Child, D. R.

Creamer, Rebecca

Gardner, Dale R.

James, L. F.

Lee, S. E.

McDaniel, K. C.

Panter, K. E.

Pfister, J. A.

Ralphs, Michael H.

Stegelmeier, B. L.

Valdez, J. R.

English

University of Kentucky

University of Kentucky UKnowledge International Grassland Congress Proceedings XXI International Grassland Congress / VIII International Rangeland Congress Integrated Research to Reduce Poisoning from Oxytropis and Astragalus spp in U.S.A. Michael H. Ralphs U.S. Department of Agriculture B. L. Stegelmeier U.S. Department of Agriculture K. E. Panter U.S. Department of Agriculture Dale R. Gardner U.S. Department of Agriculture J. A. Pfister U.S. Department of Agriculture See next page for additional authors Follow this and additional works at: https://uknowledge.uky.edu/igc  Part of the Plant Sciences Commons, and the Soil Science Commons This document is available at https://uknowledge.uky.edu/igc/21/16-1/9 The XXI International Grassland Congress / VIII International Rangeland Congress took place in Hohhot, China from June 29 through July 5, 2008. Proceedings edited by Organizing Committee of 2008 IGC/IRC Conference Published by Guangdong People's Publishing House This Event is brought to you for free and open access by the Plant and Soil Sciences at UKnowledge. It has been accepted for inclusion in International Grassland Congress Proceedings by an authorized administrator of UKnowledge. For more information, please contact UKnowledge@lsv.uky.edu. Presenter Information Michael H. Ralphs, B. L. Stegelmeier, K. E. Panter, Dale R. Gardner, J. A. Pfister, S. E. Lee, L. F. James, K. C. McDaniel, Rebecca Creamer, J. R. Valdez, and D. R. Child This event is available at UKnowledge: https://uknowledge.uky.edu/igc/21/16-1/9 　 Multifunctional Grasslands in a Changing World 　 Volume Ⅱ 　 瞯 ]807　 瞯Grasslands/Rangelands Production Systems——— Integrated Management of Harmful Organisms of Grasslands/RangelandsIntegrated research to reduce poisoning from Oxytropis and Astragalus spp in U .S .A .M .H . Ralphs , B .L .S tegelmeier , K .E . Panter , D .R . Gardner , J .A . P f ister , S .E . Lee , and L .F . James .USDA /A RS Poisonous Plant Research L ab , Logan UT 84328 (M ichael .Ralphs＠ ars .usda .gov )K .C . McDaniel and R .Creamer , New Mex ico State Univ . , L as Cruces NM 88003J .R . V aldez and D .R . Child , Colorado State Univ . , Fort Collins CO 80523Livestock poisoning from A stragalus and Oxytrop is species is the most wide‐spread poisonous plant problem in the westernUSA . There are over ４００ species of A stragalus and ２２ species of Oxytrop is in North America , but only ２４ species have beenshown to contain the toxic alkaloid swainsonine , or have been implicated in poisoning ( Ralphs et al . , ２００２) .Locoweed chemistry The locoweed toxic alkaloid , swainsonine , was first discovered in Swainsona species of Australia ( Colgateet al . ,１９７９) , and later in both A stragalus and Oxytrop is species in North America ( Molyneux and James １９８２) . Gardner etal . (２００１) reported on the current quantitative assay for swainsonine using GC and LC /MS . The concentration of swainsonineranges from ０ .００１‐０ .２％ of the plant摧s dry weight . The flowers and seeds appear to have the highest concentration , but allparts of the plant contain swainsonine , even the dry dead plant material . Enzyme‐linked immunosorbent assays ( ELISA ) andother biomarkers are being developed as sensitive and specific assays for the detection and measurement of swainsonine in plantand animal tissues .Endophyte Recently , the endophytic fungus Embellisia was found in A stragalus and Oxytrop is species and was shown tosynthesize swainsonine (Braun et al . , ２００３ , Creamer et al . ,２００７ ) . The endophyte is passed to the next generation throughthe