The Herbicides of Concern Aminopyralid, clopyralid, fluroxypyr, picloram, and triclopyr are in a class of herbicides known as pyridine carboxylic acids.
They are registered for application to pasture, grain crops, residential lawns, commercial turf, certain vegetables and fruits, and roadsides They are used to control a wide variety of broadleaf weeds including several toxic plants that can sicken or kill animals that graze them or eat them in hay. Based on USDA-EPA and European Union agency evaluations, when these herbicides are applied to hay fields or pasture, the forage can be safely consumed by horses and livestock—including livestock produced for human consumption. These herbicides pass through the animal’s digestive tract and are excreted in urine and manure. They can also remain active in the manure even after it is composted.
http://www.pesticides.montana.edu/Refer ... edsoil.pdf
http://orange.ces.ncsu.edu/files/librar ... ryover.pdf
http://www.beyondpesticides.org/gateway ... cloram.htm
http://www.beyondpesticides.org/gateway ... clopyr.htm
http://www.beyondpesticides.org/gateway ... oxypyr.htm
http://www.beyondpesticides.org/gateway ... yralid.htm