Fig. 3. Comparison of laboratory measured forage neutral detergent fiber (NDF), acid detergent fiber (ADF), crude protein (CP) concentrations, aboveground biomass, and CP availability (CPA) in the test data set with their predicted values based on the equations developed with (a) reflectance ratios, (b) first derivatives of reflectance, (c) stepwise regression of reflectance, and (d) stepwise regression of the first derivative of reflectance in Tables 2 and 3 (n = 72). Dotted line represents predicted = measured values.