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Daniel Cook - One of the best experts on this subject based on the ideXlab platform.
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Analysis of rumen contents and ocular fluid for toxic alkaloids from goats and cows dosed larkspur (Delphinium barbeyi), lupine (Lupinus leucophyllus), and death camas (Zigadenus paniculatus).
Toxicon : official journal of the International Society on Toxinology, 2020Co-Authors: Stephen T. Lee, Clinton A. Stonecipher, Daniel Cook, Kevin D. Welch, Dale R. Gardner, James A. PfisterAbstract:Abstract Larkspurs, lupines, and death camas can be acutely toxic to livestock and are serious poisonous plant problems in western North America. The toxicity of these plants depends on the composition and concentrations of the toxic alkaloids in the plants. In this study, goats and cows were dosed sub-lethal doses of larkspur, lupine, and death camas. Rumen contents and ocular fluid samples were collected, and simple extraction, sample preparation, and analytical methods were developed for the detection of toxic alkaloids in the rumen contents and ocular fluid samples. Toxic alkaloids were detected in the rumen contents and ocular fluid samples from the goats and cows dosed larkspur, lupine, and death camas. In addition, results from a case report where rumen contents were analyzed from a steer that was suspected to have died due to larkspur are reported. This demonstrates the utility of the methods described for the diagnosis of acute plant poisonings.
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Seasonal variation in toxic steroidal alkaloids of foothill death camas (Zigadenus paniculatus)
Biochemical Systematics and Ecology, 2020Co-Authors: Clinton A. Stonecipher, Daniel Cook, Kevin D. Welch, Dale R. Gardner, James A. PfisterAbstract:Abstract Death camas (Zigadenus spp.) is a common poisonous plant in North America with plants occurring in a wide variety of habitats with species of toxic concern occurring primarily in meadows, grasslands, shrublands, and mountains. The toxicity of Zigadenus species has been attributed to a series of steroidal alkaloids. The objective of this study was to evaluate zygacine and total steroidal alkaloid concentrations in different plant tissues of Zigadenus paniculatus as a function of plant maturity. Death camas plants were collected at two locations at different developmental growth stages representing vegetative, flower, seed pod, and shattered seed pod stages. Zygacine represented greater than 50% of the total steroidal alkaloids at all developmental stages. In bulbs, total steroidal alkaloid and zygacine concentrations did not change significantly as a function of plant phenology, and concentrations were lower than what were observed in above ground plant parts. Total steroidal alkaloid and zygacine concentrations in above ground parts were highest at early vegetative growth stages and decreased over the growing season. In plant reproductive parts, total steroidal alkaloid and zygacine concentrations increased until maturity and then decreased as the plant senesced. The concentrations of steroidal alkaloids reported here suggest that the toxic risk associated with death camas is greatest in the early vegetative growth stages followed by the flower and pod stages. There is a toxic risk to livestock as long as the plant is present, and caution should be taken when grazing livestock in areas with death camas until the plant senesces.
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The Effect of Co-Administration of Death Camas (Zigadenus spp.) and Low Larkspur (Delphinium spp.) in Cattle
Toxins, 2016Co-Authors: Kevin D. Welch, Clinton A. Stonecipher, Dale R. Gardner, James A. Pfister, Benedict T. Green, Daniel CookAbstract:In many rangeland settings, there is more than one potential poisonous plant. Two poisonous plants that are often found growing simultaneously in the same location in North American rangelands are death camas (Zigadenus spp.) and low larkspur (Delphinium spp.). The objective of this study was to determine if co-administration of death camas would exacerbate the toxicity of low larkspur in cattle. Cattle dosed with 2.0 g of death camas/kg BW showed slight frothing and lethargy, whereas cattle dosed with both death camas and low larkspur showed increased clinical signs of poisoning. Although qualitative differences in clinical signs of intoxication in cattle co-treated with death camas and low larkspur were observed, there were not any significant quantitative differences in heart rate or exercise-induced muscle fatigue. Co-treatment with death camas and low larkspur did not affect the serum zygacine kinetics, however, there was a difference in the larkspur alkaloid kinetics in the co-exposure group. Overall, the results from this study suggest that co-exposure to death camas and low larkspur is not significantly more toxic to cattle than exposure to the plants individually. The results from this study increase our knowledge and understanding regarding the acute toxicity of death camas and low larkspur in cattle.
