This study was conducted to determine optimum test duration for measuring performance, feed intake and feed efficiency. Sixty young Nellore bulls were submitted to feeding performance test and fed in individual pens to determine feed intake and performance over 112 days. Body weight was determined every 28 days, after fasting of water and feed for 16 hours. Changes in variance, relative variance and Pearson and Spearman correlations among data from shortened test periods (28, 56 and 84 days) 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 and residual feed intake could be shortened to 84, 28, 84 and 84 days, respectively, without reducing significantly the reliability of measurements for animals fed in individual pens.
beef cattle; feeding performance test; residual feed intake
