Seaweed may be an anomaly in North Mississippi, but animal researchers at the Prairie Research Unit in Monroe County are using this marine algae to improve production of the state's beef cattle.
Fescue is often used as forage for cattle, horses, sheep and other ruminants, and 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 this fungus.
For the past two years, Mississippi Agricultural and Forestry Experiment Station animal scientist Richard Evans and MAFES agronomist Roscoe Ivy have sprayed both fungusfree and fungus-infested tall fescue with an extract from the seaweed. Steers produced from this 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 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.
"We realize that using fungus-infected fescue as forage has problems, but because it is in most pastures in the southern U.S., we're making every effort to use it more effectively by offsetting some of the negatives," Evans said.
Losses to fescue fungus are estimated to be $6 million annually. Spraying fescue with seaweed extract may help overcome some problems related to using infected fescue as forage. Part of MAFES research includes evaluating other methods of administering the seaweed, such as mixing it into feed or using it as a mineral supplement.
"Seaweed is an environmentally-friendly product. Harvested like hay from oceans, seaweed has shown it can help in producing cattle that have slightly increased weight gains and improved immunity," Ivy said.