Downed Trees, Poisonous Plants and Livestock

Mark Landefeld, ANR OSU Extension Educator

The recent storms that came across Ohio caused many trees to be broken off or blown down in pasture fields and fence lines. A variety of plants and trees can cause serious injury/death to livestock, particularly if animals graze the plants at certain stages. All pastures and paddocks should be immediately checked for the plants listed below because wilted leaves can be extremely toxic to livestock.

WILD BLACK CHERRY, CHOKE CHERRY, AND PEACH (Prunus spp.) – Many species of cherry and peach are poisonous. These species are characterized by alternate toothed leaves, white or pink flowers, and fleshy fruits (cherries or peaches). Crushed twigs and leaves yield a strong cyanide odor. Two native species of cherry are common in Ohio. Wild black cherry (P. serotina) is a large tree that is distributed widely throughout the state in woodlands, old fields, and along fence rows. Choke cherry (P. virginiana) grows as a large shrub or small tree and is scattered throughout Ohio in a variety of habitats, though it is more frequent northward. Peach (P. persica) is a small introduced tree that occasionally escapes from orchard cultivation through seed.

Seeds, twigs, bark, and leaves contain a glycoside (amygdalin) that quickly breaks down by hydrolysis (from bruising, wilting, frost damage) to form the highly toxic compound hydrocyanic (prussic) acid (or cyanide). Poisonings occur most frequently when wilted leaves are eaten, but have also been reported when leaves are consumed directly from the tree, or sprouts, or in dried hay. The amount of hydrocyanic acid formed once the plant material is ingested is affected by the type of stomach juices and the kind of feed the animal had previously consumed. Ruminant animals appear to be more susceptible to poisoning than horses.

Cyanide poisoning results in hypoxia (deficiency of oxygen reaching the tissues). The first symptoms appear within a few minutes following consumption of plant material. Affected animals exhibit excitement, incoordination, convulsions, rapid and labored breathing, bloating, and coma. Death can occur in less than an hour due to internal asphyxiation (OSU Bulletin 762).

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Wild Black Cherry

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Red Maple

RED MAPLE (Acer rubrum) – Red maple is a large native tree found in moist woodlands and swamps throughout Ohio. Leaves are opposite, generally triangular with three or five lobes, coarsely toothed, and silvery white beneath. Poisonings result from consumption of wilted leaves and have only been reported for horses. Toxicity is most prevalent from June through October, but may be greatest in autumn foliage. Dried leaves are reported to remain toxic for 30 days. The cause of toxicity is not known. Primary effects are acute hemolytic anemia, methemoglobinemia, and Heinz body formation in the red blood cells. Symptoms develop three to four days after ingestion of leaves and include rapid breathing and heart rate, weakness, depression, jaundice, cyanosis, brownish discoloration of blood and urine, coma, and death (OSU Bulletin 762).

Also, drought conditions we are currently experiencing increase the chances that livestock will consume plants they would not normally eat if forages were plentiful. Ohio State University Extension Bulletin 762, Horse Nutrition, (http://ohioline.osu.edu/b762/index.html) and Purdue Extension Bulletin WS-37, Guide to Toxic Plants in Forages, (http://www.extension.purdue.edu/extmedia/WS/WS_37_ToxicPlants08.pdf) list many plants and shows pictures to help producers be aware of potential dangers in their fields.

EDITOR’s NOTE: This 10 minute YouTube presentation by OSU Extension Educator Jeff McCutcheon also describes many potentially toxic plants to livestock: