Southern Extension and Research Activity Information Exchange Group 8

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SERA-IEG 8 Fescue Endophyte Research and Extension

SERA-IEG 8 - Fescue Endophyte Research and Extension

Project or Activity Designation and Number: SERA-IEG-8

Project Activity Title: Fescue Endophyte Research and Education

Period Covered: 01-1-02 to 12-31-02

Annual Meeting Dates: October 27-29, 2002

Participants: Aiken, Glen, USDA-ARS-SPA-DBSFRC,; Andrae, John, Univ. of Georgia,; Atkerson, Gary, AgResearch USA Ltd.,; Bacon, Charles, USDA-ARS,; Bondurant, Jane, Univ. of Georgia,; Bouton, Joe, Univ. of Georgia,; Broome, Malcolm, Mississippi State University,; Browning, Richard, Tennessee State Univ.,; Brauer, David, USDA-ARS-SPA,; Craig, Morrie, Oregon State Univ.,; Colling, Dan, Parkville, MO,; Cross, Dee, Clemson Univ.,; Davis, Micheal, Alabama A & M and Auburn Univ.,; Dougherty, C.T., Univ. of Kentucky,; Dubbs, Tina, Knoxville, TN; Evans, Richard, Mississippi State Univ.,; Fike, John, Virginia Tech Univ.,; Fribourg, Henry, Univ. of Tennessee,; Gray, Sam, Clemson Univ.,; Gwinn, Kimberly Univ. of Tennessee,; Hohenboken, Bill, Virginia Tech Univ.,; Han, Kun-Jun, Univ. Kentucky,; Ivy, Roscoe, Mississippi State Univ.,; Jennings, John, Univ. of Arkansas,; Lang, David, Mississippi State Univ.,; Lee, Joung, South Korea,; Maccon, Bisoondat, Mississippi State Univ.,; Maubarak, Ali, Univ. of Arkansas,; Meredith, Filmore, USDA-ARS,; Nice, Lois, Equi-Tox, Central, SC; Nihsen, Mike, Univ. of Arkansas,; Ouart, Michael, Mississippi State Univ.,; Piper, Ed, Univ. of Arkansas,; Post, Nathon, Univ. of Arkansas,; Pratt, Phillip, Oklahoma State Univ.,; Rasburn, Freddie, Mississippi State Univ.,; Robertson, Benny, Pennington Seed,; Rosenkrans, Charles, Univ. of Arkansas,; Rottinghaus, George, Univ. of Missouri,; Saker, Korinn, Virginia Tech,; Seman, Dwight, USDA-ARS,; Smith, David, Univ. of North Dakota,; Smith, Ray, Virginia Tech,; Spiers, Donald, Univ. of Missouri,; Stratton, Tony, AgResearch USA Ltd.,; Stuedemann, John, USDA?ARS,; Tapper, Brian, AgResearch NZ,; Thompson, Marty, Univ. of Arkansas,; Triplett, Jr., Glover, Mississippi State Univ.,; Waller, John, Univ. of Tennessee,; Watson, Richard, Univ. of Georgia,; Weidemann, Greg, Univ. of Arkansas,; West, C., Univ. of Arkansas,; Williams, Jim, Univ. Missouri,; Winsett, Brett, FFR Cooperative,; Woods, Robert, Okahoma State Univ.,

Project or Activity Leadership: Chair: Joe Bouton,
Chair-elect/Secretary; Craig Roberts,

Brief summary of minutes of annual meeting:
Institution reports were presented by participants representing Arkansas, Georgia, Kentucky, Louisiana, Mississippi, Missouri, North Dakota, Oregon, South Carolina, Tennessee, and Virginia. Discussions were held on all the reports presented at the meeting.

As occurred the previous year, the Committee on Standards for Terminology Used in Fescue Toxicosis, chaired by Chuck West, presented their updated reports. The committee to Investigate Analytical Techniques for Alkaloids and Endophytes did not present a report. A new committee was formed to explore standards for endophyte quality control. The group approved continuing all three committees for next year.

The group reviewed a website prepared by John Waller and his colleagues at the University of Tennessee. The group voted to use the website as proposed. John Waller planned to have the website running within a few months of the meeting.

Accomplishments and Impacts: The following report summaries were submitted by members of the group and are presented in alphabetical order by state.

