The near infrared (NIR) spectra of 62 herbage samples were used to predict the in situ degradability parameters of crude protein (CP) and neutral detergent fibre (NDF). Moreover, the NIR spectra of the incubation residues generated during this experiment were also obtained in order to estimate their chemical composition and then calculate the kinetic and degradability parameters of the NDF and CP using these estimated data. Thus, the results obtained by means of these two different procedures could be compared to those achieved with the reference method (incubation residues analysed by wet analytical methods). The most accurate results were obtained when the chemical data of the incubation residues were estimated using their NIR spectra. Nevertheless, it is less laborious to estimate the degradability parameters directly from the NIR spectra of the original herbage samples.