Livestock are grazing on pastures or hay treated with persistent herbicides that are finding their way into the compost bins. Dow AgroSciences produces the herbicide aminopyralid for treating broadleaf weeds in pastures and lawns. Cows and horses graze upon the treated grass and hay which is digested, excreted and composted. For years afterward, the herbicide continues to destroy all garden plants.
For hundreds of years, farmers have used horse and cow manure to fertilize fields of corn, beans, cabbage, tomatoes and many other cash crops, as well as vegetables for home use. There has never been a problem until Monsanto, DuPont (Dow Chemical) and several other large producers of herbicides and pesticides began selling dangerous chemicals that never go away.
DuPont (Dow Chemical) has a long history of developing and selling herbicides to treat pastures and lawns that have come under the scrutiny of the US Composting Council and the EPA. Currently, the EPA depends upon chemical companies to develop their own test protocols. They may as well depend upon these companies to self-report any and all negative feedback from farmers and ranchers.
According to an article in Mother Earth News magazine (February/March 2013), it will be up to the public to pressure the EPA into taking the role of providing test protocols for herbicides and pesticides that kill for generations.
Until that time, do not apply cow and horse manure to compost bins. While you may not use the herbicides on your own crops, the feed for cows and horses contains the chemical. Time will not make the manure safe to use on cash or kitchen crops.
It may be that the Composting Council and the EPA will have to be up to their necks in manure before there is a change in policy. Meanwhile, contact the director of the EPA's Special Review and Reregistration Division at firstname.lastname@example.org. Let Keigwin know that your farm will not purchase manure for composting on your organic crops until it is proven safe by testing.