|Greasewood (Sarcobatus vermiculatus)|
Greasewood is an erect, spiny, woody perennial shrub that grows 1 to 1.5 meters tall. Flowers are small and light green to whitish. It has many thorns with thick, narrow, green leaves on rigid branches. Its bark is smooth and white.
Greasewood is a range shrub that livestock can generally eat safely in moderate amounts with other forage. It is moderately palatable. Death occurs when livestock eat large amounts in a short period of time. Losses generally occur in the fall and winter when sheep or cattle eat large quantities of leaves that have fallen to the ground or from the early growth in spring. The plant toxins, sodium and potassium oxalates, are found in the leaves with lower concentrations in other plant parts. The amount of toxin varies considerably in the different areas where it grows (from 10-22% of plant dry weight). Greasewood increases in toxicity as the growing season advances.
Where and When It Grows
How It Affects Livestock
Signs and Lesions of Poisoning
How to Reduce Losses
No treatments have definitively proven to be effective for greasewood poisoning. It has been suggested that oral dicalcium phosphate may decrease availability and absorption of the oxalates (0.25 kg per day). Although intravenous calcium gluconate reverses the hypocalcemia, it does not appear to alter all of the clinical or pathologic changes.
Greasewood can be effectively controlled with 2,4-D (1 kg ai/Ac). Two or more successive years of treatment may be necessary for effective control because of its resprouting ability. Follow all precautions for handling herbicides