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Michael H Ralphs - One of the best experts on this subject based on the ideXlab platform.
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Influence of seed endophyte amounts on swainsonine concentrations in Astragalus and Oxytropis Locoweeds.
Journal of agricultural and food chemistry, 2012Co-Authors: Daniel Grum, Dale R Gardner, James A Pfister, Daniel Cook, Jessie M. Roper, Michael H RalphsAbstract:Locoism is a toxic syndrome of livestock caused by the ingestion of a subset of legumes known as Locoweeds endemic to arid and semiarid regions of the western United States. Locoweeds contain the toxic alkaloid swainsonine, which is produced by the endophytic fungi Undifilum species. Two chemotypes of plants can coexist within toxic populations of Locoweeds: chemotype 1 plants are defined as individuals containing swainsonine concentrations greater than 0.01% and quantitatively greater amounts of Undifilum, while chemotype 2 plants are defined as individuals containing less than 0.01% swainsonine and quantitatively smaller amounts of Undifilum. To elucidate the mechanisms that govern chemotypes, the amount of Undifilum in seeds/embryos was manipulated, thus altering subsequent swainsonine concentrations in three Locoweed species: Astragalus mollissimus, Astragalus lentiginosus, and Oxytropis sericea. Chemotype 1 seeds that were fungicide-treated or had the seed coat removed resulted in plants with swainsonine concentrations comparable to those in chemotype 2 plants. Conversely, embryos from seeds of chemotypes 1 and 2 that were inoculated with the endophyte resulted in plants with swainsonine concentrations comparable to those of chemotype 1 plants. This reproducible interconversion between the two swainsonine chemotypes suggests that the quantity of endophyte present in the seed at the time of germination is a key determinant of the eventual chemotype. Additionally, this is the first report of the inoculation of Locoweeds with the endophyte Undifilum species.
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Swainsoninine Concentrations and Endophyte Amounts of Undifilum oxytropis in Different Plant Parts of Oxytropis sericea
Journal of Chemical Ecology, 2009Co-Authors: Daniel Cook, Dale R Gardner, Kevin D Welch, James A Pfister, Michael H Ralphs, Benedict T. GreenAbstract:Locoweeds are Astragalus and Oxytropis species that contain the toxic alkaloid swainsonine. Swainsonine accumulates in all parts of the plant with the highest concentrations found in the above ground parts. A fungal endophyte, Undifilum oxytropis , found in Locoweed plant species, is responsible for the synthesis of swainsonine. By using quantitative PCR, the endophyte can be quantified in Locoweed species. Endophyte amounts differ between plant parts and in some instances do not mirror the concentrations of swainsonine in the corresponding parts. Two groups of Oxytropis sericea were identified: one that accumulated high concentrations of swainsonine and another where swainsonine was not detected, or concentrations were near the detection threshold. The plants with high swainsonine concentrations had quantitatively higher amounts of endophyte. Alternatively, plants with low or no swainsonine detected had quantitatively lower endophyte amounts. In addition, swainsonine and endophyte concentrations were not distributed uniformly within the same plant when separated into stalks (leaves, scape(s), and flowers/pods). These findings provide evidence as to why plants in the same population accumulate different concentrations of swainsonine, and they have important implications for sampling of Locoweed plants.
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Quantitative PCR method to measure the fungal endophyte in Locoweeds.
Journal of agricultural and food chemistry, 2009Co-Authors: Daniel Cook, Dale R Gardner, Kevin D Welch, Michael H Ralphs, Jessie M. Roper, Benedict T. GreenAbstract:A fungal endophyte (Undifilum oxytropis) has been implicated in the synthesis of swainsonine in Oxytropis and Astragalus species, commonly known as Locoweeds. A quantitative PCR method has been developed to measure the amount of endophyte in Oxytropis and Astragalus species. The limit of quantitation was estimated to be 0.2 pg of endophyte/ng of total DNA. This method of analysis was used to quantify the amount of endophyte in 10 plants each of Oxytropis sericea (white point Locoweed), Astragalus mollissimus (wooly Locoweed), and Astragalus lentiginosus (spotted Locoweed). A significant amount of individual plant variability was observed in endophyte content among individuals in all three species. In one O. sericea and one A. lentiginosus plant swainsonine concentrations were near or below the limit of detection. These plants also had the lowest amounts of endophyte when compared to the other specimens. This method will be a useful tool in further investigating the role the endophyte plays in swainsonine ...
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relationship between the endophyte embellisia spp and the toxic alkaloid swainsonine in major Locoweed species astragalus and oxytropis
Journal of Chemical Ecology, 2008Co-Authors: Michael H Ralphs, Rebecca Creamer, Dale R Gardner, J D Graham, Daniel Cook, Stanley L. Welsh, Deana L Baucom, C Hart, B L StegelmeierAbstract:Locoweeds (Astragalus and Oxytropis spp. that contain the toxic alkaloid swainsonine) cause widespread poisoning of livestock on western rangelands. There are 354 species of Astragalus and 22 species of Oxytropis in the US and Canada. Recently, a fungal endophyte, Embellisia spp., was isolated from Astragalus and Oxytropis spp. and shown to produce swainsonine. We conducted a survey of the major Locoweeds from areas where Locoweed poisoning has occurred to verify the presence of the endophyte and to relate endophyte infection with swainsonine concentrations. Species found to contain the fungal endophyte and produce substantial amounts of swainsonine were A. wootoni, A. pubentissimus, A. mollissimus, A. lentiginosus, and O. sericea. Astragalus species generally had higher concentrations of swainsonine than Oxytropis. Swainsonine was not detected in A. alpinus, A. cibarius, A. coltonii, A. filipes, or O. campestris. The endophyte could not be cultured from A. mollissimus var. thompsonii or A. amphioxys, but was detected by polymerase chain reaction, and only 30% of these samples contained trace levels of swainsonine. Further research is necessary to determine if the endophyte is able to colonize these and other species of Astragalus and Oxytropis and determine environmental influences on its growth and synthesis of swainsonine.