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The effect of low larkspur (Delphinium spp.) co-administration on the acute toxicity of death camas (Zigadenus spp.) in sheep.
Toxicon : official journal of the International Society on Toxinology, 2013Co-Authors: Kevin D. Welch, Clinton A. Stonecipher, Dale R. Gardner, Benedict T. Green, Kip E. Panter, J. A. Pfister, Daniel CookAbstract:In most cases where livestock are poisoned by plants in a range setting, there is more than one potential poisonous plant in the same area. Two poisonous plants that are often found growing simultaneously in the same location are death camas (Zigadenus spp.) and low larkspur (Delphinium spp.). Sheep are known to be susceptible to death camas poisoning while they are thought to be resistant to larkspur. The objective of this study was to determine if co-administration of low larkspur would exacerbate the toxicity of death camas in sheep. A dose finding study was performed to find a dose of death camas that caused minimal clinical signs of poisoning. Sheep were observed for clinical signs of poisoning as well as changes in heart rate and muscle fatigue. Sheep dosed with 1.14 g of death camas per kg BW showed slight frothing and lethargy, whereas sheep dosed with death camas and low larkspur showed slightly more noticeable clinical signs of poisoning. Sheep dosed with only low larkspur, at 7.8 g/kg BW, showed no signs of poisoning. Although we observed a qualitative difference in clinical signs of intoxication in sheep co-treated with death camas and low larkspur we did not detect any quantitative differences in heart rate, exercise-induced muscle fatigue, or differences in serum zygacine kinetics. Consequently, the results from this study suggest that low larkspur does not affect the toxicity of death camas in sheep. The results from this study increase knowledge and understanding regarding the acute toxicity of death camas and low larkspur in sheep. As combined intoxications are most likely common, this information will be useful in further developing management recommendations for ranchers and in designing additional experiments to study the toxicity of death camas to other livestock species.
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The acute toxicity of the death camas (Zigadenus species) alkaloid zygacine in mice, including the effect of methyllycaconitine coadministration on zygacine toxicity.
Journal of animal science, 2011Co-Authors: Kevin D. Welch, Dale R. Gardner, Kip E. Panter, J. A. Pfister, Bryan L. Stegelmeier, B. T. Green, Daniel CookAbstract:Death camas (Zigadenus spp.) is a common poisonous plant on foothill rangelands in western North America. The steroidal alkaloid zygacine is believed to be the primary toxic component in death camas. Poisonings on rangelands generally occur in the spring when death camas is abundant, whereas other more desirable forage species are limited in availability. In most cases where livestock are poisoned by plants in a range setting, there is more than one potential poisonous plant in that area. One common poisonous plant that is often found growing simultaneously in the same area as death camas is low larkspur (Delphinium nuttallianum). Consequently, the objectives of this study were to conduct acute toxicity studies in mice and to determine if coadministration of low larkspur will exacerbate the toxicity of death camas. We first characterized the acute toxicity of zygacine in mice. The LD(50) of zygacine administered intravenously (i.v.) and orally was 2.0 ± 0.2 and 132 ± 21 mg/kg, respectively. The rate of elimination of zygacine from whole blood was determined to be 0.06 ± 0.01/min, which corresponds to an elimination half-life of 13.0 ± 2.7 min. The i.v. LD(50) of total alkaloid extracts from a Utah and a Nevada collection were 2.8 ± 0.8 and 2.2 ± 0.3 mg/kg, respectively. The i.v. LD(50) of methyllycaconitine (MLA), a major toxic alkaloid in low larkspur, was 4.6 ± 0.5 mg/kg, whereas the i.v. LD(50) of a 1:1 mixture of MLA and zygacine was 2.9 ± 0.7 mg/kg. The clinical signs in mice treated with this mixture were very similar to those of mice treated with zygacine alone, including the time of onset and death. These results suggest that there is an additive effect of coadministering these 2 alkaloids i.v. in mice. The results from this study increase knowledge and understanding regarding the acute toxicity of death camas. As combined intoxications are most likely common, this information will be useful in further developing management recommendations for ranchers and in designing additional experiments to study the toxicity of death camas to livestock.
Dale R. Gardner - One of the best experts on this subject based on the ideXlab platform.
