Life Sciences Commons^™

Drd2 And Xkr4: A Genetic Approach To Fescue Toxicosis., Kristine Marie Ely

Masters Theses

Tall fescue (Lolium arundinaceum Schreb) is the most prevalent forage in the Mid-south United States due to its observed hearty nature and ability to withstand heavy grazing. This is due to a symbiotic relationship with an endophytic fungus (Neotyphodium coenophialum). This fungus produces ergot alkaloids, which can bind to many adrenergic, serotonergic, and dopaminergic receptors. One of the primary functions of dopamine is to inhibit prolactin response. Decreased growth, reproduction, lactation, and depressed serum prolactin concentrations are commonly observed in beef cattle grazing endophyte-infected tall fescue. These symptoms are collectively referred to as fescue toxicosis, and …