Standardized Ileal Digestible Amino Acids and Digestible Energy Contents in High Protein DDGS Fed to Growing Pigs

Chemical composition and therefore potential nutritive value of corn DDGS is constantly evolving as the ethanol industry innovate processes to improve ethanol yield. The objective of the present study was to determine standardized ileal digestible (SID) of AA (Exp. 1) and DE (Exp. 2) contents in high CP (~ 45% DM) DDGS (HP). Two HP samples (HP-A and HP-B) were procured at two different time points from a local company and tested along with a commodity DDGS (C) sample for comparison. Three semi-purified corn-starch based (~20 % CP as fed) diets were formulated with DDGS as the sole source of AA. A forth N-free diet was prepared for endogenous N loss. In Exp.1, eight ileal cannulated barrows (23.9 kg BW) were used in a replicated 4 x 4 Latin square design. Pigs were fed at 2.8 times maintenance energy requirements. In each period, pigs were adjusted to diets for 5 d followed by 2-d, 8h continuous ileal digesta collection. In Exp.2, nine barrows (24.9 kg BW) were assigned to the four diets in a repeated 4 x 4 Latin square design such that in each period one of the diet was fed to an extra pig (n=9). In each period, pigs were adjusted to diets for 7 d, followed by a 5 d of fecal samples collection. In the statistical analysis, diet was fixed effect whereas period and pig were random effects. The DE content in DDGS was calculated by the difference method. The analyzed CP was 30.1, 42.3 and 43.1% DM in C, HP-A and HP-B samples, respectively; the corresponding values for GE were 5,067, 5,425 and 5,407 kcal/kg DM, respectively. The concentrations of fat and NDF were comparable among the DDGS samples. Except for Arg and Val, the SID values for indispensable AA were not different (P > 0.05) among the three DDGS samples. However, HP samples had greater (P < 0.05) SID content of indispensable and CP than C. The SID Lys content was 4.9, 6.1 and 7.4 g/kg DM for C, HP-A and HP-B, respectively and corresponding values for Met and Thr were 4.6, 6.8 and 7.4 g/kg DM and 6.8, 9.5 and 10.1 g/kg DM, respectively. The DE content in HP samples was higher than in C samples (P < 0.01; 3,614, 4,494 and 4,555 kcal/kg DM, C, HP-A, HP-B, respectively). In conclusion, HP DDGS had higher digestible AA and energy contents than C DDGS.