Wild Parsnip (Pastinaca sativa) has been in the press this Summer. Hay from non-
improved pastures should be checked for the presence of Wild Parsnip. Wild Parsnip may
contain chemicals called furanocoumarins. The concentrations of these furanocoumarins in the
parsnip may be higher than normal in many areas of the state. The concentration of
furanocoumarins in Wild parsnip has been shown to be higher in the presence of the parsnip
webworm, (Depressaria pastinacella). Furanocoumarins enhance the ultraviolet light effect of
the sun. Severe sunburn may occur if furanocoumarins are on the skin because of contact or in
the blood vessels just below the skin because of ingestion. Severe sunburn in cattle ingesting
furanocoumarin containing hay is reduced if the cattle are shaded from the sun’s ultraviolet light.
The rate of furancoumarin breakdown in hay is not well characterized.