Peer review

Five 28- to 42-d experiments involving 432 pigs initially averaging 14 kg were conducted to nutritionally evaluate corn that was genetically modified by a single mutant gene (opaque-2/floury-2, opaque-2/sugary-2, opaque-2/waxy). The mutant corns were higher in lysine (.35 to .43%) than normal corn (.24 to .26%). Inclusion of the mutant corns in a lysine deficient diet resulted in faster and more efficient gains when fed to young pigs. In diets calculated to be adequate in lysine, the substitution of opaque-2/floury-2 and opaque-2/sugary-2 corn for normal corn also tended to improve the rate and efficiency of gain in pigs. The grinding of opaque-2/floury-2 and opaque-2/waxy corns in a hammer mill reduced their particle size to a greater degree than that of normal corn and opaque-2/sugary-2 corn (30 to 50% less geometric mean diameter), but there was no evidence that the smaller particle size influenced the nutritional value of the mutant corn hybrids. Overall, pigs fed corn processed by grinding, which produced a smaller particle size in each corn type, tended to gain faster and more efficiently than those fed rolled corn.

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