This study wasconducted to determine optimum test duration for measuring performance, feedintake and feed efficiency. Sixty young Nellore bulls were submitted to feedingperformance test and fed in individual pens to determine feed intake and performanceover 112 days. Body weight was determined every 28 days, after fasting of waterand feed for 16 hours. Changes in variance, relative variance and Pearson andSpearman correlations among data from shortened test periods (28, 56 and 84days) and full test period (112 days) were used to determine optimum test duration.Test duration for average daily gain, dry matter intake, feed:gain ratio andresidual feed intake could be shortened to 84, 28, 84 and 84 days, respectively,without reducing significantly the reliability of measurements for animals fedin individual pens.