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Seeding Cool-season Grasses to Suppress White Locoweed (Oxytropis Sericea) Reestablishment and Increase Forage Production
Weed Technology, 2007Co-Authors: Michael H Ralphs, Thomas A. Monaco, Jose R. Valdez, David W GrahamAbstract:Livestock poisoning can occur on short-grass prairies when Locoweeds are actively growing in spring before warm-season grasses begin growth. White Locoweed grows in early spring, completes flowering and seed production by early summer, and goes dormant. Perennial cool-season grasses may provide competition to suppress Locoweed or reduce its reestablishment following control. Furthermore, these grasses may provide alternative palatable forage to livestock early in the spring. The objective of this study was to suppress white Locoweed reinvasion by seeding cool-season grasses at two mixed-grass and two short-grass prairie sites. White Locoweed and associated species were controlled with glyphosate (1.1 kg ai/ha) and picloram (0.38 kg ae/ha) in 3 by 15 m plots. The plots were seeded to ‘CDII’ crested wheatgrass, ‘Vavilov’ Siberian wheatgrass, ‘Luna’ pubescent wheatgrass, ‘Bozoisky’ Russian wildrye, smooth brome, ‘NewHy’ wheatgrass, sideoats grama, and ‘Immigrant’ forage kochia. In addition, a native grass pl...
Lynn F. James - One of the best experts on this subject based on the ideXlab platform.
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Pathology of Locoweed Poisoning in Sheep
2016Co-Authors: Kent R. Van Kampen, Lynn F. JamesAbstract:The poisoning of livestock by Locoweeds (plants of the genera Astragahs and Oxytropis) in the United States was first reported in 187315. Since that time, numerous reports have been published on various aspects of the disease such as the clinical signs in domestic animals, the sequelae of loco poisoning, the species of plants involved, and substances in Locoweeds that might induce the signs of poison-ing2-6 % 8 % 10912-18,209 22. Although many clinical signs have been re-ported from Locoweed intoxication, such reports have not always agreed. MARSH reported slow, staggering gait, rough coat, staring look, emaciation, lack of muscular coordination, and extreme ner-vousness15. JAMES et al.8 have emphasized the abortive and teratogenic consequences in sheep and cattle. These clinical signs might be more explicitly expressed as: central nervous impairment resulting in di-minished or lost control of motor function and proprioception, ema-ciation, and reproductive disorders resulting in abortion or teratoge-nesis. An adequate description is lacking of the lesions of Locoweed intoxication in sheep. MATHEWS17 described various gross changes and a generalized neuronal degeneration. OEHME et al.18 reported vacuolar degeneration of neurons in horses poisoned under field conditions. They did not attempt extensive histochemical studies to determine the nature of the lesions. Our own study of tissues collected from field cases of Locoweed poisoning in sheep indicated severe vacuolar degenerative changes in the parenchymal cells of central nervous system, liver, kidney, and various endocrine organs. This study was designed to induce Locoweed poisoning in sheep at PENNSYLVANIA STATE UNIV on May 11, 2016vet.sagepub.comDownloaded fro
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Grazing of spotted Locoweed (Astragalus lentiginosus) by cattle and horses in Arizona.
Journal of animal science, 2003Co-Authors: James A Pfister, Dale R Gardner, B L Stegelmeier, Lynn F. JamesAbstract:Spotted Locoweed (Astragalus lentiginosus var. diphysus) is a toxic, perennial plant that may, if sufficient precipitation occurs, dominate the herbaceous vegetation of pinyon-juniper woodlands on the Colorado Plateau. Six cow/calf pairs and four horses grazed a 20-ha pasture with dense patches of Locoweed in eastern Arizona during spring 1998. Locoweed density was 0.7 plants/m2 in the pasture. Locoweed averaged 30.4% NDF and 18.4% CP. Concentrations of the Locoweed toxin, swainsonine, fluctuated from 1.25 to 2 mg/g in Locoweed. Horses ate more (P < 0.01) bites of Locoweed than did cows (15.4 and 5.1% of bites, respectively). Horses generally increased Locoweed consumption over time since they ate approximately 5% of bites in the preflower stage compared with 25% of bites in the pod stage. Cattle consumed almost no Locoweed (< 1% of bites) until the pod stage, when they increased consumption to 15% of bites. Horses were very avid (approximately 65 to 95% of bites) in selecting the small quantities (approximately 40 to 150 kg/ha) of available green grass, and it appeared that their propensity to eat scarce green forage influenced their Locoweed consumption as well. Horses ate relatively little dry grass, even when it was abundant, whereas cattle ate large amounts of dry grass until green grasses became more abundant. Calves began eating Locoweed on the same day as their dams and ate approximately 20% of their bites as Locoweed. Serum concentrations of swainsonine were higher (P < 0.05) in horses than in cattle (433 vs. 170 ng/mL, respectively). Baseline swainsonine was zero in all animals, but swainsonine was rapidly increased to above 800 ng/mL in serum of horses as they ate Locoweed. Horses exhibited depression after eating Locoweed for about 2 wk; after 5 wk of exposure, horses became anorectic and behaviorally unstable. Although limited in scope, this study indicates that horses should not be exposed to spotted Locoweed.
