APPLICATION OF THE NEAR-INFRARED REFLECTANCE SPECTROSCOPY FOR THE FEEDSTUFF ANALYSIS OF TROPICAL FORAGE PLANTS

The present paper is part of an ecological overall analysis in the Dep artment of Atacora in Benin (West-Africa) and covers the complex of pa sture resources which consists of the detailed determination of the to tality of pasture resources, the determination of the quality of natur al and available pasture components as well as their utlization depend ing on the season. The forage plants found in this Department - 102 ki nds of natural pasture and 9 kinds of cultivated cultures, the harvest residues of which are utilized as animal pasture - were identified an d sampled by animal observations in the frame of accompanying pasturag e observations. The quality analysis of the samples was based on the p asture-specific parameters of raw protein, raw cellulose, raw lignine, raw ash, acid-detergent fiber, in vitro-digestibility as well as of t he French pasture evaluation unit ''Unite fourragere'' and the metabol izable energy. The samples originated from both the multifunctional pa sturage observations (S = 879) and from the samples taken in the frame of the phytomass determination of dominant savanna types (S = 744). F urthermore, samples (S = 97) of allochthone forage plants were analyze d, which were tested in the frame of the project ''Promotion de l'elev age dans l'Atacora'' in ''on-'' and ''off-farming'' test series. A tot al of 1,720 samples were analyzed for their pasture value using the ne ar infrared-reflection spectroscopy (NIRS). Owing to this method, the number of samples to be analyzed using wet-chemistry methods could be reduced to 30 % without jeopardizing the accuracy of the analysis resu lts. Thus, the near infrared-reflection spectroscopy has proved its ca pability and practical use - like for many other application cases (PA UL, 1989) - also for the efficient analysis of the extremely heterogen ous plant stocks of natural tropical pastures (grasses in different st adiums of growth, leaves, fruits, pods and blossoms of forage trees an d shrubs, herbs and creepers) and of harvest residues. Beside the anal ytical advantages of this method, e.g. nondestructive analysis of the sample materials, its future importance is to be seen in the quick bro adening of information bases of quality values of tropical forage plan ts at low costs, an advantage of particular significance when targe sa mple quantities are to be analyzed.