A batch of full-fat soybean (FFSB) was wet extruded at 155°C for 15 s to provide an ex- truded full-fat soybean (EFFSB) sample. The urease activity index, protein solubility in KOH, and protein dispersibility index were determined in EFFSB samples as in vitro quality tests and indicated good quality of processing. In the first experiment, the EFFSB was substituted primarily at the expense of dehulled soybean meal (DSBM) and soybean oil (SO) in the grower diet as 0, 7.5, 15, and 22.5% to provide 4 diets; then birds received the diets from 15 to 21 d and excreta were collected from 18 to 21 d for chemical analysis. The AMEn and nutrient total tract apparent retention of EFFSB were calculated by regression analysis. The AMEn value of EFFSB was 3,908 kcal/kg, whereas the coefficients of total tract apparent retention for DM, organic matter, EE, CP, CF, and ash were 76, 79, 91, 74, 20, and 61%, respectively. In the second experiment, one hundred ninety-two 1-d-old male broiler chicks were divided into 16 groups of 12 birds each and allocated to 4 diets containing 0, 7.5, 15, and 22.5% of EFFSB at the expense of DSBM and SO. Feed intake and weight gain of chickens fed the diet contained 22.5% EFFSB were reduced (P < 0.05) compared with control chicks during 0 to 42 d, but feed intake and weight gain were not influenced (P > 0.05) when birds were fed diets contain- ing up to 15% EFFSB. The mucosa absorptive surface area in duodenum and jejunum of birds fed 22.5% EFFSB was reduced (P < 0.05) compared with control birds. The relative pancreas weight of chickens fed EFFSB diets was significantly (P < 0.05) higher than control ones at 21 d, but no effect was observed at 42 d (P > 0.05). It is concluded that growth performance of broiler chickens was not influenced (P > 0.05) when birds were fed a diet containing up to 15% EFFSB in place of DSBM and SO.

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