06/13/1997

Marshall Ryegrass Dramatically Superior to Gulf Under Grazing

AUBURN, Ala. - Gulf ryegrass has been the ryegrass of choice for producers in Alabama's Gulf Coast region for many years. Research conducted through the Alabama Agricultural Experiment Station (AAES), however, suggests that Marshall ryegrass provides dramatically better steer weight gains and profit potential than Gulf.

David Bransby, professor of agronomy and soils at Auburn University, has been conducting grazing trials on these two ryegrass varieties at two locations in Alabama - along the Gulf Coast in Fairhope and in Northwest Alabama at Winfield - for the past year. Results of these initial trials indicate that Marshall produced an average of 52 percent more animal weight gain than Gulf.

Bransby noted that these latest results are in stark contrast to results from previous mowing experiments. "Over the last three years, ryegrass yields in small plot clipping tests were 4.52 tons per acre for Marshall and 4.22 tons per acre for Gulf. This is only a seven percent advantage for Marshall," he said.

According to Bransby, Gulf ryegrass was developed in the late 1950s by the Texas Agricultural Experiment Station to provide improved yield and improved tolerance of crown rust. It is, however, not very cold tolerant.

"Marshall was developed for its excellent cold tolerance, which makes it particularly well suited to regions with cold winters," said Bransby. "It was released by Mississippi State University in 1981 and is rated by most specialists as the most cold-tolerant variety on the market. However, it is a little less rust resistant than Gulf."

Because of the climate adaptations of these two varieties, Gulf ryegrass has been the predominant ryegrass used in the southern and coastal regions of Alabama, while Marshall has traditionally been used in northern Alabama. Previously, mowing tests in Alabama indicated forage yields for Marshall and Gulf were similar in the South; however, Marshall was significantly better in the North.

Knowing that mowing tests do not always truly simulate a grazing situation, Bransby decided to test these results in grazing experiments and examine animal production yields in addition to forage yields.

The AAES study was conducted to compare Marshall and Gulf ryegrass under continuous grazing in both warm and cold environments, and to relate these results to data from past mowing experiments. Stocker steers were grazed on four Marshall and four Gulf ryegrass pastures at the Gulf Coast Substation in Fairhope and the Upper Coastal Plain Substation in Winfield in winter of 1996-97. Steers weighing about 500 pounds were turned on to the pastures in early December and stocked at two animals per acre at Fairhope and 1.67 animals per acre at Winfield.

The steers were obtained from Jeff McFarland, a cattleman who owns a large number of cattle, but arranges for independent landowners to contract graze his animals. McFarland has been supplying the AAES with cattle for studies at various research substations in the state.

"This approach saves Auburn University a lot of money because we don't have to tie any dollars up in the animals," said Bransby. "Producers could get the same benefit if they contract grazed cattle for someone else instead of buying the animals themselves."

"At the Fairhope location steer weight gain was 77 percent greater for Marshall than for Gulf," said Bransby. "At Winfield, this advantage was 27 percent. However, the stocking rate in Winfield was above optimum, so this test served as a comparison of the two varieties under stress conditions."

Cattle on Gulf ryegrass at Winfield began losing weight in February and were supplemented with hay for 34 days. Steers grazing Marshall received no hay, but still gained 27 percent more than those grazing Gulf. On average, pasture height was 31 percent greater for Marshall than for Gulf (5.09 inches and 3.90 inches, respectively).

"Of particular interest is the dramatic advantage of Marshall over Gulf in the Gulf Coast region where Gulf is considered to be well adapted," said Bransby of these results. "This advantage was evident in the very first 28-day period, and continued to widen throughout the grazing season. This shows that the superiority of Marshall is evident throughout the entire season, and not only in the middle of winter. Clearly, the evidence shows that Marshall is superior to Gulf in both cold tolerance and resistance to grazing, and it may also have some other production advantages that have not yet been discovered."

According to Bransby, rust was evident on both varieties in the spring and was slightly more severe on Marshall; however it did not seem to affect animal production. Bransby noted that another ryegrass variety known as Jackson, which was developed from Marshall and is more rust tolerant, may be used as an alternative variety to Marshall when rust is a major concern. This variety will be included in future experiments for comparison with Marshall and Gulf.

An economic analysis of these preliminary results further illustrates the advantages of using Marshall ryegrass, said Bransby. "In our analysis, we assumed the animals were contract grazed by a landowner for 35 cents per pound of weight gain, paid by a separate person who owned the cattle. Profit from cattle grazing Marshall was nearly five times higher than for Gulf ($126.21 versus $21.71)," he stated. "This occurred despite a $3.90 lower seed cost per acre for Gulf (the analysis assumed a seeding rate of 30 pounds per acre and seed costs of 30 cents per pound for Gulf and 43 cents per pound for Marshall). In other words, an extra $3.90 per acre spent on seed for Marshall ryegrass yielded an additional $102.50 in profit, or nearly a 27-fold return on investment.

These results suggest that Marshall ryegrass was dramatically superior to Gulf throughout the season, even at the Gulf Coast.

"The profit advantage was substantially greater than the production advantage and the advantage of Marshall over Gulf was much greater under grazing than under mowing," said Bransby. "In addition, profit from stockers grazing Marshall ryegrass is comparable with profit from many row crops."

Bransby is not the only one singing the praises of Marshall ryegrass. McFarland, who is based in Dauphin Island, Alabama, also is sold on using Marshall. McFarland grazes about 2,000 head of cattle each year. His first-hand experience with Marshall ryegrass has made him a believer.

"After observing this trial in progress, I without hesitation plan to recommend Marshall ryegrass to people who contract graze for me," McFarland said. "Like most cattle producers in this Gulf Coast region, I would not have guessed the advantage of Marshall over Gulf is so large. It is certainly worth those extra few pennies in seed."

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Office of Ag Communications & Marketing

Auburn University College of Agriculture
Alabama Agricultural Experiment Station
3 Comer Hall, Auburn University
Auburn, AL 36849
334-844-4877 (PHONE) 334-844-5892 (FAX)

Contact Jamie Creamer, 334-844-2783 or jcreamer@auburn.edu
Contact Katie Jackson, 334-844-5886 or smithcl@auburn.edu

06/13/97