Chemical composition and in vitro digestibility of some Spanish browse plant species

Samples of leaves, flowers and fruits of four browse species were collected from uplands in the province of Leon (northwestern Spain) at different sampling times (from spring till autumn). The browse species were Erica australis (Spanish heath), Cistus laurifolius (laurel-leaved rock rose), Quercus pyrenaica (hoary oak) and Rosa canina (wild dog rose). A large variability in chemical composition and in vitro digestibility and gas production kinetics was observed among species and among sampling times within each species. The ranking order of the browse plants according to their in vitro digestibility and gas production kinetics was R canina > Q pyrenaica > C laurifolius > E australis. In the leaves of R canina and Q pyrenaica, crude protein content, digestibility and parameters of gas production tended to decrease throughout the growing season (P < 0.05 in most cases), whereas cell wall contents followed the opposite trend. Seasonal variations were less pronounced in the other browse species. There were significant (P < 0.05) correlations between in vitro digestibility and chemical composition of the browse plants, positive with the crude protein content and negative with the fibre fractions. (C) 2004 Society of Chemical Industry.