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ARS Home » Pacific West Area » Logan, Utah » Poisonous Plant Research » Research » Publications at this Location » Publication #332749
Title: Fiddleneck (Amsinckia intermedia Lehmann Boraginaceae): Toxicity in cattle potentiated by burrow weed (Isocoma acradenia)

Author
item Panter, Kip
item Colegate, Steven
item Davis, Thomas - Zane
item WELSH, STANLEY - Brigham Young University
item Gardner, Dale
item CUNEO, PEDER - University Of Arizona
item Stegelmeier, Bryan
item Stonecipher, Clinton - Clint

Submitted to: International Journal of Poisonous Plant Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/17/2016
Publication Date: 8/1/2017
Citation: Panter, K.E., Colegate, S.M., Davis, T.Z., Welsh, S.L., Gardner, D.R., Cuneo, P.S., Stegelmeier, B.L., Stonecipher, C.A. 2017. Fiddleneck (Amsinckia intermedia Lehmann Boraginaceae): Toxicity in cattle potentiated by burrow weed (Isocoma acradenia). International Journal of Poisonous Plant Research. 4(1):16-24.

Interpretive Summary: Twenty three cows of a herd of 150 died in Arizona after grazing a pasture heavily infested with fiddleneck (Amsinckia intermedia). Field investigation, necropsy of dead cows and follow up histopathology and chemical analysis confirmed the poisoning was fiddleneck. The toxic alkaloids were detected in the plant material and the livers of the dead cows. Surviving cows were removed from the pasture and no further losses were reported.

Technical Abstract: All Amsinckia species contain dehydropyrrolizidine alkaloids (DHPA) that are toxic to livestock. A case of 23 dead cows from a herd of 150 on a rangeland in Arizona was investigated and reported. Field investigation revealed an overgrazed pasture with heavy infestation of Amsinckia intermedia and other forbs and few palatable grasses. Chemical analysis of Amsinckia plants collected at the poisoning site showed multiple pyrrolizidine alkaloids and follow up chemical analysis of liver samples from dead cows confirmed the presence of the toxic pyrroles of the DHPA’s. A chemical analysis of the Amsinckia intermedia from this range was compared with Amsinckia intermedia collected in Washington State where no poisonings have been reported. Histopathology of tissues from the dead cows confirmed the diagnosis of Amsinckia-induced liver disease in these cattle. All surviving cows were removed from the pasture and no further death losses were reported.