A 42-d floor pen study was conducted to compare broiler (Ross x Ross 308) performance and carcass measurements when fed diets containing lepidopteran-protected corn combined with glyphosate-tolerant corn (MON 89034 x NK603) with those of broilers fed diets containing corn grain from the conventional control (similar genetic background to the test corn) and 6 conventional corn hybrids. It has been found that MON 89034 produces the Cry1A.105 and Cry2Ab2 insecticidal proteins that protect corn plants from feeding damage caused by European corn borer (Ostrinia nubilalis) and other lepidopteran insect pests. In addition, NK603 produces the 5-enolpyruvylshikimate-3-phosphate synthase protein from Agrobacterium sp. strain CP4 (CP4 EPSPS), which confers tolerance to glyphosate, the active ingredient in Roundup agricultural herbicides. The traditional breeding of plants that express the individual traits produced MON 89034 x NK603. Broilers were fed starter diets (approximately 57% wt/wt corn grain) from d 0 to 21 and grower-finisher diets (approximately 59% wt/wt corn grain) from d 21 to 42. The study utilized a randomized complete block design with 8 dietary treatments assigned randomly within 5 blocks of 16 pens each (8 male and 8 female) with 10 birds per pen. There were 10 pens per treatment group (5 male and 5 female). Weight at d 0 and 42, feed intake, feed conversion, and all measured carcass and meat quality parameters were not different (P > 0.05) for birds fed MON 89034 x NK603 and control corn diets. In addition, comparisons of the MON 89034 x NK603 diet to the population of the control and 6 reference corn diets showed no difference (P > 0.05) in any performance, carcass, or meat quality parameter measured. In conclusion, the diets containing MON 89034 x NK603 were nutritionally equivalent to diets containing the control or conventional reference corn grain when fed to broilers.