Ergot Alkaloids in Fattening Chickens (Broilers): Toxic Effects and Carry over Depending on Dietary Fat Proportion and Supplementation with Non-Starch-Polysaccharide (NSP) Hydrolyzing Enzymes.

Ergot alkaloids (EA) are mycotoxins produced by Claviceps purpurea. EA-toxicity is poorly characterized for fattening chickens. Therefore, a dose-response study was performed to identify the lowest, and no observed adverse effect levels (LOAEL and NOAEL, respectively) based on several endpoints. Non-starch-polysaccharide (NSP) cleaving enzyme addition and dietary fat content were additionally considered as factors potentially influencing EA-toxicity. Feed intake was proven to respond most sensitively to the EA presence in the diets. This sensitivity appeared to be time-dependent. While LOAEL corresponded to a total dietary EA content of 5.7 mg/kg until Day 14 of age, it decreased to 2.03 mg/kg when birds were exposed for a period of 35 days. Consequently, NOAEL corresponded to an EA content of 2.49 mg/kg diet until Day 14 of age, while 1.94 mg/kg diet applied until Day 35 of age. Liver lesions indicating enzyme activities in serum were increased after 14 days of exposure. Dietary fat content and NSP-enzyme supplementation modified EA toxicity in an interactive manner. The EA residues in serum, bile, liver and breast meat were <5 ng/g suggesting a negligible carry over of intact EA.

Immunochemical analysis of fumigaclavine mycotoxins in respiratory tissues and in blood serum of birds with confirmed aspergillosis.

The ergoline alkaloid fumigaclavine A (FuA) is one of the major mycotoxins produced by Aspergillus fumigatus, the main causative fungal agent of avian aspergillosis. To study in situ production of FuA, post-mortem respiratory tissues of various avian species, as well as blood samples of falcons (Falco sp.), were analysed by enzyme immunoassay (EIA). At a detection limit of 1.5 ng/ml, FuA EIA positive results were obtained for tissue samples from seven (64%) out of 11 birds with confirmed aspergillosis, with a maximum concentration of 38 ng/g, while all controls (n = 7) were negative. No FuA could be detected in blood serum (detection limit 0.7 ng/ml) of 15 falcons, experimentally inoculated with A. fumigatus conidia. Fungal mycelium material from tissue of clinical aspergillosis cases, cultured on malt extract agar, was highly positive in the FuA EIA in milligrams per gram range. Chromatographic analysis of mycelium extracts revealed the co-presence of FuA and the structurally related fumigaclavine C (FuC). Alkaline hydrolysis of FuA and FuC yielded the corresponding deacetylation products, FuB and FuE. This is the first report showing that fumigaclavine alkaloids are produced by A. fumigatus in situ during the course of clinical aspergillosis in birds; however, the role of these compounds in the pathogenesis of this disease is still unknown.

Ergot alkaloids in feed for Pekin ducks: toxic effects, metabolism and carry over into edible tissues.

Hardened sclerotia (ergots) of Claviceps purpurea contaminate cereal grains and contain toxic ergot alkaloids (EA). Information on EA toxicity in ducks is scarce. Therefore, the aim of the growth experiment (Day 0-49, n = 54/group) was to titrate the lowest observed adverse effect level (LOAEL) for total ergot alkaloids (TEA). A control diet was prepared without ergots, and the diets designated Ergot 1 to 4 contained 1, 10, 15 and 20 g ergot per kg diet, respectively, corresponding to TEA contents of 0.0, 0.6, 7.0, 11.4 and 16.4 mg/kg. Sensitivity of ducks to EA was most pronounced at the beginning of the experiment when feed intake decreased significantly by 9%, 28%, 41% and 47% in groups Ergot 1 to 4, respectively, compared to the control group. The experiment was terminated after two weeks for ducks exposed to Ergot 3 and 4 due to significant growth retardation. Ergot alkaloid residues in edible tissues were lower than 5 ng/g. Bile was tested positive for ergonovine (=ergometrine = ergobasine) with a mean concentration of 40 ng/g. Overall, the LOAEL amounted to 0.6 mg TA/kg diet suggesting that ducks are not protected by current European Union legislation (1 g ergot/kg unground cereal grains).

Antibody binding of circulating ergot alkaloids in cattle grazing tall fescue.

Direct evidence linking alkaloids found in endophyte-infected tall fescue forage with the livestock disorder known as fescue toxicosis is lacking. Physiologic effects of fescue toxicosis include reduced serum prolactin concentration in cattle. A monoclonal antibody specific to the lysergic moiety of ergot alkaloids was developed in mice after creating an immunogen by linking lysergol to human serum albumin. The antibody was specific to the lysergic moiety and, therefore, it cross-reacted with ergot alkaloids, lysergic acid, and lysergol. The antibody did not cross-react with alkaloid derivatives that had bromated or hydrogenated lysergic ring moieties. Fescue toxicosis conditions were elicited in yearling Angus steers by permitting them to graze endophyte-infected tall fescue containing > 650 micrograms/kg of ergovaline for 60 days. Passive immunization of steers by infusion of the monoclonal antibody increased serum prolactin concentration by 7 ng/ml, beginning immediately after infusion. Control steers did not respond to treatment with bovine serum albumin. Active immunization of yearling Angus heifers with immunogens containing lysergol or ergonovine linked to human serum albumin resulted in an antibody response.

HPLC method for determination of ergot alkaloids and some derivatives in human plasma.

Ergot alkaloids and their dihydrogenated methanesulphonate (ms) salts were determined and measured in human plasma. High-performance liquid chromatography (HPLC) with fluorometric detection was used for separation of ergot alkaloids in plasma. Several ergot alkaloids and their derivatives, including lysergide (LSD), can be identified in cases of poisoning.

Quantitative determination of ergot alkaloids in biological fluids by radioimmunoassay.

1 Cross-reactivity of ergot alkaloids with an antiserum produced against lysergic acid conjugated with human serum, albumin was utilized to develop a radioimmunoassay for ergotamine, dihydroergotamine, dihydroergotoxine, ergometrine and methylergometrine in biological fluids. The antisera showed no cross-reactivity with simpler indole structures. 2 A procedure for extraction and concentration of alkaloids in biological fluids was developed. 3 The assay is sensitive for 1.8 ng/ml ergotamine, 1.5 ng/ml dihydroergotamine, 2.2 ng/ml dihydroergotoxine, 0.7 ng/ml ergotmetrine and 0.5 ng/ml methylergometrine. 4 The assay is sufficiently sensitive to permit the measurement of urine and plasma ergot alkaloid levels and it is suitable for determination in cases where a known ergot alkaloid is used.