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Neurotoxic alkaloid in pollen and nectar excludes generalist bees from foraging at death-camas, Toxicoscordion paniculatum (Melanthiaceae)
Biological Journal of the Linnean Society, 2020Co-Authors: James H. Cane, Dale R. Gardner, Melissa WeberAbstract:Abstract Many plants produce broadly active toxins to which specialist herbivores—typically insects—have evolved counter-adaptations, sometimes spawning co-evolutionary arms races. Many non-social bee species are likewise taxonomic host specialists, but the specialists’ pollen hosts frequently attract diverse floral generalists as well, even to flowers of plants that are otherwise chemically defended. In this study of foothills death-camas, Toxicoscordion paniculatum (Nutt.) Rydberg (formerly Zigadenus), we show that its pollen and nectar both contain zygacine, the steroidal alkaloid responsible for this plant’s notorious mammalian toxicity. Hungry naïve adults of a generalist solitary bee, Osmia lignaria Say (Megachilidae), would briefly drink death-camas nectar or biologically relevant doses of zygacine in syrup, followed by prolonged bouts of irritable tongue grooming; many became paralyzed and some even died. Larvae fed dosed provision masses likewise often ceased feeding and sometimes died. Prolonged irritation and subsequent deterrence of foraging O. lignaria likely illustrates why it and 50+ other vernal bee species were absent from death-camas flowers in a five-state survey. The sole visiting bee, Andrena astragali, foraged exclusively at death-camas flowers for pollen and nectar. Thus, a toxic alkaloid found in death-camas pollen and nectar deters generalist bees from flowers of this pollinator-dependent monocot, restricting visitation to a single specialist bee that tolerates death-camas toxins and is its likely pollinator.
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Analysis of rumen contents and ocular fluid for toxic alkaloids from goats and cows dosed larkspur (Delphinium barbeyi), lupine (Lupinus leucophyllus), and death camas (Zigadenus paniculatus).
Toxicon : official journal of the International Society on Toxinology, 2020Co-Authors: Stephen T. Lee, Clinton A. Stonecipher, Daniel Cook, Kevin D. Welch, Dale R. Gardner, James A. PfisterAbstract:Abstract Larkspurs, lupines, and death camas can be acutely toxic to livestock and are serious poisonous plant problems in western North America. The toxicity of these plants depends on the composition and concentrations of the toxic alkaloids in the plants. In this study, goats and cows were dosed sub-lethal doses of larkspur, lupine, and death camas. Rumen contents and ocular fluid samples were collected, and simple extraction, sample preparation, and analytical methods were developed for the detection of toxic alkaloids in the rumen contents and ocular fluid samples. Toxic alkaloids were detected in the rumen contents and ocular fluid samples from the goats and cows dosed larkspur, lupine, and death camas. In addition, results from a case report where rumen contents were analyzed from a steer that was suspected to have died due to larkspur are reported. This demonstrates the utility of the methods described for the diagnosis of acute plant poisonings.
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Seasonal variation in toxic steroidal alkaloids of foothill death camas (Zigadenus paniculatus)
Biochemical Systematics and Ecology, 2020Co-Authors: Clinton A. Stonecipher, Daniel Cook, Kevin D. Welch, Dale R. Gardner, James A. PfisterAbstract:Abstract Death camas (Zigadenus spp.) is a common poisonous plant in North America with plants occurring in a wide variety of habitats with species of toxic concern occurring primarily in meadows, grasslands, shrublands, and mountains. The toxicity of Zigadenus species has been attributed to a series of steroidal alkaloids. The objective of this study was to evaluate zygacine and total steroidal alkaloid concentrations in different plant tissues of Zigadenus paniculatus as a function of plant maturity. Death camas plants were collected at two locations at different developmental growth stages representing vegetative, flower, seed pod, and shattered seed pod stages. Zygacine represented greater than 50% of the total steroidal alkaloids at all developmental stages. In bulbs, total steroidal alkaloid and zygacine concentrations did not change significantly as a function of plant phenology, and concentrations were lower than what were observed in above ground plant parts. Total steroidal alkaloid and zygacine concentrations in above ground parts were highest at early vegetative growth stages and decreased over the growing season. In plant reproductive parts, total steroidal alkaloid and zygacine concentrations increased until maturity and then decreased as the plant senesced. The concentrations of steroidal alkaloids reported here suggest that the toxic risk associated with death camas is greatest in the early vegetative growth stages followed by the flower and pod stages. There is a toxic risk to livestock as long as the plant is present, and caution should be taken when grazing livestock in areas with death camas until the plant senesces.
