Integrated Management, Ecology, and Toxicology Studies

Approach: Locoweed causes significant economic losses in the plains, prairie and desert areas of the central and southwestern U.S. Locoweed management has the potential to yield positive social returns by alleviating water scarcity while increasing land productivity and environmental quality. Proposed research for 2006-07 is as follows: a) Characterize the pathway of swainsonine production in the plant and its endophyte as influenced by environment and genetics using biochemical, molecular, and genetic techniques in whole plants and sterile cultures. b) Measure swainsonine concentrations in plants altered by insect herbivory; and, identify insects causing locoweed death using taxonomical and genetic approaches. c) In ruminally-cannulated sheep and cattle, monitor shifts in microbial populations using gel electrophoresis; and, degradation of toxicants will be measured using gas chromatography and ELISA. d) Using paired locoweed eaters and locoweed avoiders, pen studies will be conducted to evaluate the influence of social rank on peer pressure for locoweed consumption and preference for new flavors. e) Through producer surveys, correlate the occurrence of locoism with nutrient and mineral content of grazed forages, and develop preventive supplements and herding strategies. f) Initiate studies integrating biological, chemical, behavioral and grazing management strategies to enhance locoweed avoidance and mortality.