally the stalk.
Cattle will eat the more digestible and higher protein portions first. Therefore, a good mineral is probably the only supplementation needed for the first month unless the herd includes fall-calving cows or stocker calves. For them, a supplement will be necessary to meet nutrient demands of lactation and growth, respectively.
Using an equation developed at the University of Nebraska, a field that averages 200 bushels per acre yields 2,832 pounds of leaf and husk. Only 50 percent of the 2,832 pounds is available for the animal; the rest is trampled or lost in weathering. Thus, 1416 pounds of DM husk and leaf per acre are available as feed.
A 1300-pound cow consumes 884 pounds of DM per month. At 200 bushels an acre, approximately 2/3 acre of cornstalks are needed to feed the cow for 30 days. To feed the same cow on cornstalks for 60 days, 1.3 acres would be needed. Producers should scout fields for ear drop or down corn areas. A significant amount of grain loss in fields can cause acidosis or founder in animals. Fields with these areas will need careful management via strip grazing or completely fencing the problem areas out.
Advances in portable electric fencing technology can be your friend when grazing cornstalks. Strip grazing can be easily achieved with geared reels, step-in posts, and a solar fence charger. While strip grazing has showed to increase the utilization of cornstalks, it is important to be timely with moves. Paying attention to cow behavior will be the simplest way of knowing when to move the fence. Rain and wet weather can increase trampling and require quicker moves.
On the other hand, some technology may work against you. Many newer combines are equipped with mowers on the head to reduce residue build up. If you plan to graze the cornstalks it is recommended to turn the mowers off. Mowing reduces particle size and speeds up degradation of the cornstalk. Mowed residue will break down faster. Thus, less will be available for animals after a few weeks.
Extreme weather conditions during the growing season are worth reflecting on. Dry conditions can create accumulation of nitrates in the lower stalk. Fortunately, cattle will eat the stalk portion of the plant last. As a result, concern of nitrate poisoning is low when grazing. Best practice in this scenario is to ensure cows are not forced to eat the stalk. If baling cornstalks for feed, a nitrate test is recommended.
Foliar diseases were a challenge in many corn fields this year. Plant tissues that are affected by disease will break down more rapidly too. I suggest looking to healthy fields for the best cornstalk grazing or baling. Fields that had fungicide applied may be more suitable for grazing and baling this year.
If you do not have the capability to graze cornstalks, they can be baled. Baling cornstalks will add costs to the feed in the form of fuel, labor, equipment costs, and fertilizer replacement costs. Even with these costs, it can still be an economical feed. Hauling manure back to the harvested fields will displace some fertilizer costs associated with cornstalk removal.
Generally, fertilizer value of a 1200-pound round bale of cornstalks is around $12. Remember harvesting costs such as fuel, labor, transportation, and equipment wear are all real costs to evaluate.
As an aside, less wheat acres in some areas of the country translates to a shorter supply of straw. Current prices for straw are strong. So, if you need bedding, consider baling cornstalks. It will be more cost effective than buying straw.
All in all, utilize cornstalks to fill a forage gap and for bedding needs. Just like poor hay, baled cornstalks will need supplemented. Grazing cornstalks is a no-brainer. Use clean, healthy fields for the best results. Cornstalks can be great alternative forage and an opportunity to hold costs down on your cattle farm.
Written by: Travis Meteer; University of Illinois Extension Educator, Commercial Agriculture, article used with permission