Cattlemen like tall fescue grass because it has many of the
qualities they like for cattle feed. There’s just one problem:
it can also poison cattle. But there are alternatives.
Tall fescue grass is tough, grows well
and tolerates a wide-range of environmental conditions, says
John Andrae, a crop and soil scientist with the University of
Georgia College of Agricultural and Environmental Sciences.
A fungus called endophyte lives inside tall fescue. This fungus
produces compounds that make tall fescue drought tolerant and
able to handle heavy grazing — qualities prized by
cattlemen.
But this fungus also produces compounds toxic to grazing
animals
like cattle.
The biology is complicated. The toxin meddles with hormones in
the cattle. It lowers birth rates and milk production in beef
cattle. And cattle that eat it don’t gain weight as fast as
cattle that don’t.
The toxin also interferes with cattle’s ability to cool off. It
restricts blood vessels. In the heat of summer, cattle may need
to find shady places and ponds to cool down, Andrae said. But
cattle shouldn’t need these cooling places in mild springs or
even in mild summers.
“Many cattlemen have just grown used to seeing cattle standing
in shade or ponds,” he said. “But in many cases it’s not
extreme
heat but the toxin preventing the cattle’s natural cooling
abilities.”
When cattle are trying to cool off, they’re not grazing or
gaining weight, the opposite of what a cattleman wants, he
said.
In times of extreme cold, cattle can also lose hooves and tips
of tails due to poor blood circulation from the toxin, he
said.
“Many cattlemen don’t really know how bad this problem is,”
Andrae said. “They believe that many of these things are
normal.”
The overall toxic quality and presence of the endophyte in the
fescue can vary from pasture to pasture. Lower levels aren’t as
damaging. But high levels of the toxin in pastures can hurt a
cattleman’s bottom line.
Farmers have some viable options.
Tall fescues called novel endophyte-infected fescues that don’t
produce toxins that hurt cattle have been developed.
“And the novel endophyte-infected fescues retain the good
qualities wanted in a good grazing grass,” Andrae said.
One variety, marketed under the name Max Q, was developed by
Joe
Bouton, retired UGA CAES crop and soil scientist, and Gary
Latch, a scientist with AgResearch in New Zealand.
It can be costly to replace the old tall fescue pastures with
these new varieties, said Curt Lacy, livestock economist with
the UGA Extension Service.
It cost about $200 per acre to plant the newer, non-toxic
varieties, Lacy said.
Recent years of drought have made cattlemen wary of planting
any
non-irrigated pastures. It’s hard to predict the weather and
when and when not to plant. But with current strong cattle
prices, Lacy said, cattlemen should think of planting the novel
tall fescue varieties now.
“Cattlemen have to look at improving pastures as an investment,
much like investing in a better bull or upgrading other parts
of
their operation,” he said.
Lacy figures a novel endophyte-infected fescue would pay for
itself in five years. The cattleman who switched to a non-toxic
variety would, in 10 years, make about $150 more per acre than
a
cattleman who remained with the old, toxic fescue.
Tall fescue grass is a cool climate grass. Introduced in the
mid-
1900s, it’s estimated that about 30 million acres of tall
fescue
grows in the Southeastern United States.
Georgia has between 800,000 and 2 million acres of tall fescue,
primarily in the northern parts of the state.
South Georgia cattlemen grow bahia and Bermuda grasses for
their
cattle. These grasses don’t contain the endophyte fungus.
