The effects of starch or neutral detergent soluble fiber associated with twodietary levels of NDF on performance of finishing feedlot beef steers were evaluatedin this trial. Twenty-four crossbred ½ Angus x ½ Nellore steersaveraging 18 months of age and 329 ± 24 kg of body weight at the beginningof the trial were used. All four diets were balanced to supply the crude proteinrequirements for a daily weight gain of approximately 1.4 kg. Diets were composed(dry matter basis) by 40% of corn silage and 60% of concentrate containing corngrain, citrus pulp, soybean hulls, salt, and urea. Animals fed the diet containinghigh soluble fiber and low NDF content had the lowest dry matter intake (DMI),which compromised weight gain and feed conversion. This decrease in DMI canbe explained by the greater level of citrus pulp (45%) compared to the otherthree diets. Between diets with higher NDF levels, that with soluble fiber resultedin greater daily weight gain (1.435 vs. 1.262 kg) and better feed conversionratio (7.494 vs. 8.651) than the diet with starch. However, no significant differencewas observed between the diet with high NDF and soluble fiber compared to thatwith low NDF and starch for these same variables. In conclusion, animal performancecan be improved by changing the source and content of dietary soluble carbohydrates.
