THE POISONOUS plants that lurk in Missouri pastures, ditches and fencerows can harm and even kill livestock that eat them along with baled forage, a University of Missouri agronomist said.

Fred Fishel, director of the MU Integrated Pest Management program, has written a guidesheet to familiarize farmers with poisonous weeds in Missouri. MU Extension Guidesheet G-4970, Plants Poisonous to Livestock, lists, describes and illustrates the most common toxic weeds along with symptoms to look for in suspected cases of livestock poisoning.

"There are a number of producers who will send in a plant for identification," Fishel said. "Their second question usually is, `Is it poisonous to livestock?'"

Several toxic weed species are common in native or improved Missouri pastures, he said, but the animals tend to avoid them in the field. "They often have an aroma or certain characteristics like spines or thorns that make them undesirable to livestock."

Danger looms when farmers fail to scout their hayfields for toxic weeds before cutting. "In cut hay, the poisonous plants might be mixed in with desirable forage and the animal might not detect it," Fishel said. "People who are cutting hay need to pay attention to what they're seeing in the fields."