The defaunation effect on feed intake, nutrient apparent digestibilities, solid phase dynamics, ruminal fermentation parameters and in situ degradation in sheep fed on sugar cane plus urea was studied in a completely randomized design with three replicates. Ruminal passage rates of 3.05 and 1.97%/h were observed for the faunated and defaunated groups, respectively. Higher values for sugar cane NDF ruminal digestion rate (5.41%/h), extension (46.7%) and effective degradability (31.53%) were observed for the faunated group. The faunated group daily intake (57.7 and 32.3 g/kg0.75 for dry matter and NDF residue, respectively) was higher (P<0.06) than that for the defaunated group. Total VFA, acetate and propionate concentrations were higher (P<0.05) in the faunated group and were dependent on sampling time. Defaunated sheep showed higher (P<0.04) post prandial decrease in pH. Relative to apparent digestibility difference (P<0.05) between treatments was observed only for dry matter.
Rumen; ciliate protozoa; defaunation; digestibility, in situ degradability; rate of passage
