AbstractAn experiment was conducted to compare the voluntary intake and in vivo digestion for guanacos and sheep when offered perennial ryegrass at three different growth stages: vegetative growth (VG), emerging inflorescence (El) and mature inflorescence (MI). Dry-matter (DM) intake ranged from 1·19 to 2·12 kg/day for the guanacos and 0·79 to 1·52 kg/day for the sheep. When expressed on a metabolic live-weight (M0·75) basis, the intake of the guanacos (55·8, 43·1 and 44·1 g DM per kg M0·75 daily on the VG, El and MI grasses respectively) and the sheep (54·4, 45·7 and 47·4g DM per kg M0·75 daily respectively) were similar (s.e.d. = 3·70). Apparent digestibilities of all food constituents were also similar. In terms of food choice, the response of the two species to grass stem differed; the guanacos selected (El) or tolerated (MI) this fraction, while the sheep tolerated (El) or avoided (MI) it.
Distribution and Oxidation State of Arsenic in Root of Arsenic-Hyperaccumulator Fern, Pteris vittata L., by Using Synchrotron Radiation X-Ray Fluorescence Analysis