Normal, Opaque-2, Waxy, Waxy Opaque-2, Sugary-2 and Sugary-2 Opaque-2 Corn (Zea Mays L.) Endosperm Types for Rats and Pigs. Studies on Energy Utilization2

Abstract

One metabolism and two growth trials involving 140 rats and one growth and digestion trial with 36 growing pigs were conducted to compare six near isogenic versions of the maize 3-way hybrid [(Oh43 × B37) × CI03] fed in protein adequate diets. No differences in rat or pig performance were obtained comparing three endosperm starch types: waxy (100% amylopectin), sugary-2 (40% amylose, 60% amylopectin) and normal (26% amylose, 74% amylopectin). It was found that opaque-2, sugary-2 opaque-2 and sugary-2 corns contained from 3.0 to 3.3% lower digestible energy than normal corn for rats. In addition, all corns with the opaque-2 gene contained, on the average, 2.65% lower digestible nitrogen than non-opaque types. With pigs it was found that the double mutants sugary-2 opaque-2 and waxy opaque-2 did not show lower apparent digestion coefficients than normal corn as did opaque-2 corn. These experiments indicated that energy utilization in waxy, sugary-2 and double mutants with the opaque-2 gene is as good as for normal corn for growing pigs.