This year, extreme heat stress likely has decreased ear size which in turn could cause smaller ears to bounce off the combine head during harvest, increasing yield losses and leaving more whole ears on the ground in the field. If this occurs, the whole ear may be intact for cattle to scoop up and eat whole. While not as worrisome as spilled corn piles, depending on the quantity, whole ears require attention to safely graze corn fields.
If combines hit the fields and yields are less than desirable, grazing standing corn may be an option to reduce harvest and livestock feed costs. Doug Sieck, a producer from the Selby, SD area, recommends leaving 30 rows of standing corn in a field and combining a pass of 6 or 12 rows to get an idea of yield potential. Knowing yield potential then allows you to allocate enough grain and residue to meet livestock needs for your desired time. As a rule of thumb, Doug recommends allocating enough feed for one day moves or about10 pounds of corn and 10 pounds of corn residue per head per day which will meet the energy needs of a midgestation cow. However, before we can turn cows out, they need to be fed a step-up ration to adjust to this higher percentage of corn. Generally, a safe way to incorporate higher amounts of corn into the diet is to start feeding about 3 to 4 lbs. per head per day and increase by 2 lbs. per head per day until the target of 10 lbs. per head is reached. Use the combine and determine yield per acre and plan 50 pounds of corn residue is present per bushel harvested that they graze with the ear corn. With this method, cattle may still be hungry as this won’t meet the target daily intake of 2.5 percent of their body weight in dry matter. Supplemental protein, like alfalfa or cake, can be given twice weekly to help maintain cattle comfort and balance nutrient needs. As with most alternative forage options, good fencing and trained cattle are important when grazing standing corn. Jim Gerrish recommends ‘putting up tomorrow’s fence today’ as a backup plan in case cattle get out of the allocated area.
Creating Allotments
Create allotments based on yield per acre and intake goal for the herd with temporary fence. Knowing how many cows will be grazing the field is helpful when creating the allotments. If the allotment are underestimated or cow body condition declines, more frequent moves are needed. The general rule of thumb is that one pound of grain is equal to one pound of stover. Below is an example of the necessary allotment for a 100-head cow herd using one-day rotations.
Example: 50 bushels of corn per acre with 50 pounds of residue per bushel.
- 50 bu per acre × 56 lbs. per bushel = 2800 pounds of corn grain per acre
- 75% grazing efficiency = 2100 lbs. of each corn grain per acre
- Herd Size = 100 cows
- Feed Target = 10 lbs. of grain + 10 lbs. of residue
- (100 hd × 10 lbs. corn) ÷ 2100 lbs. corn per acre = 0.48 acres per day for 100 cows
A modification to this example could be moving and setting up one-acre parcels for two-day feed allotments may be more favorable than moving fence every day. Even with the labor needed to move fence, there is time and energy savings compared to spending that time driving the feed wagon to deliver feed to those same cows. If cows are supplemented every other day with protein, the feeding and fence moving can be done at the same time. Letting cattle harvest your corn will save you money harvesting, trucking, and storing the grain. Doug shared that grazing standing corn on his operation equates to roughly $0.75 per cow per day compared to roughly $4 per head per day in a feedyard. In addition, it is a fuel-efficient way to spread manure around the field and enhance soil nutrient cycling.
Best Management Practices
Best management practices of grazing corn, aside from starting cattle on corn before turn out, include keeping access to clean water and an ionophore, testing the corn for nitrates, wind protection for winter weather and a backup place to feed them if cattle can’t get out to graze. With careful management, grazing standing corn can be an efficient and cost-saving grazing system to try when forage is in short supply. For more information, listen to the Cattle HQ Podcast, Are you harvesting your corn the correct way? Tips to Graze Standing Corn.
