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ARS Home » Plains Area » Las Cruces, New Mexico » Range Management Research » Research » Publications at this Location » Publication #188802


item Anderson, Dean
item Rayson, Gary
item Obeidat, Safwan
item Ralphs, Michael
item Estell, Richard - Rick
item Frederickson, Eddie
item Parker, Eric
item Gray, Perry

Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/15/2006
Publication Date: 9/1/2006
Citation: Anderson, D.M., Rayson, G.D., Obeidat, S.M., Ralphs, M.H., Estell, R.E., Fredrickson, E.L., Parker, E., Gray, P. 2006. Use of fluorometry to differentiate among clipped species in the genera, astragalus, oxytropis and pleuraphis. Rangeland Ecology and Management. 59:557-563.

Interpretive Summary: The rapid and accurate determination of what plants constitute an animal’s diet remains a challenge when providing husbandry as well as when conducting free-ranging animal studies. Current techniques are frequently labor intensive and the data obtained are often available only after extended analysis and interpretation. These long time intervals between data collection and the implementation of appropriate management can be costly especially when it involves poisonous plants and animal health. An optical based methodology termed fluorometry appears to be a promising tool for determining the presence of individual plant species composing an animal’s diet when examined using Principal Component Analysis (PCA). These data on pre-digested plants, some of which were considered toxic to free-ranging animals, suggest fluorometry may provide a robust methodology for differentiating between toxic and non-toxic plants in an animal’s diet. Further research will be required to evaluate if the trends shown herein are similar in individual plants as well as post-digested diets.

Technical Abstract: A rapid and reproducible method to determine botanical composition of forage is an ecological and economic goal for range animal ecologists. Multidimensional fluorometry previously demonstrated the possibility of a unique optical approach for accurately determining species composition of pre- and post-digested plant materials. Fluorometry may be used to detect toxic plants in standing crop as well as diets by using electronic transitions in chemical structures at wavelengths between 370 and 580 nm. Grass hay (genus Pleuraphis) and six clipped forbs (four species of Astragalus and two species of Oxytropis) were examined. The resulting spectral signatures were evaluated for differences in the blue and green regions of the visible spectrum using Principle Component Analysis (PCA). This represents the first published data using chemometrics to differentiate among fluorophores from these plant extracts. It was possible to distinguish between the grass and forbs and among forbs. Further research will be required to evaluate these same plant species in mixed diets and fecal samples.