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The Effect of Co-Administration of Death Camas (Zigadenus spp.) and Low Larkspur (Delphinium spp.) in Cattle
Toxins, 2016Co-Authors: Kevin D. Welch, Clinton A. Stonecipher, Dale R. Gardner, James A. Pfister, Benedict T. Green, Daniel CookAbstract:In many rangeland settings, there is more than one potential poisonous plant. Two poisonous plants that are often found growing simultaneously in the same location in North American rangelands are death camas (Zigadenus spp.) and low larkspur (Delphinium spp.). The objective of this study was to determine if co-administration of death camas would exacerbate the toxicity of low larkspur in cattle. Cattle dosed with 2.0 g of death camas/kg BW showed slight frothing and lethargy, whereas cattle dosed with both death camas and low larkspur showed increased clinical signs of poisoning. Although qualitative differences in clinical signs of intoxication in cattle co-treated with death camas and low larkspur were observed, there were not any significant quantitative differences in heart rate or exercise-induced muscle fatigue. Co-treatment with death camas and low larkspur did not affect the serum zygacine kinetics, however, there was a difference in the larkspur alkaloid kinetics in the co-exposure group. Overall, the results from this study suggest that co-exposure to death camas and low larkspur is not significantly more toxic to cattle than exposure to the plants individually. The results from this study increase our knowledge and understanding regarding the acute toxicity of death camas and low larkspur in cattle.
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The effect of low larkspur (Delphinium spp.) co-administration on the acute toxicity of death camas (Zigadenus spp.) in sheep.
Toxicon : official journal of the International Society on Toxinology, 2013Co-Authors: Kevin D. Welch, Clinton A. Stonecipher, Dale R. Gardner, Benedict T. Green, Kip E. Panter, J. A. Pfister, Daniel CookAbstract:In most cases where livestock are poisoned by plants in a range setting, there is more than one potential poisonous plant in the same area. Two poisonous plants that are often found growing simultaneously in the same location are death camas (Zigadenus spp.) and low larkspur (Delphinium spp.). Sheep are known to be susceptible to death camas poisoning while they are thought to be resistant to larkspur. The objective of this study was to determine if co-administration of low larkspur would exacerbate the toxicity of death camas in sheep. A dose finding study was performed to find a dose of death camas that caused minimal clinical signs of poisoning. Sheep were observed for clinical signs of poisoning as well as changes in heart rate and muscle fatigue. Sheep dosed with 1.14 g of death camas per kg BW showed slight frothing and lethargy, whereas sheep dosed with death camas and low larkspur showed slightly more noticeable clinical signs of poisoning. Sheep dosed with only low larkspur, at 7.8 g/kg BW, showed no signs of poisoning. Although we observed a qualitative difference in clinical signs of intoxication in sheep co-treated with death camas and low larkspur we did not detect any quantitative differences in heart rate, exercise-induced muscle fatigue, or differences in serum zygacine kinetics. Consequently, the results from this study suggest that low larkspur does not affect the toxicity of death camas in sheep. The results from this study increase knowledge and understanding regarding the acute toxicity of death camas and low larkspur in sheep. As combined intoxications are most likely common, this information will be useful in further developing management recommendations for ranchers and in designing additional experiments to study the toxicity of death camas to other livestock species.
Walter S. Judd - One of the best experts on this subject based on the ideXlab platform.
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Resurrection of segregates of the polyphyletic genus Zigadenus s.l. (Liliales: Melanthiaceae) and resulting new combinations
Novon, 2002Co-Authors: Walter S. Judd, Wendy B. ZomleferAbstract:Reinstatement of segregate genera and the accompanying recombinations for species in the former polyphyletic Zigadenus complex allow for a revised, practical taxonomy that defines monophyletic groups and reflects phylogenetic relationships within tribe Melanthieae (Melanthiaceae). Nine new species combinations result from recircumscription of Zigadenus Michaux and Stenanthium (A. Gray) Kunth and from recognition of Anticlea Kunth and Toxicoscordion Rydberg. The genus Stenanthella Rydberg and the basionyms for Stenanthium leimanthoides (A. Gray) Zomlefer & Judd (Amianthium leimanthoides A. Gray) and Anticlea sachalinensis (F. Schmidt) Zomlefer & Judd (Stenanthium sachalinense F. Schmidt) are lectotypified.
