Most pastures contain a wide variety of plants, and sometimes there are a few species that can be toxic to livestock. Start by educating yourself about what plants are in your pastures—both the beneficial forages as well as the weedy species. UW Extension has publications on the common Wisconsin pasture grasses, legumes and weeds available at the on-line UW Extension Learning Store or through your local county Extension office. Your local UW Extension agent may also be able to assist you with identification of unknown plants. Once a suspicious plant has been identified, there are a several websites that can assist with determining whether a particular pasture plant has toxic properties and links are posted on the Pasture Resources page.

Once you are familiar with the common plants in your pastures, determine whether toxic species are present and develop a plan for controlling those plants. Seek advice on safe and appropriate control methods from your local Extension office or crop production center. If chemical control methods are used, read and follow all label use directions and determine how long you need to restrict livestock access to treated areas. Do not dispose of weeds from lawns or gardens in pastures as some garden plants may be toxic to animals. Observe livestock daily and note unusual behaviors that may indicate plant poisoning. Don’t forget to check your hay and other feeds for presence of toxic plants.

For all pastures, a management plan that includes rotation of livestock between several pasture areas (“paddocks”) will also help decrease weed and toxic plant concerns. Moving livestock between paddocks allows plants to rest and regrow resulting in a more dense and vigorous pasture. Rotate when pastures are grazed down to 3 – 4” of plant stubble (“residue”) to prevent overgrazing and decrease the chance that toxic plants may be ingested by hungry animals.