Some producers are turning to small-grain crops as feed for their livestock because this year’s drought is causing a severe shortage of grass and hay.
However, herbicides applied to those small-grain crops may make them unusable as livestock feed.
“Most herbicides have grazing and feeding restrictions stated on the label that limit the use of the crop for livestock feed,” North Dakota State University Extension Service weed specialist Rich Zollinger says. “However, the labels are often vague regarding specific information on use of grain crops as forage for livestock because this is not the normal use.”
Pesticides, which include herbicides, insecticides and fungicides, have contributed to substantial increases in crop yields during the past five decades.
Grazing and harvesting a crop for feed following herbicide use often is prohibited because research on residue levels in the crop is inadequate, Zollinger notes. Researchers may not know how the chemical or the products resulting from its breakdown affect livestock or whether the chemical or its breakdown products stay in the animals’ body.
“Livestock that consume crops treated with such herbicides probably would not become ill from the chemicals, but they could retain the chemicals in their system,” Zollinger says. “The concern is that herbicides could be passed in the milk of lactating animals or cause abortion in pregnant animals. The chemical also may have potential to be retained by the animals and be present in the slaughtered carcass.”
He adds that although these problems are not likely to occur, the restrictions listed on pesticide labels are enforceable under state and federal law and producers need to adhere to them.
Milk or animal meat with residues in them can be confiscated and destroyed, resulting in a loss of income to the producer. Producers who violate label restrictions may face monetary fines and loss of certification, and may not be able to sell their livestock into the marketplace, according to NDSU Extension veterinarian and livestock stewardship specialist Gerald Stokka.
NDSU’s “North Dakota Weed Control Guide” has a section titled “Z1. Restrictions on Grazing/Feeding/Haying of Crops Treated with Herbicides.” That section, also available, indicates whether crops treated with specific herbicides can be used for grazing, feeding or haying, and if so, the number of days or weeks producers must wait to use the crops after the herbicide application.