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generic circumscription and relationships in the tribe melanthieae liliales melanthiaceae with emphasis on Zigadenus evidence from its and trnl f sequence data
American Journal of Botany, 2001Co-Authors: Wendy B. Zomlefer, Norris H Williams, Mark W Whitten, Walter S. JuddAbstract:The circumscription and relationships of genera within the tribe Melanthieae (29 representative taxa) were evaluated using parsimony analyses of ITS (nuclear ribosomal) and trnL-F (plastid) DNA sequence data, alone and in combination. Proposed new generic circumscriptions, strongly supported by the tree statistics and topologies in all analyses, are correlated with potential morphological synapomorphies at the proper level of universality. Based on the molecular cladograms, Stenanthium is biphyletic, and the traditional Zigadenus s.1. (sensu lato) is polyphyletic. Amianthium and Schoenocaulon are distinct entities; the Veratrum complex is conservatively treated as one large monophyletic genus (including Melanthium). Although some generic relationships are not highly resolved, the analyses provide strong support for Zigadenus glaberrimus as sister to the rest of the tribe, and Amianthium muscitoxicum as closely related to Veratrum s.l. As a result of these analyses, seven genera (some with novel circumscription) are recognized within the tribe Melanthieae: Amianthium, Anticlea, Schoenocaulon, Stenanthium, Toxicoscordion, Veratrum, and Zigadenus.
Wendy B. Zomlefer - One of the best experts on this subject based on the ideXlab platform.
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Documentation of the Chromosome Number for Zigadenus glaberrimus (Liliales: Melanthiaceae) and its Significance in the Taxonomy of Tribe Melanthieae
Systematic Botany, 2014Co-Authors: Wendy B. Zomlefer, Michael R. Mckain, Jeremy D. RentschAbstract:Abstract The monotypic genus Zigadenus occupies a critical position in the evolution of Melanthieae as sister to the clade comprising the rest of the genera in the tribe. Meiotic (n = 27) and mitotic (2n = 54) chromosome counts for Zigadenus glaberrimus documented here do not support a long-standing tentative report of 2n = 52. The likely base chromosome number of the tribe and significance of chromosome numbers as generic synapomorphies are discussed in reference to these newly recorded counts for Zigadenus glaberrimus, a likely hexaploid.
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Resurrection of segregates of the polyphyletic genus Zigadenus s.l. (Liliales: Melanthiaceae) and resulting new combinations
Novon, 2002Co-Authors: Walter S. Judd, Wendy B. ZomleferAbstract:Reinstatement of segregate genera and the accompanying recombinations for species in the former polyphyletic Zigadenus complex allow for a revised, practical taxonomy that defines monophyletic groups and reflects phylogenetic relationships within tribe Melanthieae (Melanthiaceae). Nine new species combinations result from recircumscription of Zigadenus Michaux and Stenanthium (A. Gray) Kunth and from recognition of Anticlea Kunth and Toxicoscordion Rydberg. The genus Stenanthella Rydberg and the basionyms for Stenanthium leimanthoides (A. Gray) Zomlefer & Judd (Amianthium leimanthoides A. Gray) and Anticlea sachalinensis (F. Schmidt) Zomlefer & Judd (Stenanthium sachalinense F. Schmidt) are lectotypified.
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generic circumscription and relationships in the tribe melanthieae liliales melanthiaceae with emphasis on Zigadenus evidence from its and trnl f sequence data
American Journal of Botany, 2001Co-Authors: Wendy B. Zomlefer, Norris H Williams, Mark W Whitten, Walter S. JuddAbstract:The circumscription and relationships of genera within the tribe Melanthieae (29 representative taxa) were evaluated using parsimony analyses of ITS (nuclear ribosomal) and trnL-F (plastid) DNA sequence data, alone and in combination. Proposed new generic circumscriptions, strongly supported by the tree statistics and topologies in all analyses, are correlated with potential morphological synapomorphies at the proper level of universality. Based on the molecular cladograms, Stenanthium is biphyletic, and the traditional Zigadenus s.1. (sensu lato) is polyphyletic. Amianthium and Schoenocaulon are distinct entities; the Veratrum complex is conservatively treated as one large monophyletic genus (including Melanthium). Although some generic relationships are not highly resolved, the analyses provide strong support for Zigadenus glaberrimus as sister to the rest of the tribe, and Amianthium muscitoxicum as closely related to Veratrum s.l. As a result of these analyses, seven genera (some with novel circumscription) are recognized within the tribe Melanthieae: Amianthium, Anticlea, Schoenocaulon, Stenanthium, Toxicoscordion, Veratrum, and Zigadenus.
