Effects of reducing the particle size of corn grain on the concentration of digestible and metabolizable energy and on the digestibility of energy and nutrients in corn grain fed to growing pigs

Two experiments were conducted to determine the apparent ileal digestibility (AID) of starch and gross energy (GE), the standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AA), the concentration of digestible energy (DE) and metabolizable energy (ME), and the standardized total tract digestibility (STTD) of P in corn ground to 4 different particle sizes (i.e., 865, 677, 485, and 339 µm). In Experiment 1, 10 growing barrows (initial body weight: 29.2±1.4 kg) were surgically equipped with a T-cannula in the distal ileum and randomly allotted to a replicated 5×5 Latin square design with 5 diets and 5 periods in each square. One lot of corn was divided into 4 batches that were ground to the specified particle sizes and each batch was used in one diet that contained 965.5 g/kg corn (as-fed basis) as the only source of starch, GE, and AA. Results indicated that the AID of starch and GE was increased (linear, P