Digestibility of amino acids, but not fiber, fat, or energy, is greater in cold-fermented, low-oil distillers dried grains with solubles (DDGS) compared with conventional DDGS fed to growing pigs.

Abstract

Two experiments were conducted to test the hypothesis that the digestibility of gross energy (GE) and nutrients, and concentrations of digestible energy (DE) and metabolizable energy (ME) in two sources of distillers dried grains with solubles (DDGS) are not different despite different concentrations of fat in the two sources. Cold-fermented DDGS (6.82% fat) and a conventional DDGS (9.54% fat) were used. In experiment 1, 12 growing barrows (initial body weight = 55.2 ± 3.6 kg) that had a T-cannula installed in the distal ileum were allotted to one of three diets and two periods. Two diets contained either cold-fermented or conventional DDGS as the sole source of crude protein (CP) and amino acids (AA). The third diet was an N-free diet that was used to determine the basal endogenous losses of AA from the pigs. Each experimental period lasted 7 d and ileal digesta were collected on days 6 and 7 of each period. Results demonstrated that values for the standardized ileal digestibility (SID) of CP and most AA were greater (P < 0.05) or tended to be greater (P < 0.10) in cold-fermented than in conventional DDGS. In experiment 2, 24 barrows (initial body weight = 17.3 ± 1.3 kg) were randomly allotted to three diets with 8 replicate pigs per diet. A corn-based basal diet and two diets containing corn and either cold-fermented DDGS or conventional DDGS were formulated. Pigs were housed individually in metabolism crates and feces and urine were collected separately for 5 d after 7 d of adaptation. The apparent total tract digestibility (ATTD) of neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid-hydrolyzed ether extract (AEE) was greater (P < 0.01) in conventional DDGS than in cold-fermented DDGS, but there was no difference in ATTD of GE between the two sources of DDGS. However, conventional DDGS contained more (P < 0.001) DE and ME than cold-fermented DDGS because of greater GE. In conclusion, the SID of AA was greater in cold-fermented DDGS than in the conventional DDGS that was evaluated in this experiment, but the ATTD of NDF, ADF, and AEE, and ME were greater in conventional DDGS than in cold-fermented DDGS.