The influence of the level of forage intake on the degradability of particles of elephant grass in the sections of gastrointestinal tract (GIT) of bovines and on some traits of ruminal kinetics was studied. A completely randomized split plot design was used, with twelve treatments in the main plots (a 2x6 factorial, comprising two levels of feeding: restricted - NA1 and unrestricted - NA2, and six slaughter times) and the five sections GIT in the split plots. Thirty-six steers maintained exclusively under grazing in elephant grass were used. At the beginning of the trial and at each thirty five days, three animals from each feeding level were slaughtered, and the weights and samples of digesta from each GIT section were taken. The dry sieving was used to determine the average particle size (APS) and the modulus of fineness (MF) of digesta. The APS and de MF of digesta from RR were larger than those from the other GIT sections. Feeding level had no influence on APS. However, MF was higher in RR digesta of animals from NA2 treatment. There was evidence that particles smaller than 1.19 mm leave preferentially the rumen. There was no influence of feeding level on disappearance rates of DM, NDF and indigestible NDF from the rumen, as well as on passage rates of NDF from RR which corresponded to 3.65 and 3.75%h-1, and on digestion rates of NDF in the rumen, corresponding to 2.46 e 3.12%h-1, for treatments NA1 and NA2, respectively.
feeding level; degradability of particles; digesta; ruminal kinetics; bovines; elephantgrass
