Avaliação de Níveis de Fósforo na Dieta de Novilhos Nelore em Crescimento: Efeitos no Desempenho

Abstract

The adequacy of the recommendation of phosphorus for growing Nellore steers was evaluated by means of the weight gain, feed intake and feed:gain ratio during 250 days. Fifteen steers were fed a basal P-deficicnt but otherwise adequate in the other nutrients, enabling gains of 500 g/day. The diet was supplemented (treatment 1 = 15 g P/day, treatment 2 = 11 g P/day) or not (treatment 3 = 5 g P/day) with monoammonium phosphate. Phosphorus deficiency did not affect organic matter in vivo digestibilities determined at 60 days and at the end of the experiment, nor dry matter digestibility at the end of the experiment. Average dry matter intakes were 5.56, 5.28 and 3.69 kg/day, for treatments 1, 2 and 3, respectively. Feed intake, weight gain and feed:gain ratio were reduced by phosphorus deficiency. Steers fed 11 g of P/day gained 500-600 g/day without signs of deficiency.