Sales et al., 2008. Rev. Bras. Zootec., 37 (9): 1704-1712

The effects of multiple supplements with different urea levels on the productive performance and nutritional characteristics of finishing beef cattle kept in deferred pasture of palisade grass (Brachiaria brizantha [Urochloa brizantha] cv. Marandu) in the transition period from rainy to dry season were evaluated. The estimated dry matter availability of the pasture ranged from 16 360 to 9358 kg/ha. In the performance trial, 20 crossbred bulls aged 20 months and weighing 376 kg were grouped in lots of similar weights in a completely randomized design, in four paddocks of 1.5 ha each, where 1.5 kg/day of isoprotcic supplements (20% CP) consisting of corn grain, ground soyabean, mineral mix and urea (0.0, 1.6, 3.2 and 4.8%) was fed. The average daily gain (mean value of 0.57 kg/day) was not affected by the urea levels in the supplements. The nutritional characteristics were evaluated using four crossbred (Holstein-Friesian * zebu) bulls weighing 320 kg BW, with oesophageal, ruminal and abomasal cannulae. These animals were fed the same amounts of supplements in the experimental performance study. Urea levels did not affect the ruminal pH and ammonia concentration. Weight gains of 0.5-0.6 kg/day could be obtained using only corn, urea and mineral mix in multiple supplements for finishing beef cattle kept in deferred pasture.