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Influence of Beef Breeds (Brangus, Charolais, or Hereford) on Locoweed Consumption1
The Professional Animal Scientist, 2002Co-Authors: Glenn C. Duff, J D Graham, D A Walker, J D Rivera, Michael H Ralphs, Lynn F. JamesAbstract:Oxytropis sericea and Astragulus mollissimus (commonly referred to as Locoweeds) are responsible for significant monetary losses annually to producers in the western United States. Therefore, a study was conducted over 2 yr to evaluate the influence of beef breeds (Brangus, Charolais, and Hereford) on Locoweed consumption. Twenty-one steers (seven per breed group) were used initially in each year of the study on pastures located near Sofia, NM in yr 1 and on pastures located near Des Moines, NM in yr 2. Steers were placed in separate pastures for each breed (3 pastures/yr) and were rotated through pastures on a weekly basis. Number of bites taken of cool and warm season grasses, forbs, and Locoweed were recorded daily for each steer. Blood samples were collected on d 0, 7, 21, and 28 for determination of serum alkaline phosphatase. A breed x year interaction (P < 0.10) was observed for Locoweed consumption. During yr 1, Brangus cattle consumed more Locoweed during wk 1 of the study than Charolais or Herefords (12, 2, and 3% of bites recorded for Brangus, Charolais, and Hereford, respectively). During yr 2, Brangus cattle consumed more (P < 0.10) Locoweed during wk 1 (15, 2, and 0%), wk 2 (6, 1, and 1%), and wk 3 (9, 4, and 0% for Brangus, Charolais, and Hereford, respectively) of the experiment compared with Charolais and Hereford cattle. No differences were noted among breeds for serum alkaline phosphatase (AP) concentrations during yr 1. Serum AP was increased (P < 0.01) for Brangus versus Charolais and Hereford on d 7 and 14 during yr 2. Results suggest that differences among breeds exist for Locoweed consumption.
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Prior feeding practices do not influence Locoweed consumption.
Journal of Range Management, 2002Co-Authors: M H Ralphs, J D Graham, B L Stegelmeier, G. Greathouse, Anthony P. Knight, D. Doherty, Lynn F. JamesAbstract:Anecdotal evidence suggests that cattle fed alfalfa hay during the winter are inclined to graze Locoweed on spring range. Two studies were conducted to compare the influence of feeding alfalfa hay vs grass hay during the winter on subsequent consumption of white Locoweed (Oxytropis sericea Nutt. ex T&G) in the spring. Eight cows were daily fed alfalfa hay (15.2% CP in 1998, 17.1% CP in 2000) and 8 cows were daily fed grass hay (10.7% CP in 1998, 12.1% CP in 2000) plus 20% protein molasses block during the January-April winter feeding period. Treatment groups grazed in separate pastures (8 ha) on white Locoweed-infested range in May and June in northern Colorado in 1998 and in northeast New Mexico in 2000. Diets were estimated by bite count. There was no difference in Locoweed consumption between the 2 groups (P > 0.22). Cattle grazed Locoweed for 5% of diets in Colorado and 10% of diets in New Mexico. Feeding alfalfa hay over winter did not predispose cattle to graze Locoweed in the spring. Previous research showed other feeding practices or supplements do not affect Locoweed consumption or poisoning. Prevention of Locoweed poisoning requires denying access to Locoweed when it is relatively more palatable than associated forages. DOI:10.2458/azu_jrm_v55i4_ralphs
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Cattle preferences for Lambert Locoweed over white Locoweed
Journal of Range Management, 2001Co-Authors: M H Ralphs, G. Greathouse, Anthony P. Knight, Lynn F. JamesAbstract:White (Oxytropis sericea Nutt. in T.& G.) and Lambert (O. lambertii var. biglovii Pursh) Locoweed grow adjacent to each other on the foothills of the Rocky Mountains from southeastern Wyoming to northeastern New Mexico. Lambert Locoweed matures later and flowers about 3-4 weeks after white Locoweed, thus potentially increasing the critical period of poisoning when livestock graze areas infested by both species. The objective of this study was to evaluate cattle consumption of these 2 species as they progress phenologically. In 1998, 15 Hereford cows grazed a 32 ha pasture infested with both species from the time white Locoweed flowered in mid June until both species were mature and senesced in August. In 1999, 4 cows were placed in a 5 ha pasture infested with both species for 4 days in each of the following periods: (1) flower stage of white Locoweed, (2) flower stage of Lambert Locoweed, immature pod at white Locoweed, (3) immature pod stage of Lambert Locoweed, mature pod while (4) mature pod and seed shatter stage respectively. Diets were estimated by bite-count. Lambert Locoweed was preferred over white Locoweed in the season-long grazing trial in 1998, and in each of the 4 intensive grazing trials in 1999. The cows consumed white Locoweed as availability of Lambert Locoweed declined in 1998, but little white Locoweed was consumed in the 4 intensive grazing trials in 1999. The toxic Locoweed alkaloid swainsonine ranged from 0.04 to 0.06% in white Locoweed, but was not detected in Lambert Locoweed in this study. DOI:10.2458/azu_jrm_v54i3_ralphs
Dale R Gardner - One of the best experts on this subject based on the ideXlab platform.
