Which plant is known to be poisonous to sheep?

Horsetail is known to be poisonous to sheep primarily due to its high content of alkaloids and other toxic compounds such as thiaminase, which can disrupt vitamin B1 metabolism. When sheep consume horsetail, it can lead to thiamine deficiency, resulting in neurological issues and potentially fatal outcomes. The presence of these toxic compounds makes horsetail particularly hazardous in pastures where sheep could have access.

In contrast, clover, fescue, and bluegrass are generally considered safe for sheep under normal circumstances. Clover is often actively grazed by sheep, although certain types can cause bloating if consumed in large quantities. Fescue and bluegrass also serve as important forage grasses for sheep without the same toxic risks presented by horsetail. Understanding which plants are toxic is essential for ensuring the health and safety of livestock, particularly in pasture management and animal husbandry.