Diferencias, según sus fracciones orgánicas y digestibilidad, de especies dominantes en seis comunidades de pastizal

Resum

The present study established the differences, on the basis of their nutritional quality, between wild species which are of interest owing to their abundance in semiarid grasslands. In order to do so and as a first approach, six grassland communites were considered, with differing degrees of trophism and utilization, all situated in the province of Salamanca (Spain). In the aerial biomass samples of the dominant species, taken throughout the phenological cycle (5 consecutive cuts), determinations were made of the organic fractions and digestibility. The results were subjected to factorial analysis, individually for each community. The orderings obtained revealed the separation of the gramineae towards the first axis extracted, with respect to its high contents in hemicellulose, principally, NDF and cellulose, implying a high DNDF. The remaining species are situated on the principal plañe, according to their contents in NDF, ADF, cellulose, lignin, protein, CC, DCC and DMD, the distinction between the leguminosae and other families being more or less clear, according to the individual case. Overlapping the interespecies differentiation, it was possible to detect temporal variations of intraspecific nature, which were in general fairly precise.