|
Description
Goathead is an annual weed in the caltrop family.
The prostrate stems radiate from a tap root. The opposite
leaves are pinnate. The flattened fruit breaks in five nutlets,
with two strong, woody spines. The flowers are small and have
5 yellow petals.
Distribution and Habitat
Goathead is an introduced weed from Europe. It is
widely distributed in disturbed areas, along trails, roadsides
and may become abundant in severely overgrazed pastures. It
is found throughout Texas except on the gulf coast and extreme
eastern portion of the state.
Regions: 2, 3,
4, 5,
6, 7,
8, 9,
10.
Toxic Agent
The plant causes hepatogenic photosensitization in
sheep and is suspected in cattle. All parts of the plant are
toxic at all stages of growth but wilted plants are the most
hazardous. In addition, goathead has been reported to contain
high levels of nitrate. The spiny burs produced by this plant
are mechanically dangerous, producing lesions of the mouth
or feet.
|
Livestock Symptoms
In natural cases , typical lesions of severe photosensitization
were seen including
- blindness
- necrosis of skin
- loss of lips and ears
- high mortality of young animals
High levels of nitrate in the plant can complicate
the issue and produce symptoms of nitrate poisoning in sheep
and cattle. Typical nitrate poisoning symptoms may be evident
(see Description of Animal Conditions).
Integrated Management Strategies
The first and foremost management
strategy to reduce potential livestock losses from goathead
is good range management strategies. Given the opportunity,
this plant will be avoided in preference for more palatable
forage species. Additionally, if goathead is being eaten,
chances are stocking rates are too high. If symptoms appear
in livestock, remove animals from infested pastures and
provide a good quality diet and water. The plant is easily
controlled with most broadleaf herbicides but caution should
be used when treating with 2,4-D as this chemical has been
shown to increase the nitrate accumulation in the plant.
Mechanical improvement techniques which disturb the soil
surface may increase the infestation of this plant for a
short time after treatment.
Printable
Version (PDF) 
  
|
