PSXII-40 Encapsulated nitrate to beef cattle growing under grazing system supplemented during the dry-rainy season

Abstract

Abstract This study evaluated the effects of the encapsulated calcium ammonium nitrate as a partial substitute for soybean meals in the concentrate on performance and rate consumption of Nellore young bulls under grazing conditions, supplemented during the growing phase. Sixty-four Nellore young bulls (initial BW = 246.69 ± 7.43 kg) where allotted into 16 paddocks of 1.0 ha each of Urochloa brizantha, randomly assigned into one of two treatments: (CTL) supplement with 22% CP, without nitrate inclusion and; (ENP): supplement with 22% CP, with a inclusion of 50 g of encapsulated calcium ammonium nitrate to each 100 kg of body weight. The experimental period lasted 84 d, during the dry-rainy transition season. Animals were supplemented with 1.0% of BW, once a day (at 1000 h). Supplementation disappearance rate were evaluated the during continuous 24h after feeding, with intervals of 3 hours. For performance evaluation, animals were weighted every 28 days. Data were analyzed as a completely randomized design, using ANOVA (α = 0.05). There were no differences in ADG (1,039 vs 1,012 kg, P < 0.4468), G:F (0.299 vs 0.331, P < 0.1435) and final BW (336.44 vs 329.86 kg, P < 0.2063). The treatments affected the rate of supplementation disappearance (P < 0.0001). Control animals consumed all supplement offered 9h after fed. On the other hand, animals from the nitrate supplementation consumed only 54.65% in the same period. The nitrate decreased the overall supplement intake (P < 0.0011) with CTL consumed 2.844 kg, while ENP consumed 2.492 kg. The inclusion of 50 g of encapsulated calcium ammonium nitrate to each 100 kg of body weight in the supplement of growing cattle under grazing conditions, on dry-rainy transition season decreases DMI and the rate of supplemental disappearance, however, this not affected the performance.