1. Arkansas-- The University of Arkansas licensed a population of HiMag tall fescue infected with an endophyte selected for lack of ability to produce ergot-like alkaloids. The licensee is FFR Cooperative and the seed is marketed under the brand name ArkPlus. The selected endophyte improved stand persistence in southwest Arkansas over endophyte-free HiMag (20% vs. 2% ground cover, respectively) and similar to >Kentucky-31' with its endemic, toxic endophyte. ArkPlus is expected to be well adapted to the Ozark region of the south-central U.S. and similar climatic zones to the east across the mid- to upper South. HiMag with nontoxic strains of endophyte supported steer weight gains grazing during the winter on fall-stockpiled tall fescue as high as steers on endophyte-free HiMag (average of 1.7 lb/d), which was only slightly greater than gains on toxic KY-31 (1.4 lb/d). Cow-calf trials on pastures in north-central Arkansas (Batesville) dominated by E+ KY-31 tall fescue (~70%) showed that rotation frequency (2x monthly vs. 2x weekly) had no effect on calf weaning weights or species composition; however, this is only the first 2 years of a 5-year study. Early weaned calves (6 months) tended to have lower immune function than later weaned calves (8 months). In a cow-calf trial, orchardgrass, E- KY-31 tall fescue and E+ fescue were compared at the same two rotation frequencies. Calf weaning weights were highest with orchardgrass rotated 2x weekly (600 lbs.), followed by orchardgrass 2x monthly (546 lbs.), while the other treatments were similarly low (mean 501 lbs.).
2. Georgia-- Extensive testing during the past 5 years was concluded for the Jesup cultivar with the MaxQ endophyte. Jesup (MaxQ) averaged % stand survival nearly twice that of Jesup (E-), and about 85% of Jesup (E+). In animal trails, cows grazing MaxQ pastures were significantly better in liveweight and condition at weaning than cows grazing the toxic pasture while their calves grazing the MaxQ pasture showed a significant advantage in weaning weight over calves raised on toxic pasture, reflecting better average daily gain (e.g. 66lbs in steer calves and 44lbs in heifer calves). Stocker growth on MaxQ tall fescue pastures was similar to cattle growth on E- and exceeded cattle growth on E+ tall fescue. Indicators of toxicosis, depressed serum prolactin levels and elevated rectal temperatures, were observed only in animals grazing E+ pastures. These results indicate that the general concept of non-ergot alkaloid-producing endophyte technology, and specifically the MaxQ endophtye in the Jesup cultivar, is a promising option for alleviating tall fescue toxicosis in livestock while retaining the agronomic advantage of the wild type endophytes.
3. Kentucky – Small plot studies were used to determine tolerance to overgrazing by cattle of commercial and experimental tall fescue varieties. Some endophyte-free (E-) tall fescues were able to persist as well as endophyte infected (E+) KY 31, but E- varieties were not always consistent among trials. Novel endophyte insertions into Georgia tall fescue lines persisted well and were equivalent to E+ KY 31 in most instances. These data indicate that both E- and novel endophytes inserted into adapted tall fescue varieties are valid alternatives to E+ KY 31 and would offer some of the same tolerance to overgrazing. The potential role of endophyte-infected tall fescue in Mare Reproductive Loss Syndrome was investigated by monitoring alkaloid content of forage on 13 horse farms in spring 2002. Treatments (forage type) for farms containing cherry trees on or near the perimeter of the farm were: 1) pure tall fescue, 2) composite weed/forage mixture, 3) inside the cherry tree drip line, 4) and outside the cherry tree drip line. Tall fescue samples had greater (P < 0.01) concentrations of both ergovaline and total lolines than composite and inside and outside of the drip line. Concentrations of ergovaline in tall fescue samples, averaged across all farms, was highest during the month of May with peak levels at 0.6 mg×g-1 and only 0.2 mg×g-1 for those in the composite group. Ergovaline concentrations in tall fescue samples were higher than 0.3 mg×g-1 for 8 of 13 farms in the monitoring program. However, COMP samples for all farms were below the 0.3 mg×g-1 ergovaline level suggested by literature to be a potential toxicological problem for pregnant mares grazing endophyte-infected tall fescue. Although alkaloid concentrations reached levels that should not be dismissed by horse producers, they do not appear to play a role in MRLS.
4. Mississippi -- Preliminary results with the non ergot-alkaloid producing endophyte tall fescue indicate that animal performance is similar to animals grazing ryegrass or endophyte free tall fescue. Beneficial results have been demonstrated with stocker steers , heifers , lactating dairy cows and horses Persistence of non-toxic (non alkaloid producing) endophyte infected tall fescue has been shown to be equal to toxic endophyte tall fescue.
5. Missouri -- Plant studies revealed that making hay then treating it with ammonia drastically reduced ergot alkaoids in tall fescue, while ensiling tall fescue preserved the alkaloids. Other plant studies showed that treating the growing pasture with low rates of Select herbicide reduced ergot alkaloid concentration by two-thirds. Finally, the plant work at Missouri showed that ergot alkaloids could be measured by near-infrared spectroscopy when the spectrophotometer was calibrated with immunochemistry data. Animal studies conducted with both rat and cattle showed that exogenous nitric oxide supplementation (NO) reduced the impact of fescue toxicosis. In both studies, NO overrode the vasoconstrictive effects of fescue toxicosis and reduced the associated hyperthermia. There were no effects of NO on the heat stress response alone. A pair-fed study using rats determined that the reduction in feed intake associated with fescue toxicosis was not responsible for the reduction in body temperature that occurs under non-heat stress conditions. Cattle were implanted with telemetric temperature transmitters for real-time monitoring of core body temperature while on endophyte-infected or uninfected fescue pastures. Initial analyses show that cattle on endophyte-infected pastures exhibit a higher temperature during days when air temperature is increasing.
6. Oregon - The overall objective of Oregon State University’s (OSU) research thrust is the degradation of the ergopeptides in tall fescue by ruminal microbes. This degradation will render the toxins non-toxic to the host animal. The objectives involve the investigation and elucidation of ruminal degradation, endophyte analyses of plant material (straw/hay/seed) samples, and toxicology diagnostics. This year OSU searched for additional sources of anaerobic degraders for the ergopeptides. A species that has obligate anaerobic bacteria in their intestinal tract is the earthworm. We found that earthworms on high-endophyte compost could be induced to degrade ergopeptides. Therefore, earthworms may be a potential source of alkaloid degrading microbes.