Kevin D. Welch - One of the best experts on this subject based on the ideXlab platform.
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Analysis of rumen contents and ocular fluid for toxic alkaloids from goats and cows dosed larkspur (Delphinium barbeyi), lupine (Lupinus leucophyllus), and death camas (Zigadenus paniculatus).
Toxicon : official journal of the International Society on Toxinology, 2020Co-Authors: Stephen T. Lee, Clinton A. Stonecipher, Daniel Cook, Kevin D. Welch, Dale R. Gardner, James A. PfisterAbstract:Abstract Larkspurs, lupines, and death camas can be acutely toxic to livestock and are serious poisonous plant problems in western North America. The toxicity of these plants depends on the composition and concentrations of the toxic alkaloids in the plants. In this study, goats and cows were dosed sub-lethal doses of larkspur, lupine, and death camas. Rumen contents and ocular fluid samples were collected, and simple extraction, sample preparation, and analytical methods were developed for the detection of toxic alkaloids in the rumen contents and ocular fluid samples. Toxic alkaloids were detected in the rumen contents and ocular fluid samples from the goats and cows dosed larkspur, lupine, and death camas. In addition, results from a case report where rumen contents were analyzed from a steer that was suspected to have died due to larkspur are reported. This demonstrates the utility of the methods described for the diagnosis of acute plant poisonings.
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Seasonal variation in toxic steroidal alkaloids of foothill death camas (Zigadenus paniculatus)
Biochemical Systematics and Ecology, 2020Co-Authors: Clinton A. Stonecipher, Daniel Cook, Kevin D. Welch, Dale R. Gardner, James A. PfisterAbstract:Abstract Death camas (Zigadenus spp.) is a common poisonous plant in North America with plants occurring in a wide variety of habitats with species of toxic concern occurring primarily in meadows, grasslands, shrublands, and mountains. The toxicity of Zigadenus species has been attributed to a series of steroidal alkaloids. The objective of this study was to evaluate zygacine and total steroidal alkaloid concentrations in different plant tissues of Zigadenus paniculatus as a function of plant maturity. Death camas plants were collected at two locations at different developmental growth stages representing vegetative, flower, seed pod, and shattered seed pod stages. Zygacine represented greater than 50% of the total steroidal alkaloids at all developmental stages. In bulbs, total steroidal alkaloid and zygacine concentrations did not change significantly as a function of plant phenology, and concentrations were lower than what were observed in above ground plant parts. Total steroidal alkaloid and zygacine concentrations in above ground parts were highest at early vegetative growth stages and decreased over the growing season. In plant reproductive parts, total steroidal alkaloid and zygacine concentrations increased until maturity and then decreased as the plant senesced. The concentrations of steroidal alkaloids reported here suggest that the toxic risk associated with death camas is greatest in the early vegetative growth stages followed by the flower and pod stages. There is a toxic risk to livestock as long as the plant is present, and caution should be taken when grazing livestock in areas with death camas until the plant senesces.
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The Effect of Co-Administration of Death Camas (Zigadenus spp.) and Low Larkspur (Delphinium spp.) in Cattle
Toxins, 2016Co-Authors: Kevin D. Welch, Clinton A. Stonecipher, Dale R. Gardner, James A. Pfister, Benedict T. Green, Daniel CookAbstract:In many rangeland settings, there is more than one potential poisonous plant. Two poisonous plants that are often found growing simultaneously in the same location in North American rangelands are death camas (Zigadenus spp.) and low larkspur (Delphinium spp.). The objective of this study was to determine if co-administration of death camas would exacerbate the toxicity of low larkspur in cattle. Cattle dosed with 2.0 g of death camas/kg BW showed slight frothing and lethargy, whereas cattle dosed with both death camas and low larkspur showed increased clinical signs of poisoning. Although qualitative differences in clinical signs of intoxication in cattle co-treated with death camas and low larkspur were observed, there were not any significant quantitative differences in heart rate or exercise-induced muscle fatigue. Co-treatment with death camas and low larkspur did not affect the serum zygacine kinetics, however, there was a difference in the larkspur alkaloid kinetics in the co-exposure group. Overall, the results from this study suggest that co-exposure to death camas and low larkspur is not significantly more toxic to cattle than exposure to the plants individually. The results from this study increase our knowledge and understanding regarding the acute toxicity of death camas and low larkspur in cattle.
