scholarly journals Tall fescue ergot alkaloids are vasoactive in equine vasculature1,2

2017 ◽  
Vol 95 (11) ◽  
pp. 5151-5160 ◽  
Author(s):  
J. L. Klotz ◽  
K. J. McDowell
Keyword(s):  
Tall Fescue ◽  
Ergot Alkaloids

Performance of Tall Fescue Germplasms Bred for High- and Low-Ergot Alkaloids

Crop Science ◽  
2002 ◽  
Vol 42 (2) ◽  
pp. 518 ◽  
Author(s):  
N. S. Hill ◽  
J. H. Bouton ◽  
F. N. Thompson ◽  
L. Hawkins ◽  
C. S. Hoveland ◽  
...  
Keyword(s):  
Tall Fescue ◽  
Ergot Alkaloids

scholarly journals 111 Metsulfuron and variable nitrogen application rates on infected tall fescue: effects on stocker performance, forage yield, nutritive value, ergovaline concentration and botanical composition

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 31-31
Author(s):  
Kevin R Meng ◽  
Eric Bailey ◽  
Josh Zeltwanger ◽  
Hannah Allen ◽  
Mikaela Adams ◽  
...  
Keyword(s):  
Species Composition ◽  
Tall Fescue ◽  
Nutritive Value ◽  
Ergot Alkaloids ◽  
Fertilization Rate ◽  
Forage Yield ◽  
Nitrogen Application ◽  
Forage Production ◽  
Seed Head ◽  
Application Rates

Abstract Chemical seed-head suppression of endophyte infected tall fescue (Lolium arundinaceum) improves stocker cattle performance but may decrease forage yield. Spring nitrogen application increases tall fescue growth with a concomitant increase in ergot alkaloids, produced by the symbiotic endophyte Epichloë coenophiala. We hypothesized that greater amounts of nitrogen applied to tall fescue would increase forage yield and offset losses in forage production from chemical suppression of seed-heads with metsulfuron without effect on alkaloid concentration. Ninety-six steers (270 ± 20 kg) were randomly assigned to one of sixteen paddocks (1.8 ha) on April 18 and continuously grazed for 57 d. Paddocks were blocked by previous use (n = 4) and randomly assigned to one of four treatments; no metsulfuron, no nitrogen (NEGCON), metsulfuron with 0 (MET0), 67 (MET67), or 134 (MET134) kg/ha of ammonium nitrate, applied March 11. Steers grazing MET0 paddocks were removed 17 d early due to insufficient forage availability. Steer weight, forage yield, forage nutritive value and ergot alkaloids in forage samples were measured monthly. Seed-head frequency and species composition were determined in June. Metsulfuron application reduced (P < 0.01) tall fescue seed-heads by 80%. Metsulfuron decreased (P = 0.03) ergovaline but ergovaline increased (P < 0.01) at each monthly sampling across treatments. Nitrogen had no impact on ergovaline concentration (P = 0.50). Forage yield tended to be least (P = 0.07) for MET0, intermediate for NEGCON and MET67, and tended to be greatest for MET134 (P = 0.08). Steer ADG was not affected by treatment (P < 0.80). Metsulfuron decreased NDF (P=0.02) regardless of fertilization rate. Forage CP increased with fertilization (P < 0.01) and no differences were detected between NEGCON and MET0 (P = 0.45). Species composition was not impacted (P >0.07) by treatment. Metsulfuron decreased seed-head growth and ergovaline concentration in tall fescue. Additional nitrogen fertilizer ameliorated forage yield lost to metsulfuron application but did not impact steer gain.

