Influence of corn and soybean meal substitution in a diet on digestibility of nutrients in pigs

Abstract

Two metabolic assays were carried out. In the first, 12 crossbred barrows were used during four periods, in a 2 x 4 x 2 factorial experimental design, with three replications, two samples of corn (A and B), four excreta collection periods - ECP (3, 5, 7 and 9 days) and two weights (27.4 ± 0.3 and 64.3 ± 0.5 kg). In the second, 24 crossbred barrows (46.7 ± 1.0 kg) were used in a 2 x 4 hierarchical design with three replications, two feedstuffs (corn C and soybean meal) and four levels of substitution in the reference diet (30%, 45%, 60%  and 100%). ECP had only a significant effect (P < 0.01) on digestible energy values corn. Confidence intervals for digestibility coefficients varied with the ECP. The period of five days gave enough accuracy for digestibility of corn nutrients. Values of digestible and metabolizable energy of corn and soybean meal were influenced by levels of substitution. Levels above 30% for corn and 45% for soybean meal in the reference diet influenced dry matter, protein digestibility and energetic values of feedstuffs.