Statistical analyses of fluorometry data obtained from chloroform filtrate of lamb feces

TitleStatistical analyses of fluorometry data obtained from chloroform filtrate of lamb feces
Publication TypeJournal Article
Year of Publication2001
AuthorsMukkherjee A., Anderson D.M., Daniel D., Murray L.W., Tisone G., Fredrickson E.L., Estell R.E., Rayson G.D., Havstad K
JournalJournal of Range Management
Date PublishedJuly 2001
ARIS Log Number111536
Keywordschloroform filtrate, fluorometry data, lamb feces, statistical analyses

Using fecal samples obtained from 13 lambs maintained in metabolism stalls and fed 4 identical basal diets composed of tobosa hay (Pleuraphis mutica) Buckley, which contained 4 different levels (0, 10, 20 and 30%) of tarbush (Flourensia cernua) D.C. leaf material, a data set of spectral signatures were obtained using fluorometry techniques. A chloroform filtrate obtained from the lamb's feces was exposed to xenon light. This caused certain molecules in the filtrate called fluorophores to have their outer shell electrons move to a higher energy state as a result of the energy coming from the xenon light. Upon removal of the xenon light, which had been focused at 310, 320, 330, 340, 350 and 355 nm, the fluorophores returned to their ground state giving off light. This fluorescence light varied in intensity and when captured using appropriate electronics, produced 1024 pairs of light intensities and fluorescent wavelengths between 175 and 818 nm in 0.6288972 increments. This research demonstrated the entire fluorescence data set could be used to determine statistical differences among diets. Five increasingly complex statistical approaches were evaluated: two-dimensional plots, polynomial regression models, confidence interval plots, discriminant analysis and three-dimensional plots. There was a high statistical reliability when separating diets containing no tarbush leaf from diets containing 30% tarbush leaf; however, it was not possible to routinely statistically separate diets containing intermediate (10 and 20%) amounts of tarbush leaf material from themselves or the two extremes (0 and 30% tarbush leaf). These results suggest spectral signatures arising from fluorometry data may be useful for differentiating among diet botanical compositions that differ in plant form.