1. This study was carried out to evaluate the effect of steam-conditioning time and different levels of processed sodium bentonite (PSB) on pellet quality, growth performance, intestinal development and morphology, and nutrient digestibilities in broilers during finisher period (d 24–45). 2. A total of 810 male chicks were reared in commercial conditions on floor pens till d 24. Then, birds were weighed and used in a completely randomised design experiment with a 3 × 3 factorial arrangement, including three levels of conditioning times (0, 2 and 4 min) and three PSB levels (0, 7.5 and 15 g/kg diet). Each of the 9 diets fed to 6 replicates group of 15 birds each. 3. The results showed that 2-min steam conditioning and 15 g/kg PSB supplementation significantly increased pellet durability index (PDI) and hardness, and decreased electrical consumption of pelleting. Diets had no significant effects on body weight, feed intake and feed conversion ratio. Although dietary treatments did not influence relative weight and length of three segments of small intestine, 2-min steam conditioning significantly improved villus height (VH) and crypt depth. Steam conditioning of diet for 2 min significantly increased apparent metabolisable energy (AME), ether extract (EE), calcium (Ca) and dry matter (DM) retention in birds measured during 38–42 d of age. 4. It could be concluded that 2-min steam conditioning improved PDI and hardness, VH and nutrient retention (AME, EE, Ca and DM), but did not affect growth performance in broilers during finisher period.

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