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Influence of seed endophyte amounts on swainsonine concentrations in Astragalus and Oxytropis Locoweeds.
Journal of agricultural and food chemistry, 2012Co-Authors: Daniel Grum, Dale R Gardner, James A Pfister, Daniel Cook, Jessie M. Roper, Michael H RalphsAbstract:Locoism is a toxic syndrome of livestock caused by the ingestion of a subset of legumes known as Locoweeds endemic to arid and semiarid regions of the western United States. Locoweeds contain the toxic alkaloid swainsonine, which is produced by the endophytic fungi Undifilum species. Two chemotypes of plants can coexist within toxic populations of Locoweeds: chemotype 1 plants are defined as individuals containing swainsonine concentrations greater than 0.01% and quantitatively greater amounts of Undifilum, while chemotype 2 plants are defined as individuals containing less than 0.01% swainsonine and quantitatively smaller amounts of Undifilum. To elucidate the mechanisms that govern chemotypes, the amount of Undifilum in seeds/embryos was manipulated, thus altering subsequent swainsonine concentrations in three Locoweed species: Astragalus mollissimus, Astragalus lentiginosus, and Oxytropis sericea. Chemotype 1 seeds that were fungicide-treated or had the seed coat removed resulted in plants with swainsonine concentrations comparable to those in chemotype 2 plants. Conversely, embryos from seeds of chemotypes 1 and 2 that were inoculated with the endophyte resulted in plants with swainsonine concentrations comparable to those of chemotype 1 plants. This reproducible interconversion between the two swainsonine chemotypes suggests that the quantity of endophyte present in the seed at the time of germination is a key determinant of the eventual chemotype. Additionally, this is the first report of the inoculation of Locoweeds with the endophyte Undifilum species.
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Swainsoninine Concentrations and Endophyte Amounts of Undifilum oxytropis in Different Plant Parts of Oxytropis sericea
Journal of Chemical Ecology, 2009Co-Authors: Daniel Cook, Dale R Gardner, Kevin D Welch, James A Pfister, Michael H Ralphs, Benedict T. GreenAbstract:Locoweeds are Astragalus and Oxytropis species that contain the toxic alkaloid swainsonine. Swainsonine accumulates in all parts of the plant with the highest concentrations found in the above ground parts. A fungal endophyte, Undifilum oxytropis , found in Locoweed plant species, is responsible for the synthesis of swainsonine. By using quantitative PCR, the endophyte can be quantified in Locoweed species. Endophyte amounts differ between plant parts and in some instances do not mirror the concentrations of swainsonine in the corresponding parts. Two groups of Oxytropis sericea were identified: one that accumulated high concentrations of swainsonine and another where swainsonine was not detected, or concentrations were near the detection threshold. The plants with high swainsonine concentrations had quantitatively higher amounts of endophyte. Alternatively, plants with low or no swainsonine detected had quantitatively lower endophyte amounts. In addition, swainsonine and endophyte concentrations were not distributed uniformly within the same plant when separated into stalks (leaves, scape(s), and flowers/pods). These findings provide evidence as to why plants in the same population accumulate different concentrations of swainsonine, and they have important implications for sampling of Locoweed plants.
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Quantitative PCR method to measure the fungal endophyte in Locoweeds.
Journal of agricultural and food chemistry, 2009Co-Authors: Daniel Cook, Dale R Gardner, Kevin D Welch, Michael H Ralphs, Jessie M. Roper, Benedict T. GreenAbstract:A fungal endophyte (Undifilum oxytropis) has been implicated in the synthesis of swainsonine in Oxytropis and Astragalus species, commonly known as Locoweeds. A quantitative PCR method has been developed to measure the amount of endophyte in Oxytropis and Astragalus species. The limit of quantitation was estimated to be 0.2 pg of endophyte/ng of total DNA. This method of analysis was used to quantify the amount of endophyte in 10 plants each of Oxytropis sericea (white point Locoweed), Astragalus mollissimus (wooly Locoweed), and Astragalus lentiginosus (spotted Locoweed). A significant amount of individual plant variability was observed in endophyte content among individuals in all three species. In one O. sericea and one A. lentiginosus plant swainsonine concentrations were near or below the limit of detection. These plants also had the lowest amounts of endophyte when compared to the other specimens. This method will be a useful tool in further investigating the role the endophyte plays in swainsonine ...
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relationship between the endophyte embellisia spp and the toxic alkaloid swainsonine in major Locoweed species astragalus and oxytropis
Journal of Chemical Ecology, 2008Co-Authors: Michael H Ralphs, Rebecca Creamer, Dale R Gardner, J D Graham, Daniel Cook, Stanley L. Welsh, Deana L Baucom, C Hart, B L StegelmeierAbstract:Locoweeds (Astragalus and Oxytropis spp. that contain the toxic alkaloid swainsonine) cause widespread poisoning of livestock on western rangelands. There are 354 species of Astragalus and 22 species of Oxytropis in the US and Canada. Recently, a fungal endophyte, Embellisia spp., was isolated from Astragalus and Oxytropis spp. and shown to produce swainsonine. We conducted a survey of the major Locoweeds from areas where Locoweed poisoning has occurred to verify the presence of the endophyte and to relate endophyte infection with swainsonine concentrations. Species found to contain the fungal endophyte and produce substantial amounts of swainsonine were A. wootoni, A. pubentissimus, A. mollissimus, A. lentiginosus, and O. sericea. Astragalus species generally had higher concentrations of swainsonine than Oxytropis. Swainsonine was not detected in A. alpinus, A. cibarius, A. coltonii, A. filipes, or O. campestris. The endophyte could not be cultured from A. mollissimus var. thompsonii or A. amphioxys, but was detected by polymerase chain reaction, and only 30% of these samples contained trace levels of swainsonine. Further research is necessary to determine if the endophyte is able to colonize these and other species of Astragalus and Oxytropis and determine environmental influences on its growth and synthesis of swainsonine.
