The objective of this study was to evaluate the feeding behavior and performance of Santa Ines sheep subjected to different levels of substitution of corn by cactus pear in the diet. Forty-fivenon-castrated male Santa Inês sheep with initial live weight of 27.50±0.48 kg were distributed in a completely randomized design with five treatments (0, 70, 140, 210 and 280 g/kg DM) and nine replicates. Dry matter and neutral detergent fiberintakes showed quadratic behavior. Times spent eating, ruminating and total ruminating chews showed increasing linear behavior, while the idle time decreased with increasing amounts of dietary cactus. The feeding efficiency (gDM/h) increased linearly, while differences in rumination efficiency of the DM (g DM/h); NDF intake efficiency (gNDF/h) and NDF rumination efficiency (gNDF/h) were not significant. There was no significant effect for the number of ruminated boli and number of ruminating chews per bolus. The number of chews per day increased linearly. These results indicate that cactus pear in substitution of corn had no influence on the feeding behavior of feedlot sheep.
