Desempenho de novilhos suplementados com sais proteinados em pastagem nativa

Abstract

idade de 18 meses, em delineamento completamente casualizado. A pastagem apresentou valores médios de 6,8% de proteína bruta, 73,3% de fibra em detergente neutro, e 42,5% de digestibilidade in vitro da matéria orgânica, sem que fossem detectadas diferenças significativas entre tratamentos. O ganho médio diário (0,287 kg) dos animais suplementados com o sal proteinado com amiréia e levedura, foi superior ao apresentado pelos animais que consumiram sal mineralizado (0,019 kg) mas não houve diferenças entre uréia (0,159 kg) e amiréia (0,124 kg). O consumo diário dos suplementos proteinados (0,400 kg) foi superior ao consumo do suplemento mineral (0,038 kg). A adição de levedura ativa, ao sal proteinado formulado com amiréia, melhora o desempenho de novilhos em pastagem nativa diferida.Termos para indexação: suplementação protéica, uréia, amiréia, levedura, campo nativo. Performance of steers supplemented with protein salts on native pasturesAbstract -The objective of this work was to evaluate the effect of protein salts supplementation on performance of beef steers grazing differed native pasture in Rio Grande do Sul State, Brazil. Protein salts were supplemented with: urea, starea, starea plus yeast, and mineral salt. The experiment was conducted during 118 days, and utilized 8 paddocks with 7.5 ha each one, with 8 steers averaging 264 kg and 18 months old, in a completely randomized design. Average composition of pasture was 6.8% of crude protein, 73.3% of neutral detergent fiber, and 42.5% in vitro organic matter digestibility; significative differences weren't detected among treatments. Average daily weight gain of animals fed protein salt with starea plus yeast (0.287 kg), was higher than the weight gain of animals fed mineral salt (0.019 kg); differences weren't detected among urea (0.159 kg) and starea (0.124 kg). Daily intake of protein supplements (0.400 kg) was higher than that of mineral supplement (0.038 kg). Addition of live yeast to the protein salt formulated with starea resulted in better performance of steers grazing differed native pasture.