Ragwort Hysteria UK This plant isn't that toxic!
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In recent years in the UK there has been a big campaign against ragwort. I think hysteria is the right word since having looked into it nearly every story about it is grossly exagerated or plainly untrue. As you can see the evidence suggests it isn't a big problem. The veterinary diagnosis of the problem isn't always clear. There is one example in the literature where Ragwort was blamed and the problem turned out to be contamination from an incinerator. It is liver damage which has lots of causes. Here are a few facts which put things into context a bit. Ragwort toxicity. The figure that gets quoted for horse toxicity is around 7% of body weight.For cattle it is usually quoted as less but the best study I have found is one in the USA 400lb calves fed 2.4lb of undried ragwort daily for 20 days showed only a 75% mortality. ( The plant was disguised in their feed because they normally hate the taste). The total dose was 48 pounds (nearly 3.5 stone) or about 12% of body weight In Horses another study on Ragwort poisoning showed an example where a 114kg horse (around 250lb or nearly 18 stone was fed 25kg ( around 31lb or about 2 stone 3lbs) over 140 days. In this case the ragwort was consumed was between a fifth and an quarter of its body weight. The horse survived. It probably wasn't very well though but even so it survived . It is also important to note that this large amount was dried ragwort not fresh growing ragwort which means that the toxins werr more concentrated. One French paper has a title which translates into "Is ragwort poisoning possible in France" .It concludes that the researchers couldn't find an example. There is a single example mentioned in a subsequent paper, but it may be Marsh Ragwort. A Dutch paper published in 2002 about a bad case of poisoning caused by really bad management of silage says that "Ragwort poisoning has not been diagnosed in the Netherlands for years." The only British figures I have found are from State-Veterinary-Journal. 1991, 1: 4, 16. published by MAFF and I quote" The number of reported incidents of ragwort (Senecio jacobaea) poisoning in cattle in England, Wales and Scotland were 26 (1985), 10 (1986), 16 (1987), 13 (1988), 7 (1989), 10 (1990). " As you can see the evidence suggests it isn't a big problem. The veterinary diagnosis of the problem isn't always clear. There is one example in the literature where Ragwort was blamed and the problem turned out to be contamination from an incinerator. It is liver damage which has lots of causes. Ragwort Dispersal Several studes have been carried out. The most comprehensive was carried out by scientists at Oregon State University and published by The Ecological Society of America in their scientific journal Ecology. It showed that, when tested in a variety of conditions 31% of the seeds traveled only 1 metre, 89% 5 metres or less and none were collected more than 14 metres from the source. The study involved studying the dispersal of over fifty three thousand individual seeds. Granted it may disperse more but not as much as people think. 14 Metres is about 46 feet. Again this indicates it is not a problem. Ragwort Hysteria some examples. A letter about Ragwort in the Sunday Telegraph. Ragwort 6500 deaths. What bad science!
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