Steers performances in grazing submitted by two supplementation intervals during dry season/Desempenho de bovinos em pastejo submetidos a duas frequencias de suplementacao no periodo da seca

This work was carried out to evaluate different frequencies of supplementation during the dry season. Forty-eight Nellore steers with 320 kg of initial live weight were fed with Brachiaria brizantha cv. Marandu pasture on a continuous stocking rate. The animals were submitted to following treatments: daily supplementation and supplementation three times a week. The animals in both treatments received 7 kg of supplementation [animal.sup.-1] weekly, and were weighted at 28-day intervals. The data were analyzed by the MIXED procedure in SAS (2004), with measurements repeated over time. The study observed average forage allowance of 4.2 tons of DM [ha.sup.-1], with 3.5% CP, 82.24% NDF and 64.97% ADF. There was no difference (p < 0.01) among daily weight gains of animals who received daily supplementation and those received supplementation three times a week (0.23 and 0.13 kg [day.sup.-1], respectively). Therefore, the supplementation intervals did not influence steer performance during the dry season. Key words: weight gain, Marandu, rotational grazing fixed, supplement. Com o objetivo de avaliar diferentes frequencias de suplementacao no periodo da seca foram utilizados 48 bovinos da raca Nelore com peso medio inicial de 320 kg, em pastagem de Brachiaria brizantha cv. Marandu, submetidos aos tratamentos: suplementacao diaria e suplementacao tres vezes por semana, a fim de avaliar o ganho medio diario de peso corporal dos animais nesse periodo. Os animais de ambos os tratamentos receberam, semanalmente 7,0 kg de suplemento [animal.sup.-1] e foram pesados em intervalos de 28 dias. Os dados foram analisados pelo procedimento MIXED do SAS (2004) com medidas repetidas no tempo. Observou-se oferta de forragem media de 4,2 toneladas de MS [ha.sup.- 1], com teores medios de 3,5% de PB, 82,24% de FDN e 64,97% de FDA na forragem. Nao foi observada diferenca (p > 0,01) nos ganhos de peso medio diario entre os animais que receberam o suplemento diariamente (0,23 kg [dia.sup.-1]) e aqueles que receberam tres vezes por semana (0,13 kg [dia.sup.-1]). Portanto, as frequencias de suplementacao nao influenciaram no ganho diario de peso corporal dos animais no periodo da seca. Palavras-chave: ganho de peso, Marandu, pastejo rotacionado fixo, suplemento.