Ileal Digestibility of Amino Acids in Corn Condensed Distiller’s Solubles and Whole Stillage for Pigs

The immense growth in global bioethanol production has greatly increased the supply of by-products such as whole stillage and condensed distiller’s solubles, which could be potentially used for animal feeding. The objective of this experiment was to determine apparent ileal digestibility coefficients (AID) and standardized ileal digestibility coefficients (SID) of crude protein and amino acids in corn condensed distiller’s solubles (CCDS) and corn whole stillage (CWS) when fed to pigs. A total of 18 finishing barrows with an average initial body weight 79.4 ± 4.5 kg and a simple T cannula in the distal ileum were used in this experiment. Two test diets were formulated with CCDS or CWS as the sole source of amino acids, and a nitrogen free diet was used for estimation of basal ileal endogenous losses of crude protein and amino acids. The direct procedure was employed for calculation of AID and SID in the two co-products. Compared with CWS, CCDS had higher SID (%) of crude protein(86.4±2.0 vs. 79.6±1.8; P=0.03) and lysine (82.1±3.4 vs. 74.3±2.7, P=0.10), but lower SID of methionine (73.0±2.8 vs. 83.1±1.4, P=0.009), and similar SID of threonine (76.2±3.4 vs. 71.0±2.7, P=0.26), tryptophan (86.2±2.1 vs. 86.3±2.9, P=0.98), and cysteine (67.5±2.7 vs. 68.6±1.5, P=0.74). The information generated from this experiment can be used for formulation of swine diets containing these two ethanol co-products.