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This website is the English version of our Dutch Ragwort
website.
Recently, Ragwort has received quite a bit of media coverage. Many
facts are presented, but also many myths. It is, for instance, a fact
that species of Ragwort are poisonous to mammals, but it is a myth that
an animal dies if it ingests only a mouthful. It is also a fact that
Ragwort is poisonous to humans, but a myth that it is a serious health
hazard to people. Furthermore, it is a fact that Ragwort is currently
more common in the Netherlands than 30 years ago, but a myth that this
species is an extremely efficient wind disperser.
Although Ragworts can be a significant nuisance to horse
keepers, these species are a very important source of nectar and
pollen. About 150 species of insects, such as bees, flies and
butterflies, visit the plant. Therefore, even it were possible,
eradicating the plant is not a desirable option. We will have to find
other ways to protect our livestock. There are no easy solutions to the
Ragwort problem, but that doesn’t mean that there is nothing we
can do.
The aim of this website is to distinguish facts from myths
by using a scientific approach based on research and advice from
biologists, toxicologists, and other experts. In this way, we want to
determine the nature and scale of the problem that Ragwort presents to
our horses and other livestock. In this way, I would like to contribute
to a solution of the Ragwort problem; as a horse lover AND as a Ragwort
enthusiast.
Frequently Asked Questions.
A: Yes, that is right. Only in exceptional circumstances or when there
is a food shortage, horses will eat fresh Ragwort. Horses, however,
don't recognize dried Ragwort plants as poisonous and contaminated hay
may cause Ragwort poisoning. More info
A; No, incidentally ingesting small amounts of Ragwort will not result
in illness. If, however, horses eat several kilograms of Ragwort a day
or small amounts for extended periods, this may lead to irreparable
liver damage. More info
A: No. The toxins (pyrrolizidine alkaloids) are excreted within 24-48
hours. If an animal consumes pyrrolidizine alkaloids regularly though,
liver damage will accumulate and the animal will show signs of illness. More info
A: The exact number of victims of Ragwort poisoning is unknown. The
symptoms of Ragwort poisoning cannot be distinguished from other liver
disorders and poisoning can only be confirmed by means of a post-mortem
liver exam. These exams are, however, not common practice, and reliable
data on the number of victims are therefore not available. There could
be more than hundreds of victims, but there could also be much fewer. More info
A: No. Ragwort poisoning takes place in the digestive system. In the
plant, pyrrolidizine alkaloids are stored in their non-toxic form. Only
if these substances end up in the digestive system, they will be
converted into their toxic form. There is no scientific evidence that
skin contact leads to the conversion of non-toxic alkaloids into their
toxic form. Some people experience an allergic reaction after skin
contact (compositae dermatitis), but this response is cause by
sesquiterpene lactones rather than pyrrolizidine alkaloids. These
sesquiterpene lactones are common chemical compounds of members of the
Sunflower family. More info
A: Yes, all Dutch Ragworts contain pyrrolizidine alkaloids. These are also found in Comfrey and Butterbur.
A: Ragwort needs a bare spot to germinate. Horses easily churn up the
ground when running, and graze the grass very short, thereby easily
creating open spots suitable for seed germination. More info
A: Ragworts are presumably more common in the Netherlands and
neighboring countries than 30 years ago, because the number of suitable
habitats has increased due to large-scale renewal of infrastructure,
building activities, and efforts to give agricultural land back to
nature. In addition, Ragwort seeds have been used to enrich roadsides.
There is no evidence that Ragworts have a different habitat preference
or better dispersal capabilities than in the days when this species was
much less common in the Netherlands.
More info
A: Ragwort is a biennial. In the first it only has leaves organized in
a rosettes. These can be found throughout most parts of the year.
Ragwort usually flowers in the second year (June till October). After
the plant has produced seeds, it dies. The leaves of Ragwort are
pinnately lobed. Flowerheads often occur in clusters called corymbs.
They are yellow with ray and disk flowers. Click here for pictures of Ragwort and other Ragwort species.
A: Ragwort is difficult to eradicate and most methods to remove the
plants, such as pulling by hand, mowing, and using herbicides, may have
increase rather than decrease the number of Ragwort plants at a given
site. The best way is probably to prevent ragwort from establishing in
a pasture. Good pasture management is therefore of utmost importance. More info
A: No. The toxins remain in the plant and don't 'contaminate' the rest
of the hay. It is advisable though not to use the rest of the bale for
consumption, because undetected parts of the plant may have remained in
the hay and can potentially lead to Ragwort poisoning.
A: Everything that is published on the web should be regarded with
skepticism, because everybody can create a website these days and
everybody claims to be an expert. It is therefore important to check if
statements are supported by the results of professional scientific
studies published in peer-reviewed journals. If a statement on a
website is not accompanied by a reference to such a scientific paper,
it is safest to assume that the statement reflects the views of the
author rather than a scientific fact. Otherwise the author would have
bothered to refer the reader to where the evidence supporting the
statement can be found.
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