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Effect of previous Locoweed (Astragalus and Oxytropis species) intoxication on conditioned taste aversions in horses and sheep.
Journal of animal science, 2007Co-Authors: James A Pfister, B L Stegelmeier, Carl D. Cheney, Dale R GardnerAbstract:Locoweed species (Astragalus and Oxytropis spp.) are a serious toxic plant problem for grazing livestock. Horses and sheep have been conditioned to avoid eating Locoweed using the aversive agent LiC1. The objective of this study was to determine if previous Locoweed intoxication affects food aversion learning in horses and sheep. Horses and sheep were divided into 3 treatment groups: control (not fed Locoweed and not averted to a novel feed); Locoweed-novel feed averted (fed Locoweed and averted to a novel feed); and averted (not fed Locoweed and averted to a novel feed). Animals in the Locoweed-novel feed averted groups were fed Locoweed during 2 periods of 21 and 14 d, respectively, with each feeding period followed by a 14-d recovery period. Animals were averted to a novel test feed at the end of the first Locoweed-feeding period, and periodically evaluated for the strength and persistence of the aversion. During the first recovery period, Locoweed-novel feed averted horses ate less (9.5% of amount offered) of the test feed than did control horses (99.8%) and did not generally differ from averted horses (0%). During recovery period 2, Locoweed-novel feed averted horses (4.3%) differed (P = 0.001) in consumption (% of offered) of the test feed from controls (100%) and the averted group (0%). Locoweed-novel feed averted sheep differed (P = 0.001) from controls (14.4 vs. 99.5%, respectively, during recovery period 1), whereas Locoweed-novel feed averted sheep did not differ (P > 0.50) from averted sheep (0.6%). During the second recovery period, control sheep (100%) differed (P < 0.05) from averted (0%) and Locoweed-novel feed averted (12.2%) groups. Two intoxicated sheep (Locoweed-novel feed averted) partially extinguished the aversion during the first recovery period, but an additional dose of LiCl restored the aversion. Two of 3 intoxicated horses had strong aversions that persisted without extinction; 1 horse in the Locoweed-novel feed averted group had a weaker aversion. These findings suggest that horses and sheep previously intoxicated by Locoweeds can form strong and persistent aversions to a novel feed, but in some animals, those aversions may not be as strong as in animals that were never intoxicated.
James L. F. - One of the best experts on this subject based on the ideXlab platform.
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Prior feeding practices do not influence Locoweed consumption
'JSTOR', 2002Co-Authors: Ralphs M. H., Greathouse G., Knight A. P., Stegelmeier B. L., Doherty D., Graham J. D., James L. F.Abstract:Anecdotal evidence suggests that cattle fed alfalfa hay during the winter are inclined to graze Locoweed on spring range. Two studies were conducted to compare the influence of feeding alfalfa hay vs grass hay during the winter on subsequent consumption of white Locoweed (Oxytropis sericea Nutt. ex TG) in the spring. Eight cows were daily fed alfalfa hay (15.2% CP in 1998, 17.1% CP in 2000) and 8 cows were daily fed grass hay (10.7% CP in 1998, 12.1% CP in 2000) plus 20% protein molasses block during the January-April winter feeding period. Treatment groups grazed in separate pastures (8 ha) on white Locoweed-infested range in May and June in northern Colorado in 1998 and in northeast New Mexico in 2000. Diets were estimated by bite count. There was no difference in Locoweed consumption between the 2 groups (P > 0.22). Cattle grazed Locoweed for 5% of diets in Colorado and 10% of diets in New Mexico. Feeding alfalfa hay over winter did not predispose cattle to graze Locoweed in the spring. Previous research showed other feeding practices or supplements do not affect Locoweed consumption or poisoning. Prevention of Locoweed poisoning requires denying access to Locoweed when it is relatively more palatable than associated forages.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information.Migrated from OJS platform August 202
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Reproductive losses to poisonous plants: Influence of management strategies
'JSTOR', 2002Co-Authors: Panter K. E., Ralphs M. H., James L. F., Stegelmeier B. L., Gardner D. R., Pfister J. A., Lee S. T.Abstract:Poisonous plants that impair normal reproductive functions in livestock include Veratrum californicum Durand, lupines, ponderosa pine (Pinus ponderosa Dougl.), broom snakeweed (Gutierrezia sarothrae (Pursh) Britt. Rusby), Locoweeds (Astragalus and Oxytropis spp.), selenium-containing forages, phytoestrogenic plants, endophyte-infected grasses and others. In this review we focus on lupines, Locoweeds and ponderosa pine needles to demonstrate the broad and diverse effects that poisonous plants have on reproduction. Certain lupines (Lupinus spp.) contain quinolizidine and piperidine alkaloids that are fetotoxic and when grazed by pregnant cattle during specific stages of gestation induce skeletal birth defects and cleft palate, "crooked calf disease". Poison-hemlock (Conium maculatum) and some Nicotiana spp. contain similar alkaloids and induce identical birth defects in cattle, pigs, goats and sheep when ingested at certain stages of gestation. Locoweeds (species of the Astragalus and Oxytropis genera containing the indolizidine alkaloid swainsonine) interfere with most processes of reproduction when grazed for prolonged periods of time. Animals can recover normal reproductive function if withdrawn from Locoweed grazing before severe poisoning occurs. While most animals may recover reproductive function, permanent neurological deficits may preclude normal reproductive behavior. Ponderosa and lodgepole pine needles (Pinus spp.) cause abortion in cattle when grazed during the last trimester of gestation. The specific chemical constituents responsible for the abortions belong to a class of compounds called labdane resin acids, including isocupressic acid (ICA), succinyl ICA, and acetyl ICA. Basic management recommendations to reduce reproductive losses to poisonous plants include: (1) keep good records; (2) know what poisonous plants grow on ranges and understand their effects; (3) develop a management plan to provide for alternate grazing in poisonous plant-free pastures during critical times; (4) provide for balanced nutrition, including protein, energy, minerals and vitamins; (5) maintain a good herd health program; (6) integrate an herbicide treatment program to reduce poisonous plant populations or to maintain clean pastures for alternate grazing; and, (7) manage the range for maximum forage production.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information.Migrated from OJS platform August 202
