| endocrine and respiratory responses to ergotamine in brahman and hereford steers. | ergot alkaloids are considered causative agents of fescue toxicosis, a syndrome experienced by cattle consuming tall fescue (festuca arundinacea) infected with the fungal endophyte neotyphodium coenophialum. one sign of fescue toxicosis in cattle is severe hyperthermia. this study assessed hormonal responses to ergotamine in heat-sensitive and heat-tolerant cattle. seven hereford (heat-sensitive, bos taurus) and 7 brahman (heat-tolerant, bos indicus) steers on a fescue-free diet received ergotam ... | 2002 | 12046966 |
| effects of endophyte status of tall fescue tissues on the earthworm (eisenia fetida). | a cryptic fungal endophyte, neotyphodium coenophialum, infects most tall fescue (festuca arundinacea) pastures in the united states. cattle, sheep, and horses that consume the endophyte-infected grass can suffer fescue toxicosis caused by toxic alkaloids in the infected plants. the effects of the endophyte on mammalian herbivores have been well documented, but less is known regarding the quality of the grass (infected vs noninfected) as a food material for soil invertebrates. we conducted 21-d t ... | 2001 | 11392146 |
| association between feeding perennial ryegrass (lolium perenne cultivar grasslands impact) containing high concentrations of ergovaline, and health and productivity in a herd of lactating dairy cows. | perennial ryegrasses are frequently infected with fungal endophyte (neotyphodium lolii) to increase the resistance of the plant to insect damage. unfortunately, a side effect of endophyte infection can be the production of alkaloids, including lolitrem b and ergovaline, that produce toxic effects in animals. a significant 4.6 litre decrease in milk production in a herd of holstein-friesian dairy cows was associated with high concentrations of ergovaline in ryegrass silage. simultaneously, milk s ... | 2001 | 11349413 |
| endophytic fungal toxin effect on adrenergic receptors in lateral saphenous veins (cranial branch) of cattle grazing tall fescue. | the objective of this research was to characterize the adrenergic receptor response in veins of cattle that grazed tall fescue (festuca arundinacea schreb.), with (e+) and without (e-) fungal endophyte (neotyphodium coenophialum) infection. measurement of contractile response of lateral saphenous veins to selective adrenergic receptor agonists (alphal, phenylephrine; alpha2, bht-920) revealed enhanced reactivity (greater contractile response) only for the alpha2 adrenergic receptor in e+ pasture ... | 1998 | 9856395 |
| bovine plasma vitamin a responses to selected nutrients, monensin, and endophytic fescue. | previous research at this station adapted a maximal dose response (mdr) method of evaluating vitamin a status and utilization for use in beef cattle. this method was used in two experiments. in this first experiment, forty-eight crossbred steers (average weight, 284 kg) were fed diets supplemented with salt, monensin or both, and injected with vitamin e, zinc or selenium. steers receiving monensin had higher (38.5 micrograms/dl, monensin; 31.0 micrograms/dl, controls) initial plasma concentratio ... | 1993 | 8407168 |
| occurrence of peptide and clavine ergot alkaloids in tall fescue grass. | evidence is presented that ergot alkaloids are ubiquitous in tall fescue pastures infected with the clavicipitaceous fungal endophyte sphacelia typhina (or acremonium coenophialum). ergopeptide alkaloids, predominantly ergovaline, constituted 10 to 50 percent of the total ergot alkaloid concentration, which was as high as 14 milligrams per kilogram in sheaths and 1.5 milligrams per kilogram in blades. ergot alkaloid concentrations were substantially increased by application of large amounts (10 ... | 1986 | 3008328 |
| alkaloid toxins in endophyte-infected grasses. | grasses infected with clavicipitaceous fungi have been associated with a variety of diseases including classical ergotism in humans and animals, fescue foot and summer syndrome in cattle, and rye-grass staggers in sheep. during the last decade it has been recognized that many of these fungal infections are endophytic; a fungal endophyte is a fungus that grows entirely within the host plant. inspection of field collections and herbarium specimens has revealed that such infections are widespread i ... | 1992 | 1344917 |