The performanceof steers raised on elephant and mombasa grass pastures was evaluated from Octoberto December 2006. A rotational grazing system with a regulated forage offerwas adopted. The experimental area consisted of two repetitions containing 180.25-ha paddocks divided into nine paddocks with elephant grass and nine withmombasa grass. Forage species, area repetition, the interaction among theseeffects, paddocks within the interaction, and the experimental error were theeffects of the treatments. This model was used to analyze pasture attributes.For analyses of intake, digestibility and gain, 24 steers were randomly assignedto the respective interactions among forage vs. repetition vs. grazing system,totaling three animals per triple interaction. The grazing systems consistedof ad libitum (AL) and restricted (PR) grazing. Elephant-grass showedthe highest total dry matter biomass (TB) and green leaf dry matter biomass(GLDM). There were no differences among forage plants for production of biomassof green leaf dry matter; leaf proportion was the greatest in mombasa grass,however. Extrusas showed similar bromatological composition. Only crude proteinintake, which was the highest for mombasa pasture, differed among forage plants.Ad libitum feeding enabled a higher intake of all nutrients from bothpastures. Digestibility of nutrients was higher for elephant-grass but it didnot differ among feeding levels: only crude protein content was the higheston pasture where grazing was restrict and gross energy content of pasture washigher for ad libitum grazing system. Despite qualitative and quantitativedifferences among forage plants, differences of weight gain per animal and perarea were not found. For animal with ad libitum feeding, average bodymass gain was 850 g/day and gain per area was 246 kg/ha during the experimentalperiod.
