This study was carried out to evaluate the effect of cannula placement site and hour of collection on the botanical composition of sheep diet. Ten castrated sheep Santa Inês breed were used, with five of them using permanent ruminal cannula and the five others with esophageal cannula. Water and mineral mix were available ad libitum. Samples collected from both cannulas revealed 39 species with an average of 20 species occurring in each monthly sampling. In addition, other Poaceae species were not identified. There was a significant effect of collection time on the botanical composition and on the plant fractions selected by the sheeps. Leaf was the most consumed fraction, corresponding to 55% of the extrusa sample. Stem proportion was affected by month x hour of collection interaction. There was no effect of the place of fistula or time of collection on botanical composition of the diet, however, the interaction of month of collection, fistula placement and, time of collection affected botanical composition and proportion of plant fractions consumed. The selectivity index varied during the study for several species, being directly related to the ingestive behavior of the sheep. Feed selected by sheep presented a large number of plant species with malvaceae and poaceae being the most important families. Ruminal cannula instead of esophageal cannula can be used to characterize the botanical composition of the diet consumed by small ruminants.
esophageal cannula; ruminal cannula; semi-arid
