Although the physiology of substances produced in photosynthesis is known, few studies with tropical forage species have been done to provide information about animal grazing patterns and performance. The objective of this study was to investigate the effects of diurnal time of allocating animals to a new paddock on ingestive behavior, forage nonstructural carbohydrates concentration (NSC: sugar and starch) and performance of beef heifers grazing Brachiaria brizantha ‘Marandu’. The experiment was conducted in southeastern Brazil (21° 59′ N; 47° 26′ W). Treatments were daily time of allocating animals to new paddocks at 0600 h (AM) and 1500 h (PM) in a randomized complete block design with 3 replicates. Heifers (n = 60, initial BW = 230 kg) were managed by 78 d in rotational stocking, with 1 d grazing period and 25 d resting period during the summer of 2012/2013. All variables were measured every 26 d. Treatments had similar forage allowances (P > 0.05, 3.7 ± 0.1 kg DM/kg BW). Times spent grazing, ruminating and other activities were acoustically recorded during a 24 h period. Animals were weighed after a 14–16 h fasting. NSC was determined in forage samples hand-plucked at 0600 and 1500 h, in both treatments. Data were analyzed with Proc Mixed of SAS, with treatment and month as fixed effects and block as a random effect. Total daily grazing time was greater for AM (P < 0.05, 490 vs. 450 ± 5.4 min), however, PM concentrated diurnal grazing time in the afternoon (P < 0.05, ~66%), whereas AM did not concentrate grazing activities in the morning when compared with the afternoon (P > 0.05, ~50% in each period). There was no difference of NSC between treatments for a given time of the day (P > 0.05, 36 and 79 ± 2.7 g/kg DM at 0600 and 1500 h, respectively), although PM had 50 g NSC/kg DM more than AM at 1500 h (P < 0.05). Thus, compensating between grazing time and forage NSC throughout the day resulted in similar ADG (0.75 ± 0.04 kg/d). The schedule for allocating beef cattle in new paddocks may be done according to the convenience of each farm, as it does not affect performance.