Common seaweed extract offers promise for improving forage quality and livestock performance.

Helping plants stay healthy could also be the answer to keeping animals healthy. And it appears seaweed could be the cure to do just that.

Recent research indicates applying Ascophyllum seaweed extract to forages, like tall fescue, helps plants ward off stress and improves the immune system of grazing animals, according to Vivien Allen, a Texas Tech University agronomist.

Long used as a fertilizer on agricultural lands, seaweed extract has been studied primarily to improve the stress tolerance of turf grasses. While at Virginia Tech, Allen and animal scientist Joe Fontenot wondered about improving the stress tolerance of forages.

"We hypothesized that if we could reduce fescue toxicity or improve stress tolerance of endophyte-free tall fescue, it would also improve the animal's performance because the animal was grazing better forage," says Allen.

Instead, researchers found an even greater benefit to the animal.

Builds Immunity The unique treatment did indeed help reduce some of the problems from fescue toxicity, but it also boosted the immune systems of cattle grazed on seaweed-treated pastures.

In a first-year trial, cattle that grazed seaweed-treated tall fescue at Virginia Tech and Mississippi State University developed improved immune systems. After the cattle were shipped to Texas Tech, Allen and researcher Kevin Pond found the improved immunity remained with the cattle throughout a 130-day feeding period.

"By boosting animals immune function, animals are more resistant to disease and shipping stresses which leads to better overall performance," says Allen.

"We are confident that the seaweed triggers antioxidants (such as superoxide dismutase and other vitamins) to respond in the plant. The antioxidants are involved in the plant's stress function," says Allen.

The antioxidants appear to help plants, like endophyte-free fescue, persist longer and be less susceptible to drought, overgrazing, insect damage and other stresses, according to Allen. Allen suggests that the antioxidants in the plants stimulate a similar stress tolerance response in the animal.

"It's the plant's alteration that apparently triggers a response in cattle. It's not acting as a feed additive to improve gains, it looks like a health benefit," says Allen.

That may explain why direct application of seaweed to a grain sorghum-based diet did alter the immune system of cattle, but not as much as the forage.

Future Applications Allen believes seaweed treatment could become an important part of pasture programs in the future. The extract comes as a soluble powder or liquid that is mixed with water and sprayed on forages.

Sean Carson, sales manager for Acadian Seaplants, Ltd. - a Canadian based company that produces Ascophyllum seaweed extract fertilizers and sells it in the U.S. - says the product has been available commercially for 15-20 years.

"The market for natural-based products is growing and seaweed extract is environmentally friendly," Carson says. While the seaweed extract's primary market is as a foliar fertilizer for fruits and vegetables, Acadian is investigating uses for the extract in forage and direct feed applications. They sell the extract for $6-8/lb.

In university research, the seaweed extract has been applied at a rate of 3 lbs./acre in early spring, with a second application made in July.

"I think there is a real possibility that the rate and number of applications is too high," says Allen. But further research is needed to know for sure and to make its use cost-effective, she says.

While most research to date has looked at applying the seaweed extract to tall fescue pastures, Allen believes it can benefit other pasture forages, too.

Virginia Tech research revealed that seaweed-treated alfalfa produced better late-season yields, possibly indicating that the extract was preventing plants from aging.

Future Texas Tech studies will include seaweed treated wheat, bromegrass and other forages.