Fecal NIRS equations for predicting diet quality of free-ranging cattle

摘要: The usefulness of near infrared reflectance spectroscopy (NIRS) for predicting diet quality free-ranging cattle through fecal analysis was examined. Diet samples were obtained with esophageal fistulated steers; subsequently, study areas grazed nonfistulated lactating and dry cows to provide representing differing forage quality. samples, which analyzed by conventional laboratory procedures in vivo corrected digestible organic matter (DOM) crude protein (CP), provided dependent variable reference data while sample spectra independent development NIRS predictive equations stepwise regression. Equations developed from a set at one location subsequent equation using expanded ranges adding second location. Standard errors calibration (SEC) validation (SEV) the DOM range 1.66 1.65, respectively; these values nearly equivalent standard error (SEL) 1.68. SEC SEV CP 0.89 0.93, respectively, compared 0.44 SEL. Coeffkients determination 0.80 0.92, respectively. These statistical parameters predict are equal or better than statistics reported literature spectra. Furthermore, within acceptable limits calibrations. No effects physiological stage animals on noted this study. Results interpreted This manuscript published approval Director, Texas Agricultural Experiment Station, AM Evelyn Kapes work laboratory; Drs. J.E. Huston, J.W. Holloway, C.W. HanL Behmann Foundation, Corpus Christi, Texas, providing funds support research. Manuscnpt accepted 5 Sept. 1991.