A digestibility assay were carried out to evaluate, in consecutives periods, the total excreta collection method and the chromium oxide method as a marker. Apparent metabolizable energy corrected by nitrogen retention (AMEn) and aparent digestibility of dry matter coefficient (ADDMC) of broiler diet based in a ground corn and soybean meal containing 19% crude protein and 3.100 kcal ME/kg. Sixty adult Leghorn cockerels weigh, in average, 2.350±105 g were used. Each cockerel participates in the evaluation of the two methods simutannialy in consecutives periods. A split plots experimental design experiment was used to evaluate the two métodhs. In the chromium oxid method the treatments were defined as a 4x5 factorial arrangemente (chromium oxide levels 0.2, 0.4, 0.6 and 0.8% and collection time 1 to 5 days), totalizing 20 treatments in the plot, in two continuous periods (sub-plots), with three replicates by period. In the total excreta collection method the treatments were defined as five collection times (1 to 5 days) in the plot and the two continuous periods in the subplot with twelve replicates per period. The use of continuous periods did not affect AMEn or ADDMC. In the total excreta collection method the values of AMEn and ADDMC reached a plateau after two days of collection, showing that the collection time could be reduced by three days without affecting the determinated values. The data showed interaction between chromium oxide levels with collection times for the AMEn and ADDMC. Three days of excreta collection were enough to determine with accuracy both AMEn and ADDMC of the diets based on ground corn and soybean meal. The use of three days of collection and 0.665% of chromium oxide in the diet was possible to determine similar values for AMEn and ADDMC in the two methods.
adult cockerels; chromium oxide; dry matter; metabolizable energy; total collection
