Pathophysiology of fescue toxicosis

Thompson, F. N.; Stuedemann, J. A.

doi:10.1016/0167-8809(93)90050-y

Cited by 107 publications

(60 citation statements)

References 52 publications

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“…The ergopeptides also suppress prolactin secretion by binding to dopamine receptors; prolactin concentration is, therefore, often used as an indicator of fescue toxicosis in livestock. 13 Depressed serum prolactin in prepartum cattle can result in reduced milk yield but has negligible effects once lactogenesis occurs. Conception and calving by heifers feeding on endophyte-infected hay is also decreased, leading to reproductive efficiency problems.…”

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confidence: 99%

Semiquantitative Determination of Ergot Alkaloids in Seed, Straw, and Digesta Samples Using a Competitive Enzyme-Linked Immunosorbent Assay

et al. 2001

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Abstract. Ergot alkaloids present in endophyte-infected (Eϩ) tall fescue cause fescue toxicosis and other toxic effects in livestock that consume infected plant tissue, leading to significant financial losses in livestock production each year. The predominant method currently in use for quantifying ergot alkaloid content in plant tissue is through high-performance liquid chromatography (HPLC), which quantifies the amount of ergovaline, one of many ergot alkaloids in Eϩ plant tissue. The enzyme-linked immunosorbent assay (ELISA) method used in this study detects quantities of nonspecific ergot alkaloids and therefore accounts for greater amounts of the total ergot alkaloid content in Eϩ tissue than does HPLC. The ELISA can also be used to more expediently analyze a larger number of forage samples without sophisticated and costly analytical equipment and therefore could be more desirable in a diagnostic setting. The purpose of this study was to evaluate the between-day and within-run variability of the ELISA and to determine the binding efficiency of 6 ergot alkaloids to the 15F3.E5 antibody used in the competitive ELISA to ascertain its feasibility as a quick analysis tool for ergot alkaloids. Straw samples had an average coefficient of variation (CV) for concentration of 10.2% within runs and 18.4% between runs, and the seed samples had an average CV for concentration of 13.3% within runs and 24.5% between runs. The grass tissue-based lysergic acid standard curve calculated from the ELISA had an average r 2 of 0.99, with a CV of 2.1%. Ergocryptine, ergocristine, ergocornine, and ergotamine tartrate did not bind strongly to the 15F3.E5 antibody because of the presence of large side groups on these molecules, which block their binding to the antibody, whereas ergonovine and ergonovine maleate were bound much more efficiently because of their structural similarity to lysergic acid. Clarified rumen fluid was tested as an additional matrix for use in the ergot alkaloid competitive ELISA to determine whether future livestock metabolism experiments on the postingestion fate of ergot alkaloids in ruminants could utilize this assay as a quick screening tool for the presence of nonspecific ergot alkaloids in rumen fluid. HPLC and ELISA procedures were compared for their ability in determining ergot alkaloid toxicity based on the repeatability of the procedures and on the specific compounds they measure. The ratio of ELISA concentration to HPLC concentration (ergovaline) varied from 2.00 to 2.81 in seed samples and from 0.62 to 8.66 in straw samples, showing no consistent pattern between the 2 methods. Based on the lack of data at present for the identity of the toxin causing endophyte toxicosis and the lack of agreement between the ergovaline HPLC and ELISA analyses for ergot alkaloids, each method is equally valid as an indicator of toxicity and is the best means for determining the quantity of the specific toxin(s) they measure.Tall fescue (Festuca arundinacea) plants are often infected with the endophyte Neotyphodium c...

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Semiquantitative Determination of Ergot Alkaloids in Seed, Straw, and Digesta Samples Using a Competitive Enzyme-Linked Immunosorbent Assay

et al. 2001

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“…However, the temperature and humidity index can still be rather low and so interaction between ergovaline and environmental conditions known to exacerbate the negative effect of the toxin on animal health and production is rather unlikely. However, these alkaloid concentrations may be sufficient to cause negative effects on animal performance such as lowered weight gain and milk production and disturbed reproductive performances (Thompson & Stuedmann 1993;Valentine et al 1993).…”

Section: Discussionmentioning

confidence: 99%

Ergovaline concentration in perennial ryegrass infected with a lolitrem B‐free fungal endophyte in north‐west Spain

Oliveira¹,

Rottinghaus

González³

2003

New Zealand Journal of Agricultural Research

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Ergovaline concentrations in two perennial ryegrass genotypes (EI 19 and EI24) infected with one lolitrem B-free fungal endophyte were determined over a 3-year period at two different locations in north-west Spain. There was a significant sampling date effect over 3 years and two locations (P < 0.05). The mean ergovaline concentrations ranged from 0.06 ppm in early spring to 0.57 ppm in June. EI19 genotype had significantly (P < 0.05) higher ergovaline concentrations (0.37 ppm, SE = 0.09) than EI24 genotype (0.33 ppm, SE = 0.08) only at one location in year 2000. Under north-west Spanish conditions, ergovaline levels obtained in this study were not so high to reach values potentially toxic for animals. The results presented in this paper suggest that agriculturally useful ryegrass endophyte associations can be developed free from lolitrem B, and which do not accumulate excessive concentrations of ergovaline.

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“…In the United States, but not in Australia, some pasture cultivars of tall fescue contain a toxinproducing endophyte {Acremonium coenophialum). While this has extended the geographic range of adaptability of the grass beyond its ideal environment, removal of the endophyte has dramatically improved animal health, heat tolerance, milk production, calf production, weaning weight, and the rate of liveweight gain (West 1989;Thompson & Stuedemann 1993). Over two grazing seasons, Stuedemann et al (1989) found intake by steers was c. 50% greater on endophyte-free tall fescue.…”

Section: Cultivars With or Without Endophytementioning

confidence: 99%

Improved grass cultivars increase milk and meat production—A review

Reed

1994

New Zealand Journal of Agricultural Research

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Plant breeding and the merit-testing of grass cultivars in multi-site small-plot studies should be supported with some animal production trials if plant improvement is to maintain credibility and remain focussed on feasible, commercially relevant goals. Lactating animals are the most sensitive test animals. Animal production results from cultivar comparisons are considerably influenced by the system(s) of management used. Between-cultivar differences are rarely detected unless pasture is utilised to a high degree. The economic benefits flow mainly from a reduced need for supplementary feed, or in increased carrying capacity. A range of rates of stocking, or a variable stocking policy dependent on minimal sward height or some other objective basis needs to be employed. Where animal production trials have been conducted, they have mainly focussed on cultivars emanating from those plant improvement programmes aimed at improving nutritive value. Given this limitation the reports reviewed provide evidence that grass improvement programmes have raised the feeding value of pasture considerably.

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Pathophysiology of fescue toxicosis

Cited by 107 publications

References 52 publications

Semiquantitative Determination of Ergot Alkaloids in Seed, Straw, and Digesta Samples Using a Competitive Enzyme-Linked Immunosorbent Assay

Semiquantitative Determination of Ergot Alkaloids in Seed, Straw, and Digesta Samples Using a Competitive Enzyme-Linked Immunosorbent Assay

Ergovaline concentration in perennial ryegrass infected with a lolitrem B‐free fungal endophyte in north‐west Spain

Improved grass cultivars increase milk and meat production—A review

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