By Chris Teutsch and Michelle Arnold
As temperatures fall, livestock producers should pay close attention to forages that can cause prussic acid poisoning. Sorghum, sudangrass, sorghum-sudan hybrids, Johnsongrass and wild cherry contain compounds that may release cyanide when plants are damaged by frost, drought or other stress. The toxin can interfere with an animal’s ability to use oxygen and may cause death quickly.
The risk of prussic acid poisoning is highest in the fall because the first frosts and freezes can make these plants especially dangerous. Young shoots and regrowth also may contain higher toxin levels. Remove ruminants from pastures containing high-risk plants when frost is expected, and don’t allow animals to graze those fields at night when a frost is likely.
Testing removes the guesswork from grazing decisions. Before turning livestock into a questionable field, contact your county Extension office. Local extension offices are equipped with Cyanide Field Test kits that can help to assess risk levels. Because toxin levels can vary across a field and change after frost or new growth, follow the sampling instructions carefully and discuss whether additional testing is needed before grazing or feeding the forage.
Source : uky.edu