Desempenho de bezerros depois da inclusão de ureia de liberação lenta em suplemento proteico para bovinos

The objective was to evaluate the substitution of soybean meal (SM) of the protein supplement for encapsulated urea (UE; Optigen ®) on performance of beef calves during the dry season. Sixty Nellore calves were used, with body weight (BW) of 172.37 ± 19.93 kg, kept under grazing pasture of marandu-grass. The treatments were: 0% UE (100% SM e 0% UE); 25% UE (75% SM e 25% UE); 75% UE (25% SM e 75% UE); 100% UE (0% SM e 100% UE). A randomized blocks design was used with three replicates. There was no effect of the level of substitution of SM by UE on the average daily gain (ADG) and BW. ADG and BW were influenced by the period. For ADG the highest value observed in the last period (days 112-140) and smaller on the second period (day 56-112). There was an increase in BW until day 56, which did not differ from day 112 and then increased on day 140. The supplement intake was reduced by the inclusion of UE. It can be concluded that in pastures containing green leaf, the SM can be replace by UE without adversely affecting the productive performance of calves in the dry season.