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The effect of low larkspur (Delphinium spp.) co-administration on the acute toxicity of death camas (Zigadenus spp.) in sheep.
Toxicon : official journal of the International Society on Toxinology, 2013Co-Authors: Kevin D. Welch, Clinton A. Stonecipher, Dale R. Gardner, Benedict T. Green, Kip E. Panter, J. A. Pfister, Daniel CookAbstract:In most cases where livestock are poisoned by plants in a range setting, there is more than one potential poisonous plant in the same area. Two poisonous plants that are often found growing simultaneously in the same location are death camas (Zigadenus spp.) and low larkspur (Delphinium spp.). Sheep are known to be susceptible to death camas poisoning while they are thought to be resistant to larkspur. The objective of this study was to determine if co-administration of low larkspur would exacerbate the toxicity of death camas in sheep. A dose finding study was performed to find a dose of death camas that caused minimal clinical signs of poisoning. Sheep were observed for clinical signs of poisoning as well as changes in heart rate and muscle fatigue. Sheep dosed with 1.14 g of death camas per kg BW showed slight frothing and lethargy, whereas sheep dosed with death camas and low larkspur showed slightly more noticeable clinical signs of poisoning. Sheep dosed with only low larkspur, at 7.8 g/kg BW, showed no signs of poisoning. Although we observed a qualitative difference in clinical signs of intoxication in sheep co-treated with death camas and low larkspur we did not detect any quantitative differences in heart rate, exercise-induced muscle fatigue, or differences in serum zygacine kinetics. Consequently, the results from this study suggest that low larkspur does not affect the toxicity of death camas in sheep. The results from this study increase knowledge and understanding regarding the acute toxicity of death camas and low larkspur in sheep. As combined intoxications are most likely common, this information will be useful in further developing management recommendations for ranchers and in designing additional experiments to study the toxicity of death camas to other livestock species.
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The acute toxicity of the death camas (Zigadenus species) alkaloid zygacine in mice, including the effect of methyllycaconitine coadministration on zygacine toxicity.
Journal of animal science, 2011Co-Authors: Kevin D. Welch, Dale R. Gardner, Kip E. Panter, J. A. Pfister, Bryan L. Stegelmeier, B. T. Green, Daniel CookAbstract:Death camas (Zigadenus spp.) is a common poisonous plant on foothill rangelands in western North America. The steroidal alkaloid zygacine is believed to be the primary toxic component in death camas. Poisonings on rangelands generally occur in the spring when death camas is abundant, whereas other more desirable forage species are limited in availability. In most cases where livestock are poisoned by plants in a range setting, there is more than one potential poisonous plant in that area. One common poisonous plant that is often found growing simultaneously in the same area as death camas is low larkspur (Delphinium nuttallianum). Consequently, the objectives of this study were to conduct acute toxicity studies in mice and to determine if coadministration of low larkspur will exacerbate the toxicity of death camas. We first characterized the acute toxicity of zygacine in mice. The LD(50) of zygacine administered intravenously (i.v.) and orally was 2.0 ± 0.2 and 132 ± 21 mg/kg, respectively. The rate of elimination of zygacine from whole blood was determined to be 0.06 ± 0.01/min, which corresponds to an elimination half-life of 13.0 ± 2.7 min. The i.v. LD(50) of total alkaloid extracts from a Utah and a Nevada collection were 2.8 ± 0.8 and 2.2 ± 0.3 mg/kg, respectively. The i.v. LD(50) of methyllycaconitine (MLA), a major toxic alkaloid in low larkspur, was 4.6 ± 0.5 mg/kg, whereas the i.v. LD(50) of a 1:1 mixture of MLA and zygacine was 2.9 ± 0.7 mg/kg. The clinical signs in mice treated with this mixture were very similar to those of mice treated with zygacine alone, including the time of onset and death. These results suggest that there is an additive effect of coadministering these 2 alkaloids i.v. in mice. The results from this study increase knowledge and understanding regarding the acute toxicity of death camas. As combined intoxications are most likely common, this information will be useful in further developing management recommendations for ranchers and in designing additional experiments to study the toxicity of death camas to livestock.
