This experiment was undertaken to evaluate the effect of 40, 55 and 70% of concentrate, associated with a low-quality roughage, on the intake and weight gain of 16 crossbred steers, with an average age of 10 months and 312kg of initial liveweight in a completely ramdomized design with three replicates during 63 days. The roughage consisted of oat (Avena strigosa) treated with urea and the concentrate consisted of corn, rice bran, soybean meal and minerals. All diets contained 12% crude protein. A positive linear response was observed for daily weight gain and dry matter intake (expressed either as kg/animal/day, percentage of live weight or metabolic weight), and a negative linear response was observed for feed:gain ratio. The dry matter intake and daily weight gain increased as the concentrate content became higher. The low quality of the roughage possibly limited the feed and nutrient intake of the animals.
Cattle; feedlot; concentrate level; performance
