Corn harvest is underway in much of Nebraska. Corn residue is a tremendous feed resource for cattle in Nebraska. With Nebraska’s 9 million corn acres and 1.8 million beef cows, there is more than twice the number of corn stalk acres needed for grazing all of Nebraska’s beef cows! The Nebraska Extension Circular “Grazing Crop Residues with Beef Cattle” (http://go.unl.edu/4m7m) is an excellent resource on grazing corn stalks. The following are keys from that resource when planning for grazing cornstalks.
• Scout fields prior to grazing to determine the amount of corn present and to look for piles that could cause grain overload which can result in bloat or death in cattle. If there is more than 8-10 bushels of ears of corn per acre on the ground, a grazing strategy to control corn intake will need to be used.
• Stocking rate should be determined based on corn bushel yield per acre and the average weight of cattle that will be grazing. The “Corn Stalk Grazing Calculator” (http://go.unl.edu/7ejj) is an Excel® spreadsheet that can be used to calculate this and is available for download or as a Mobile App (http://beef.unl.edu/mobile-apps).
• A quick way to estimate grazing days per acre available for a 1200 pound non-lactating cow is to take corn bushel yield and divide by 3.5. For example, 180 bushel yield / 3.5 = 51 grazing days per acre.
• Quality of grazing starts high at approximately 70% total digestible nutrients (TDN) and then decrease to a low of 45% TDN at the end of the grazing period. The rate of quality decline is dependent on stocking rate and environmental factors such as moisture and field conditions.
• Mature non-lactating, spring calving cows in a body condition score 5 or better will not need protein supplement when grazed at recommended stocking rates according to UNL research.
• First-calf heifers in the 90 days prior to calving will need protein and energy supplementation to meet nutrient requirements. Feeding 3.5 lbs. per head per day of dried distillers grains would meet this need.
• Fall-calving cows will need additional protein and energy to meet nutrient requirements. Cows less than three months after calving will need 4.5 lbs. per head per day of a supplement that is at least 30% protein and 90% total digestible nutrients (TDN) on a dry matter basis. Feeding 5 lbs. per head per day of dried distillers grains would meet this need.
• Weaned calves grazing corn stalks with a targeted gain of 1.0 lbs. per day will need to be feed an energy and protein supplement. Research has demonstrated that dried distillers grains fed at 2 lbs. per head per day when calves are grazing corn stalks will usually meet this targeted gain.
• Deep snow and ice can severely limit the ability of cattle to graze corn stalks. Have a backup plan and other feed resources available to meet cattle needs when this occurs.
Corn stalks can be an excellent, economical resource for late fall and winter grazing in many parts of the state. For more information on grazing corn stalks with cattle visit beef.unl.edu/cropland.