Seaweed may be an anomaly in north Mississippi, but animal researchers at the Prairie Research Unit in Monroe County are using the marine algae to improve production of the state's beef cattle.
Fescue, often used as forage for cattle, horses, sheep and other ruminants, grows abundantly north of Highway 82. Much of it is infested with an intracellular endophyte that grows between cell walls and is harder to overcome than intercellular bacteria that grow within cell walls. No foliar treatment has been found for treating the fungus.
For the past two years, Mississippi Agricultural and Forestry Experiment Station animal scientist Richard Evans and MAFES agronomist Roscoe Ivy have sprayed both fungus-free and fungus-infested tall fescue with an extract from the seaweed. Steers produced from the preliminary research have shown positive responses to the seaweed extract.
"Many cattle produced in Southern states are shipped west to the Southern Plains for grazing and finishing in the feedlots and are then processed for shipment back to Eastern markets. Animal health has always been a concern with Southeastern cattle grazing on fescue. Treating fescue with a seaweed emulsion has produced steers with increased resistance to diseases and better weight increase," Evans said.
Fungus-infested fescue is frequently planted as groundcover for lawns and golf courses because of its resistance to insects. When used as forage for cattle, though, results have not been as beneficial.
"The endophyte causes reduced adult weight gains, depletion of hair, rougher coats, elevated body temperatures, lower weaning weights in calves, and a depressed immune system," Evans said.
Additionally, fescue raises body temperatures three to four degrees or more, which is detrimental to fertilization. Both egg and sperm are affected, and reproductive rates decrease, Evans said.
Fescue toxicity causes major negative economic problems for livestock industries in Mississippi. Production of beef cattle contributed $1.66 million to the state's economy in 1998.
In the 1980s, Virginia Tech began investigating the effects of treating tall fescue with seaweed extract. MAFES joined the project in 1996. Trials at both institutions were comparable.
After grazing on both infected and uninfected tall fescue that had been treated with a seaweed extract, cattle showed improved immune function, an effect that appears to be long lasting. Responses were measured after transporting cattle from Virginia and Mississippi to a feedlot in Texas. Measurement continued every 28 days over the 130-day feedlot-finishing period.
"Seaweed-treated fescue is an additional tool available for increasing animal health and may be particularly helpful for north Mississippi cattle producers where fescue coverage is heavy," Evans said.
Fescue covers more than 600,000 acres in Mississippi and grows especially well in the Prairie and Hill sections of the northeast area of the state. Mississippi is one of several Southern states located in the "fescue belt," an area in the Southeast comprising 35 million acres.
Cattle can detect fungus-infected fescue and tend to shy away from it if other more-palatable forage is in the area. In many cases, though, this is the only forage available.