Performance of Tall Fescue Germplasms Bred for High‐ and Low‐Ergot Alkaloids

Crop Science ◽  
2002 ◽  
Vol 42 (2) ◽  
pp. 518-523 ◽  
Author(s):  
N. S. Hill ◽  
J. H. Bouton ◽  
F. N. Thompson ◽  
L. Hawkins ◽  
C. S. Hoveland ◽  
...  
Keyword(s):  
Tall Fescue ◽  
Ergot Alkaloids

Physiological Responses in Rats Fed Extracts of Endophyte-Free and Endophyte-Infected Tall Fescue Seed Relative to Some Known Ergot Alkaloids

1989 ◽  
Vol 12 (2) ◽  
pp. 147-164 ◽  
Author(s):  
J. A. Jackson ◽  
S. G. Yates ◽  
R. G. Powell ◽  
R. W. Hemken ◽  
L. P. Bush ◽  
...  
Keyword(s):  
Tall Fescue ◽  
Physiological Responses ◽  
Ergot Alkaloids

Response of Pratylenchus spp. in tall fescue infected with different strains of the fungal endophyte Neotyphodium coenophialum

Nematology ◽  
2005 ◽  
Vol 7 (1) ◽  
pp. 105-110 ◽  
Author(s):  
Patricia Timper ◽  
Roger N. Gates ◽  
Joe H. Bouton
Keyword(s):  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Ergot Alkaloids ◽  
Nematode Resistance ◽  
Fungal Endophyte ◽  
Parasitic Nematodes ◽  
Small Subset ◽  
Neotyphodium Coenophialum ◽  
Different Strains ◽  
Endemic Strain

Abstract The presence of the fungal endophyte Neotyphodium coenophialum in tall fescue (Festuca arundinacea) confers resistance to some plant-parasitic nematodes but also results in the production of ergot alkaloids. Recently, new strains of N. coenophialum have been isolated from wild tall fescue and artificially inoculated into elite tall fescue cultivars. These strains produce low to nil levels of ergot alkaloids and are referred to as non-ergot strains. Our objective was to determine whether non-ergot strains of the endophyte confer the same level of resistance to Pratylenchus spp. as the endemic strain in tall fescue. In a glasshouse experiment, nematode resistance was compared in two fescue cultivars (Jesup and Georgia 5) infected with either the endemic strain (E+), or two non-ergot strains, AR542 and AR584. An additional non-ergot strain, AR514, was tested only in cv. Jesup. Cultivars Georgia 5 and Jesup without endophytes (E−) were used as controls. The endophtye status of the plants was confirmed and then three plants per cultivar/endophyte combination were transplanted into 10 cm square pots. The pots were inoculated with a mixed culture of Pratylenchus zeae and P. scribneri in the first trial and a pure culture of P. scribneri in the second trial of the experiment. After 8 weeks, the number of nematodes within the roots from each pot was determined. Numbers of Pratylenchus spp. in either cv. Georgia 5 or cv. Jesup containing the non-ergot strain AR542 were not different from numbers in E− plants. AR514 also did not confer resistance to the nematodes in cv. Jesup. By contrast, the non-ergot strain AR584 appears to confer resistance to Pratylenchus spp. in cv. Georgia 5, but not in cv. Jesup; however, the level of resistance in cv. Georgia 5 was less than the resistance conferred by the endemic endophyte. Genetic differences between the two tall fescue cultivars may affect growth of the endophyte or production of a nematode toxin or deterrent by the endophyte. As only a small subset of endophyte strains has been tested, we are screening additional non-ergot strains for resistance to P. scribneri.

Changes in Cytochrome P450 in Katahdin Ewes Fed Endophyte-infected Tall Fescue Seed Diets in Spring and Fall

2021 ◽  
Vol 99 (Supplement_2) ◽  
pp. 40-41
Author(s):  
Mohan Acharya ◽  
Joan M Burke ◽  
Erin Wood ◽  
Yan Huang ◽  
Palika Dias Morse ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Serum Concentration ◽  
Rectal Temperature ◽  
Tall Fescue ◽  
Repeated Measures ◽  
Ergot Alkaloids ◽  
Serum Prolactin ◽  
Fescue Toxicosis ◽  
Pregnancy Status ◽  
Soy Hulls

