Fescue seedheads begin appearing in Missouri fields during early May. By late May cattle will be stripping them from the fescue stem.

"If you've followed research and extension reports on managing fescue you know that seedhead management is important," said Eldon Cole, a livestock specialist with University of Missouri Extension. "The highest concentration of the toxic alkaloids, especially ergovaline, occurs in the stem and seedheads."

In Missouri, cattle seem to start the stripping by mid-to-late-May. As the plant matures, they reduce their interest in the seed. Consequently, a management tool MU Extension specialists encourage is to clip the heads off earlier than late-May or June.

FESCUE FUNGUS: Ergot found in a fescue seed head. When consumed, this fungus reduces cattle preformance. Farmers should consider clipping fescue pasture early.

"Early clipping also can change the reproductive growth of the fescue plant to more vegetative growth," Cole said. "This change improves the future nutritional value of the plant."

The friendly endophyte fescue varieties — of which there are numerous ones nowadays — produce very little or no ergovaline. However, all fescues and other cool season grasses, as well as small grains, may be subject to another fungus, ergot.

What to look for

"Ergot is easily visible in a plants seedhead," Cole noted. "It appears as a kernel-like object on the seedhead in place of the regular seed produced by the plant. Some describe the appearance as tiny mouse droppings on the seedhead."

Ergot typically appears in early June and shows up in southwest Missouri fields every year but is much worse some years than others. According to Cole, 2015 was an extremely bad year for ergot in southwest Missouri fescue fields that were allowed to go to seed.

Cole does not know the severity of ergot for this year. However, he said cattle producers should remain vigilant.

The symptoms of ergot alkaloids and the ergovaline produced by "hot," fescue in cattle are similar: heat stress, increased respiration rates, elevated body temperatures, and failure to shed their winter hair coat. Overall, those symptoms result in poor growth and reproductive performance.

Management tips

According to Cole, clipping fescue seedheads is also valuable as an aid in reducing ergot toxicity. Timely application of certain herbicides that delay seedhead development has shown similar results but it is now too late for those in 2016.

"Research has shown that cattle genomics are involved in the fescue toxicity dilemma but in all likelihood, there are numerous other factors that combine to make the problem worse," Cole said. He wonders if all cattle "strip" seed or if different ones have different tendencies in that regard. It will take additional research to answer that question.

Source: University of Missouri