Grasses Like Fescue Need Fungal Endophytes

Fodder for Thought

Recent research shows how important endophytes are for sustainability of grazing systems.

Published on: July 19, 2012

Fungal endophytes are much maligned but play an important role in pasture ecosystems.

Many cool -season grasses, tall fescue and perennial ryegrass being two of the most well-known, live in a mutualistic association with fungal endophytes.

Endophyte-infected (Neotyphodium coenophialum ) tall fescue (Schedonorus arundinaceous) comprises nearly 37 million acres of grazing lands in the upper transition zone of the United States and serves as important grazing forage for livestock in this region.

During a unique Forage and Pastures Symposium held on Monday, July 16, of the Joint Annual Meeting of the American Dairy Science Association and the American Society of Animal Science, speakers discussed the impact fungal endophytes play in pasture and environmental sustainability, along with the challenges they pose for livestock producers.

Carolyn Young of the Noble Foundation discussed the complex realm of fungal endophytes which consists of multiple species, each with unique characteristics. She explained the endophyte which resides in tall fescue imparts benefits of increased persistence and tolerances to drought and pests. However, negative effects on animal performance also accompany this forage. In recent years, novel-endophyte varieties of tall fescue have been developed that maintain the beneficial qualities to the forage, without decreases in animal performance.

According to research by Rebecca McCulley from the University of Kentucky, fungal endophyte associations may play a key role in sustainability of grazing systems into the future as effects of climate change continue.

McCulley’s research found that endophyte-infected tall fescue plants sequestered greater amounts of soil organic carbon and nitrogen compared with their endophyte-free counterparts. Soil-to-atmosphere fluxes of CO2 and N2O varied across novel-endophyte varieties, with some lower than others.

In addition, endophyte-infected varieties were promoted in environments with higher CO2 concentration. While further research is needed, McCulley’s findings emphasize a clear need to consider novel endophyte-infected forage varieties in future planning of sustainable livestock grazing systems.