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Cattle preferences for Lambert Locoweed over white Locoweed
'JSTOR', 2001Co-Authors: Ralphs M. H., Greathouse G., Knight A. P., James L. F.Abstract:White (Oxytropis sericea Nutt. in T. G.) and Lambert (O. lambertii var. biglovii Pursh) Locoweed grow adjacent to each other on the foothills of the Rocky Mountains from southeastern Wyoming to northeastern New Mexico. Lambert Locoweed matures later and flowers about 3-4 weeks after white Locoweed, thus potentially increasing the critical period of poisoning when livestock graze areas infested by both species. The objective of this study was to evaluate cattle consumption of these 2 species as they progress phenologically. In 1998, 15 Hereford cows grazed a 32 ha pasture infested with both species from the time white Locoweed flowered in mid June until both species were mature and senesced in August. In 1999, 4 cows were placed in a 5 ha pasture infested with both species for 4 days in each of the following periods: (1) flower stage of white Locoweed, (2) flower stage of Lambert Locoweed, immature pod at white Locoweed, (3) immature pod stage of Lambert Locoweed, mature pod while (4) mature pod and seed shatter stage respectively. Diets were estimated by bite-count. Lambert Locoweed was preferred over white Locoweed in the season-long grazing trial in 1998, and in each of the 4 intensive grazing trials in 1999. The cows consumed white Locoweed as availability of Lambert Locoweed declined in 1998, but little white Locoweed was consumed in the 4 intensive grazing trials in 1999. The toxic Locoweed alkaloid swainsonine ranged from 0.04 to 0.06% in white Locoweed, but was not detected in Lambert Locoweed in this study.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information.Migrated from OJS platform August 202
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Impact of Locoweed poisoning on grazing steer weight gains
'JSTOR', 2000Co-Authors: Ralphs M. H., Graham D., Duff G., Stegelmeier B. L., James L. F.Abstract:Emaciation is one of the clinical signs of Locoweed poisoning but few studies have documented impacts of Locoweed poisoning on weight gains. Stocker steers (British X Continental cross, 200-210 kg) were grazed on Locoweed-infested, short-grass prairie in 1996 and 1997 in northeast New Mexico. Each year, half the steers were averted to Locoweed to allow them to graze Locoweed-infested pastures without eating Locoweed. They did not graze Locoweed and steadily gained weight (0.50 kg/day in 1996 and 0.71 kg/day in 1997). The other group of steers were allowed to graze Locoweed under natural grazing conditions and became intoxicated. Weight gains were not affected for the first 3 weeks, but thereafter the steers lost weight in both years. In 1996, non-averted steers consumed Locoweed for a season average of 20% of bites. They were severely intoxicated and did not begin gaining weight for 50 days after they stopped eating Locoweed. Steers in the 1997 trial consumed less Locoweed (11% of bites) than those in 1996 and they recovered more rapidly. Seasonal weight gains were 21 to 30 kg less for locoed steers than control steers in 1996 and 1997, respectively. Locoweed poisoning will cause weight loss, and severely intoxicated cattle require a lengthy recover period after they cease grazing Locoweed before weight gains resume. Stocker cattle should not be placed on Locoweed-infested rangelands until green grass is abundant and Locoweed begins to mature.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information.Migrated from OJS platform August 202
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Creating aversions to Locoweed in naive and familiar cattle
'JSTOR', 1997Co-Authors: Ralphs M. H., Graham D., Galyean M. L., James L. F.Abstract:The objective of this study was to determine if cattle that were familiar with white Locoweed (Oxytropis sericea Nutt, ex T&G) could be aversively conditioned to avoid eating it. In the first preliminary trial, we tried to aversely condition native steers that were already eating Locoweed. Six of 12 steers were penned, fed fresh-picked Locoweed, then dosed via a stomach tube with lithium chloride (LiCl, 200 mg/kg BW). When released into the Locoweed-infested pasture, they gradually increased Locoweed consumption over the next 5 days. The conditioning procedure was repeated with a lower dose (100 mg/kg BW), but Locoweed consumption increased within 10 days until they were consuming as much as the non-averted controls. In the second trial, we compared the strength and longevity of aversion between steers that were familiar with Locoweed (n = 6) and naive steers (n = 6). Both groups were averted to Locoweed as described in Trial 1 and returned to Locoweed-infested pasture. The Familiar group decreased Locoweed consumption for the first 2 days, then gradually increased Locoweed consumption and extinguished the aversion. The Naive group subsequently refused to graze Locoweed. In the third trial, aversions were reinforced following grazing Locoweed in the pasture. Three steers from the Familiar group were allowed to graze Locoweed for 30 min. periods, then were returned to the pen and dosed with LiCl (100 mg/kg BW). These steers were kept in the pen and allowed to recover for 36 hours. This reinforcement process following grazing was repeated 4 times. Steers in the Reinforced group abstained from eating Locoweed when released into the Locoweed-infested pasture for the remainder of the trial. Reinforcement of aversions following field grazing of Locoweed prevented cattle that were familiar with Locoweed from grazing it.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information.Migrated from OJS platform August 202
B L Stegelmeier - One of the best experts on this subject based on the ideXlab platform.
