. A standard corn-SBM-based broiler starter was fed from 1 to 14 d (3,050 kcal/kg AMEn, 21.7% CP, 1.05% Ca, and 0.53% non-phytate P), whereas the experimental diets are presented in Table 1. A 2 × 3 factorial arrangement of 2 control diets (basal = corn-soy basal diet without added phytase or PHY = corn-soy diet formulated with phytase) and 3 carbohydrase supplements (0, α-amylase, or α-amylase + β-xylanase) was provided from 14 to 25 d.