Abstract Objective was to examine the activity of cytochrome P450 (CYP), a liver enzyme that metabolizes ergot alkaloids which is hindered by this fescue toxin, as an indicator of fescue toxicosis in sheep. In spring and fall, ewes were blocked by age and BW, and randomly assigned to 1 kg/ewe/d of endophyte-infected (E+; 61% of diet in fall, 13% of diet in spring; 0.8 µg/g of ergovaline; and soy hulls, alfalfa pellets, cottonseed hulls, molasses) or non-infected (E-; same proportion of E+/season and same feeds) tall fescue seed supplement (n = 10/diet in each season) for 28 d, plus hay, mineral and water. Ewes were exposed to teaser, d -21 to 0, and intact rams, d 0 (first day of diet) to 30. Rectal temperature (RT), serum concentration of prolactin (using RIA), and CYP were determined every 7–14 d between d 0–28, and pregnancy status on d 56. PromegaTM P450-Glo assay was used to determine CYP from serum. Data were analyzed by using PROC MIXED with repeated measures (SAS). Rectal temperature of E+ compared with E- ewes was elevated on at least one day in fall and spring (diet × season × d, P < 0.001). Serum prolactin was lower in E+ compared with E- ewes (diet × d, P < 0.001) and lower in fall (P < 0.001). CYP was higher in E- ewes on d 28 in fall (diet × season × d, P = 0.008), but otherwise similar between diets, and higher in fall than spring (P < 0.001). There was an unexpected negative correlation between CYP and prolactin (R = -0.24; P < 0.009), but there appears to be a subpopulation of ewes with low prolactin and lower CYP. CYP activity in sera may not be a marker for fescue toxicosis in ewes.

scholarly journals Nematotoxic effects of endophyte-infected tall fescue toxins and extracts in an in vitro bioassay using the nematode Pratylenchus scribneri

2007 ◽  
Vol 13 ◽  
pp. 357-361
Author(s):  
A.A. Bacetty ◽  
M.E. Snook ◽  
A.E. Glenn ◽  
C.W. Bacon ◽  
P. Nagabhyru ◽  
...  
Keyword(s):  
Tall Fescue ◽  
Pyrrolizidine Alkaloid ◽  
Ergot Alkaloids ◽  
Nematode Species ◽  
In Vitro Assay ◽  
Total Phenolic ◽  
Vitro Assay ◽  
Interactive Nature ◽  
Pratylenchus Scribneri

Biotypes of the Neotyphodium coenophialum-tall fescue grass symbiota are provided with enhanced protection from grazing vertebrate herbivores due to the production of toxic secondary metabolites. However, considerable controversy exists concerning this symbiotum and its toxicity to nematode species. A sterile in vitro system was developed to determine the interactive nature of known toxins specific to this mutualistic association and compounds within grass extracts known to be nematotoxic. The in vitro assay used Pratylenchus scribneri, the lesion nematode, as the target organism to determine the interactive nature of ergot alkaloids, the pyrrolizidine alkaloid (the lolines), total phenolic fractions, and specific phenolic compounds. The in vitro assay is described along with methods for testing toxicity. The results indicate that only two of three ergot alkaloids were toxic to P. scribneri, and there were possible potentiating or synergistic effects with other alkaloids and water soluble polyphenolics. HPLC analysis and UV mass spectrometry of root extracts revealed the presence of two major polyphenolics, chlorogenic and di-caffeoylquinic acids, both of which are natural constituents of this and other plants and have known toxicity to several species of nematodes. Further, it was determined that there were quantitative differences between the total phenolic and specific phenolic contents in roots of endophyte infected and noninfected tall fescue, cultivar Jesup. This in vitro assay offers a rapid and routine screen for acute testing chemical components of the tall fescue-endophyte symbiotum for toxicity to this nematode species. Keywords: Chlorogenic acid, di-caffeoylquinic acids, ergot alkaloid, lolines, nematode, polyphenolics, Pratylenchus scribneri, pyrrolizidine alkaloid

077 Hair Coat Phenotype in Heifers Alters Physiological Responsiveness to Ergot Alkaloids Commonly Found in Endophyte-Infected Tall Fescue

2016 ◽  
Vol 94 (suppl_1) ◽  
pp. 38-38
Author(s):  
T. L. Devine ◽  
J. C. Mackey ◽  
G. Shaeffer ◽  
M. H. Poore ◽  
D. H. Poole
Keyword(s):  
Tall Fescue ◽  
Ergot Alkaloids ◽  
Hair Coat
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