Ragworth dividing opinions for farmers and horse owners

“A weed is just a plant in the wrong place”, and a plant to which the right or wrong place applies more than many is the common ragwort or Senecio jacobaea.
This leggy three-foot-high plant with ragged green leaves and bright yellow, daisy-like flowers, petals arrayed like the spokes of a cartwheel, was eulogised by John Clare and has been the subject of its fair share of controversy and even legislation. Regarded as “injurious” in the 1959 Weeds Act and subject to control by landowners legislation, these innocently sunny plants (Clare’s “shining blossoms”) contain alkaloids that are toxic to livestock. Horses in particular can suffer fatal liver damage, and so there is pressure to prevent the spread of the plant.
Conservation bodies say the threats from ragwort “spread” are exaggerated, and that it has an important role in the ecosystem as the main or sole food plant of at least 30 specialist invertebrates, including solitary bees, moths, beetles and hoverflies. Ragwort has been grown deliberately for insects. The plants are often covered in caterpillars, ringed in yellow and black. These are the caterpillars of the spectacular black-and-red cinnabar moth.
Ragwort germinates in the autumn (mainly) and spring. A seed can germinate anywhere the soil surface is exposed and conditions are favourable. In grassland situations this can be due to poor sward establishment, poaching etc. Ragwort does not tolerate regular soil cultivation and is rarely a problem in arable fields.
Poisoning. Ragwort is a highly poisonous plant if eaten. Ragwort is toxic to cattle, horses, deer, goats, pigs and chickens. Sheep are less affected by it but some trials would suggest lower thrive due to eating ragwort The poisonous substances in ragwort are toxic alkaloids (Jacobine, Jacodine and Jaconine). These cause the liver to accumulate copper, causing ill health and death. On good pastures livestock avoid eating ragwort, as it is unpalatable, but where there is over-stocking and grass is scarce the weed is unavoidably eaten. The poisonous material contained in ragwort is not destroyed by drying. Hay containing ragwort is particularly dangerous. Grass silage containing ragwort is also a serious source of poisoning. Cases of poisoning occurring in late winter and spring often result from the feeding for some months previously of hay or silage cut from ragwort infested swards.
Control of Ragwort. The only way to safeguard against loss from ragwort poisoning is to eradicate the weed either by pulling, ploughing, cutting or chemical control. There is no doubt that more control is needed in our area and I hope this article will make people more aware of the dangers of ragwort and the importance of controlled growth of this plant in order to both protect livestock, horse and many species of insects.
Please feel free to contact me for any question or comments on this subject or any other animal related subject by
email info@kenmarevc.ie or on 064-6642695
Henk Offereins DVM, MVSc
Kenmare Veterinary Centre, your registered animal hospital and supplier, Mart Road, Kenmare