Grazing corn residue with beef cattle
Corn residue is a valuable feed resource for beef cattle. The number of acres planted to corn in Nebraska is about 10.3 million acres (6.3 irrigated; 4.0 dryland/rain-fed). It is estimated that less than 25% of the corn acres in Nebraska are grazed.
We understand how important it is to leave corn residue in the field for all the beneficial attributes that encompasses with regard to cover, organic matter, water holding capacity of the soil, and grain yield. Two experiments, one with 18 years of data (eastern Nebraska location) and one with 7 years of data (west-central Nebraska), show that grazing corn residue using recommendations developed by University of Nebraska Animal Science faculty will not reduce the beneficial attributes of corn residue cover.
1. There is no reduction in grain yield for the growing year following corn residue grazing.
• For corn soybean rotations.
• For corn followed by corn.
2. There is little or no compaction of the soil due to grazing cattle in corn residue fields.
University of Nebraska recommendations for grazing corn residue are based on research showing cattle are selective grazers of a corn residue field. Parts of the corn plant selected by cattle are based on palatability of the different components of corn residue remaining in the field. Cattle will select grain first, followed by husk and leaf, and will select the cob and stem/stalk last.
For every bushel of corn (56 lb per bushel) there is about 45 pounds of residue on a dry matter basis. Research shows that for every bushel of corn there is about 16 pounds of husk and leaves on a dry matter basis.
UNL corn residue grazing recommendation is to remove 8 pounds of husk and leaves per bushel of corn produced. Only about 60% of the husks and leaves are digestible, meaning 40% is not digestible. Using these numbers and targeting a grazing strategy for removal of 8 pounds of husks and leaves per bushel calculates that only 12% of the total residue is removed.
The video “Cornstalk Grazing Recommendations” (http://bit.ly/13NIdlW) highlights this information.
A residue grazing “tool” is available for producers in two formats.
• Corn Stalk Calculator (http://bit.ly/1uC1O4s): Excel spreadsheet that allows users to consider corn yield as criteria for calculating the worth of cornstalks.
• NUBeef-cowQlate app (http://bit.ly/1GudVU4): Collection of calculators (peer-reviewed feed cost calculator, a dry matter conversion calculator, a corn stalks calculator and a bovine gestation calculator)
For additional information, please see these resources.
• Effect of Grazing Corn Residue on Corn and Soybean Yields – http://bit.ly/1thIFNV (2013 Nebraska Beef Cattle Report)
• Grazing Corn Stalk Residue – http://bit.ly/1wAfPya (September 2013)