Standardized ileal digestibility of amino acids and metabolizable energy in three sources of high-protein corn distillers dried grains fed to weanling pigs

Two experiments were conducted to test the null hypothesis that there are no differences in the standardized ileal digestibility (SID) of amino acids (AA) and metabolizable energy (ME) among three sources of high-protein distillers dried grains (HP-DDG) fed to weanling pigs. The three sources included an experimental HP-DDG product and two commercial HP-DDG products (i.e., HP-DDG 40 and HP-DDG 50) that were fed to weanling pigs. In experiment 1, eight barrows (initial body weight: 11.09 kg) were allotted to one of four diets using a replicated 4 × 4 Latin square design with four diets and four periods of seven days in each square. A nitrogen-free diet and three diets containing each source of HP-DDG as the sole source of AA were prepared. Results indicated that values for the SID of Lys in the experimental HP-DDG; HP-DDG 50, and HP-DDG 40 were 0.524, 0.638, and 0.642, respectively. The SID of most AA in the experimental HP-DDG was less (P < 0.05) than in the other sources of HP-DDG, but no differences were observed between HP-DDG 40 and HP-DDG 50. In experiment 2, thirty-two weanling pigs (initial body weight: 18.0 kg) were randomly allotted to one of four diets. A corn diet was formulated to contain corn as the sole source of energy and three additional diets contained corn and each source of HP-DDG. Pigs were housed individually in metabolism crates and feces and urine were collected separately for four days after five days of adaptation. Digestible energy (DE) and ME in the three sources of HP-DDG were calculated by difference. Results from experiment 2 indicated that the apparent total tract digestibility (ATTD) of gross energy (GE) in the corn diet was greater (P < 0.05) than in the diets containing the experimental HP-DDG or HP-DDG 40, and the ATTD of GE in the diets containing the experimental HP-DDG or HP-DDG 50 was greater (P < 0.05) than in the diet containing HP-DDG 40. On a dry matter basis, ME in the experimental HP-DDG, HP-DDG 40, and HP-DDG 50 were 17.05, 16.72, and 18.23 MJ/kg, respectively, with the ME of HP-DDG 50 being greater (P < 0.05) than in HP-DDG 40, but not different from the ME in the experimental HP-DDG. In conclusion, the SID of most AA in HP-DDG 40 and HP-DDG 50 was greater than in the experimental HP-DDG. The DE and ME in HP-DDG 50 was greater than in HP-DDG 40, but DE and ME in HP-DDG 40 were not different from DE and ME in the experimental HP-DDG.