Common ragwort

The ragwort, also called Jacob’s ragwort, is an old native, golden-yellow flowering plant up to 1 metre high, whose flowering period extends from mid-June to August. What is new about it is its extremely strong spread, especially on pastures and grasslands that are hardly mown or not mown at all, as well as on roadsides and embankments. Its proliferation is a major risk for grazing animals, as its offshoots contain toxic pyrrolizidine alkaloids that lead to chronic liver poisoning and, in the accumulation of prolonged consumption, can cause further chronic diseases.

Horses and cattle in particular react much more sensitively to smaller amounts of the ragwort than sheep or goats. Not only do its alkaloids have a toxic effect when fresh, but also after hay and silage preparation. For horses, an intake of 40 g/kg bw is a lethal dose, for cattle an intake of 140 g/kg bw. Symptoms of poisoning in horses include fever, sweating, hives, diarrhoea, flatulence, apathy and unnatural foaming. Further consumption leads to impaired vision, convulsions, muscle tremors and paralysis. Therefore, any feeding of ragwort should be avoided or its spread prevented by frequent mowing.