Novel alkaloid management strategies for improved beef cattle production in the fescue belt

Abstract

Tall fescue (Schedonorus arundinaceus) is an important forage crop for agriculture in Missouri and much of the eastern United States. Tall fescue is known for hardiness and herbage accumulation, much of which is attributed to a symbiotic relationship with the fungal endophyte Epichloe coenophiala. This endophyte produces alkaloids, which negatively affect livestock performance after consumption. Tall fescue is a species well adapted to Missouri forage systems and takes considerable resources and time to remove from pastures and replace with a new species. Due to these negative factors, most research efforts have focused on managing tall fescue to reduce toxicity risk. One strategy includes reducing alkaloid load by removing one of the most toxic part of the plant (seedheads). The results will be presented from research projects using prescribed fire on infected tall fescue plots and metsulfuron plus nitrogen on pastures grazed by stocker cattle as management strategies to reduce toxicity and improve productivity of tall fescue forage systems. Prescribed burning of tall fescue in April resulted in reduced seedheads by 49 percent, lower alkaloid concentrations and improved forage nutritive value in months following burning. Metsulfuron herbicide reduced seedhead density by 80 percent and decreased ergovaline production while nitrogen fertilizer recovered forage yield losses due to metsulfuron. Seedhead reduction in response to prescribed fire and metsulfuron has potential for reducing alkaloid exposure when grazing endophyte-infected tall fescue.