Table 2.
Comparison among different spectra correction methods to the prediction performance of nutritive parameters using partial least squares regression (PLSR) approach.
| Nutritive parameters | Spectra data | Statistical indicators |
|||
|---|---|---|---|---|---|
| R2 | r | RMSE | RPD | ||
| IVOMD | Raw | 0.590 | 0.770 | 2.510 | 1.599 |
| SNV | 0.810 | 0.922 | 1.710 | 2.347 | |
| BSC | 0.750 | 0.861 | 1.960 | 2.048 | |
| DT | 0.690 | 0.832 | 2.180 | 1.841 | |
| IVDMD | Raw | 0.610 | 0.780 | 2.032 | 2.284 |
| SNV | 0.860 | 0.936 | 1.201 | 3.911 | |
| BSC | 0.720 | 0.861 | 1.651 | 3.706 | |
| DT | 0.720 | 0.852 | 1.712 | 3.362 | |
BSC: baseline shift correction, DT: de-trending, IVOMD: in vitro organic matter digestibility (IVOMD), IVDMD: in vitro dry matter digestibility, R2: coefficient of determination, r: correlation coefficient, RMSE: the root mean square error, RPD: residual predictive deviation. SNV: standard normal variate.