The aim of this study was to evaluate the effects of diets containing different levels of Pilosocereus gounellei, (xiquexique), (0, 120, 240 and 360 g/kg DM) on intake, performance, ingestive behaviour and water use efficiency in sheep finished in confinement. Twenty non-castrated Santa Inês male lambs with an initial mean body weight of 18.86 ± 1.41 kg and approximately 100 days of age were distributed in a completely randomised design of four diets containing different levels of xiquexique (0, 120, 240 and 360 g/kg DM) with five replications. The inclusion of xiquexique in the diet resulted in a quadratic response (P < 0.05) in the consumption of fresh matter and non-fibrous carbohydrates. The consumption of dry matter and of other nutrients decreased (P < 0.05) with the levels of xiquexique in the diet. Feed conversion, rumination time, idle time, rumination efficiency (g/h DM), total water intake and total water conversion were not influenced (P > 0.05) by the levels of xiquexique. Total weight gain, average daily gain (ADG), feeding time, feeding efficiency (g NDF/h), rumination efficiency, frequency of water intake and voluntary water intake decreased (P < 0.05) linearly. Water intake from the feed increased (P < 0.05) with the levels of xiquexique, and there was a quadratic response for water conversion (WC), with a minimum value of 16.27 g water/g ADG, when the proportion of xiquexique in the diet reached 316 g/kg DM. Xiquexique can be used for intermediate levels of performance, and contributes to the water supply of sheep in regions that are more susceptible to climatic vulnerability.