All feeds were conditioned for
15 s at 85°C and then pelleted through a Master Model
HD 1000 series California Pellet Mill (California Pellet
Mill Co., Crawfordsville, IN) equipped with a die of 4
× 32 mm. Experiment 2 and 3 included the same 3
treatments as in Exp. 1 but with additional treatments
of SDP blended into the meal and conditioned at 90
or 95°C before pelleting. In Exp. 4, treatments were
arranged as a 2 × 2 factorial with 2 levels of SDP (0
or 1%) and 2 processing procedures (not expanded or
expanded at 149°C final effective temperature before
pelleting at 85°C conditioning temperature).