The number of endophyte analyses at OSU has steadily increased during the year. 1300 samples were analyzed between July 1, 2001 and June 30, 2002. These analyses assisted many local producers as well as national and international colleagues with critical information for determining the appropriate use of pasture grasses and grass seed residues. Quality control for endophyte analyses is checked with Dr. Rottinghaus’s laboratory at Missouri State University; moreover, we are working with Japan’s Ministry of Agriculture in establishing a check laboratory to insure quality control for straw exports to the Pacific Rim. Additionally, OSU is involved with the diagnostic toxicology of perennial ryegrass and tall fescue toxicosis. During the winter of 2002, fescue toxicosis was a major factor in devastating cattle losses in both eastern and western Oregon. The combination of cold weather and high-endophyte-infected feed affected over 2,500 animals; 600 were lost. These events cost the Oregon livestock industry an estimated $1.5 million. The OSU College of Veterinary Medicine provided analyses to help determine the causes of the morbidity. It prompted the Oregon grass seed producers to change their protocols and procedures to lessen the chance of a repeat occurrence. Moreover, it reemphasized the importance of endophyte analysis for the pasture grasses and grass seed residues fed to livestock.
Tennessee (UT) - Pastures of tall fescue containing AR542 (MaxQ) that were seeded in fall 1997 at Ames Plantation in southwest Tennessee remain productive in 2002. During the past five years these pastures have been grazed at a moderate stocking density and have survived two consecutive years of drought. Based on this study the endophyte appears promising for Tennessee livestock producers.
South Carolina -- A dose-titration study was completed to determine the minimum effective dose of a D-2 dopamine receptor antagonist (domperidone) for treatment and prevention of fescue toxicosis in late gestation mares. Domperidone was a highly effective for prevention/treatment of fescue toxicosis and a minimum effective dose was established. The mare reproductive loss syndrome (MRLS) that occurred in Kentucky and surrounding areas was studied. Level of fescue in the pasture was not related (P<.05) to MRLS but presence of poison hemlock (Conium maculatum) in and around the pastures was related (P<.01). Early term pregnant mares were dosed with poison hemlock and only one abortion occurred at the highest dose level. It is unlikely that poison hemlock was a primary cause of MRLS.

Publications: The reports published and distributed at the meeting will be presented on the home page for this group as titles with email addresses for contact person for anyone seeing more information.

Submitted by: Craig Roberts, Chair-elect/Secretary Date Submitted: January 23, 2003




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