The relationship of fecal nitrogen fractions and condensed tannins dietary crude protein, in vitro organic matter digestibility, and intake of steers was assessed to determine the suitability of these multiple fecal indices for predicting quality of animal diets under free-roaming conditions. Research was conducted on the Texas A&M Native Plant and Animal Conservancy near College Station, located in the Post Oak Savannah region of Texas. Regression equations were used to evaluate relationships between dietary intake and quality to fecal variables. Dietary crude protein, digestible organic matter, organic matter intake, crude protein intake, and digestible energy intake were determined from previous studies. Corresponding fecal samples were analyzed for absolute output, proportions, and concentrations of nitrogen and selected fractions of fecal organic matter, as well as fecal condensed tannins, proportions of fecal monocot and dicot fragments, and fecal organic matter. In general, no fecal parameter by itself had a high correlation with dietary variables when expressed on a proportion or concentration basis. A combination of fecal indexes accounted for more variation in dietary parameters than fecal nitrogen. Fecal nitrogen fractions did not improve the predictive power of multiple variable models. Equations predicting dietary crude protein (%) and crude protein intake yielded the highest coefficients of determination (R2 = .57 and .51, respectively). Multiple fecal indices used in this study were of limited value in predicting diet quality and intake. This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries. The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information. Migrated from OJS platform August 2020
Scholarly peer-reviewed articles published by the Society for Range Management. Access articles on a rolling-window basis from vol. 1, 1948 up to 5 years from the current year. Formerly Journal of Range Management (JRM). More recent content is available by subscription from SRM.