Forage quality evaluation using differential scanning calorimetry and thermogravimetric analysis technique

Differential scanning calorimetry (DSC) and thermogravimetry (TG) were used to estimate forage chemical composition and cattle intake and digestibility parameters. Ninety-three hay samples were assayed using DSC. Calibration equation developed for 56 samples were then validated using the remaining 37 samples. Predictions for crude protein and neutral detergent fibre demonstrated the greatest accuracy (R$sp2$ 0.61 and 0.72 respectively). Intake and digestibility were not well predicted by DSC (eg. R$sp2$ 0.13 for both dry matter intake and dry matter digestibility). Analysis of 18 hay samples in a preliminary study using two different TG procedures gave results that were not always consistent with each other or with the DSC study. A greater proportion of the variation in intake and digestibility measurements was explained by chemical analysis when equations developed from multiple regression analysis rather than simple regression analysis were used for prediction purposes. Thermal analysis does not appear to have potential for the evaluation of forage nutritive value.