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Targeted Grazing of White Locoweed: Short-Term Effects of Herbivory Regime on Vegetation and Sheep
Rangeland Ecology & Management, 2014Co-Authors: Laura E. Goodman, B L Stegelmeier, Kirk C. Mcdaniel, Andres F. Cibils, Stephanie C. Lopez, Robert L. Steiner, John D. Graham, Laurie B. Abbott, Dennis M. HallfordAbstract:White Locoweed (Oxytropis sericea Nuttall) and nontarget vegetation response to 2 yr of targeted grazing by sheep, one treatment of picloram plus 2, 4-D (HER) or no treatment (CON) were compared. Serum of sheep that grazed Locoweed intermittently (IGZ, 5 d on Locoweed followed by 3 d off Locoweed) vs. counterparts that grazed Locoweed continuously for 24 d (CGZ) was also examined. Alkaloid toxicity was inferred by serum levels of thyroxine (T4), triiodothyronine (T3), alkaline phosphatase (ALKP), aspartate aminotransferase (AST), and swainsonine, as well as behavior and body weight gains. Three sites were used in a randomized complete block design. IGZ, CGZ, and HER treatments reduced Locoweed density (P ,0.01), canopy cover (P ,0.01), number of flower stalks (IGZ: P¼0.02, CGZ and HER: P¼0.01), and plant size (P ,0.01). White Locoweed seed density in the soil seed bank was not reduced with grazing, and nontarget vegetation was mostly unaffected by treatments. Grass canopy cover increased in grazed and herbicide plots throughout the study (IGZ: P¼0.03, CGZ and HER: P ,0.01). Percentage bare ground was unchanged (IGZ: P¼0.46, CGZ: P¼0.44) in grazed plots but decreased (P¼0.03) in HER plots. After 24 d, ewes in the IGZ treatment had lower levels of serum ALKP (P ,0.01) and AST (P¼0.02) and marginally lower swainsonine levels (P ,0.07) than CGZ ewes that tended to exhibit lower serum T3 (P ,0.07) and similar serum T4 (P¼0.25) levels. Time spent feeding on Locoweed tended to differ (P¼0.06) between treatments. Body weight gain was the same (P¼0.19) regardless of treatment. IGZ of Locoweed-infested rangeland with sheep may be a viable short-term means of reducing Locoweed density without detrimentally affecting animal health.
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relationship between the endophyte embellisia spp and the toxic alkaloid swainsonine in major Locoweed species astragalus and oxytropis
Journal of Chemical Ecology, 2008Co-Authors: Michael H Ralphs, Rebecca Creamer, Dale R Gardner, J D Graham, Daniel Cook, Stanley L. Welsh, Deana L Baucom, C Hart, B L StegelmeierAbstract:Locoweeds (Astragalus and Oxytropis spp. that contain the toxic alkaloid swainsonine) cause widespread poisoning of livestock on western rangelands. There are 354 species of Astragalus and 22 species of Oxytropis in the US and Canada. Recently, a fungal endophyte, Embellisia spp., was isolated from Astragalus and Oxytropis spp. and shown to produce swainsonine. We conducted a survey of the major Locoweeds from areas where Locoweed poisoning has occurred to verify the presence of the endophyte and to relate endophyte infection with swainsonine concentrations. Species found to contain the fungal endophyte and produce substantial amounts of swainsonine were A. wootoni, A. pubentissimus, A. mollissimus, A. lentiginosus, and O. sericea. Astragalus species generally had higher concentrations of swainsonine than Oxytropis. Swainsonine was not detected in A. alpinus, A. cibarius, A. coltonii, A. filipes, or O. campestris. The endophyte could not be cultured from A. mollissimus var. thompsonii or A. amphioxys, but was detected by polymerase chain reaction, and only 30% of these samples contained trace levels of swainsonine. Further research is necessary to determine if the endophyte is able to colonize these and other species of Astragalus and Oxytropis and determine environmental influences on its growth and synthesis of swainsonine.
