Locoweeds

Locoweeds are a group of plants belonging to the genera Astragalus and Oxytropis. These plants are known for their toxic properties, particularly their ability to cause a neurological disorder in livestock called "locoism." The toxicity is primarily due to the presence of swainsonine, a potent alkaloid that inhibits alpha-mannosidase, an enzyme crucial for cellular metabolism.

Locoism manifests in various ways depending on the species consumed, the amount ingested, and the duration of exposure. Symptoms can include aimless wandering, impaired coordination, loss of appetite, tremors, and behavioral changes. Pregnant animals may abort or give birth to deformed offspring. Horses, cattle, sheep, and goats are particularly susceptible.

The term "locoweed" is commonly applied to several species, including spotted locoweed (Astragalus lentiginosus), purple locoweed (Oxytropis lambertii), and white locoweed (Oxytropis sericea). These plants are often found in arid and semi-arid regions of North America, typically in grasslands and rangelands. They are herbaceous perennials that can grow in diverse soil types.

Management of locoweeds involves various strategies to minimize livestock exposure. This can include pasture rotation, supplementary feeding during periods of scarcity, and removal of infested areas. Identifying and eradicating locoweed infestations is challenging due to their widespread distribution and resilience. The economic impact of locoweed poisoning on the livestock industry is significant, leading to reduced weight gain, decreased reproductive rates, and animal losses. Research continues to explore effective control methods and a deeper understanding of the plant's toxicology.