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Cows and calfs in a field with Ragwort

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Comments (3)

Erik van den Ham on November 6, 2007

Poisonous effects

Ragwort contains many different alkaloids, making it poisonous to animals. Pyrrolizidine Alkaloids have been reported by the WHO to be toxic to humans. (EHC 80,section 9.1.4). Alkaloids which have been found in the plant confirmend by the WHO report EHC 80 are -- jacobine, jaconine, jacozine, otosenine, retrorsine, seneciphylline, senecionine, and senkirkine (pp322 Appendix II). Other alkaloids claimed to be present but from an undeclared source are acetylerucifoline, (Z)-erucifoline, (E)-erucifoline, 21-hydroxyintegerrimine, integerrimine, jacoline, riddelline, senecivernine, spartioidine, and usaramine.

Ragwort is of concern to people who keep horses and cattle. In areas of the world where ragwort is a native plant, such as Britain and continental Europe, documented cases of proven poisoning are rare because the result of ragwort poisoning may only become apparent many months after ingestion of the alkaloids. Although horses do not normally eat ragwort due to its bitter taste. The result, if sufficient quantity is consumed, can be irreversible cirrhosis of the liver. Signs that a horse has been poisoned include yellow mucus membranes, depression, and lack of coordination. Animals may also resort to the consumption of ragwort when there is shortage of food. In rare cases they can even become addicted to it. Sheep, in marked contrast, eat small quantities of the plant with relish. The WHO warns however that sheep and goats suffer the same process of liver destruction but at a reduced rate to horses and pigs. They seem to profit slightly from eating it, according to some reports [attribution needed] the alkaloids kill worms in the sheep's stomach.

The danger of Ragwort is that the toxin can have a cumulative effect. The alkaloid does not actually accumulate in the liver but a breakdown product can damage DNA and progressively kills cells. About 3-7% of the body weight is sometimes claimed as deadly for horses, but an example in the scientific literature exists of a horse surviving being fed over 20% of its body weight. The WHO warns that frequent ingestion of very small doses is just as harmful as ingesting one lethal dose in one meal. The WHO warns that humans using herbal remedies suffering jaundice from ingesting PAs have a high risk of death 18 months to 24 months later. The effect of low doses is lessened by the destruction of the original alkaloids by the action of bacteria in the digestive track before they reach the bloodstream. There is no known antidote or cure to poisoning, but at least one example is known from the scientific literature [attribution needed]of a horse making a full recovery once consumption has been stopped.

Honey collected over Ragwort has been found to contain small quantities of jacoline, jacobine, jacozine, senecionine, and seneciphylline.

Taken from:Wikipedia Ragwort

Amelia Royan on December 8, 2008

I know this is a dangerous combination. It is a 'reportable weed' in the UK. I don't know about Holland, but I suspect it's the same.

Greetings, Amelia

Erik van den Ham on December 8, 2008

No its not! There is a certain policy on it. Farmers should remove it from their hay meadows. The fresh plant is no direct threat as the cattle does not eat it. In hay however the bitter taste disappears and than they will eat it and be poisoned

Greetings Erik.

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  • Uploaded on November 6, 2007
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    by Erik van den Ham