seed coat . Oxytrop is sereicea has the ability to sustain a symbiosis with the endophyte and dinitrogen fixing bacteria , thusincreasing levels of swainsonine when soil nitrogen is limited ( Valdez Barillas et al . , ２００７) .Pathology of locoweed poisoning Swainsonine inhibits essential glycosidase enzymes : lysosomal α‐mannosidase ( which altersglycoprotein processing ) , and mannosidase II ( which impairs cell to cell communication , cell movement , cellular adhesion andintracellular trafficking ) . Swainsonine intoxication results in various physiologic changes , including grow th inhibition , impairedcardiovascular function , compromised immunity to infectious disease , decreased feed efficiency , and neurologic damage( Stegelmeier et al . ,１９９９ ) . Locoweed dramatically increases the incidence of high mountain disease or congestive right‐heartfailure in cattle grazing locoweed at high elevations ( James et al . , １９９１) .Effects of locoweed on reproduction Locoweeds inhibit all reproductive processes in livestock : spermatogenesis and oogenesis ,ovarian function and estrous behavior , delays placentation , reduces placental and uterine vascular development resulting inabnormal cotyledonary development . This results in embryonic death , birth defects , induces abortion and hydrops amnii( Panter et al . , １９９９ ) . Neonates are born small and weak , prone to secondary infection , have difficulty nursing and havedifficulty bonding with mothers ( Pfister et al . , ２００６ ) .Grazing management to reduce risk of poisoning Consumption and subsequent poisoning generally occurs when locoweed is greenand growing and associated grasses are dormant , or in short supply ( Ralphs , １９９９) . Grazing management strategies have beendeveloped to prevent livestock from grazing locoweeds during critical periods when they are relatively more palatable thanassociated forages ( Ralphs et al . , ２００２) : restrict access to locoweeds by fencing locoweed‐infested areas or herd them away ;don�t overstock locoweed‐infested range‐ensure animals have adequate desirable forage ; watch livestock closely and removethem if they start eating locoweed to prevent poisoning and prevent them from influencing others to start ; conditioned foodaversion can be used to train cattle and horses to avoid grazing locoweed .Locoweed population cycles and control Many locoweeds experience extreme population cycles , and outbreaks are followed bycatastrophic livestock loss ( Ralphs et al . , ２００３) . A stragalus and Oxytrop is species can be controlled using common rangelandherbicides picloram ( ０ .４２ kg / ha ) , clopyralid ( ０ .２８ kg / ha ) , and metsulfuron ( ０ .０１２ kg / ha ) ( McDaniel et al . , ２００７ ) .However , their seed remain viable for many years and germinate whenever environmental conditions are favorable .ReferencesBraun K , Romero J , Liddell C , Creamer R . ２００３ . Production of swainsonine by fungal endophytes of locoweed . Mycol . Res .１０７ :９８０‐９８８ .Colgate SM , Dorling PR , Huxtable CR . １９７９ . A spectroscopic investigation of swainsonine : an α‐mannosidase inhibitorisolated from Swainsona canescens . A ust . J . Chem . ３２ :２２５７‐２２６４ .Creamer R , McLain‐Romero J , Oldrup E . ２００７ . Fungal endophytes of locoweed : an overview , pp . ３３８‐３４４ . in : K .E . Panterand J .A . Pfister ( eds) . Poisonous Plants : G lobal Research and Solutions . CABI , Wallingford , UK .

Integrated Research to Reduce Poisoning from \u3ci\u3eOxytropis\u3c/i\u3e and \u3ci\u3eAstragalus\u3c/i\u3e spp in U.S.A.

https://uknowledge.uky.edu/cgi/viewcontent.cgi?article=3657&amp;context=igc

Integrated Research to Reduce Poisoning from \u3ci\u3eOxytropis\u3c/i\u3e and \u3ci\u3eAstragalus\u3c/i\u3e spp in U.S.A.

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