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Effect of previous Locoweed (Astragalus and Oxytropis species) intoxication on conditioned taste aversions in horses and sheep.
Journal of animal science, 2007Co-Authors: James A Pfister, B L Stegelmeier, Carl D. Cheney, Dale R GardnerAbstract:Locoweed species (Astragalus and Oxytropis spp.) are a serious toxic plant problem for grazing livestock. Horses and sheep have been conditioned to avoid eating Locoweed using the aversive agent LiC1. The objective of this study was to determine if previous Locoweed intoxication affects food aversion learning in horses and sheep. Horses and sheep were divided into 3 treatment groups: control (not fed Locoweed and not averted to a novel feed); Locoweed-novel feed averted (fed Locoweed and averted to a novel feed); and averted (not fed Locoweed and averted to a novel feed). Animals in the Locoweed-novel feed averted groups were fed Locoweed during 2 periods of 21 and 14 d, respectively, with each feeding period followed by a 14-d recovery period. Animals were averted to a novel test feed at the end of the first Locoweed-feeding period, and periodically evaluated for the strength and persistence of the aversion. During the first recovery period, Locoweed-novel feed averted horses ate less (9.5% of amount offered) of the test feed than did control horses (99.8%) and did not generally differ from averted horses (0%). During recovery period 2, Locoweed-novel feed averted horses (4.3%) differed (P = 0.001) in consumption (% of offered) of the test feed from controls (100%) and the averted group (0%). Locoweed-novel feed averted sheep differed (P = 0.001) from controls (14.4 vs. 99.5%, respectively, during recovery period 1), whereas Locoweed-novel feed averted sheep did not differ (P > 0.50) from averted sheep (0.6%). During the second recovery period, control sheep (100%) differed (P < 0.05) from averted (0%) and Locoweed-novel feed averted (12.2%) groups. Two intoxicated sheep (Locoweed-novel feed averted) partially extinguished the aversion during the first recovery period, but an additional dose of LiCl restored the aversion. Two of 3 intoxicated horses had strong aversions that persisted without extinction; 1 horse in the Locoweed-novel feed averted group had a weaker aversion. These findings suggest that horses and sheep previously intoxicated by Locoweeds can form strong and persistent aversions to a novel feed, but in some animals, those aversions may not be as strong as in animals that were never intoxicated.
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The comparative pathology of Locoweed poisoning in livestock, wildlife and rodents.
2007Co-Authors: B L Stegelmeier, D. R. Gardner, M H Ralphs, L F James, Stephen T. Lee, K. E. Panter, J. A. Pfister, T. WierengaAbstract:Over 500 Astragalus and Oxytropis species and varieties have been identified in North America (Welsh et ale 2003). Many are nutritious forages; however, a few are toxic. Of the toxic species about 20 are known as Locoweeds. Locoweeds contain the endophyteproduced toxin, swainsonine, which with prolonged ingestion produces wasting and neurologic disease. Extended exposure to Locoweed inhibits cellular a-mannosidases and Golgi mannosidase II, resulting in cytoplasmic vacuolation, accumulations of incompletely metabolized hybrid oligosaccharides and glycoproteins (Stegelmeier et ale 1999a). Though all animals appear to be susceptible to poisoning, there are species-specific differences in Locoweed-induced neurologic disease and the distribution and severity of histologic lesions. The purpose of this study is to compare the distribution, severity and nature of Locoweed poisoning in rodents, sheep, cattle, horses and mule deer.
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maternal ingestion of Locoweed i effects on ewe lamb bonding and behaviour
Small Ruminant Research, 2006Co-Authors: J. A. Pfister, K. E. Panter, B L Stegelmeier, J.b. Astorga, Russell J. MolyneuxAbstract:This study investigated whether exposure of ewes to Locoweed (Oxytropis sericea; Leguminosae) during gestation would affect ewe behaviour during parturition, ewe–lamb bonding and related behaviours postpartum, and maternal responsiveness of ewes to alien and own lambs. Twenty-nine nulliparous Columbia-Targhee ewes bearing a single fetus were divided into two feeding treatments: (1) Locoweed (L, n = 15), fed as a 10% Locoweed pellet at 3 kg/day from day 100 to 130 of gestation, or (2) controls (C, n = 14) fed 3 kg/day of alfalfa hay. Lamb birth weights were reduced about 25% (P < 0.001) from maternal Locoweed ingestion. There was a distinct lack of maternal–infant bonding due to Locoweed intoxication of lambs. Only 1 lamb born to L ewes was able to nurse without assistance within 120 min. Lambs born to L ewes took longer to stand (P < 0.05), to initiate teat-seeking behaviour (P < 0.03), and to suckle (P < 0.0007). The behavioural toxicosis did not persist in lambs, as behavioural anomalies largely disappeared within 10 days following parturition. Locoweed-intoxicated ewes in general had an increased propensity (P < 0.1) for locomotor activity, notably during fetal expulsion, and longer fetal expulsion times (P < 0.1). There were few behavioural differences induced by Locoweed up to 30 min postpartum, when L ewes became inattentive to lambs (P < 0.1). After the first (human assisted) suckling bout, L ewes were attentive toward both their own and alien lambs. Both L and C dams were equally aggressive toward alien lambs. These results indicate that lamb survival after maternal Locoweed exposure will depend greatly on human intervention. If Locoweed-exposed lambs survive the first 24–48 h after birth, then the prognosis for survival improves greatly. Published by Elsevier B.V.
